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• Web API, JavaScript, Chrome &amp; Cross-Origin Resource Sharing

  - by Brian Lanham

  The team spent much of the week working through this issues related to Chrome running on Windows 8 consuming cross-origin resources using Web API.  We thought it was resolved on day 2 but it resurfaced the next day.  We definitely resolved it today though.  I believe I do not fully understand the situation but I am going to explain what I know in an effort to help you avoid and/or resolve a similar issue. References We referenced many sources during our trial-and-error troubleshooting.  These are the links we reference in order of applicability to the solution: Zoiner Tejada JavaScript and other material from -> http://www.devproconnections.com/content1/topic/microsoft-azure-cors-141869/catpath/windows-azure-platform2/page/3 WebDAV Where I learned about “Accept” –>  http://www-jo.se/f.pfleger/cors-and-iis? IT Hit Tells about NOT using ‘*’ –> http://www.webdavsystem.com/ajax/programming/cross_origin_requests Carlos Figueira Sample back-end code (newer) –> http://code.msdn.microsoft.com/windowsdesktop/Implementing-CORS-support-a677ab5d (older version) –> http://code.msdn.microsoft.com/CORS-support-in-ASPNET-Web-01e9980a   Background As a measure of protection, Web designers (W3C) and implementers (Google, Microsoft, Mozilla) made it so that a request, especially a JSON request (but really any URL), sent from one domain to another will only work if the requestee “knows” about the requester and allows requests from it. So, for example, if you write a ASP.NET MVC Web API service and try to consume it from multiple apps, the browsers used may (will?) indicate that you are not allowed by showing an “Access-Control-Allow-Origin” error indicating the requester is not allowed to make requests. Internet Explorer (big surprise) is the odd-hair-colored step-child in this mix. It seems that running locally at least IE allows this for development purposes.  Chrome and Firefox do not.  In fact, Chrome is quite restrictive.  Notice the images below. IE shows data (a tabular view with one row for each day of a week) while Chrome does not (trust me, neither does Firefox).  Further, the Chrome developer console shows an XmlHttpRequest (XHR) error. Screen captures from IE (left) and Chrome (right). Note that Chrome does not display data and the console shows an XHR error. Why does this happen? The Web browser submits these requests and processes the responses and each browser is different. Okay, so, IE is probably the only one that’s truly different.  However, Chrome has a specific process of performing a “pre-flight” check to make sure the service can respond to an “Access-Control-Allow-Origin” or Cross-Origin Resource Sharing (CORS) request.  So basically, the sequence is, if I understand correctly:  1)Page Loads –> 2)JavaScript Request Processed by Browser –> 3)Browsers Prepares to Submit Request –> 4)[Chrome] Browser Submits Pre-Flight Request –> 5)Server Responds with HTTP 200 –> 6)Browser Submits Request –> 7)Server Responds with Data –> 8)Page Shows Data This situation occurs for both GET and POST methods.  Typically, GET methods are called with query string parameters so there is no data posted.  Instead, the requesting domain needs to be permitted to request data but generally nothing more is required.  POSTs on the other hand send form data.  Therefore, more configuration is required (you’ll see the configuration below).  AJAX requests are not friendly with this (POSTs) either because they don’t post in a form. How to fix it. The team went through many iterations of self-hair removal and we think we finally have a working solution.  The trial-and-error approach eventually worked and we referenced many sources for the information.  I indicate those references above.  There are basically three (3) tasks needed to make this work. Assumptions: You are using Visual Studio, Web API, JavaScript, and have Cross-Origin Resource Sharing, and several browsers. 1. Configure the client Joel Cochran centralized our “cors-oriented” JavaScript (from here). There are two calls including one for GET and one for POST function(url, data, callback) {             console.log(data);             $.support.cors = true;             var jqxhr = $.post(url, data, callback, "json")                 .error(function(jqXhHR, status, errorThrown) {                     if ($.browser.msie && window.XDomainRequest) {                         var xdr = new XDomainRequest();                         xdr.open("post", url);                         xdr.onload = function () {                             if (callback) {                                 callback(JSON.parse(this.responseText), 'success');                             }                         };                         xdr.send(data);                     } else {                         console.log(">" + jqXhHR.status);                         alert("corsAjax.post error: " + status + ", " + errorThrown);                     }                 });         }; The GET CORS JavaScript function (credit to Zoiner Tejada) function(url, callback) {             $.support.cors = true;             var jqxhr = $.get(url, null, callback, "json")                 .error(function(jqXhHR, status, errorThrown) {                     if ($.browser.msie && window.XDomainRequest) {                         var xdr = new XDomainRequest();                         xdr.open("get", url);                         xdr.onload = function () {                             if (callback) {                                 callback(JSON.parse(this.responseText), 'success');                             }                         };                         xdr.send();                     } else {                         alert("CORS is not supported in this browser or from this origin.");                     }                 });         }; The POST CORS JavaScript function (credit to Zoiner Tejada) Now you need to call these functions to get and post your data (instead of, say, using $.Ajax). Here is a GET example: corsAjax.get(url, function(data) { if (data !== null && data.length !== undefined) { // do something with data } }); And here is a POST example: corsAjax.post(url, item); Simple…except…you’re not done yet. 2. Change Web API Controllers to Allow CORS There are actually two steps here.  Do you remember above when we mentioned the “pre-flight” check?  Chrome actually asks the server if it is allowed to ask it for cross-origin resource sharing access.  So you need to let the server know it’s okay.  This is a two-part activity.  a) Add the appropriate response header Access-Control-Allow-Origin, and b) permit the API functions to respond to various methods including GET, POST, and OPTIONS.  OPTIONS is the method that Chrome and other browsers use to ask the server if it can ask about permissions.  Here is an example of a Web API controller thus decorated: NOTE: You’ll see a lot of references to using “*” in the header value.  For security reasons, Chrome does NOT recognize this is valid. [HttpHeader("Access-Control-Allow-Origin", "http://localhost:51234")] [HttpHeader("Access-Control-Allow-Credentials", "true")] [HttpHeader("Access-Control-Allow-Methods", "ACCEPT, PROPFIND, PROPPATCH, COPY, MOVE, DELETE, MKCOL, LOCK, UNLOCK, PUT, GETLIB, VERSION-CONTROL, CHECKIN, CHECKOUT, UNCHECKOUT, REPORT, UPDATE, CANCELUPLOAD, HEAD, OPTIONS, GET, POST")] [HttpHeader("Access-Control-Allow-Headers", "Accept, Overwrite, Destination, Content-Type, Depth, User-Agent, X-File-Size, X-Requested-With, If-Modified-Since, X-File-Name, Cache-Control")] [HttpHeader("Access-Control-Max-Age", "3600")] public abstract class BaseApiController : ApiController {     [HttpGet]     [HttpOptions]     public IEnumerable<foo> GetFooItems(int id)     {         return foo.AsEnumerable();     }     [HttpPost]     [HttpOptions]     public void UpdateFooItem(FooItem fooItem)     {         // NOTE: The fooItem object may or may not         // (probably NOT) be set with actual data.         // If not, you need to extract the data from         // the posted form manually.         if (fooItem.Id == 0) // However you check for default...         {             // We use NewtonSoft.Json.             string jsonString = context.Request.Form.GetValues(0)[0].ToString();             Newtonsoft.Json.JsonSerializer js = new Newtonsoft.Json.JsonSerializer();             fooItem = js.Deserialize<FooItem>(new Newtonsoft.Json.JsonTextReader(new System.IO.StringReader(jsonString)));         }         // Update the set fooItem object.     } } Please note a few specific additions here: * The header attributes at the class level are required.  Note all of those methods and headers need to be specified but we find it works this way so we aren’t touching it. * Web API will actually deserialize the posted data into the object parameter of the called method on occasion but so far we don’t know why it does and doesn’t. * [HttpOptions] is, again, required for the pre-flight check. * The “Access-Control-Allow-Origin” response header should NOT NOT NOT contain an ‘*’. 3. Headers and Methods and Such We had most of this code in place but found that Chrome and Firefox still did not render the data.  Interestingly enough, Fiddler showed that the GET calls succeeded and the JSON data is returned properly.  We learned that among the headers set at the class level, we needed to add “ACCEPT”.  Note that I accidentally added it to methods and to headers.  Adding it to methods worked but I don’t know why.  We added it to headers also for good measure. [HttpHeader("Access-Control-Allow-Methods", "ACCEPT, PROPFIND, PROPPA... [HttpHeader("Access-Control-Allow-Headers", "Accept, Overwrite, Destin... Next Steps That should do it.  If it doesn’t let us know.  What to do next?  * Don’t hardcode the allowed domains.  Note that port numbers and other domain name specifics will cause problems and must be specified.  If this changes do you really want to deploy updated software?  Consider Miguel Figueira’s approach in the following link to writing a custom HttpHeaderAttribute class that allows you to specify the domain names and then you can do it dynamically.  There are, of course, other ways to do it dynamically but this is a clean approach. http://code.msdn.microsoft.com/windowsdesktop/Implementing-CORS-support-a677ab5d

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• Organizations &amp; Architecture UNISA Studies &ndash; Chap 7

  - by MarkPearl

  Learning Outcomes Name different device categories Discuss the functions and structure of I/.O modules Describe the principles of Programmed I/O Describe the principles of Interrupt-driven I/O Describe the principles of DMA Discuss the evolution characteristic of I/O channels Describe different types of I/O interface Explain the principles of point-to-point and multipoint configurations Discuss the way in which a FireWire serial bus functions Discuss the principles of InfiniBand architecture External Devices An external device attaches to the computer by a link to an I/O module. The link is used to exchange control, status, and data between the I/O module and the external device. External devices can be classified into 3 categories… Human readable – e.g. video display Machine readable – e.g. magnetic disk Communications – e.g. wifi card I/O Modules An I/O module has two major functions… Interface to the processor and memory via the system bus or central switch Interface to one or more peripheral devices by tailored data links Module Functions The major functions or requirements for an I/O module fall into the following categories… Control and timing Processor communication Device communication Data buffering Error detection I/O function includes a control and timing requirement, to coordinate the flow of traffic between internal resources and external devices. Processor communication involves the following… Command decoding Data Status reporting Address recognition The I/O device must be able to perform device communication. This communication involves commands, status information, and data. An essential task of an I/O module is data buffering due to the relative slow speeds of most external devices. An I/O module is often responsible for error detection and for subsequently reporting errors to the processor. I/O Module Structure An I/O module functions to allow the processor to view a wide range of devices in a simple minded way. The I/O module may hide the details of timing, formats, and the electro mechanics of an external device so that the processor can function in terms of simple reads and write commands. An I/O channel/processor is an I/O module that takes on most of the detailed processing burden, presenting a high-level interface to the processor. There are 3 techniques are possible for I/O operations Programmed I/O Interrupt[t I/O DMA Access Programmed I/O When a processor is executing a program and encounters an instruction relating to I/O it executes that instruction by issuing a command to the appropriate I/O module. With programmed I/O, the I/O module will perform the requested action and then set the appropriate bits in the I/O status register. The I/O module takes no further actions to alert the processor. I/O Commands To execute an I/O related instruction, the processor issues an address, specifying the particular I/O module and external device, and an I/O command. There are four types of I/O commands that an I/O module may receive when it is addressed by a processor… Control – used to activate a peripheral and tell it what to do Test – Used to test various status conditions associated with an I/O module and its peripherals Read – Causes the I/O module to obtain an item of data from the peripheral and place it in an internal buffer Write – Causes the I/O module to take an item of data form the data bus and subsequently transmit that data item to the peripheral The main disadvantage of this technique is it is a time consuming process that keeps the processor busy needlessly I/O Instructions With programmed I/O there is a close correspondence between the I/O related instructions that the processor fetches from memory and the I/O commands that the processor issues to an I/O module to execute the instructions. Typically there will be many I/O devices connected through I/O modules to the system – each device is given a unique identifier or address – when the processor issues an I/O command, the command contains the address of the address of the desired device, thus each I/O module must interpret the address lines to determine if the command is for itself. When the processor, main memory and I/O share a common bus, two modes of addressing are possible… Memory mapped I/O Isolated I/O (for a detailed explanation read page 245 of book) The advantage of memory mapped I/O over isolated I/O is that it has a large repertoire of instructions that can be used, allowing more efficient programming. The disadvantage of memory mapped I/O over isolated I/O is that valuable memory address space is sued up. Interrupts driven I/O Interrupt driven I/O works as follows… The processor issues an I/O command to a module and then goes on to do some other useful work The I/O module will then interrupts the processor to request service when is is ready to exchange data with the processor The processor then executes the data transfer and then resumes its former processing Interrupt Processing The occurrence of an interrupt triggers a number of events, both in the processor hardware and in software. When an I/O device completes an I/O operations the following sequence of hardware events occurs… The device issues an interrupt signal to the processor The processor finishes execution of the current instruction before responding to the interrupt The processor tests for an interrupt – determines that there is one – and sends an acknowledgement signal to the device that issues the interrupt. The acknowledgement allows the device to remove its interrupt signal The processor now needs to prepare to transfer control to the interrupt routine. To begin, it needs to save information needed to resume the current program at the point of interrupt. The minimum information required is the status of the processor and the location of the next instruction to be executed. The processor now loads the program counter with the entry location of the interrupt-handling program that will respond to this interrupt. It also saves the values of the process registers because the Interrupt operation may modify these The interrupt handler processes the interrupt – this includes examination of status information relating to the I/O operation or other event that caused an interrupt When interrupt processing is complete, the saved register values are retrieved from the stack and restored to the registers Finally, the PSW and program counter values from the stack are restored. Design Issues Two design issues arise in implementing interrupt I/O Because there will be multiple I/O modules, how does the processor determine which device issued the interrupt? If multiple interrupts have occurred, how does the processor decide which one to process? Addressing device recognition, 4 general categories of techniques are in common use… Multiple interrupt lines Software poll Daisy chain Bus arbitration For a detailed explanation of these approaches read page 250 of the textbook. Interrupt driven I/O while more efficient than simple programmed I/O still requires the active intervention of the processor to transfer data between memory and an I/O module, and any data transfer must traverse a path through the processor. Thus is suffers from two inherent drawbacks… The I/O transfer rate is limited by the speed with which the processor can test and service a device The processor is tied up in managing an I/O transfer; a number of instructions must be executed for each I/O transfer Direct Memory Access When large volumes of data are to be moved, an efficient technique is direct memory access (DMA) DMA Function DMA involves an additional module on the system bus. The DMA module is capable of mimicking the processor and taking over control of the system from the processor. It needs to do this to transfer data to and from memory over the system bus. DMA must the bus only when the processor does not need it, or it must force the processor to suspend operation temporarily (most common – referred to as cycle stealing). When the processor wishes to read or write a block of data, it issues a command to the DMA module by sending to the DMA module the following information… Whether a read or write is requested using the read or write control line between the processor and the DMA module The address of the I/O device involved, communicated on the data lines The starting location in memory to read from or write to, communicated on the data lines and stored by the DMA module in its address register The number of words to be read or written, communicated via the data lines and stored in the data count register The processor then continues with other work, it delegates the I/O operation to the DMA module which transfers the entire block of data, one word at a time, directly to or from memory without going through the processor. When the transfer is complete, the DMA module sends an interrupt signal to the processor, this the processor is involved only at the beginning and end of the transfer. I/O Channels and Processors Characteristics of I/O Channels As one proceeds along the evolutionary path, more and more of the I/O function is performed without CPU involvement. The I/O channel represents an extension of the DMA concept. An I/O channel ahs the ability to execute I/O instructions, which gives it complete control over I/O operations. In a computer system with such devices, the CPU does not execute I/O instructions – such instructions are stored in main memory to be executed by a special purpose processor in the I/O channel itself. Two types of I/O channels are common A selector channel controls multiple high-speed devices. A multiplexor channel can handle I/O with multiple characters as fast as possible to multiple devices. The external interface: FireWire and InfiniBand Types of Interfaces One major characteristic of the interface is whether it is serial or parallel parallel interface – there are multiple lines connecting the I/O module and the peripheral, and multiple bits are transferred simultaneously serial interface – there is only one line used to transmit data, and bits must be transmitted one at a time With new generation serial interfaces, parallel interfaces are becoming less common. In either case, the I/O module must engage in a dialogue with the peripheral. In general terms the dialog may look as follows… The I/O module sends a control signal requesting permission to send data The peripheral acknowledges the request The I/O module transfers data The peripheral acknowledges receipt of data For a detailed explanation of FireWire and InfiniBand technology read page 264 – 270 of the textbook

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• SATA errors reported during boot: exception Emask 0x40 SAct 0x0 SErr 0x80800 action 0x0

  - by digby280

  I have noticed some error during the Linux boot. They seem to continue to occur after the boot adding lines to the log every few seconds. Once booted this normally does not appear to be causing any problems. However, around 1 in 10 boots results in a kernel panic and the computer has on two or three occasions suddenly rebooted after being powered on for a number of hours. I presume the cause of the reboot is a kernel panic as well. I am running Ubuntu 11.10 and I have had Ubuntu installed on the computer for around a year. I have googled around and not found anything useful. I have provided the kernel log lines and the output of smartctl. Can anyone explain exactly what these errors mean, or better still how to resolve them? Apr 2 16:51:27 dell580 kernel: [ 19.831140] EXT4-fs (sdb2): re-mounted. Opts: errors=remount-ro,user_xattr,commit=0 Apr 2 16:51:27 dell580 kernel: [ 19.934194] tg3 0000:03:00.0: eth0: Link is down Apr 2 16:51:28 dell580 kernel: [ 20.929468] tg3 0000:03:00.0: eth0: Link is up at 100 Mbps, full duplex Apr 2 16:51:28 dell580 kernel: [ 20.929471] tg3 0000:03:00.0: eth0: Flow control is on for TX and on for RX Apr 2 16:51:28 dell580 kernel: [ 20.929727] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready Apr 2 16:51:29 dell580 kernel: [ 21.609381] EXT4-fs (sdb2): re-mounted. Opts: errors=remount-ro,user_xattr,commit=0 Apr 2 16:51:29 dell580 kernel: [ 21.616515] ata2.01: exception Emask 0x40 SAct 0x0 SErr 0x80800 action 0x0 Apr 2 16:51:29 dell580 kernel: [ 21.616519] ata2.01: SError: { HostInt 10B8B } Apr 2 16:51:29 dell580 kernel: [ 21.616525] ata2.00: hard resetting link Apr 2 16:51:29 dell580 kernel: [ 21.934036] ata2.01: hard resetting link Apr 2 16:51:29 dell580 kernel: [ 22.408890] ata2.00: SATA link up 1.5 Gbps (SStatus 113 SControl 300) Apr 2 16:51:29 dell580 kernel: [ 22.408907] ata2.01: SATA link up 3.0 Gbps (SStatus 123 SControl 300) Apr 2 16:51:29 dell580 kernel: [ 22.440934] ata2.00: configured for UDMA/100 Apr 2 16:51:29 dell580 kernel: [ 22.449040] ata2.01: configured for UDMA/133 Apr 2 16:51:29 dell580 kernel: [ 22.449818] ata2: EH complete Apr 2 16:51:33 dell580 kernel: [ 26.122664] ata2.01: exception Emask 0x40 SAct 0x0 SErr 0x80800 action 0x0 Apr 2 16:51:33 dell580 kernel: [ 26.122670] ata2.01: SError: { HostInt 10B8B } Apr 2 16:51:33 dell580 kernel: [ 26.122677] ata2.00: hard resetting link Apr 2 16:51:33 dell580 kernel: [ 26.442684] ata2.01: hard resetting link Apr 2 16:51:34 dell580 kernel: [ 26.925545] ata2.00: SATA link up 1.5 Gbps (SStatus 113 SControl 300) Apr 2 16:51:34 dell580 kernel: [ 26.925561] ata2.01: SATA link up 3.0 Gbps (SStatus 123 SControl 300) Apr 2 16:51:34 dell580 kernel: [ 26.961542] ata2.00: configured for UDMA/100 Apr 2 16:51:34 dell580 kernel: [ 26.969616] ata2.01: configured for UDMA/133 Apr 2 16:51:34 dell580 kernel: [ 26.970400] ata2: EH complete Apr 2 16:51:35 dell580 kernel: [ 28.111180] ata2.01: exception Emask 0x40 SAct 0x0 SErr 0x80800 action 0x0 Apr 2 16:51:35 dell580 kernel: [ 28.111184] ata2.01: SError: { HostInt 10B8B } Apr 2 16:51:35 dell580 kernel: [ 28.111191] ata2.00: hard resetting link Apr 2 16:51:35 dell580 kernel: [ 28.429674] ata2.01: hard resetting link Apr 2 16:51:36 dell580 kernel: [ 28.904557] ata2.00: SATA link up 1.5 Gbps (SStatus 113 SControl 300) Apr 2 16:51:36 dell580 kernel: [ 28.904572] ata2.01: SATA link up 3.0 Gbps (SStatus 123 SControl 300) Apr 2 16:51:36 dell580 kernel: [ 28.936609] ata2.00: configured for UDMA/100 Apr 2 16:51:36 dell580 kernel: [ 28.944692] ata2.01: configured for UDMA/133 Apr 2 16:51:36 dell580 kernel: [ 28.945464] ata2: EH complete Apr 2 16:51:38 dell580 kernel: [ 31.581756] eth0: no IPv6 routers present Apr 2 16:51:38 dell580 kernel: [ 32.103066] ata2.01: exception Emask 0x40 SAct 0x0 SErr 0x80800 action 0x0 Apr 2 16:51:38 dell580 kernel: [ 32.103074] ata2.01: SError: { HostInt 10B8B } Apr 2 16:51:38 dell580 kernel: [ 32.103085] ata2.00: hard resetting link Apr 2 16:51:38 dell580 kernel: [ 32.419669] ata2.01: hard resetting link Apr 2 16:51:39 dell580 kernel: [ 32.894518] ata2.00: SATA link up 1.5 Gbps (SStatus 113 SControl 300) Apr 2 16:51:39 dell580 kernel: [ 32.894533] ata2.01: SATA link up 3.0 Gbps (SStatus 123 SControl 300) Apr 2 16:51:39 dell580 kernel: [ 32.926536] ata2.00: configured for UDMA/100 Apr 2 16:51:39 dell580 kernel: [ 32.934715] ata2.01: configured for UDMA/133 Apr 2 16:51:39 dell580 kernel: [ 32.935578] ata2: EH complete Here's the output of smartctl for the drive. smartctl 5.41 2011-06-09 r3365 [x86_64-linux-3.0.0-17-generic] (local build) Copyright (C) 2002-11 by Bruce Allen, http://smartmontools.sourceforge.net === START OF INFORMATION SECTION === Model Family: SAMSUNG SpinPoint F1 DT Device Model: SAMSUNG HD103UJ Serial Number: S13PJ90QC19706 LU WWN Device Id: 5 0000f0 00b1c7960 Firmware Version: 1AA01113 User Capacity: 1,000,204,886,016 bytes [1.00 TB] Sector Size: 512 bytes logical/physical Device is: In smartctl database [for details use: -P show] ATA Version is: 8 ATA Standard is: ATA-8-ACS revision 3b Local Time is: Mon Apr 2 17:13:48 2012 BST SMART support is: Available - device has SMART capability. SMART support is: Enabled === START OF READ SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED General SMART Values: Offline data collection status: (0x00) Offline data collection activity was never started. Auto Offline Data Collection: Disabled. Self-test execution status: ( 41) The self-test routine was interrupted by the host with a hard or soft reset. Total time to complete Offline data collection: (11772) seconds. Offline data collection capabilities: (0x7b) SMART execute Offline immediate. Auto Offline data collection on/off support. Suspend Offline collection upon new command. Offline surface scan supported. Self-test supported. Conveyance Self-test supported. Selective Self-test supported. SMART capabilities: (0x0003) Saves SMART data before entering power-saving mode. Supports SMART auto save timer. Error logging capability: (0x01) Error logging supported. General Purpose Logging supported. Short self-test routine recommended polling time: ( 2) minutes. Extended self-test routine recommended polling time: ( 197) minutes. Conveyance self-test routine recommended polling time: ( 21) minutes. SCT capabilities: (0x003f) SCT Status supported. SCT Error Recovery Control supported. SCT Feature Control supported. SCT Data Table supported. SMART Attributes Data Structure revision number: 16 Vendor Specific SMART Attributes with Thresholds: ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x000f 100 100 051 Pre-fail Always - 0 3 Spin_Up_Time 0x0007 076 076 011 Pre-fail Always - 7940 4 Start_Stop_Count 0x0032 099 099 000 Old_age Always - 521 5 Reallocated_Sector_Ct 0x0033 100 100 010 Pre-fail Always - 0 7 Seek_Error_Rate 0x000f 253 253 051 Pre-fail Always - 0 8 Seek_Time_Performance 0x0025 100 100 015 Pre-fail Offline - 0 9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 642 10 Spin_Retry_Count 0x0033 100 100 051 Pre-fail Always - 0 11 Calibration_Retry_Count 0x0012 100 100 000 Old_age Always - 0 12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 482 13 Read_Soft_Error_Rate 0x000e 100 100 000 Old_age Always - 0 183 Runtime_Bad_Block 0x0032 100 100 000 Old_age Always - 759 184 End-to-End_Error 0x0033 100 100 000 Pre-fail Always - 0 187 Reported_Uncorrect 0x0032 100 100 000 Old_age Always - 0 188 Command_Timeout 0x0032 100 100 000 Old_age Always - 0 190 Airflow_Temperature_Cel 0x0022 073 069 000 Old_age Always - 27 (Min/Max 16/27) 194 Temperature_Celsius 0x0022 073 067 000 Old_age Always - 27 (Min/Max 16/28) 195 Hardware_ECC_Recovered 0x001a 100 100 000 Old_age Always - 320028 196 Reallocated_Event_Count 0x0032 100 100 000 Old_age Always - 0 197 Current_Pending_Sector 0x0012 100 100 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0030 100 100 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x003e 099 099 000 Old_age Always - 1494 200 Multi_Zone_Error_Rate 0x000a 100 100 000 Old_age Always - 0 201 Soft_Read_Error_Rate 0x000a 253 253 000 Old_age Always - 0 SMART Error Log Version: 1 ATA Error Count: 211 (device log contains only the most recent five errors) CR = Command Register [HEX] FR = Features Register [HEX] SC = Sector Count Register [HEX] SN = Sector Number Register [HEX] CL = Cylinder Low Register [HEX] CH = Cylinder High Register [HEX] DH = Device/Head Register [HEX] DC = Device Command Register [HEX] ER = Error register [HEX] ST = Status register [HEX] Powered_Up_Time is measured from power on, and printed as DDd+hh:mm:SS.sss where DD=days, hh=hours, mm=minutes, SS=sec, and sss=millisec. It "wraps" after 49.710 days. Error 211 occurred at disk power-on lifetime: 0 hours (0 days + 0 hours) When the command that caused the error occurred, the device was active or idle. After command completion occurred, registers were: ER ST SC SN CL CH DH -- -- -- -- -- -- -- 84 51 0f 31 63 8f e1 Error: ICRC, ABRT 15 sectors at LBA = 0x018f6331 = 26174257 Commands leading to the command that caused the error were: CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name -- -- -- -- -- -- -- -- ---------------- -------------------- c8 00 00 40 62 8f e1 08 00:01:00.460 READ DMA c8 00 20 00 7c 30 e0 08 00:01:00.450 READ DMA c8 00 00 10 49 8f e1 08 00:01:00.440 READ DMA c8 00 e0 20 d0 30 e0 08 00:01:00.420 READ DMA c8 00 00 c0 59 90 e1 08 00:01:00.400 READ DMA Error 210 occurred at disk power-on lifetime: 0 hours (0 days + 0 hours) When the command that caused the error occurred, the device was active or idle. After command completion occurred, registers were: ER ST SC SN CL CH DH -- -- -- -- -- -- -- 84 51 cf e9 cf 66 e0 Error: ICRC, ABRT 207 sectors at LBA = 0x0066cfe9 = 6737897 Commands leading to the command that caused the error were: CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name -- -- -- -- -- -- -- -- ---------------- -------------------- c8 00 00 b8 cf 66 e0 08 00:08:29.780 READ DMA c8 00 60 60 c9 18 e0 08 00:08:29.770 READ DMA c8 00 40 20 c9 18 e0 08 00:08:29.770 READ DMA c8 00 20 00 c9 18 e0 08 00:08:29.760 READ DMA c8 00 20 98 cf 66 e0 08 00:08:29.750 READ DMA Error 209 occurred at disk power-on lifetime: 0 hours (0 days + 0 hours) When the command that caused the error occurred, the device was active or idle. After command completion occurred, registers were: ER ST SC SN CL CH DH -- -- -- -- -- -- -- 84 51 2f d1 74 e0 e0 Error: ICRC, ABRT 47 sectors at LBA = 0x00e074d1 = 14709969 Commands leading to the command that caused the error were: CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name -- -- -- -- -- -- -- -- ---------------- -------------------- c8 00 00 00 74 e0 e0 08 00:00:30.940 READ DMA c8 00 20 18 36 de e0 08 00:00:30.930 READ DMA c8 00 08 48 f1 dd e0 08 00:00:30.930 READ DMA c8 00 08 a8 f0 dd e0 08 00:00:30.930 READ DMA c8 00 08 90 f0 dd e0 08 00:00:30.930 READ DMA Error 208 occurred at disk power-on lifetime: 0 hours (0 days + 0 hours) When the command that caused the error occurred, the device was active or idle. After command completion occurred, registers were: ER ST SC SN CL CH DH -- -- -- -- -- -- -- 84 51 7f 21 88 9d e0 Error: ICRC, ABRT 127 sectors at LBA = 0x009d8821 = 10324001 Commands leading to the command that caused the error were: CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name -- -- -- -- -- -- -- -- ---------------- -------------------- c8 00 a0 00 88 9d e0 08 00:00:27.610 READ DMA c8 00 58 a8 e7 9c e0 08 00:00:27.610 READ DMA c8 00 00 28 e6 9c e0 08 00:00:27.610 READ DMA c8 00 00 e0 e4 9c e0 08 00:00:27.610 READ DMA c8 00 00 90 e0 9c e0 08 00:00:27.600 READ DMA Error 207 occurred at disk power-on lifetime: 0 hours (0 days + 0 hours) When the command that caused the error occurred, the device was active or idle. After command completion occurred, registers were: ER ST SC SN CL CH DH -- -- -- -- -- -- -- 04 51 26 6a 6a c3 e0 Error: ABRT at LBA = 0x00c36a6a = 12806762 Commands leading to the command that caused the error were: CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name -- -- -- -- -- -- -- -- ---------------- -------------------- ca 00 00 90 69 c3 e0 08 00:29:39.350 WRITE DMA ca 00 40 90 68 c3 e0 08 00:29:39.350 WRITE DMA ca 00 40 50 65 c3 e0 08 00:29:39.350 WRITE DMA ca 00 40 d0 64 c3 e0 08 00:29:39.350 WRITE DMA ca 00 40 90 63 c3 e0 08 00:29:39.350 WRITE DMA SMART Self-test log structure revision number 1 Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error # 1 Short offline Interrupted (host reset) 90% 638 - # 2 Short offline Interrupted (host reset) 90% 638 - # 3 Extended offline Interrupted (host reset) 90% 638 - # 4 Short offline Interrupted (host reset) 90% 638 - # 5 Extended offline Interrupted (host reset) 90% 638 - SMART Selective self-test log data structure revision number 1 SPAN MIN_LBA MAX_LBA CURRENT_TEST_STATUS 1 0 0 Not_testing 2 0 0 Not_testing 3 0 0 Not_testing 4 0 0 Not_testing 5 0 0 Not_testing Selective self-test flags (0x0): After scanning selected spans, do NOT read-scan remainder of disk. If Selective self-test is pending on power-up, resume after 0 minute delay.

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• Install NPM Packages Automatically for Node.js on Windows Azure Web Site

  - by Shaun

  In one of my previous post I described and demonstrated how to use NPM packages in Node.js and Windows Azure Web Site (WAWS). In that post I used NPM command to install packages, and then use Git for Windows to commit my changes and sync them to WAWS git repository. Then WAWS will trigger a new deployment to host my Node.js application. Someone may notice that, a NPM package may contains many files and could be a little bit huge. For example, the “azure” package, which is the Windows Azure SDK for Node.js, is about 6MB. Another popular package “express”, which is a rich MVC framework for Node.js, is about 1MB. When I firstly push my codes to Windows Azure, all of them must be uploaded to the cloud. Is that possible to let Windows Azure download and install these packages for us? In this post, I will introduce how to make WAWS install all required packages for us when deploying.   Let’s Start with Demo Demo is most straightforward. Let’s create a new WAWS and clone it to my local disk. Drag the folder into Git for Windows so that it can help us commit and push. Please refer to this post if you are not familiar with how to use Windows Azure Web Site, Git deployment, git clone and Git for Windows. And then open a command windows and install a package in our code folder. Let’s say I want to install “express”. And then created a new Node.js file named “server.js” and pasted the code as below. 1: var express = require("express"); 2: var app = express(); 3: 4: app.get("/", function(req, res) { 5: res.send("Hello Node.js and Express."); 6: }); 7: 8: console.log("Web application opened."); 9: app.listen(process.env.PORT); If we switch to Git for Windows right now we will find that it detected the changes we made, which includes the “server.js” and all files under “node_modules” folder. What we need to upload should only be our source code, but the huge package files also have to be uploaded as well. Now I will show you how to exclude them and let Windows Azure install the package on the cloud. First we need to add a special file named “.gitignore”. It seems cannot be done directly from the file explorer since this file only contains extension name. So we need to do it from command line. Navigate to the local repository folder and execute the command below to create an empty file named “.gitignore”. If the command windows asked for input just press Enter. 1: echo > .gitignore Now open this file and copy the content below and save. 1: node_modules Now if we switch to Git for Windows we will found that the packages under the “node_modules” were not in the change list. So now if we commit and push, the “express” packages will not be uploaded to Windows Azure. Second, let’s tell Windows Azure which packages it needs to install when deploying. Create another file named “package.json” and copy the content below into that file and save. 1: { 2: "name": "npmdemo", 3: "version": "1.0.0", 4: "dependencies": { 5: "express": "*" 6: } 7: } Now back to Git for Windows, commit our changes and push it to WAWS. Then let’s open the WAWS in developer portal, we will see that there’s a new deployment finished. Click the arrow right side of this deployment we can see how WAWS handle this deployment. Especially we can find WAWS executed NPM. And if we opened the log we can review what command WAWS executed to install the packages and the installation output messages. As you can see WAWS installed “express” for me from the cloud side, so that I don’t need to upload the whole bunch of the package to Azure. Open this website and we can see the result, which proved the “express” had been installed successfully.   What’s Happened Under the Hood Now let’s explain a bit on what the “.gitignore” and “package.json” mean. The “.gitignore” is an ignore configuration file for git repository. All files and folders listed in the “.gitignore” will be skipped from git push. In the example below I copied “node_modules” into this file in my local repository. This means,  do not track and upload all files under the “node_modules” folder. So by using “.gitignore” I skipped all packages from uploading to Windows Azure. “.gitignore” can contain files, folders. It can also contain the files and folders that we do NOT want to ignore. In the next section we will see how to use the un-ignore syntax to make the SQL package included. The “package.json” file is the package definition file for Node.js application. We can define the application name, version, description, author, etc. information in it in JSON format. And we can also put the dependent packages as well, to indicate which packages this Node.js application is needed. In WAWS, name and version is necessary. And when a deployment happened, WAWS will look into this file, find the dependent packages, execute the NPM command to install them one by one. So in the demo above I copied “express” into this file so that WAWS will install it for me automatically. I updated the dependencies section of the “package.json” file manually. But this can be done partially automatically. If we have a valid “package.json” in our local repository, then when we are going to install some packages we can specify “--save” parameter in “npm install” command, so that NPM will help us upgrade the dependencies part. For example, when I wanted to install “azure” package I should execute the command as below. Note that I added “--save” with the command. 1: npm install azure --save Once it finished my “package.json” will be updated automatically. Each dependent packages will be presented here. The JSON key is the package name while the value is the version range. Below is a brief list of the version range format. For more information about the “package.json” please refer here. Format Description Example version Must match the version exactly. "azure": "0.6.7" >=version Must be equal or great than the version. "azure": ">0.6.0" 1.2.x The version number must start with the supplied digits, but any digit may be used in place of the x. "azure": "0.6.x" ~version The version must be at least as high as the range, and it must be less than the next major revision above the range. "azure": "~0.6.7" * Matches any version. "azure": "*" And WAWS will install the proper version of the packages based on what you defined here. The process of WAWS git deployment and NPM installation would be like this.   But Some Packages… As we know, when we specified the dependencies in “package.json” WAWS will download and install them on the cloud. For most of packages it works very well. But there are some special packages may not work. This means, if the package installation needs some special environment restraints it might be failed. For example, the SQL Server Driver for Node.js package needs “node-gyp”, Python and C++ 2010 installed on the target machine during the NPM installation. If we just put the “msnodesql” in “package.json” file and push it to WAWS, the deployment will be failed since there’s no “node-gyp”, Python and C++ 2010 in the WAWS virtual machine. For example, the “server.js” file. 1: var express = require("express"); 2: var app = express(); 3: 4: app.get("/", function(req, res) { 5: res.send("Hello Node.js and Express."); 6: }); 7:  8: var sql = require("msnodesql"); 9: var connectionString = "Driver={SQL Server Native Client 10.0};Server=tcp:tqy4c0isfr.database.windows.net,1433;Database=msteched2012;Uid=shaunxu@tqy4c0isfr;Pwd=P@ssw0rd123;Encrypt=yes;Connection Timeout=30;"; 10: app.get("/sql", function (req, res) { 11: sql.open(connectionString, function (err, conn) { 12: if (err) { 13: console.log(err); 14: res.send(500, "Cannot open connection."); 15: } 16: else { 17: conn.queryRaw("SELECT * FROM [Resource]", function (err, results) { 18: if (err) { 19: console.log(err); 20: res.send(500, "Cannot retrieve records."); 21: } 22: else { 23: res.json(results); 24: } 25: }); 26: } 27: }); 28: }); 29: 30: console.log("Web application opened."); 31: app.listen(process.env.PORT); The “package.json” file. 1: { 2: "name": "npmdemo", 3: "version": "1.0.0", 4: "dependencies": { 5: "express": "*", 6: "msnodesql": "*" 7: } 8: } And it failed to deploy to WAWS. From the NPM log we can see it’s because “msnodesql” cannot be installed on WAWS. The solution is, in “.gitignore” file we should ignore all packages except the “msnodesql”, and upload the package by ourselves. This can be done by use the content as below. We firstly un-ignored the “node_modules” folder. And then we ignored all sub folders but need git to check each sub folders. And then we un-ignore one of the sub folders named “msnodesql” which is the SQL Server Node.js Driver. 1: !node_modules/ 2:  3: node_modules/* 4: !node_modules/msnodesql For more information about the syntax of “.gitignore” please refer to this thread. Now if we go to Git for Windows we will find the “msnodesql” was included in the uncommitted set while “express” was not. I also need remove the dependency of “msnodesql” from “package.json”. Commit and push to WAWS. Now we can see the deployment successfully done. And then we can use the Windows Azure SQL Database from our Node.js application through the “msnodesql” package we uploaded.   Summary In this post I demonstrated how to leverage the deployment process of Windows Azure Web Site to install NPM packages during the publish action. With the “.gitignore” and “package.json” file we can ignore the dependent packages from our Node.js and let Windows Azure Web Site download and install them while deployed. For some special packages that cannot be installed by Windows Azure Web Site, such as “msnodesql”, we can put them into the publish payload as well. With the combination of Windows Azure Web Site, Node.js and NPM it makes even more easy and quick for us to develop and deploy our Node.js application to the cloud.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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• Spooling in SQL execution plans

  - by Rob Farley

  Sewing has never been my thing. I barely even know the terminology, and when discussing this with American friends, I even found out that half the words that Americans use are different to the words that English and Australian people use. That said – let’s talk about spools! In particular, the Spool operators that you find in some SQL execution plans. This post is for T-SQL Tuesday, hosted this month by me! I’ve chosen to write about spools because they seem to get a bad rap (even in my song I used the line “There’s spooling from a CTE, they’ve got recursion needlessly”). I figured it was worth covering some of what spools are about, and hopefully explain why they are remarkably necessary, and generally very useful. If you have a look at the Books Online page about Plan Operators, at http://msdn.microsoft.com/en-us/library/ms191158.aspx, and do a search for the word ‘spool’, you’ll notice it says there are 46 matches. 46! Yeah, that’s what I thought too... Spooling is mentioned in several operators: Eager Spool, Lazy Spool, Index Spool (sometimes called a Nonclustered Index Spool), Row Count Spool, Spool, Table Spool, and Window Spool (oh, and Cache, which is a special kind of spool for a single row, but as it isn’t used in SQL 2012, I won’t describe it any further here). Spool, Table Spool, Index Spool, Window Spool and Row Count Spool are all physical operators, whereas Eager Spool and Lazy Spool are logical operators, describing the way that the other spools work. For example, you might see a Table Spool which is either Eager or Lazy. A Window Spool can actually act as both, as I’ll mention in a moment. In sewing, cotton is put onto a spool to make it more useful. You might buy it in bulk on a cone, but if you’re going to be using a sewing machine, then you quite probably want to have it on a spool or bobbin, which allows it to be used in a more effective way. This is the picture that I want you to think about in relation to your data. I’m sure you use spools every time you use your sewing machine. I know I do. I can’t think of a time when I’ve got out my sewing machine to do some sewing and haven’t used a spool. However, I often run SQL queries that don’t use spools. You see, the data that is consumed by my query is typically in a useful state without a spool. It’s like I can just sew with my cotton despite it not being on a spool! Many of my favourite features in T-SQL do like to use spools though. This looks like a very similar query to before, but includes an OVER clause to return a column telling me the number of rows in my data set. I’ll describe what’s going on in a few paragraphs’ time. So what does a Spool operator actually do? The spool operator consumes a set of data, and stores it in a temporary structure, in the tempdb database. This structure is typically either a Table (ie, a heap), or an Index (ie, a b-tree). If no data is actually needed from it, then it could also be a Row Count spool, which only stores the number of rows that the spool operator consumes. A Window Spool is another option if the data being consumed is tightly linked to windows of data, such as when the ROWS/RANGE clause of the OVER clause is being used. You could maybe think about the type of spool being like whether the cotton is going onto a small bobbin to fit in the base of the sewing machine, or whether it’s a larger spool for the top. A Table or Index Spool is either Eager or Lazy in nature. Eager and Lazy are Logical operators, which talk more about the behaviour, rather than the physical operation. If I’m sewing, I can either be all enthusiastic and get all my cotton onto the spool before I start, or I can do it as I need it. “Lazy” might not the be the best word to describe a person – in the SQL world it describes the idea of either fetching all the rows to build up the whole spool when the operator is called (Eager), or populating the spool only as it’s needed (Lazy). Window Spools are both physical and logical. They’re eager on a per-window basis, but lazy between windows. And when is it needed? The way I see it, spools are needed for two reasons. 1 – When data is going to be needed AGAIN. 2 – When data needs to be kept away from the original source. If you’re someone that writes long stored procedures, you are probably quite aware of the second scenario. I see plenty of stored procedures being written this way – where the query writer populates a temporary table, so that they can make updates to it without risking the original table. SQL does this too. Imagine I’m updating my contact list, and some of my changes move data to later in the book. If I’m not careful, I might update the same row a second time (or even enter an infinite loop, updating it over and over). A spool can make sure that I don’t, by using a copy of the data. This problem is known as the Halloween Effect (not because it’s spooky, but because it was discovered in late October one year). As I’m sure you can imagine, the kind of spool you’d need to protect against the Halloween Effect would be eager, because if you’re only handling one row at a time, then you’re not providing the protection... An eager spool will block the flow of data, waiting until it has fetched all the data before serving it up to the operator that called it. In the query below I’m forcing the Query Optimizer to use an index which would be upset if the Name column values got changed, and we see that before any data is fetched, a spool is created to load the data into. This doesn’t stop the index being maintained, but it does mean that the index is protected from the changes that are being done. There are plenty of times, though, when you need data repeatedly. Consider the query I put above. A simple join, but then counting the number of rows that came through. The way that this has executed (be it ideal or not), is to ask that a Table Spool be populated. That’s the Table Spool operator on the top row. That spool can produce the same set of rows repeatedly. This is the behaviour that we see in the bottom half of the plan. In the bottom half of the plan, we see that the a join is being done between the rows that are being sourced from the spool – one being aggregated and one not – producing the columns that we need for the query. Table v Index When considering whether to use a Table Spool or an Index Spool, the question that the Query Optimizer needs to answer is whether there is sufficient benefit to storing the data in a b-tree. The idea of having data in indexes is great, but of course there is a cost to maintaining them. Here we’re creating a temporary structure for data, and there is a cost associated with populating each row into its correct position according to a b-tree, as opposed to simply adding it to the end of the list of rows in a heap. Using a b-tree could even result in page-splits as the b-tree is populated, so there had better be a reason to use that kind of structure. That all depends on how the data is going to be used in other parts of the plan. If you’ve ever thought that you could use a temporary index for a particular query, well this is it – and the Query Optimizer can do that if it thinks it’s worthwhile. It’s worth noting that just because a Spool is populated using an Index Spool, it can still be fetched using a Table Spool. The details about whether or not a Spool used as a source shows as a Table Spool or an Index Spool is more about whether a Seek predicate is used, rather than on the underlying structure. Recursive CTE I’ve already shown you an example of spooling when the OVER clause is used. You might see them being used whenever you have data that is needed multiple times, and CTEs are quite common here. With the definition of a set of data described in a CTE, if the query writer is leveraging this by referring to the CTE multiple times, and there’s no simplification to be leveraged, a spool could theoretically be used to avoid reapplying the CTE’s logic. Annoyingly, this doesn’t happen. Consider this query, which really looks like it’s using the same data twice. I’m creating a set of data (which is completely deterministic, by the way), and then joining it back to itself. There seems to be no reason why it shouldn’t use a spool for the set described by the CTE, but it doesn’t. On the other hand, if we don’t pull as many columns back, we might see a very different plan. You see, CTEs, like all sub-queries, are simplified out to figure out the best way of executing the whole query. My example is somewhat contrived, and although there are plenty of cases when it’s nice to give the Query Optimizer hints about how to execute queries, it usually doesn’t do a bad job, even without spooling (and you can always use a temporary table). When recursion is used, though, spooling should be expected. Consider what we’re asking for in a recursive CTE. We’re telling the system to construct a set of data using an initial query, and then use set as a source for another query, piping this back into the same set and back around. It’s very much a spool. The analogy of cotton is long gone here, as the idea of having a continual loop of cotton feeding onto a spool and off again doesn’t quite fit, but that’s what we have here. Data is being fed onto the spool, and getting pulled out a second time when the spool is used as a source. (This query is running on AdventureWorks, which has a ManagerID column in HumanResources.Employee, not AdventureWorks2012) The Index Spool operator is sucking rows into it – lazily. It has to be lazy, because at the start, there’s only one row to be had. However, as rows get populated onto the spool, the Table Spool operator on the right can return rows when asked, ending up with more rows (potentially) getting back onto the spool, ready for the next round. (The Assert operator is merely checking to see if we’ve reached the MAXRECURSION point – it vanishes if you use OPTION (MAXRECURSION 0), which you can try yourself if you like). Spools are useful. Don’t lose sight of that. Every time you use temporary tables or table variables in a stored procedure, you’re essentially doing the same – don’t get upset at the Query Optimizer for doing so, even if you think the spool looks like an expensive part of the query. I hope you’re enjoying this T-SQL Tuesday. Why not head over to my post that is hosting it this month to read about some other plan operators? At some point I’ll write a summary post – once I have you should find a comment below pointing at it. @rob_farley

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• Enabling XML-documentation for code contracts

  - by DigiMortal

  One nice feature that code contracts offer is updating of code documentation. If you are using source code documenting features of Visual Studio then code contracts may automate some tasks you otherwise have to implement manually. In this posting I will show you some XML documentation files with documented contracts. I will also explain how this feature works. Enabling XML-documentation in project settings As a first thing let’s enable generating of code documentation under project settings. Open project properties, move to Build page and make check to checkbox called “XML documentation file”. Save project settings and rebuild project. When project is built go to bin/Debug folder and open the XML-file. Here is my XML. <?xml version="1.0"?> <doc>     <assembly>         <name>Eneta.Examples.CodeContracts.Testable</name>     </assembly>     <members>         <member name="T:Eneta.Examples.CodeContracts.Testable.Randomizer">             <summary>             Class for generating random integers in user specified range.             </summary>         </member>         <member name="M:Eneta.Examples.CodeContracts.Testable.Randomizer.#ctor(Eneta.Examples.CodeContracts.Testable.IRandomGenerator)">             <summary>             Constructor of Randomizer. Initializes Randomizer class.             </summary>             <param name="generator">Instance of random number generator.</param>         </member>         <member name="M:Eneta.Examples.CodeContracts.Testable.Randomizer.GetRandomFromRangeContracted(System.Int32,System.Int32)">             <summary>             Returns random integer in given range.             </summary>             <param name="min">Minimum value of random integer.</param>             <param name="max">Maximum value of random integer.</param>         </member>     </members> </doc> You can see nothing about code contracts here. Enabling code contracts documentation Code contracts have their own settings and conditions for documentation. Open project properties and move to Code Contracts tab. From “Contract Reference Assembly” dropdown check Build and make check to checkbox “Emit contracts into XML doc file”. And again – save project setting, build the project and move to bin/Debug folder. Now you can see that there are two files for XML-documentation: <assembly name>.XML <assembly name>.old.XML First files is documentation with contracts, second file is original documentation without contracts. Let’s see now what is inside our new XML-documentation file. <?xml version="1.0"?> <doc>   <assembly>     <name>Eneta.Examples.CodeContracts.Testable</name>   </assembly>   <members>     <member name="T:Eneta.Examples.CodeContracts.Testable.Randomizer">       <summary>             Class for generating random integers in user specified range.             </summary>     </member>     <member name="M:Eneta.Examples.CodeContracts.Testable.Randomizer.#ctor(Eneta.Examples.CodeContracts.Testable.IRandomGenerator)">       <summary>             Constructor of Randomizer. Initializes Randomizer class.             </summary>       <param name="generator">Instance of random number generator.</param>     </member>     <member name="M:Eneta.Examples.CodeContracts.Testable.Randomizer.GetRandomFromRangeContracted(System.Int32,System.Int32)">       <summary>             Returns random integer in given range.             </summary>       <param name="min">Minimum value of random integer.</param>       <param name="max">Maximum value of random integer.</param>       <requires description="Min must be less than max" exception="T:System.ArgumentOutOfRangeException">                 min &lt; max</requires>       <exception cref="T:System.ArgumentOutOfRangeException">                 min &gt;= max</exception>       <ensures description="Return value is out of range">                 Contract.Result&lt;int&gt;() &gt;= min &amp;&amp;                 Contract.Result&lt;int&gt;() &lt;= max</ensures>     </member>   </members> </doc> As you can see then code contracts are pretty well documented. Messages that I provided with code contracts are also available in documentation. If I wrote very good and informative messages then these messages are very useful also in contracts documentation. Code contracts and Sandcastle Sandcastle knows nothing about code contracts by default. There is separate package of file for Sandcastle that is provided you by code contracts installation. You can read from code contracts manual: “Sandcastle (http://www.codeplex.com/Sandcastle) is a freely available tool that generates help les and web sites describing your APIs, based on the XML doc comments in your source code. The CodeContracts install contains a set of les that can be copied over a Sandcastle installation to take advantage of the additional contract information. The produced documentation adds a contract section to methods with declared requires and/or ensures. In order for Sandcastle to produce Contract sections, you need to patch a number of files in its installation. Please refer to the Sandcastle Readme.txt found under Start Menu/CodeContracts/Sandcastle for instructions. A future release of Sandcastle will hopefully support contract sections without the need for this patching step.” Integrating code contracts documentation to Sandcastle will be one of my next postings about code contracts. Conclusion if you are using code documentation then documentation about code contracts can be added to documentation very easily. All you have to do is to enable XML-documentation for contracts and build your project. Later you can use Sandcastle files provided by code contracts installer to integrate contracts documentation to your output documentation package.

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• Day 6 - Game Menuing Woes and Future Screen Sneak Peeks

  - by dapostolov

  So, after my last post on Day 5 I dabbled with my game class design. I took the approach where each game objects is tightly coupled with a graphic. The good news is I got the menu working but not without some hard knocks and game growing pains. I'll explain later, but for now...here is a class diagram of my first stab at my class structure and some code...   Ok, there are few mistakes, however, I'm going to leave it as is for now... As you can see I created an inital abstract base class called GameSprite. This class when inherited will provide a simple virtual default draw method:        public virtual void DrawSprite(SpriteBatch spriteBatch)         {             spriteBatch.Draw(Sprite, Position, Color.White);         } The benefits of coding it this way allows me to inherit the class and utilise the method in the screen draw method...So regardless of what the graphic object type is it will now have the ability to render a static image on the screen. Example: public class MyStaticTreasureChest : GameSprite {} If you remember the window draw method from Day 3's post, we could use the above code as follows...         protected override void Draw(GameTime gameTime)         {             GraphicsDevice.Clear(Color.CornflowerBlue);             spriteBatch.Begin(SpriteBlendMode.AlphaBlend);             foreach(var gameSprite in ListOfGameObjects)            {                 gameSprite.DrawSprite(spriteBatch);            }             spriteBatch.End();             base.Draw(gameTime);         } I have to admit the GameSprite object is pretty plain as with its DrawSprite method... But ... we now have the ability to render 3 static menu items on the screen ... BORING! I want those menu items to do something exciting, which of course involves animation... So, let's have a peek at AnimatedGameSprite in the above game diagram. The idea with the AnimatedGameSprite is that it has an image to animate...such as ... characters, fireballs, and... menus! So after inheriting from GameSprite class, I added a few more options such as UpdateSprite...         public virtual void UpdateSprite(float elapsed)         {             _totalElapsed += elapsed;             if (_totalElapsed > _timePerFrame)             {                 _frame++;                 _frame = _frame % _framecount;                 _totalElapsed -= _timePerFrame;             }         }  And an overidden DrawSprite...         public override void DrawSprite(SpriteBatch spriteBatch)         {             int FrameWidth = Sprite.Width / _framecount;             Rectangle sourcerect = new Rectangle(FrameWidth * _frame, 0, FrameWidth, Sprite.Height);             spriteBatch.Draw(Sprite, Position, sourcerect, Color.White, _rotation, _origin, _scale, SpriteEffects.None, _depth);         } With these two methods...I can animate and image, all I had to do was add a few more lines to the screens Update Method (From Day 3), like such:             float elapsed = (float) gameTime.ElapsedGameTime.TotalSeconds;             foreach (var item in ListOfAnimatedGameObjects)             {                 item.UpdateSprite(elapsed);             } And voila! My images begin to animate in one spot, on the screen... Hmm, but how do I interact with the menu items using a mouse...well the mouse cursor was easy enough... this.IsMouseVisible = true; But, to have it "interact" with an image was a bit more tricky...I had to perform collision detection!             mouseStateCurrent = Mouse.GetState();             var uiEnabledSprites = (from s in menuItems                                    where s.IsEnabled                                    select s).ToList();             foreach (var item in uiEnabledSprites)             {                 var r = new Rectangle((int)item.Position.X, (int)item.Position.Y, item.Sprite.Width, item.Sprite.Height);                 item.MenuState = MenuState.Normal;                 if (r.Intersects(new Rectangle(mouseStateCurrent.X, mouseStateCurrent.Y, 0, 0)))                 {                     item.MenuState = MenuState.Hover;                     if (mouseStatePrevious.LeftButton == ButtonState.Pressed                         && mouseStateCurrent.LeftButton == ButtonState.Released)                     {                         item.MenuState = MenuState.Pressed;                     }                 }             }             mouseStatePrevious = mouseStateCurrent; So, basically, what it is doing above is iterating through all my interactive objects and detecting a rectangle collision and the object , plays the state animation (or static image).  Lessons Learned, Time Burned... So, I think I did well to start, but after I hammered out my prototype...well...things got sloppy and I began to realise some design flaws... At the time: I couldn't seem to figure out how to open another window, such as the character creation screen Input was not event based and it was bugging me My menu design relied heavily on mouse input and I couldn't use keyboard. Mouse input, is tightly bound with graphic rendering / positioning, so its logic will have to be in each scene. Menu animations would stop mid frame, then continue when the action occured again. This is bad, because...what if I had a sword sliding onthe screen? Then it would slide a quarter of the way, then stop due to another action, then render again mid-slide... it just looked sloppy. Menu, Solved!? To solve the above problems I did a little research and I found some great code in the XNA forums. The one worth mentioning was the GameStateManagementSample. With this sample, you can create a basic "text based" menu system which allows you to swap screens, popup screens, play the game, and quit....basic game state management... In my next post I'm going to dwelve a bit more into this code and adapt it with my code from this prototype. Text based menus just won't cut it for me, for now...however, I'm still going to stick with my animated menu item idea. A sneak peek using the Game State Management Sample...with no changes made... Cool Things to Mention: At work ... I tend to break out in random conversations every-so-often and I get talking about some of my challenges with this game (or some stupid observation about something... stupid) During one conversation I was discussing how I should animate my images; I explained that I knew I had to use the Update method provided, but I didn't know how (at the time) to render an image at an appropriate "pace" and how many frames to use, etc.. I also got thinking that if a machine rendered my images faster / slower, that was surely going to f-up my animations. To which a friend, Sheldon,  answered, surely the Draw method is like a camera taking a snapshot of a scene in time. Then it clicked...I understood the big picture of the game engine... After some research I discovered that the Draw method attempts to keep a framerate of 60 fps. From what I understand, the game engine will even leave out a few calls to the draw method if it begins to slow down. This is why we want to put our sprite updates in the update method. Then using a game timer (provided by the engine), we want to render the scene based on real time passed, not framerate. So even the engine renders at 20 fps, the animations will still animate at the same real time speed! Which brings up another point. Why 60 fps? I'm speculating that Microsoft capped it because LCD's dont' refresh faster than 60 fps? On another note, If the game engine knows its falling behind in rendering...then surely we can harness this to speed up our games. Maybe I can find some flag which tell me if the game is lagging, and what the current framerate is, etc...(instead of coding it like I did last time) Sheldon, suggested maybe I can render like WoW does, in prioritised layers...I think he's onto something, however I don't think I'll have that many graphics to worry about such a problem of graphic latency. We'll see. People to Mention: Well,as you are aware I hadn't posted in a couple days and I was surprised to see a few emails and messenger queries about my game progress (and some concern as to why I stopped). I want to thank everyone for their kind words of support and put everyone at ease by stating that I do intend on completing this project. Granted I only have a few hours each night, but, I'll do it. Thank you to Garth for mailing in my next screen! That was a nice surprise! The Sneek Peek you've been waiting for... Garth has also volunteered to render me some wizard images. He was a bit shocked when I asked for them in 2D animated strips. He said I was going backward (and that I have really bad Game Development Lingo). But, I advised Garth that I will use 3D images later...for now...2D images. Garth also had some great game design ideas to add on. I advised him that I will save his ideas and include them in the future design document (for the 3d version?). Lastly, my best friend Alek, is going to join me in developing this game. This was a project we started eons ago but never completed because of our careers. Now, priorities change and we have some spare time on our hands. Let's see what trouble Alek and I can get into! Tonight I'll be uploading my prototypes and base game to a source control for both of us to work off of. D.

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• Adding and accessing custom sections in your C# App.config

  - by deadlydog

  So I recently thought I’d try using the app.config file to specify some data for my application (such as URLs) rather than hard-coding it into my app, which would require a recompile and redeploy of my app if one of our URLs changed.  By using the app.config it allows a user to just open up the .config file that sits beside their .exe file and edit the URLs right there and then re-run the app; no recompiling, no redeployment necessary. I spent a good few hours fighting with the app.config and looking at examples on Google before I was able to get things to work properly.  Most of the examples I found showed you how to pull a value from the app.config if you knew the specific key of the element you wanted to retrieve, but it took me a while to find a way to simply loop through all elements in a section, so I thought I would share my solutions here.   Simple and Easy The easiest way to use the app.config is to use the built-in types, such as NameValueSectionHandler.  For example, if we just wanted to add a list of database server urls to use in my app, we could do this in the app.config file like so: 1: <?xml version="1.0" encoding="utf-8" ?> 2: <configuration> 3: <configSections> 4: <section name="ConnectionManagerDatabaseServers" type="System.Configuration.NameValueSectionHandler" /> 5: </configSections> 6: <startup> 7: <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" /> 8: </startup> 9: <ConnectionManagerDatabaseServers> 10: <add key="localhost" value="localhost" /> 11: <add key="Dev" value="Dev.MyDomain.local" /> 12: <add key="Test" value="Test.MyDomain.local" /> 13: <add key="Live" value="Prod.MyDomain.com" /> 14: </ConnectionManagerDatabaseServers> 15: </configuration>   And then you can access these values in code like so: 1: string devUrl = string.Empty; 2: var connectionManagerDatabaseServers = ConfigurationManager.GetSection("ConnectionManagerDatabaseServers") as NameValueCollection; 3: if (connectionManagerDatabaseServers != null) 4: { 5: devUrl = connectionManagerDatabaseServers["Dev"].ToString(); 6: }   Sometimes though you don’t know what the keys are going to be and you just want to grab all of the values in that ConnectionManagerDatabaseServers section.  In that case you can get them all like this: 1: // Grab the Environments listed in the App.config and add them to our list. 2: var connectionManagerDatabaseServers = ConfigurationManager.GetSection("ConnectionManagerDatabaseServers") as NameValueCollection; 3: if (connectionManagerDatabaseServers != null) 4: { 5: foreach (var serverKey in connectionManagerDatabaseServers.AllKeys) 6: { 7: string serverValue = connectionManagerDatabaseServers.GetValues(serverKey).FirstOrDefault(); 8: AddDatabaseServer(serverValue); 9: } 10: }   And here we just assume that the AddDatabaseServer() function adds the given string to some list of strings.  So this works great, but what about when we want to bring in more values than just a single string (or technically you could use this to bring in 2 strings, where the “key” could be the other string you want to store; for example, we could have stored the value of the Key as the user-friendly name of the url).   More Advanced (and more complicated) So if you want to bring in more information than a string or two per object in the section, then you can no longer simply use the built-in System.Configuration.NameValueSectionHandler type provided for us.  Instead you have to build your own types.  Here let’s assume that we again want to configure a set of addresses (i.e. urls), but we want to specify some extra info with them, such as the user-friendly name, if they require SSL or not, and a list of security groups that are allowed to save changes made to these endpoints. So let’s start by looking at the app.config: 1: <?xml version="1.0" encoding="utf-8" ?> 2: <configuration> 3: <configSections> 4: <section name="ConnectionManagerDataSection" type="ConnectionManagerUpdater.Data.Configuration.ConnectionManagerDataSection, ConnectionManagerUpdater" /> 5: </configSections> 6: <startup> 7: <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" /> 8: </startup> 9: <ConnectionManagerDataSection> 10: <ConnectionManagerEndpoints> 11: <add name="Development" address="Dev.MyDomain.local" useSSL="false" /> 12: <add name="Test" address="Test.MyDomain.local" useSSL="true" /> 13: <add name="Live" address="Prod.MyDomain.com" useSSL="true" securityGroupsAllowedToSaveChanges="ConnectionManagerUsers" /> 14: </ConnectionManagerEndpoints> 15: </ConnectionManagerDataSection> 16: </configuration>   The first thing to notice here is that my section is now using the type “ConnectionManagerUpdater.Data.Configuration.ConnectionManagerDataSection” (the fully qualified path to my new class I created) “, ConnectionManagerUpdater” (the name of the assembly my new class is in).  Next, you will also notice an extra layer down in the <ConnectionManagerDataSection> which is the <ConnectionManagerEndpoints> element.  This is a new collection class that I created to hold each of the Endpoint entries that are defined.  Let’s look at that code now: 1: using System; 2: using System.Collections.Generic; 3: using System.Configuration; 4: using System.Linq; 5: using System.Text; 6: using System.Threading.Tasks; 7:  8: namespace ConnectionManagerUpdater.Data.Configuration 9: { 10: public class ConnectionManagerDataSection : ConfigurationSection 11: { 12: /// <summary> 13: /// The name of this section in the app.config. 14: /// </summary> 15: public const string SectionName = "ConnectionManagerDataSection"; 16: 17: private const string EndpointCollectionName = "ConnectionManagerEndpoints"; 18:  19: [ConfigurationProperty(EndpointCollectionName)] 20: [ConfigurationCollection(typeof(ConnectionManagerEndpointsCollection), AddItemName = "add")] 21: public ConnectionManagerEndpointsCollection ConnectionManagerEndpoints { get { return (ConnectionManagerEndpointsCollection)base[EndpointCollectionName]; } } 22: } 23:  24: public class ConnectionManagerEndpointsCollection : ConfigurationElementCollection 25: { 26: protected override ConfigurationElement CreateNewElement() 27: { 28: return new ConnectionManagerEndpointElement(); 29: } 30: 31: protected override object GetElementKey(ConfigurationElement element) 32: { 33: return ((ConnectionManagerEndpointElement)element).Name; 34: } 35: } 36: 37: public class ConnectionManagerEndpointElement : ConfigurationElement 38: { 39: [ConfigurationProperty("name", IsRequired = true)] 40: public string Name 41: { 42: get { return (string)this["name"]; } 43: set { this["name"] = value; } 44: } 45: 46: [ConfigurationProperty("address", IsRequired = true)] 47: public string Address 48: { 49: get { return (string)this["address"]; } 50: set { this["address"] = value; } 51: } 52: 53: [ConfigurationProperty("useSSL", IsRequired = false, DefaultValue = false)] 54: public bool UseSSL 55: { 56: get { return (bool)this["useSSL"]; } 57: set { this["useSSL"] = value; } 58: } 59: 60: [ConfigurationProperty("securityGroupsAllowedToSaveChanges", IsRequired = false)] 61: public string SecurityGroupsAllowedToSaveChanges 62: { 63: get { return (string)this["securityGroupsAllowedToSaveChanges"]; } 64: set { this["securityGroupsAllowedToSaveChanges"] = value; } 65: } 66: } 67: }   So here the first class we declare is the one that appears in the <configSections> element of the app.config.  It is ConnectionManagerDataSection and it inherits from the necessary System.Configuration.ConfigurationSection class.  This class just has one property (other than the expected section name), that basically just says I have a Collection property, which is actually a ConnectionManagerEndpointsCollection, which is the next class defined.  The ConnectionManagerEndpointsCollection class inherits from ConfigurationElementCollection and overrides the requied fields.  The first tells it what type of Element to create when adding a new one (in our case a ConnectionManagerEndpointElement), and a function specifying what property on our ConnectionManagerEndpointElement class is the unique key, which I’ve specified to be the Name field. The last class defined is the actual meat of our elements.  It inherits from ConfigurationElement and specifies the properties of the element (which can then be set in the xml of the App.config).  The “ConfigurationProperty” attribute on each of the properties tells what we expect the name of the property to correspond to in each element in the app.config, as well as some additional information such as if that property is required and what it’s default value should be. Finally, the code to actually access these values would look like this: 1: // Grab the Environments listed in the App.config and add them to our list. 2: var connectionManagerDataSection = ConfigurationManager.GetSection(ConnectionManagerDataSection.SectionName) as ConnectionManagerDataSection; 3: if (connectionManagerDataSection != null) 4: { 5: foreach (ConnectionManagerEndpointElement endpointElement in connectionManagerDataSection.ConnectionManagerEndpoints) 6: { 7: var endpoint = new ConnectionManagerEndpoint() { Name = endpointElement.Name, ServerInfo = new ConnectionManagerServerInfo() { Address = endpointElement.Address, UseSSL = endpointElement.UseSSL, SecurityGroupsAllowedToSaveChanges = endpointElement.SecurityGroupsAllowedToSaveChanges.Split(',').Where(e => !string.IsNullOrWhiteSpace(e)).ToList() } }; 8: AddEndpoint(endpoint); 9: } 10: } This looks very similar to what we had before in the “simple” example.  The main points of interest are that we cast the section as ConnectionManagerDataSection (which is the class we defined for our section) and then iterate over the endpoints collection using the ConnectionManagerEndpoints property we created in the ConnectionManagerDataSection class.   Also, some other helpful resources around using app.config that I found (and for parts that I didn’t really explain in this article) are: How do you use sections in C# 4.0 app.config? (Stack Overflow) <== Shows how to use Section Groups as well, which is something that I did not cover here, but might be of interest to you. How to: Create Custom Configuration Sections Using Configuration Section (MSDN) ConfigurationSection Class (MSDN) ConfigurationCollectionAttribute Class (MSDN) ConfigurationElementCollection Class (MSDN)   I hope you find this helpful.  Feel free to leave a comment.  Happy Coding!

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• Metro: Dynamically Switching Templates with a WinJS ListView

  - by Stephen.Walther

  Imagine that you want to display a list of products using the WinJS ListView control. Imagine, furthermore, that you want to use different templates to display different products. In particular, when a product is on sale, you want to display the product using a special “On Sale” template. In this blog entry, I explain how you can switch templates dynamically when displaying items with a ListView control. In other words, you learn how to use more than one template when displaying items with a ListView control. Creating the Data Source Let’s start by creating the data source for the ListView. Nothing special here – our data source is a list of products. Two of the products, Oranges and Apples, are on sale. (function () { "use strict"; var products = new WinJS.Binding.List([ { name: "Milk", price: 2.44 }, { name: "Oranges", price: 1.99, onSale: true }, { name: "Wine", price: 8.55 }, { name: "Apples", price: 2.44, onSale: true }, { name: "Steak", price: 1.99 }, { name: "Eggs", price: 2.44 }, { name: "Mushrooms", price: 1.99 }, { name: "Yogurt", price: 2.44 }, { name: "Soup", price: 1.99 }, { name: "Cereal", price: 2.44 }, { name: "Pepsi", price: 1.99 } ]); WinJS.Namespace.define("ListViewDemos", { products: products }); })(); The file above is saved with the name products.js and referenced by the default.html page described below. Declaring the Templates and ListView Control Next, we need to declare the ListView control and the two Template controls which we will use to display template items. The markup below appears in the default.html file: <!-- Templates --> <div id="productItemTemplate" data-win-control="WinJS.Binding.Template"> <div class="product"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> </div> </div> <div id="productOnSaleTemplate" data-win-control="WinJS.Binding.Template"> <div class="product onSale"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> (On Sale!) </div> </div> <!-- ListView --> <div id="productsListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: ListViewDemos.products.dataSource, layout: { type: WinJS.UI.ListLayout } }"> </div> In the markup above, two Template controls are declared. The first template is used when rendering a normal product and the second template is used when rendering a product which is on sale. The second template, unlike the first template, includes the text “(On Sale!)”. The ListView control is bound to the data source which we created in the previous section. The ListView itemDataSource property is set to the value ListViewDemos.products.dataSource. Notice that we do not set the ListView itemTemplate property. We set this property in the default.js file. Switching Between Templates All of the magic happens in the default.js file. The default.js file contains the JavaScript code used to switch templates dynamically. Here’s the entire contents of the default.js file: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll().then(function () { var productsListView = document.getElementById("productsListView"); productsListView.winControl.itemTemplate = itemTemplateFunction; });; } }; function itemTemplateFunction(itemPromise) { return itemPromise.then(function (item) { // Select either normal product template or on sale template var itemTemplate = document.getElementById("productItemTemplate"); if (item.data.onSale) { itemTemplate = document.getElementById("productOnSaleTemplate"); }; // Render selected template to DIV container var container = document.createElement("div"); itemTemplate.winControl.render(item.data, container); return container; }); } app.start(); })(); In the code above, a function is assigned to the ListView itemTemplate property with the following line of code: productsListView.winControl.itemTemplate = itemTemplateFunction;   The itemTemplateFunction returns a DOM element which is used for the template item. Depending on the value of the product onSale property, the DOM element is generated from either the productItemTemplate or the productOnSaleTemplate template. Using Binding Converters instead of Multiple Templates In the previous sections, I explained how you can use different templates to render normal products and on sale products. There is an alternative approach to displaying different markup for normal products and on sale products. Instead of creating two templates, you can create a single template which contains separate DIV elements for a normal product and an on sale product. The following default.html file contains a single item template and a ListView control bound to the template. <!-- Template --> <div id="productItemTemplate" data-win-control="WinJS.Binding.Template"> <div class="product" data-win-bind="style.display: onSale ListViewDemos.displayNormalProduct"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> </div> <div class="product onSale" data-win-bind="style.display: onSale ListViewDemos.displayOnSaleProduct"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> (On Sale!) </div> </div> <!-- ListView --> <div id="productsListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: ListViewDemos.products.dataSource, itemTemplate: select('#productItemTemplate'), layout: { type: WinJS.UI.ListLayout } }"> </div> The first DIV element is used to render a normal product: <div class="product" data-win-bind="style.display: onSale ListViewDemos.displayNormalProduct"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> </div> The second DIV element is used to render an “on sale” product: <div class="product onSale" data-win-bind="style.display: onSale ListViewDemos.displayOnSaleProduct"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> (On Sale!) </div> Notice that both templates include a data-win-bind attribute. These data-win-bind attributes are used to show the “normal” template when a product is not on sale and show the “on sale” template when a product is on sale. These attributes set the Cascading Style Sheet display attribute to either “none” or “block”. The data-win-bind attributes take advantage of binding converters. The binding converters are defined in the default.js file: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll(); } }; WinJS.Namespace.define("ListViewDemos", { displayNormalProduct: WinJS.Binding.converter(function (onSale) { return onSale ? "none" : "block"; }), displayOnSaleProduct: WinJS.Binding.converter(function (onSale) { return onSale ? "block" : "none"; }) }); app.start(); })(); The ListViewDemos.displayNormalProduct binding converter converts the value true or false to the value “none” or “block”. The ListViewDemos.displayOnSaleProduct binding converter does the opposite; it converts the value true or false to the value “block” or “none” (Sadly, you cannot simply place a NOT operator before the onSale property in the binding expression – you need to create both converters). The end result is that you can display different markup depending on the value of the product onSale property. Either the contents of the first or second DIV element are displayed: Summary In this blog entry, I’ve explored two approaches to displaying different markup in a ListView depending on the value of a data item property. The bulk of this blog entry was devoted to explaining how you can assign a function to the ListView itemTemplate property which returns different templates. We created both a productItemTemplate and productOnSaleTemplate and displayed both templates with the same ListView control. We also discussed how you can create a single template and display different markup by using binding converters. The binding converters are used to set a DIV element’s display property to either “none” or “block”. We created a binding converter which displays normal products and a binding converter which displays “on sale” products.

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• Constant game speed independent of variable FPS in OpenGL with GLUT?

  - by Nazgulled

  I've been reading Koen Witters detailed article about different game loop solutions but I'm having some problems implementing the last one with GLUT, which is the recommended one. After reading a couple of articles, tutorials and code from other people on how to achieve a constant game speed, I think that what I currently have implemented (I'll post the code below) is what Koen Witters called Game Speed dependent on Variable FPS, the second on his article. First, through my searching experience, there's a couple of people that probably have the knowledge to help out on this but don't know what GLUT is and I'm going to try and explain (feel free to correct me) the relevant functions for my problem of this OpenGL toolkit. Skip this section if you know what GLUT is and how to play with it. GLUT Toolkit: GLUT is an OpenGL toolkit and helps with common tasks in OpenGL. The glutDisplayFunc(renderScene) takes a pointer to a renderScene() function callback, which will be responsible for rendering everything. The renderScene() function will only be called once after the callback registration. The glutTimerFunc(TIMER_MILLISECONDS, processAnimationTimer, 0) takes the number of milliseconds to pass before calling the callback processAnimationTimer(). The last argument is just a value to pass to the timer callback. The processAnimationTimer() will not be called each TIMER_MILLISECONDS but just once. The glutPostRedisplay() function requests GLUT to render a new frame so we need call this every time we change something in the scene. The glutIdleFunc(renderScene) could be used to register a callback to renderScene() (this does not make glutDisplayFunc() irrelevant) but this function should be avoided because the idle callback is continuously called when events are not being received, increasing the CPU load. The glutGet(GLUT_ELAPSED_TIME) function returns the number of milliseconds since glutInit was called (or first call to glutGet(GLUT_ELAPSED_TIME)). That's the timer we have with GLUT. I know there are better alternatives for high resolution timers, but let's keep with this one for now. I think this is enough information on how GLUT renders frames so people that didn't know about it could also pitch in this question to try and help if they fell like it. Current Implementation: Now, I'm not sure I have correctly implemented the second solution proposed by Koen, Game Speed dependent on Variable FPS. The relevant code for that goes like this: #define TICKS_PER_SECOND 30 #define MOVEMENT_SPEED 2.0f const int TIMER_MILLISECONDS = 1000 / TICKS_PER_SECOND; int previousTime; int currentTime; int elapsedTime; void renderScene(void) { (...) // Setup the camera position and looking point SceneCamera.LookAt(); // Do all drawing below... (...) } void processAnimationTimer(int value) { // setups the timer to be called again glutTimerFunc(TIMER_MILLISECONDS, processAnimationTimer, 0); // Get the time when the previous frame was rendered previousTime = currentTime; // Get the current time (in milliseconds) and calculate the elapsed time currentTime = glutGet(GLUT_ELAPSED_TIME); elapsedTime = currentTime - previousTime; /* Multiply the camera direction vector by constant speed then by the elapsed time (in seconds) and then move the camera */ SceneCamera.Move(cameraDirection * MOVEMENT_SPEED * (elapsedTime / 1000.0f)); // Requests to render a new frame (this will call my renderScene() once) glutPostRedisplay(); } void main(int argc, char **argv) { glutInit(&argc, argv); (...) glutDisplayFunc(renderScene); (...) // Setup the timer to be called one first time glutTimerFunc(TIMER_MILLISECONDS, processAnimationTimer, 0); // Read the current time since glutInit was called currentTime = glutGet(GLUT_ELAPSED_TIME); glutMainLoop(); } This implementation doesn't fell right. It works in the sense that helps the game speed to be constant dependent on the FPS. So that moving from point A to point B takes the same time no matter the high/low framerate. However, I believe I'm limiting the game framerate with this approach. Each frame will only be rendered when the time callback is called, that means the framerate will be roughly around TICKS_PER_SECOND frames per second. This doesn't feel right, you shouldn't limit your powerful hardware, it's wrong. It's my understanding though, that I still need to calculate the elapsedTime. Just because I'm telling GLUT to call the timer callback every TIMER_MILLISECONDS, it doesn't mean it will always do that on time. I'm not sure how can I fix this and to be completely honest, I have no idea what is the game loop in GLUT, you know, the while( game_is_running ) loop in Koen's article. But it's my understanding that GLUT is event-driven and that game loop starts when I call glutMainLoop() (which never returns), yes? I thought I could register an idle callback with glutIdleFunc() and use that as replacement of glutTimerFunc(), only rendering when necessary (instead of all the time as usual) but when I tested this with an empty callback (like void gameLoop() {}) and it was basically doing nothing, only a black screen, the CPU spiked to 25% and remained there until I killed the game and it went back to normal. So I don't think that's the path to follow. Using glutTimerFunc() is definitely not a good approach to perform all movements/animations based on that, as I'm limiting my game to a constant FPS, not cool. Or maybe I'm using it wrong and my implementation is not right? How exactly can I have a constant game speed with variable FPS? More exactly, how do I correctly implement Koen's Constant Game Speed with Maximum FPS solution (the fourth one on his article) with GLUT? Maybe this is not possible at all with GLUT? If not, what are my alternatives? What is the best approach to this problem (constant game speed) with GLUT? I originally posted this question on Stack Overflow before being pointed out about this site. The following is a different approach I tried after creating the question in SO, so I'm posting it here too. Another Approach: I've been experimenting and here's what I was able to achieve now. Instead of calculating the elapsed time on a timed function (which limits my game's framerate) I'm now doing it in renderScene(). Whenever changes to the scene happen I call glutPostRedisplay() (ie: camera moving, some object animation, etc...) which will make a call to renderScene(). I can use the elapsed time in this function to move my camera for instance. My code has now turned into this: int previousTime; int currentTime; int elapsedTime; void renderScene(void) { (...) // Setup the camera position and looking point SceneCamera.LookAt(); // Do all drawing below... (...) } void renderScene(void) { (...) // Get the time when the previous frame was rendered previousTime = currentTime; // Get the current time (in milliseconds) and calculate the elapsed time currentTime = glutGet(GLUT_ELAPSED_TIME); elapsedTime = currentTime - previousTime; /* Multiply the camera direction vector by constant speed then by the elapsed time (in seconds) and then move the camera */ SceneCamera.Move(cameraDirection * MOVEMENT_SPEED * (elapsedTime / 1000.0f)); // Setup the camera position and looking point SceneCamera.LookAt(); // All drawing code goes inside this function drawCompleteScene(); glutSwapBuffers(); /* Redraw the frame ONLY if the user is moving the camera (similar code will be needed to redraw the frame for other events) */ if(!IsTupleEmpty(cameraDirection)) { glutPostRedisplay(); } } void main(int argc, char **argv) { glutInit(&argc, argv); (...) glutDisplayFunc(renderScene); (...) currentTime = glutGet(GLUT_ELAPSED_TIME); glutMainLoop(); } Conclusion, it's working, or so it seems. If I don't move the camera, the CPU usage is low, nothing is being rendered (for testing purposes I only have a grid extending for 4000.0f, while zFar is set to 1000.0f). When I start moving the camera the scene starts redrawing itself. If I keep pressing the move keys, the CPU usage will increase; this is normal behavior. It drops back when I stop moving. Unless I'm missing something, it seems like a good approach for now. I did find this interesting article on iDevGames and this implementation is probably affected by the problem described on that article. What's your thoughts on that? Please note that I'm just doing this for fun, I have no intentions of creating some game to distribute or something like that, not in the near future at least. If I did, I would probably go with something else besides GLUT. But since I'm using GLUT, and other than the problem described on iDevGames, do you think this latest implementation is sufficient for GLUT? The only real issue I can think of right now is that I'll need to keep calling glutPostRedisplay() every time the scene changes something and keep calling it until there's nothing new to redraw. A little complexity added to the code for a better cause, I think. What do you think?

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• CodePlex Daily Summary for Wednesday, October 09, 2013

  CodePlex Daily Summary for Wednesday, October 09, 2013Popular ReleasesxFunc: xFunc 2.7.3: Fixed memory leak. Small fixes.SmartStore.NET - Free ASP.NET MVC Ecommerce Shopping Cart Solution: SmartStore.NET 1.2.0: HighlightsMulti-store support "Trusted Shops" plugins Highly improved SmartStore.biz Importer plugin Add custom HTML content to pages Performance optimization New FeaturesMulti-store-support: now multiple stores can be managed within a single application instance (e.g. for building different catalogs, brands, landing pages etc.) Added 3 new Trusted Shops plugins: Seal, Buyer Protection, Store Reviews Added Display as HTML Widget to CMS Topics (store owner now can add arbitrary HT...Wrangle for Windows: Wrangle Beta 0.1.0.6: + Various Bugs Fixes + Notification are now available + Many small features added - Does not contain user profiles yet - Conclusions not available yetAD ACL Scanner: 1.3: New features:Effective rights, select a security principal and match it agains the permissions in AD. Color coded permissions based on criticality when using effective rights scan. Search levels : Base, One Level, Subtree. List you domains and select one from the list. Get the size of the security descriptor (bytes). Rerporting on disabled inheritance . Better search functianlity; you can use wildcards on Trustee. Get all inherited permissions in report.MoreTerra (Terraria World Viewer): MoreTerra 1.11.2: Release 1.11.2 Full 1.2 Support =========== =Bug Fixes= =========== We have all markers solsund made sure the tile and background colors are correct. (map looks correct with no missing pink) Added better error tracking for those having trouble.Fast YouTube Downloader: Youtube Downloader 2.1: Youtube Downloader 2.1MSCRM ToolKit: MSCRMToolKit 0.5.5: Increased MaxStringContextLength property in the Reference Data Transporter in response of the Issue: https://mscrmtoolkit.codeplex.com/workitem/1520NuGet: NuGet 2.7.1: Released October 07, 2013. Release notes: http://docs.nuget.org/docs/release-notes/nuget-2.7.1 Important note: After downloading the signed build of NuGet.exe, if you perform an update using the "nuget.exe update -self" command, it will revert back to the unsigned build.Mugen MVVM Toolkit: Mugen MVVM Toolkit 2.0: IntroductionMugen MVVM Toolkit makes it easier to develop Silverlight, WPF, WinRT and WP applications using the Model-View-ViewModel design pattern. The purpose of the toolkit is to provide a simple framework and set of tools for getting up to speed quickly with applications based on the MVVM design pattern. The core of Toolkit contains a navigation system, windows management system, models, validation, etc. Mugen MVVM Toolkit contains all the MVVM classes such as ViewModelBase, RelayCommand,...Office Ribbon Project (under active development): Ribbon (07. Oct. 2013): Fixed Scrollbar Bug if DropDown Button is bigger than screen Added Office 2013 Theme Fixed closing the Ribbon caused a null reference exception in the RibbonButton.Dispose if the DropDown was not created yet Fixed Memory leak fix (unhooked events after Dispose) Fixed ToolStrip Selected Text 2013 and 2007 for Blue and Standard themesGhostscript.NET: Ghostscript.NET v.1.1.0.: v.1.1.0. added GhostscriptViewer state handling (SaveState, RestoreState) GhostscriptRasterizer constructor is extended in order to support usage of the existing GhostscriptViewer instance. fixed problem while using a 32-bit assembly with 32-bit version of Ghostscript on 64-bit Windows: It couldn't find a registry key of installed Ghostscript. Reported and fixed by "r0land". v.1.0.9. implemented EPS (Encapsulated PostScript) support for the GhostscriptViewer. added GhostscriptRasterize...Ghostscript Studio: Ghostscript.Studio v.1.0.2: Ghostscript Studio is easy to use Ghostscript IDE, a tool that facilitates the use of the Ghostscript interpreter by providing you with a graphical interface for postscript editing and file conversions. Ghostscript Studio allows you to preview postscript files, edit the code and execute them in order to convert PDF documents and other formats. The program allows you to convert between PDF, Postscript, EPS, TIFF, JPG and PNG by using the Ghostscript.NET Processor. v.1.0.2. added custom -c s...cmdradio: v0.1.1 binary: Default download in win32. For other OS see here. This is alpha version. Please report all bugs.Squiggle - A free open source LAN Messenger: Squiggle 3.3 Alpha: Allow using environment variables in configuration file (history db connection string, download folder location, display name, group and message) Fix for history viewer to show the correct history entries History saved with UTC timestamp This is alpha release and not recommended for use in productionMedia Companion: Media Companion MC3.579b: Fixed IMDB actor scraping for Movies and TV. Note: there are a couple of new functions that are not active, as this release needed to be done due to IMDB change. New* TV - context menu for rescrapeing Poster image/Banner image Fixed* Both - Fixed actor scraping from IMDB * Movie - Fixed Tableview if Movie's movieset was not in MC's list of moviesets * Movie - Rename with mediainfo now lowercase. * Both - added ignore "A " in titles. Separate option in General Preferences. * Tv - Changing ...VidCoder: 1.5.7 Beta: Updated HandBrake core to SVN 4819. About dialog now pulls down HandBrake version from the DLL. Added a confirmation dialog to Stop if the encode has been going on for more than 5 minutes. Fixed handling of unicode characters for input and output filenames. We now encode to UTF-8 before passing to HandBrake. Fixed a crash in the queue multiple titles dialog. Added code to rescue tool windows which get placed outside of the visible screen area.Wsus Package Publisher: Release v1.3.1310.05: Enhance the "Reboot Remote Computers", by adding a timer before the reboot occure. So that remote users can save their documents and close applications. You can also add a message to be display. In 'Tools'->'Settings'-> Misc Tab, you can set a default message. Enhance the "Compare Computers against AD", by choosing OUs to include in the comparison.Pulse: Pulse 0.6.7.3: Pulse is now accepting donations. To donate by Bitcoin or PayPal see https://pulse.codeplex.com/wikipage?title=Donations Lots of updates in v0.6.7.3: (Feature) New option allows you to disable wallpaper changing when a full screen application is running. This way Pulse doesn't slow down/lag your videos and games :) (Fix) Some users were getting Wallbase errors when logging in. This has been fixed. (Feature) Right click a provider and you can now make a copy of it by selecting the "Dupl...VG-Ripper & PG-Ripper: PG-Ripper 1.4.19: NEW: Added Option to login as Guest NEW: Added Menu Option to delete an Forum Account NEW: Added Support for "ImageTeam.org links FIXED: Fixed Ripping of http://forum.babeunion.com ForumsSimpleExcelReportMaker: Serm 0.03: SourceCode and Sample .Net Framework 3.5 AnyCPU compile.New ProjectsA library of helpers to augment InfoPath code behind development.: A library providing useful helpers to augment and speed up deveopment of complex InfoPath forms requiring code behind.A Simple Online Document Management System Using Asp.net MVC 3: A system to manage documents on-line.ASP.NET Testing: ASP.NET testingAutoSPUpdater: Automated Updating for SharePoint Server 2010/2013Currency Calculator for Microsoft Dynamics AX: The Currency calculator is a tool for calculating amounts between currencies which uses the rates as setup in the Exchange rates of Microsoft Dynamics AX.Daystate Configuration Manager: To be filled later.Djikstra's Algorithm SGGW: It's university student project presenting Djikstra algorithm usage in finding the shortest path between two points in single graph.eCommMongo: eCommMongoFast YouTube Downloader: Fast Youtube Downloader downloads video from YouTube. You could choose different video formats and qualities, and download multiple videos at the same time.FirebirdWars: Firebird Wars online strategy game.FlowSimulation: ???????????? ????????????? ???????????? ?????????Guild Wars 2 VALORUS Command and Control System: The VALORUS Command and Control System is a tool to help track and manage large numbers of people on Guild Wars 2. Useful for WvW and Guild Missions.IntelliCommand: Visual Studio Extension. Helps to remember shortcut keys. This extension is supported for Visual Studio 2010/2012/2013... Professional and higher.myonlyle: gaoOnline War Game: aOracle Portal to SharePoint Migration Scripts: These scripts will assit you in moving from Oracle Portal 10g to SharePoint!OrderingPlatform: OrderingPlatform ?? ??PSEncrypt: Powershell cmdlets to do common encryption\decryption stuffReorderListBox: ReorderListBox is an enhancement to the standard ListBox control for Windows Phone apps that allows users to drag-and-drop list items to reorder the list.SampleTileAnimation: The Windows store application targets to create a Image to appear as a tile and Animate it using StoryBoard feature using C# /Xaml code. SharePoint Friends: Open source SharePoint app library projectSharing memory between user and kernel mode processes- WinCE 6/WEC7/2013: This is a sample driver that explain how to share a block of memory between Kernel mode driver and user mode application in Windows CE 6.0/ WEC7 and WEC2013.SharpHadoop: SharpHadoop facilitates access to WebHDFS from .Net. The library can easily be dependencies and solely relies on the .net standard library Features: 1) UploaSSRS Admin Tasks: Admin GUI Tool for SQL Server Reporting ServicesTimeWatcher: TimeWatcher is an application allowing you keep track of the time passed on tasks, even across multiple working sessions. A good tool for developers who need toTinyMIS: TinyMistmask: tmaskVitaliyPianykhStuff: Here I'll publish handy code snippets.World Simulator: Will the universe expand or will it collapse? Hundreds of experts are about to discuss this question and this program was designed to give an answer... :-)WSccTravel: This is the project created during class WScc 2013

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• Organising levels / rooms in a MUD-style text based world

  - by Polynomial

  I'm thinking of writing a small text-based adventure game, but I'm not particularly sure how I should design the world from a technical standpoint. My first thought is to do it in XML, designed something like the following. Apologies for the huge pile of XML, but I felt it important to fully explain what I'm doing. <level> <start> <!-- start in kitchen with empty inventory --> <room>Kitchen</room> <inventory></inventory> </start> <rooms> <room> <name>Kitchen</name> <description>A small kitchen that looks like it hasn't been used in a while. It has a table in the middle, and there are some cupboards. There is a door to the north, which leads to the garden.</description> <!-- IDs of the objects the room contains --> <objects> <object>Cupboards</object> <object>Knife</object> <object>Batteries</object> </objects> </room> <room> <name>Garden</name> <description>The garden is wild and full of prickly bushes. To the north there is a path, which leads into the trees. To the south there is a house.</description> <objects> </objects> </room> <room> <name>Woods</name> <description>The woods are quite dark, with little light bleeding in from the garden. It is eerily quiet.</description> <objects> <object>Trees01</object> </objects> </room> </rooms> <doors> <!-- a door isn't necessarily a door. each door has a type, i.e. "There is a <type> leading to..." from and to are references the rooms that this door joins. direction specifies the direction (N,S,E,W,Up,Down) from <from> to <to> --> <door> <type>door</type> <direction>N</direction> <from>Kitchen</from> <to>Garden</to> </door> <door> <type>path</type> <direction>N</direction> <from>Garden</type> <to>Woods</type> </door> </doors> <variables> <!-- variables set by actions --> <variable name="cupboard_open">0</variable> </variables> <objects> <!-- definitions for objects --> <object> <name>Trees01</name> <displayName>Trees</displayName> <actions> <!-- any actions not defined will show the default failure message --> <action> <command>EXAMINE</command> <message>The trees are tall and thick. There aren't any low branches, so it'd be difficult to climb them.</message> </action> </actions> </object> <object> <name>Cupboards</name> <displayName>Cupboards</displayName> <actions> <action> <!-- requirements make the command only work when they are met --> <requirements> <!-- equivilent of "if(cupboard_open == 1)" --> <require operation="equal" value="1">cupboard_open</require> </requirements> <command>EXAMINE</command> <!-- fail message is the message displayed when the requirements aren't met --> <failMessage>The cupboard is closed.</failMessage> <message>The cupboard contains some batteires.</message> </action> <action> <requirements> <require operation="equal" value="0">cupboard_open</require> </requirements> <command>OPEN</command> <failMessage>The cupboard is already open.</failMessage> <message>You open the cupboard. It contains some batteries.</message> <!-- assigns is a list of operations performed on variables when the action succeeds --> <assigns> <assign operation="set" value="1">cupboard_open</assign> </assigns> </action> <action> <requirements> <require operation="equal" value="1">cupboard_open</require> </requirements> <command>CLOSE</command> <failMessage>The cupboard is already closed.</failMessage> <message>You closed the cupboard./message> <assigns> <assign operation="set" value="0">cupboard_open</assign> </assigns> </action> </actions> </object> <object> <name>Batteries</name> <displayName>Batteries</displayName> <!-- by setting inventory to non-zero, we can put it in our bag --> <inventory>1</inventory> <actions> <action> <requirements> <require operation="equal" value="1">cupboard_open</require> </requirements> <command>GET</command> <!-- failMessage isn't required here, it'll just show the usual "You can't see any <blank>." message --> <message>You picked up the batteries.</message> </action> </actions> </object> </objects> </level> Obviously there'd need to be more to it than this. Interaction with people and enemies as well as death and completion are necessary additions. Since the XML is quite difficult to work with, I'd probably create some sort of world editor. I'd like to know if this method has any downfalls, and if there's a "better" or more standard way of doing it.

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• Highlighting rows and columns in an HTML table using JQuery

  - by nikolaosk

  A friend of mine was seeking some help regarding HTML tables and JQuery. I have decided to write a few posts demonstrating the various techniques I used with JQuery to achieve the desired functionality. ?here are other posts in my blog regarding JQuery.You can find them all here.I have received some comments from visitors of this blog that are "complaining" about the length of the blog posts. I will not write lengthy posts anymore...I mean I will try not to do so..We will demonstrate this with a step by step example. I will use Visual Studio 2012 Ultimate. You can also use Visual Studio 2012 Express Edition. You can also use VS 2010 editions. 1) Launch Visual Studio. Create an ASP.Net Empty Web application. Choose an appropriate name for your application.2) Add a web form, default.aspx page to the application.3) Add a table from the HTML controls tab control (from the Toolbox) on the default.aspx page4) Now we need to download the JQuery library. Please visit the http://jquery.com/ and download the minified version.5) We will add a stylesheet to the application (Style.css)5) Obviously at some point we need to reference the JQuery library and the external stylesheet. In the head section ? add the following lines.   <link href="Style.css" rel="stylesheet" type="text/css" />       <script src="jquery-1_8_2_min.js" type="text/javascript"></script> 6) Now we need to highlight the rows when the user hovers over them.7) First we need to type the HTML markup<body>    <form id="form1" runat="server">    <div>        <h1>Liverpool Legends</h1>        <table style="width: 50%;" border="1" cellpadding="10" cellspacing ="10">            <thead>                <tr><th>Defenders</th><th>MidFielders</th><th>Strikers</th></tr>            </thead>            <tbody>            <tr>                <td>Alan Hansen</td>                <td>Graeme Souness</td>                <td>Ian Rush</td>            </tr>            <tr>                <td>Alan Kennedy</td>                <td>Steven Gerrard</td>                <td>Michael Owen</td>            </tr>            <tr>                <td>Jamie Garragher</td>                <td>Kenny Dalglish</td>                <td>Robbie Fowler</td>            </tr>            <tr>                <td>Rob Jones</td>                <td>Xabi Alonso</td>                <td>Dirk Kuyt</td>            </tr>                </tbody>        </table>            </div>    </form></body>8) Now we need to write the simple rules in the style.css file.body{background-color:#eaeaea;}.hover { background-color:#42709b; color:#ff6a00;} 8) Inside the head section we also write the simple JQuery code.  <script type="text/javascript"> $(document).ready(function() { $('tr').hover( function() { $(this).find('td').addClass('hover'); }, function() { $(this).find('td').removeClass('hover'); } ); }); </script>9) Run your application and see the row changing background color and text color every time the user hovers over it. Let me explain how this functionality is achieved.We have the .hover style rule in the style.css file that contains some properties that define the background color value and the color value when the mouse will be hovered on the row.In the JQuery code we do attach the hover() event to the tr elements.The function that is called when the hovering takes place, we search for the td element and through the addClass function we apply the styles defined in the .hover class rule in the style.css file.I remove the .hover rule styles with the removeClass function. Now let's say that we want to highlight only alternate rows of the table.We need to add another rule in the style.css.alternate { background-color:#42709b; color:#ff6a00;} The JQuery code (comment out the previous JQuery code) follows  <script type="text/javascript">        $(document).ready(function() {                     $('table tr:odd').addClass('alternate');        });    </script>  When I run my application through VS I see the following result You can do that with columns as well. You can highlight alternate columns as well.The JQuery code (comment out the previous JQuery code) follows  <script type="text/javascript">        $(document).ready(function() {                      $('td:nth-child(odd)').addClass('alternate');        });    </script>  In this script I use the nth-child() method in the JQuery code.This method retrieves all the elements that are nth children of their parent.Have a look at the picture below to see the resultsYou can also change color to each individual cell when hovered on.The JQuery code (comment out the previous JQuery code) follows    <script type="text/javascript">        $(document).ready(function() {          $('td').hover(                  function() {                 $(this).addClass('hover');               },                function() {                    $(this).removeClass('hover');                }                );        });    </script> Have a look at the picture below to see the results. Hope it helps!!!

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• CodePlex Daily Summary for Tuesday, December 11, 2012

  CodePlex Daily Summary for Tuesday, December 11, 2012Popular ReleasesDirectX Tool Kit: December 11, 2012: December 11, 2012 Ex versions of DDSTextureLoader and WICTextureLoader Removed use of ATL's CComPtr in favor of WRL's ComPtr for all platforms to support VS Express editions Updated VS 2010 project for official 'property sheet' integration for Windows 8.0 SDK Minor fix to CommonStates for Feature Level 9.1 Tweaked AlphaTestEffect.cpp to work around ARM NEON compiler codegen bug Added dxguid.lib as a default library for Debug builds to resolve GUID link issuesCleverBobCat: CleverBobCat 1.1.3: Fixed: - Cart code now works in vab, wheels retract correctly and no more anchors visible - No more exceptions on VAB Added: - ResourceTransfer beam now has a wide array of configurable options for beam material, size and colors - Added an optional offset to resource transfer, if specificed the "beam" will start from part center + the specified offsetSharpCompress - a fully native C# library for RAR, 7Zip, Zip, Tar, GZip, BZip2: SharpCompress 0.8.2: This release just contains some fixes that have been done since the last release. Plus, this is strong named as well. I apologize for the lack of updates but my free time is less these days.re-linq: 1.13.178.0: This is build 1.13.178.0 of re-linq. Find the complete release notes for the build here: Release NotesMedia Companion: MediaCompanion3.511b release: Two more bug fixes: - General Preferences were not getting restored - Fanart and poster image files were being locked, preventing changes to themVodigi Open Source Interactive Digital Signage: Vodigi Release 5.5: The following enhancements and fixes are included in Vodigi 5.5. Vodigi Administrator - Manage Music Files - Add Music Files to Image Slide Shows - Manage System Messages - Display System Messages to Users During Login - Ported to Visual Studio 2012 and MVC 4 - Added New Vodigi Administrator User Guide Vodigi Player - Improved Login/Schedule Startup Procedure - Startup Using Last Known Schedule when Disconnected on Startup - Improved Check for Schedule Changes - Now Every 15 Minutes - Pla...Secretary Tool: Secretary Tool v1.1.0: I'm still considering this version a beta version because, while it seems to work well for me, I haven't received any feedback and I certainly don't want anyone relying solely on this tool for calculations and such until its correct functioning is verified by someone. This version includes several bug fixes, including a rather major one with Emergency Contact Information not saving. Also, reporting is completed. There may be some tweaking to the reporting engine, but it is good enough to rel...VidCoder: 1.4.10 Beta: Added progress percent to the title bar/task bar icon. Added MPLS information to Blu-ray titles. Fixed the following display issues in Windows 8: Uncentered text in textbox controls Disabled controls not having gray text making them hard to identify as disabled Drop-down menus having hard-to distinguish white on light-blue text Added more logging to proxy disconnect issues and increased timeout on initial call to help prevent timeouts. Fixed encoding window showing the built-in pre...WPF Application Framework (WAF): WPF Application Framework (WAF) 2.5.0.400: Version 2.5.0.400 (Release): This release contains the source code of the WPF Application Framework (WAF) and the sample applications. Requirements .NET Framework 4.0 (The package contains a solution file for Visual Studio 2010) The unit test projects require Visual Studio 2010 Professional Changelog Legend: [B] Breaking change; [O] Marked member as obsolete Update the documentation. InfoMan: Write the documentation. Other Downloads Downloads OverviewHome Access Plus+: v8.5: v8.5.1211.1240 Fixed: changed to using the thumbnailPhoto attribute instead of jpegPhoto v8.5.1208.1500 This is a point release, for the other parts of HAP+ see the v8.3 release. Fixed: #me#me issue with the Edit Profile Link Updated: 8.5.1208 release Updated: Documentation with hidden booking system feature Added: Room Drop Down to the Booking System (no control panel interface), can be Resource Specific Fixed: Recursive AD Group Membership Lookup Fixed: User.IsInRole with recursive lookup...Http Explorer: httpExplorer-1.1: httpExplorer now has the ability to connect to http server via web proxies. The proxy may be explicitly specified by hostname or IP address. Or it may be specified via the Internet Options settings of Windows. You may also specify credentials to pass to the proxy if the proxy requires them. These credentials may be NTLM or basic authentication (clear text username and password).Bee OPOA Platform: Bee OPOA Demo V1.0.001: Initial version.Microsoft Ajax Minifier: Microsoft Ajax Minifier 4.78: Fix for issue #18924 - using -pretty option left in ///#DEBUG blocks. Fix for issue #18980 - bad += optimization caused bug in resulting code. Optimization has been removed pending further review.Dynamics Crm 2011 Solution Manager: Crm Solution Manager 1.0: First Version.Lava JS: Lava JS 1.0: Sourcemp3player-xslt-plugin: mp3player module 1.0: This is a mp3 player module that you can install on your umbraco project. It can display the list of the media and you can click the button to play or stop.STeaL : stealed functionarities from STL: STeaL 0.4.1(prelerease): + fill / fill-nMi-DevEnv: Development 0.5: Ran a new test scenario where I created a DC, then created a web server, blew it away, then re-created the web server. The purpose of the test was to see how the installers would handle information existing in AD, like the OU for CRM. This revealed yet another silly issue in retrieving details of existing OU's, where I had the syntax wrong. I should read exception details more closely :) Apologies also, I've just now started labelling the solution according to these "snapshots". Sorry for...Yahoo! UI Library: YUI Compressor for .Net: Version 2.2.0.0 - Epee: New : Web Optimization package! Cleaned up the nuget packages BugFix: minifying lots of files will now be faster because of a recent regression in some code. (We were instantiating something far too many times).DtPad - .NET Framework text editor: DtPad 2.9.0.40: http://dtpad.diariotraduttore.com/files/images/flag-eng.png English + A new built-in editor for the management of CSV files, including the edit of cells, deleting and adding new rows, replacement of delimiter character and much more (issue #1137) + The limit of rows allowed before the decommissioning of their side panel has been raised (new default: 1.000) (issue #1155, only partially solved) + Pressing CTRL+TAB now DtPad opens a screen that shows the list of opened tabs (issue #1143) + Note...New ProjectsAmazon S3 Upload with Uploadify: ASP.MVC upload file from client browser direct to Amazon S3Ameoto DEV: Bin for all of our software sources :DAutonomic Computing Library: This framework will simplify the development of Autonomic Computing Systems. BIUUITest: BIUUITestBotvaBot: This project should help tothe Botva.Ru gamers to automize their game proces. It is a set of libraries for simple sending of the HTTP requests with list of the main requests to the botva.ru web-site. Also project contains the clients forsimple using this request umulators.Cartellino: Scopo del progetto è la realizzazione di un software in grado di rilevare i dati dai rilevatori 3Tec (www.3tec.it) e stampare i cartellini presenza dei dipendenticmsforbeginner: in this project explain how to edit, create multiple webpages to a single website with less knowledge on html ,.net languagesContact Us Module: This is an Umbraco based module for feedback. You can upload the contact us module in the dashboard and then display those module anywhere in your site.CrmXpress Security Roles Helper For Microsoft Dynamics CRM 2011: CrmXpress Security Roles Helper is a tool/utility. It lets you compare the Security Roles for their differences at the privilege level with their scopes.DarkSky Helpdesk: DarkSky Helpdesk is an Orchard module that turns your Orchard application into a Helpdesk system.DataEntity: A Framework that help us to make persistences and materializations from any SQLServer DataBase Tables to Entity classes. Better performance with native ADO.NET.Edisfera DNN Training Task Module: This is a training project to familiarize with codeplex and dnn module creation.eyoung events description language: Eyoung is a event driven language. It can be used in many fields, such as intrusion action definition.FastBuild: Fast build VS2010 C++ project with the options OpenCV, QT, Boost and OpenGL.Find Changeset By Comment: This extension is used to find changesets that contain a specific phrase in a comment.Gatepass System: This application under development is my first application on codeplex. It is meant primarily as a learning tool while developing a Gatepass System. This GateHandle Template Library (HTL): Handle Template Library (HTL) is a C++ library for developing Windows applications and services. It provides a set of classes for files, threads, events, and more.iDoklad API: iDoklad API Demo je Open Source projekt spolecnosti Cígler Software. Ukázková aplikace demonstruje napojení na fakturacní službu iDokladIronBefunge: IronBefunge is an interpretor (written in .NET) for Befunge programs.Iterator Tasks: Iterator Tasks is a iterator-based coroutine class library.Javacc-Compile-N14: Javacc - compile - N14 is a students' compiler project and we use javacc to compiler XYZ-2 languageMessenger Game - Starter Kit: Kom godt i gang med at lave spil til Messenger med dette komplette Starter Kit. Indeholder et komplet netværksspil lavet med Messenger Activity API og Silverlight.MOBZcript: MOBZcript is a simple batch file editor for cmd scripts. It saves and runs your scripts as if you started them from a command line.NET.Library: The NET.Library will be available in different versions to run on the .Net 2, 3 and 4 frameworks and consists of various .Net programming utilities. proxificator: Proxificator is component for getting the appropriate proxyRetailManagement: abcStudentManage: testWebQQ Interface: A library that enable programmers to access QQ much easier via codeZytonic Screenshot: Upload Images From your Computer Harddrive or Screen With Ease!

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• Why unhandled exceptions are useful

  - by Simon Cooper

  It’s the bane of most programmers’ lives – an unhandled exception causes your application or webapp to crash, an ugly dialog gets displayed to the user, and they come complaining to you. Then, somehow, you need to figure out what went wrong. Hopefully, you’ve got a log file, or some other way of reporting unhandled exceptions (obligatory employer plug: SmartAssembly reports an application’s unhandled exceptions straight to you, along with the entire state of the stack and variables at that point). If not, you have to try and replicate it yourself, or do some psychic debugging to try and figure out what’s wrong. However, it’s good that the program crashed. Or, more precisely, it is correct behaviour. An unhandled exception in your application means that, somewhere in your code, there is an assumption that you made that is actually invalid. Coding assumptions Let me explain a bit more. Every method, every line of code you write, depends on implicit assumptions that you have made. Take this following simple method, that copies a collection to an array and includes an item if it isn’t in the collection already, using a supplied IEqualityComparer: public static T[] ToArrayWithItem( ICollection<T> coll, T obj, IEqualityComparer<T> comparer) { // check if the object is in collection already // using the supplied comparer foreach (var item in coll) { if (comparer.Equals(item, obj)) { // it's in the collection already // simply copy the collection to an array // and return it T[] array = new T[coll.Count]; coll.CopyTo(array, 0); return array; } } // not in the collection // copy coll to an array, and add obj to it // then return it T[] array = new T[coll.Count+1]; coll.CopyTo(array, 0); array[array.Length-1] = obj; return array; } What’s all the assumptions made by this fairly simple bit of code? coll is never null comparer is never null coll.CopyTo(array, 0) will copy all the items in the collection into the array, in the order defined for the collection, starting at the first item in the array. The enumerator for coll returns all the items in the collection, in the order defined for the collection comparer.Equals returns true if the items are equal (for whatever definition of ‘equal’ the comparer uses), false otherwise comparer.Equals, coll.CopyTo, and the coll enumerator will never throw an exception or hang for any possible input and any possible values of T coll will have less than 4 billion items in it (this is a built-in limit of the CLR) array won’t be more than 2GB, both on 32 and 64-bit systems, for any possible values of T (again, a limit of the CLR) There are no threads that will modify coll while this method is running and, more esoterically: The C# compiler will compile this code to IL according to the C# specification The CLR and JIT compiler will produce machine code to execute the IL on the user’s computer The computer will execute the machine code correctly That’s a lot of assumptions. Now, it could be that all these assumptions are valid for the situations this method is called. But if this does crash out with an exception, or crash later on, then that shows one of the assumptions has been invalidated somehow. An unhandled exception shows that your code is running in a situation which you did not anticipate, and there is something about how your code runs that you do not understand. Debugging the problem is the process of learning more about the new situation and how your code interacts with it. When you understand the problem, the solution is (usually) obvious. The solution may be a one-line fix, the rewrite of a method or class, or a large-scale refactoring of the codebase, but whatever it is, the fix for the crash will incorporate the new information you’ve gained about your own code, along with the modified assumptions. When code is running with an assumption or invariant it depended on broken, then the result is ‘undefined behaviour’. Anything can happen, up to and including formatting the entire disk or making the user’s computer sentient and start doing a good impression of Skynet. You might think that those can’t happen, but at Halting problem levels of generality, as soon as an assumption the code depended on is broken, the program can do anything. That is why it’s important to fail-fast and stop the program as soon as an invariant is broken, to minimise the damage that is done. What does this mean in practice? To start with, document and check your assumptions. As with most things, there is a level of judgement required. How you check and document your assumptions depends on how the code is used (that’s some more assumptions you’ve made), how likely it is a method will be passed invalid arguments or called in an invalid state, how likely it is the assumptions will be broken, how expensive it is to check the assumptions, and how bad things are likely to get if the assumptions are broken. Now, some assumptions you can assume unless proven otherwise. You can safely assume the C# compiler, CLR, and computer all run the method correctly, unless you have evidence of a compiler, CLR or processor bug. You can also assume that interface implementations work the way you expect them to; implementing an interface is more than simply declaring methods with certain signatures in your type. The behaviour of those methods, and how they work, is part of the interface contract as well. For example, for members of a public API, it is very important to document your assumptions and check your state before running the bulk of the method, throwing ArgumentException, ArgumentNullException, InvalidOperationException, or another exception type as appropriate if the input or state is wrong. For internal and private methods, it is less important. If a private method expects collection items in a certain order, then you don’t necessarily need to explicitly check it in code, but you can add comments or documentation specifying what state you expect the collection to be in at a certain point. That way, anyone debugging your code can immediately see what’s wrong if this does ever become an issue. You can also use DEBUG preprocessor blocks and Debug.Assert to document and check your assumptions without incurring a performance hit in release builds. On my coding soapbox… A few pet peeves of mine around assumptions. Firstly, catch-all try blocks: try { ... } catch { } A catch-all hides exceptions generated by broken assumptions, and lets the program carry on in an unknown state. Later, an exception is likely to be generated due to further broken assumptions due to the unknown state, causing difficulties when debugging as the catch-all has hidden the original problem. It’s much better to let the program crash straight away, so you know where the problem is. You should only use a catch-all if you are sure that any exception generated in the try block is safe to ignore. That’s a pretty big ask! Secondly, using as when you should be casting. Doing this: (obj as IFoo).Method(); or this: IFoo foo = obj as IFoo; ... foo.Method(); when you should be doing this: ((IFoo)obj).Method(); or this: IFoo foo = (IFoo)obj; ... foo.Method(); There’s an assumption here that obj will always implement IFoo. If it doesn’t, then by using as instead of a cast you’ve turned an obvious InvalidCastException at the point of the cast that will probably tell you what type obj actually is, into a non-obvious NullReferenceException at some later point that gives you no information at all. If you believe obj is always an IFoo, then say so in code! Let it fail-fast if not, then it’s far easier to figure out what’s wrong. Thirdly, document your assumptions. If an algorithm depends on a non-trivial relationship between several objects or variables, then say so. A single-line comment will do. Don’t leave it up to whoever’s debugging your code after you to figure it out. Conclusion It’s better to crash out and fail-fast when an assumption is broken. If it doesn’t, then there’s likely to be further crashes along the way that hide the original problem. Or, even worse, your program will be running in an undefined state, where anything can happen. Unhandled exceptions aren’t good per-se, but they give you some very useful information about your code that you didn’t know before. And that can only be a good thing.

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• Using Native Drag and Drop in HTML 5 pages

  - by nikolaosk

  This is going to be the eighth post in a series of posts regarding HTML 5. You can find the other posts here, here , here , here, here , here and here. In this post I will show you how to implement Drag and Drop functionality in an HTML 5 page using JQuery.This is a great functionality and we do not need to resort anymore to plugins like Silverlight and Flash to achieve this great feature. This is also called a native approach on Drag and Drop.I will use some events and I will write code to respond when these events are fired.As I said earlier we need to write Javascript to implement the drag and drop functionality. I will use the very popular JQuery Library. Please download the library (minified version) from http://jquery.com/downloadI will create a simple HTML page.There will be two thumbnails pics on it. There will also be the drag and drop area where the user will drag the thumb pics into it and they will resize to their actual size. The HTML markup for the page follows<!doctype html><html lang="en"><head><title>Liverpool Legends Gallery</title><meta charset="utf-8"><link rel="stylesheet" type="text/css" href="style.css"><script type="text/javascript" charset="utf-8" src="jquery-1.8.1.min.js"></script>  <script language="JavaScript" src="drag.js"></script>   </head><body><header><h1>A page dedicated to Liverpool Legends</h1><h2>Drag and Drop the thumb image in the designated area to see the full image</h2></header><div id="main"><img src="thumbs/steven-gerrard.jpg"  big="large-images/steven-gerrard-large.jpg" alt="John Barnes"><img src="thumbs/robbie-fowler.jpg" big="large-images/robbie-fowler-large.jpg" alt="Ian Rush"><div id="drag"><p>Drop your image here</p> </div></body></html> There is nothing difficult or fancy in the HTML markup above. I have a link to the external JQuery library and another javascript file that I will implement the whole drag and drop functionality.The code for the css file (style.css) follows#main{  float: left;  width: 340px;  margin-right: 30px;}#drag{  float: left;  width: 400px;  height:300px;  background-color: #c0c0c0;}These are simple CSS rules. This post cannot be a tutorial on CSS.For all these posts I assume that you have the basic HTML,CSS,Javascript skills.Now I am going to create a javascript file (drag.js) to implement the drag and drop functionality.I will provide the whole code for the drag.js file and then I will explain what I am doing in each step.$(function() {          var players = $('#main img');          players.attr('draggable', 'true');                    players.bind('dragstart', function(event) {              var data = event.originalEvent.dataTransfer;               var src = $(this).attr("big");              data.setData("Text", src);               return true;          });          var target = $('#drag');          target.bind('drop', function(event) {            var data = event.originalEvent.dataTransfer;            var src = ( data.getData('Text') );                         var img = $("<img></img>").attr("src", src);            $(this).html(img);            if (event.preventDefault) event.preventDefault();            return(false);          });                   target.bind('dragover', function(event) {                if (event.preventDefault) event.preventDefault();            return false;          });           players.bind('dragend', function(event) {             if (event.preventDefault) event.preventDefault();             return false;           });        });   In these lines var players = $('#main img'); players.attr('draggable', 'true');We grab all the images in the #main div and store them in a variable and then make them draggable.Then in following lines I am using the dragstart event.  players.bind('dragstart', function(event) {              var data = event.originalEvent.dataTransfer;               var src = $(this).attr("big");              data.setData("Text", src);               return true;          }); In this event I am associating the custom data attribute value with the item I am dragging.Then I create a variable to get hold of the dropping area var target = $('#drag'); Then in the following lines I implement the drop event and what happens when the user drops the image in the designated area on the page. target.bind('drop', function(event) {            var data = event.originalEvent.dataTransfer;            var src = ( data.getData('Text') );                         var img = $("<img></img>").attr("src", src);            $(this).html(img);            if (event.preventDefault) event.preventDefault();            return(false);          }); The dragend  event is fired when the user has finished the drag operation        players.bind('dragend', function(event) {             if (event.preventDefault) event.preventDefault();             return false;           }); When this method event.preventDefault() is called , the default action of the event will not be triggered.Please have a look a the picture below to see how the page looks before the drag and drop takes place. Then simply I drag and drop a picture in the dropping area.Have a look at the picture below It works!!! Hope it helps!!  

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• Azure &ndash; Part 5 &ndash; Repository Pattern for Table Service

  - by Shaun

  In my last post I created a very simple WCF service with the user registration functionality. I created an entity for the user data and a DataContext class which provides some methods for operating the entities such as add, delete, etc. And in the service method I utilized it to add a new entity into the table service. But I didn’t have any validation before registering which is not acceptable in a real project. So in this post I would firstly add some validation before perform the data creation code and show how to use the LINQ for the table service.   LINQ to Table Service Since the table service utilizes ADO.NET Data Service to expose the data and the managed library of ADO.NET Data Service supports LINQ we can use it to deal with the data of the table service. Let me explain with my current example: I would like to ensure that when register a new user the email address should be unique. So I need to check the account entities in the table service before add. If you remembered, in my last post I mentioned that there’s a method in the TableServiceContext class – CreateQuery, which will create a IQueryable instance from a given type of entity. So here I would create a method under my AccountDataContext class to return the IQueryable<Account> which named Load. 1: public class AccountDataContext : TableServiceContext 2: { 3: private CloudStorageAccount _storageAccount; 4:  5: public AccountDataContext(CloudStorageAccount storageAccount) 6: : base(storageAccount.TableEndpoint.AbsoluteUri, storageAccount.Credentials) 7: { 8: _storageAccount = storageAccount; 9:  10: var tableStorage = new CloudTableClient(_storageAccount.TableEndpoint.AbsoluteUri, 11: _storageAccount.Credentials); 12: tableStorage.CreateTableIfNotExist("Account"); 13: } 14:  15: public void Add(Account accountToAdd) 16: { 17: AddObject("Account", accountToAdd); 18: SaveChanges(); 19: } 20:  21: public IQueryable<Account> Load() 22: { 23: return CreateQuery<Account>("Account"); 24: } 25: } The method returns the IQueryable<Account> so that I can perform the LINQ operation on it. And back to my service class, I will use it to implement my validation. 1: public bool Register(string email, string password) 2: { 3: var storageAccount = CloudStorageAccount.FromConfigurationSetting("DataConnectionString"); 4: var accountToAdd = new Account(email, password) { DateCreated = DateTime.Now }; 5: var accountContext = new AccountDataContext(storageAccount); 6:  7: // validation 8: var accountNumber = accountContext.Load() 9: .Where(a => a.Email == accountToAdd.Email) 10: .Count(); 11: if (accountNumber > 0) 12: { 13: throw new ApplicationException(string.Format("Your account {0} had been used.", accountToAdd.Email)); 14: } 15:  16: // create entity 17: try 18: { 19: accountContext.Add(accountToAdd); 20: return true; 21: } 22: catch (Exception ex) 23: { 24: Trace.TraceInformation(ex.ToString()); 25: } 26: return false; 27: } I used the Load method to retrieve the IQueryable<Account> and use Where method to find the accounts those email address are the same as the one is being registered. If it has I through an exception back to the client side. Let’s run it and test from my simple client application. Oops! Looks like we encountered an unexpected exception. It said the “Count” is not support by the ADO.NET Data Service LINQ managed library. That is because the table storage managed library (aka. TableServiceContext) is based on the ADO.NET Data Service and it supports very limit LINQ operation. Although I didn’t find a full list or documentation about which LINQ methods it supports I could even refer a page on msdn here. It gives us a roughly summary of which query operation the ADO.NET Data Service managed library supports and which doesn't. As you see the Count method is not in the supported list. Not only the query operation, there inner lambda expression in the Where method are limited when using the ADO.NET Data Service managed library as well. For example if you added (a => !a.DateDeleted.HasValue) in the Where method to exclude those deleted account it will raised an exception said "Invalid Input". Based on my experience you should always use the simple comparison (such as ==, >, <=, etc.) on the simple members (such as string, integer, etc.) and do not use any shortcut methods (such as string.Compare, string.IsNullOrEmpty etc.). 1: // validation 2: var accountNumber = accountContext.Load() 3: .Where(a => a.Email == accountToAdd.Email) 4: .ToList() 5: .Count; 6: if (accountNumber > 0) 7: { 8: throw new ApplicationException(string.Format("Your account {0} had been used.", accountToAdd.Email)); 9: } We changed the a bit and try again. Since I had created an account with my mail address so this time it gave me an exception said that the email had been used, which is correct.   Repository Pattern for Table Service The AccountDataContext takes the responsibility to save and load the account entity but only for that specific entity. Is that possible to have a dynamic or generic DataContext class which can operate any kinds of entity in my system? Of course yes. Although there's no typical database in table service we can threat the entities as the records, similar with the data entities if we used OR Mapping. As we can use some patterns for ORM architecture here we should be able to adopt the one of them - Repository Pattern in this example. We know that the base class - TableServiceContext provide 4 methods for operating the table entities which are CreateQuery, AddObject, UpdateObject and DeleteObject. And we can create a relationship between the enmity class, the table container name and entity set name. So it's really simple to have a generic base class for any kinds of entities. Let's rename the AccountDataContext to DynamicDataContext and make the type of Account as a type parameter if it. 1: public class DynamicDataContext<T> : TableServiceContext where T : TableServiceEntity 2: { 3: private CloudStorageAccount _storageAccount; 4: private string _entitySetName; 5:  6: public DynamicDataContext(CloudStorageAccount storageAccount) 7: : base(storageAccount.TableEndpoint.AbsoluteUri, storageAccount.Credentials) 8: { 9: _storageAccount = storageAccount; 10: _entitySetName = typeof(T).Name; 11:  12: var tableStorage = new CloudTableClient(_storageAccount.TableEndpoint.AbsoluteUri, 13: _storageAccount.Credentials); 14: tableStorage.CreateTableIfNotExist(_entitySetName); 15: } 16:  17: public void Add(T entityToAdd) 18: { 19: AddObject(_entitySetName, entityToAdd); 20: SaveChanges(); 21: } 22:  23: public void Update(T entityToUpdate) 24: { 25: UpdateObject(entityToUpdate); 26: SaveChanges(); 27: } 28:  29: public void Delete(T entityToDelete) 30: { 31: DeleteObject(entityToDelete); 32: SaveChanges(); 33: } 34:  35: public IQueryable<T> Load() 36: { 37: return CreateQuery<T>(_entitySetName); 38: } 39: } I saved the name of the entity type when constructed for performance matter. The table name, entity set name would be the same as the name of the entity class. The Load method returned a generic IQueryable instance which supports the lazy load feature. Then in my service class I changed the AccountDataContext to DynamicDataContext and that's all. 1: var accountContext = new DynamicDataContext<Account>(storageAccount); Run it again and register another account. The DynamicDataContext now can be used for any entities. For example, I would like the account has a list of notes which contains 3 custom properties: Account Email, Title and Content. We create the note entity class. 1: public class Note : TableServiceEntity 2: { 3: public string AccountEmail { get; set; } 4: public string Title { get; set; } 5: public string Content { get; set; } 6: public DateTime DateCreated { get; set; } 7: public DateTime? DateDeleted { get; set; } 8:  9: public Note() 10: : base() 11: { 12: } 13:  14: public Note(string email) 15: : base(email, string.Format("{0}_{1}", email, Guid.NewGuid().ToString())) 16: { 17: AccountEmail = email; 18: } 19: } And no need to tweak the DynamicDataContext we can directly go to the service class to implement the logic. Notice here I utilized two DynamicDataContext instances with the different type parameters: Note and Account. 1: public class NoteService : INoteService 2: { 3: public void Create(string email, string title, string content) 4: { 5: var storageAccount = CloudStorageAccount.FromConfigurationSetting("DataConnectionString"); 6: var accountContext = new DynamicDataContext<Account>(storageAccount); 7: var noteContext = new DynamicDataContext<Note>(storageAccount); 8:  9: // validate - email must be existed 10: var accounts = accountContext.Load() 11: .Where(a => a.Email == email) 12: .ToList() 13: .Count; 14: if (accounts <= 0) 15: throw new ApplicationException(string.Format("The account {0} does not exsit in the system please register and try again.", email)); 16:  17: // save the note 18: var noteToAdd = new Note(email) { Title = title, Content = content, DateCreated = DateTime.Now }; 19: noteContext.Add(noteToAdd); 20: } 21: } And updated our client application to test the service. I didn't implement any list service to show all notes but we can have a look on the local SQL database if we ran it at local development fabric.   Summary In this post I explained a bit about the limited LINQ support for the table service. And then I demonstrated about how to use the repository pattern in the table service data access layer and make the DataContext dynamically. The DynamicDataContext I created in this post is just a prototype. In fact we should create the relevant interface to make it testable and for better structure we'd better separate the DataContext classes for each individual kind of entity. So it should have IDataContextBase<T>, DataContextBase<T> and for each entity we would have class AccountDataContext<Account> : IDataContextBase<Account>, DataContextBase<Account> { … } class NoteDataContext<Note> : IDataContextBase<Note>, DataContextBase<Note> { … }   Besides the structured data saving and loading, another common scenario would be saving and loading some binary data such as images, files. In my next post I will show how to use the Blob Service to store the bindery data - make the account be able to upload their logo in my example.   Hope this helps, Shaun   All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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• Code Behaviour via Unit Tests

  - by Dewald Galjaard

  Normal 0 false false false EN-ZA X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Some four months ago my car started acting up. Symptoms included a sputtering as my car’s computer switched between gears intermittently. Imagine building up speed, then when you reach 80km/h the car magically and mysteriously decide to switch back to third or even second gear. Clearly it was confused! I managed to track down a technician, an expert in his field to help me out. As he fitted his handheld computer to some hidden port under the dash, he started to explain “These cars are quite intelligent, you know. When they sense something is wrong they run in a restrictive program which probably account for how you managed to drive here in the first place...”  I was surprised and thought this was certainly going to be an interesting test drive. The car ran smoothly down the first couple of stretches as the technician ran through routine checks. Then he said “Ok, all looking good. We need to start testing aspects of the gearbox. Inside the gearbox there are a couple of sensors. One of them is a speed sensor which talks to the computer, which in turn will decide which gear to switch to. The restrictive program avoid these sensors altogether and allow the computer to obtain its input from other [non-affected] sources”. Then, as soon as he forced the speed sensor to come back online the symptoms and ill behaviour re-emerged... What an incredible analogy for getting into a discussion on unit testing software? Besides I should probably put my ill fortune to some good use, right? This example provide a lot of insight into how and why we should conduct unit tests when writing code. More importantly, it captures what is easily and unfortunately often the most overlooked goal of writing unit tests by those new to the art and those who oppose it alike - The goal of writing unit tests is to test the behaviour of our code under predefined conditions. Although it is very possible to test the intrinsic workings of each and every component in your code, writing several tests for each method in practise will soon prove to be an exhausting and ultimately fruitless exercise given the certain and ever changing nature of business requirements. Consequently it is true and quite possible whilst conducting proper unit tests, to call any single method several times as you examine and contemplate different scenarios. Let’s write some code to demonstrate what I mean. In my example I make use of the Moq framework and NUnit to create my tests. Truly you can use whatever you’re comfortable with. First we’ll create an ISpeedSensor interface. This is to represent the speed sensor located in the gearbox.  Then we’ll create a Gearbox class which we’ll pass to a constructor when we instantiate an object of type Computer. All three are described below.   ISpeedSensor.cs namespace AutomaticVehicle {     public interface ISpeedSensor     {         int ReportCurrentSpeed();     } }   Gearbox.cs namespace AutomaticVehicle {      public class Gearbox     {         private ISpeedSensor _speedSensor;           public Gearbox( ISpeedSensor gearboxSpeedSensor )         {             _speedSensor = gearboxSpeedSensor;         }         /// <summary>         /// This method obtain it's reading from the speed sensor.         /// </summary>         /// <returns></returns>         public int ReportCurrentSpeed()         {             return _speedSensor.ReportCurrentSpeed();         }     } } Computer.cs namespace AutomaticVehicle {     public class Computer     {         private Gearbox _gearbox;         public Computer( Gearbox gearbox )         {                     }          public int GetCurrentSpeed()         {             return _gearbox.ReportCurrentSpeed( );         }     } } Since this post is about Unit testing, that is exactly what we’ll create next. Create a second project in your solution. I called mine AutomaticVehicleTests and I immediately referenced the respective nunit, moq and AutomaticVehicle dll’s. We’re going to write a test to examine what happens inside the Computer class. ComputerTests.cs namespace AutomaticVehicleTests {     [TestFixture]     public class ComputerTests     {         [Test]         public void Computer_Gearbox_SpeedSensor_DoesThrow()         {             // Mock ISpeedSensor in gearbox             Mock< ISpeedSensor > speedSensor = new Mock< ISpeedSensor >( );             speedSensor.Setup( n => n.ReportCurrentSpeed() ).Throws<Exception>();             Gearbox gearbox = new Gearbox( speedSensor.Object );               // Create Computer instance to test it's behaviour  towards an exception in gearbox             Computer carComputer = new Computer( gearbox );             // For simplicity let’s assume for now the car only travels at 60 km/h.             Assert.AreEqual( 60, carComputer.GetCurrentSpeed( ) );          }     } }   What is happening in this test? We have created a mocked object using the ISpeedsensor interface which we've passed to our Gearbox object. Notice that I created the mocked object using an interface, not the implementation. I’ll talk more about this in future posts but in short I do this to accentuate the fact that I'm not not really concerned with how SpeedSensor work internally at this particular point in time. Next I’ve gone ahead and created a scenario where I’ve declared the speed sensor in Gearbox to be faulty by forcing it to throw an exception should we ask Gearbox to report on its current speed. Sneaky, sneaky. This test is a simulation of how things may behave in the real world. Inevitability things break, whether it’s caused by mechanical failure, some logical error on your part or a fellow developer which didn’t consult the documentation (or the lack thereof ) - whether you’re calling a speed sensor, making a call to a database, calling a web service or just trying to write a file to disk. It’s a scenario I’ve created and this test is about how the code within the Computer instance will behave towards any such error as I’ve depicted. Now, if you’ve followed closely in my final assert method you would have noticed I did something quite unexpected. I might be getting ahead of myself now but I’m testing to see if the value returned is equal to what I expect it to be under perfect conditions – I’m not testing to see if an error has been thrown! Why is that? Well, in short this is TDD. Test Driven Development is about first writing your test to define the result we want, then to go back and change the implementation within your class to obtain the desired output (I need to make sure I can drive back to the repair shop. Remember? ) So let’s go ahead and run our test as is. It’s fails miserably... Good! Let’s go back to our Computer class and make a small change to the GetCurrentSpeed method.   Computer.cs public int GetCurrentSpeed() {   try   {     return _gearbox.ReportCurrentSpeed( );   }   catch   {     RunRestrictiveProgram( );   } }     This is a simple solution, I know, but it does provide a way to allow for different behaviour. You’re more than welcome to provide an implementation for RunRestrictiveProgram should you feel the need to. It's not within the scope of this post or related to the point I'm trying to make. What is important is to notice how the focus has shifted in our approach from how things can break - to how things behave when broken.   Happy coding!

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• Auto-hydrate your objects with ADO.NET

  - by Jake Rutherford

  Recently while writing the monotonous code for pulling data out of a DataReader to hydrate some objects in an application I suddenly wondered "is this really necessary?" You've probably asked yourself the same question, and many of you have: - Used a code generator - Used a ORM such as Entity Framework - Wrote the code anyway because you like busy work     In most of the cases I've dealt with when making a call to a stored procedure the column names match up with the properties of the object I am hydrating. Sure that isn't always the case, but most of the time it's 1 to 1 mapping.  Given that fact I whipped up the following method of hydrating my objects without having write all of the code. First I'll show the code, and then explain what it is doing.      /// <summary>     /// Abstract base class for all Shared objects.     /// </summary>     /// <typeparam name="T"></typeparam>     [Serializable, DataContract(Name = "{0}SharedBase")]     public abstract class SharedBase<T> where T : SharedBase<T>     {         private static List<PropertyInfo> cachedProperties;         /// <summary>         /// Hydrates derived class with values from record.         /// </summary>         /// <param name="dataRecord"></param>         /// <param name="instance"></param>         public static void Hydrate(IDataRecord dataRecord, T instance)         {             var instanceType = instance.GetType();                         //Caching properties to avoid repeated calls to GetProperties.             //Noticable performance gains when processing same types repeatedly.             if (cachedProperties == null)             {                 cachedProperties = instanceType.GetProperties().ToList();             }                         foreach (var property in cachedProperties)             {                 if (!dataRecord.ColumnExists(property.Name)) continue;                 var ordinal = dataRecord.GetOrdinal(property.Name);                 var isNullable = property.PropertyType.IsGenericType &&                                  property.PropertyType.GetGenericTypeDefinition() == typeof (Nullable<>);                 var isNull = dataRecord.IsDBNull(ordinal);                 var propertyType = property.PropertyType;                 if (isNullable)                 {                     if (!string.IsNullOrEmpty(propertyType.FullName))                     {                         var nullableType = Type.GetType(propertyType.FullName);                         propertyType = nullableType != null ? nullableType.GetGenericArguments()[0] : propertyType;                     }                 }                 switch (Type.GetTypeCode(propertyType))                 {                     case TypeCode.Int32:                         property.SetValue(instance,                                           (isNullable && isNull) ? (int?) null : dataRecord.GetInt32(ordinal), null);                         break;                     case TypeCode.Double:                         property.SetValue(instance,                                           (isNullable && isNull) ? (double?) null : dataRecord.GetDouble(ordinal),                                           null);                         break;                     case TypeCode.Boolean:                         property.SetValue(instance,                                           (isNullable && isNull) ? (bool?) null : dataRecord.GetBoolean(ordinal),                                           null);                         break;                     case TypeCode.String:                         property.SetValue(instance, (isNullable && isNull) ? null : isNull ? null : dataRecord.GetString(ordinal),                                           null);                         break;                     case TypeCode.Int16:                         property.SetValue(instance,                                           (isNullable && isNull) ? (int?) null : dataRecord.GetInt16(ordinal), null);                         break;                     case TypeCode.DateTime:                         property.SetValue(instance,                                           (isNullable && isNull)                                               ? (DateTime?) null                                               : dataRecord.GetDateTime(ordinal), null);                         break;                 }             }         }     }   Here is a class which utilizes the above: [Serializable] [DataContract] public class foo : SharedBase<foo> {     [DataMember]     public int? ID { get; set; }     [DataMember]     public string Name { get; set; }     [DataMember]     public string Description { get; set; }     [DataMember]     public string Subject { get; set; }     [DataMember]     public string Body { get; set; }            public foo(IDataRecord record)     {         Hydrate(record, this);                }     public foo() {} }   Explanation: - Class foo inherits from SharedBase specifying itself as the type. (NOTE SharedBase is abstract here in the event we want to provide additional methods which could be overridden by the instance class) public class foo : SharedBase<foo> - One of the foo class constructors accepts a data record which then calls the Hydrate method on SharedBase passing in the record and itself. public foo(IDataRecord record) {      Hydrate(record, this); } - Hydrate method on SharedBase will use reflection on the object passed in to determine its properties. At the same time, it will effectively cache these properties to avoid repeated expensive reflection calls public static void Hydrate(IDataRecord dataRecord, T instance) {      var instanceType = instance.GetType();      //Caching properties to avoid repeated calls to GetProperties.      //Noticable performance gains when processing same types repeatedly.      if (cachedProperties == null)      {           cachedProperties = instanceType.GetProperties().ToList();      } . . . - Hydrate method on SharedBase will iterate each property on the object and determine if a column with matching name exists in data record foreach (var property in cachedProperties) {      if (!dataRecord.ColumnExists(property.Name)) continue;      var ordinal = dataRecord.GetOrdinal(property.Name); . . . NOTE: ColumnExists is an extension method I put on IDataRecord which I’ll include at the end of this post. - Hydrate method will determine if the property is nullable and whether the value in the corresponding column of the data record has a null value var isNullable = property.PropertyType.IsGenericType && property.PropertyType.GetGenericTypeDefinition() == typeof (Nullable<>); var isNull = dataRecord.IsDBNull(ordinal); var propertyType = property.PropertyType; . . .  - If Hydrate method determines the property is nullable it will determine the underlying type and set propertyType accordingly - Hydrate method will set the value of the property based upon the propertyType   That’s it!!!   The magic here is in a few places. First, you may have noticed the following: public abstract class SharedBase<T> where T : SharedBase<T> This says that SharedBase can be created with any type and that for each type it will have it’s own instance. This is important because of the static members within SharedBase. We want this behavior because we are caching the properties for each type. If we did not handle things in this way only 1 type could be cached at a time, or, we’d need to create a collection that allows us to cache the properties for each type = not very elegant.   Second, in the constructor for foo you may have noticed this (literally): public foo(IDataRecord record) {      Hydrate(record, this); } I wanted the code for auto-hydrating to be as simple as possible. At first I wasn’t quite sure how I could call Hydrate on SharedBase within an instance of the class and pass in the instance itself. Fortunately simply passing in “this” does the trick. I wasn’t sure it would work until I tried it out, and fortunately it did.   So, to actually use this feature when utilizing ADO.NET you’d do something like the following:        public List<foo> GetFoo(int? fooId)         {             List<foo> fooList;             const string uspName = "usp_GetFoo";             using (var conn = new SqlConnection(_dbConnection))             using (var cmd = new SqlCommand(uspName, conn))             {                 cmd.CommandType = CommandType.StoredProcedure;                 cmd.Parameters.Add(new SqlParameter("@FooID", SqlDbType.Int)                                        {Direction = ParameterDirection.Input, Value = fooId});                 conn.Open();                 using (var dr = cmd.ExecuteReader())                 {                     fooList= (from row in dr.Cast<DbDataRecord>()                                             select                                                 new foo(row)                                            ).ToList();                 }             }             return fooList;         }   Nice! Instead of having line after line manually assigning values from data record to an object you simply create a new instance and pass in the data record. Note that there are certainly instances where columns returned from stored procedure do not always match up with property names. In this scenario you can still use the above method and simply do your manual assignments afterward.

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• Software development is (mostly) a trade, and what to do about it

  - by Jeff

  (This is another cross-post from my personal blog. I don’t even remember when I first started to write it, but I feel like my opinion is well enough baked to share.) I've been sitting on this for a long time, particularly as my opinion has changed dramatically over the last few years. That I've encountered more crappy code than maintainable, quality code in my career as a software developer only reinforces what I'm about to say. Software development is just a trade for most, and not a huge academic endeavor. For those of you with computer science degrees readying your pitchforks and collecting your algorithm interview questions, let me explain. This is not an assault on your way of life, and if you've been around, you know I'm right about the quality problem. You also know the HR problem is very real, or we wouldn't be paying top dollar for mediocre developers and importing people from all over the world to fill the jobs we can't fill. I'm going to try and outline what I see as some of the problems, and hopefully offer my views on how to address them. The recruiting problem I think a lot of companies are doing it wrong. Over the years, I've had two kinds of interview experiences. The first, and right, kind of experience involves talking about real life achievements, followed by some variation on white boarding in pseudo-code, drafting some basic system architecture, or even sitting down at a comprooder and pecking out some basic code to tackle a real problem. I can honestly say that I've had a job offer for every interview like this, save for one, because the task was to debug something and they didn't like me asking where to look ("everyone else in the company died in a plane crash"). The other interview experience, the wrong one, involves the classic torture test designed to make the candidate feel stupid and do things they never have, and never will do in their job. First they will question you about obscure academic material you've never seen, or don't care to remember. Then they'll ask you to white board some ridiculous algorithm involving prime numbers or some kind of string manipulation no one would ever do. In fact, if you had to do something like this, you'd Google for a solution instead of waste time on a solved problem. Some will tell you that the academic gauntlet interview is useful to see how people respond to pressure, how they engage in complex logic, etc. That might be true, unless of course you have someone who brushed up on the solutions to the silly puzzles, and they're playing you. But here's the real reason why the second experience is wrong: You're evaluating for things that aren't the job. These might have been useful tactics when you had to hire people to write machine language or C++, but in a world dominated by managed code in C#, or Java, people aren't managing memory or trying to be smarter than the compilers. They're using well known design patterns and techniques to deliver software. More to the point, these puzzle gauntlets don't evaluate things that really matter. They don't get into code design, issues of loose coupling and testability, knowledge of the basics around HTTP, or anything else that relates to building supportable and maintainable software. The first situation, involving real life problems, gives you an immediate idea of how the candidate will work out. One of my favorite experiences as an interviewee was with a guy who literally brought his work from that day and asked me how to deal with his problem. I had to demonstrate how I would design a class, make sure the unit testing coverage was solid, etc. I worked at that company for two years. So stop looking for algorithm puzzle crunchers, because a guy who can crush a Fibonacci sequence might also be a guy who writes a class with 5,000 lines of untestable code. Fashion your interview process on ways to reveal a developer who can write supportable and maintainable code. I would even go so far as to let them use the Google. If they want to cut-and-paste code, pass on them, but if they're looking for context or straight class references, hire them, because they're going to be life-long learners. The contractor problem I doubt anyone has ever worked in a place where contractors weren't used. The use of contractors seems like an obvious way to control costs. You can hire someone for just as long as you need them and then let them go. You can even give them the work that no one else wants to do. In practice, most places I've worked have retained and budgeted for the contractor year-round, meaning that the $90+ per hour they're paying (of which half goes to the person) would have been better spent on a full-time person with a $100k salary and benefits. But it's not even the cost that is an issue. It's the quality of work delivered. The accountability of a contractor is totally transient. They only need to deliver for as long as you keep them around, and chances are they'll never again touch the code. There's no incentive for them to get things right, there's little incentive to understand your system or learn anything. At the risk of making an unfair generalization, craftsmanship doesn't matter to most contractors. The education problem I don't know what they teach in college CS courses. I've believed for most of my adult life that a college degree was an essential part of being successful. Of course I would hold that bias, since I did it, and have the paper to show for it in a box somewhere in the basement. My first clue that maybe this wasn't a fully qualified opinion comes from the fact that I double-majored in journalism and radio/TV, not computer science. Eventually I worked with people who skipped college entirely, many of them at Microsoft. Then I worked with people who had a masters degree who sucked at writing code, next to the high school diploma types that rock it every day. I still think there's a lot to be said for the social development of someone who has the on-campus experience, but for software developers, college might not matter. As I mentioned before, most of us are not writing compilers, and we never will. It's actually surprising to find how many people are self-taught in the art of software development, and that should reveal some interesting truths about how we learn. The first truth is that we learn largely out of necessity. There's something that we want to achieve, so we do what I call just-in-time learning to meet those goals. We acquire knowledge when we need it. So what about the gaps in our knowledge? That's where the most valuable education occurs, via our mentors. They're the people we work next to and the people who write blogs. They are critical to our professional development. They don't need to be an encyclopedia of jargon, but they understand the craft. Even at this stage of my career, I probably can't tell you what SOLID stands for, but you can bet that I practice the principles behind that acronym every day. That comes from experience, augmented by my peers. I'm hell bent on passing that experience to others. Process issues If you're a manager type and don't do much in the way of writing code these days (shame on you for not messing around at least), then your job is to isolate your tradespeople from nonsense, while bringing your business into the realm of modern software development. That doesn't mean you slap up a white board with sticky notes and start calling yourself agile, it means getting all of your stakeholders to understand that frequent delivery of quality software is the best way to deal with change and evolving expectations. It also means that you have to play technical overlord to make sure the education and quality issues are dealt with. That's why I make the crack about sticky notes, because without the right technique being practiced among your code monkeys, you're just a guy with sticky notes. You're asking your business to accept frequent and iterative delivery, now make sure that the folks writing the code can handle the same thing. This means unit testing, the right instrumentation, integration tests, automated builds and deployments... all of the stuff that makes it easy to see when change breaks stuff. The prognosis I strongly believe that education is the most important part of what we do. I'm encouraged by things like The Starter League, and it's the kind of thing I'd love to see more of. I would go as far as to say I'd love to start something like this internally at an existing company. Most of all though, I can't emphasize enough how important it is that we mentor each other and share our knowledge. If you have people on your staff who don't want to learn, fire them. Seriously, get rid of them. A few months working with someone really good, who understands the craftsmanship required to build supportable and maintainable code, will change that person forever and increase their value immeasurably.

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• Contract Work - Lessons Learned

  - by samerpaul

  I thought I would write a post of a different nature today, but still relevant to the tech world. I do a lot of contract jobs myself and really enjoy it. It's nice to keep jumping from project to project, and not having to go to an office or keep regular hours, etc. I really enjoy it. I have learned a lot in the past few years of doing it (both from experience and from help given to me from others, and the internet) so I thought I'd share some of that knowledge/experience today.So here's my own personal "lesson's learned" that hopefully will help you if you find yourself doing contract work:Should I take the job?Ok, so this is the first step. Assuming you were given sufficient information about what they want, then you should really think about what you're capable of doing and whether or not you should take this job. Personally, my rule is, if I know it's possible, I'll say yes, even if I don't yet know how to do it. That's because the internet is such a great help, it would be rare to run into an issue that you can't figure out with some help. So if your clients are asking for something that you don't yet know how to program, but you know you can do it on the platform then go for it. How else are you going to learn?Use this rule with some limitation, however. If you're really lacking the expertise or foundation in something, then unless you have tons of time to complete the project, then I wouldn't say yes. For example, I haven't personally done any 3d/openGL programming yet so I wouldn't say yes to a project that extensively uses it. OK, so I want the job, but how much do I charge?This part can be tricky. There is no set formula really, but I have some tips for pricing that will hopefully give you a better idea on how to confidently ask your price and have them accept. Here are some personal guidelinesHow much time do you have to complete the project? If it's shorter than average, then charge more. You can even make a subtle note about this (or not so subtle if they still don't get it.) If it seems too short of a time (i.e. near impossible to complete), be sure to say that. It looks bad to promise a time that you can't keep--and it makes it less likely for them to return to you for work.Your Hourly rate: How long have you been working in that language? Do you have existing projects to back you up? Or previous contacts that can vouch for your work? Are there very few people with your particular skill set? All of these things will lend themselves to setting an hourly rate. I'd also try out a quick google search of what your line of work is, to see what the industry standard is at that point in time.I wouldn't price too low, because you want to make your time worth it. You also want them to feel like they're paying for quality work (assuming you can deliver it :) ). Finally, think about your client. If it's a small business, then don't price it too high if you want the job. If it's an enterprise (like a Fortune company), then don't be afraid to price higher. They have the budget for it.Fixed price: If they want a fixed price project, then you need to think about how many hours it will take you to complete it and multiply it by the hourly rate you set for yourself. Then, honestly, I would add 10-20% on top of that. Why? Because nothing ever works exactly how you want it to. There are lots of times that something "trivial" is way harder than it should be, or something that "should work" doesn't for hours and it eats away at your hourly rate. I can't count the number of times I encountered a logical bug that took away an entire's day work because debuggers don't help in those cases. By adding that padding in, it's still OK to have those days where you don't get as much done as you want. And another useful tip: Depending on your client, and the scope, you most likely want to set that you both sign off on a specification sheet before doing any work, and that any changes will result in a re-evaulation of the price. This is to help protect you from being handed a huge new addition to the project half-way in, without any extra payment.Scope of project: Finally, is it a huge project? Is it really small/fast? This affects how much your client will be willing to pay. If it sounds big, they will be willing to pay more for it. If it seems really small, then you won't be able to get away with a large asking price (as easily).Ok, I priced it, now what?So now that you have the price, you want to make sure it feels justified to your client. I never set a price before I can really think about everything. For example, if you're still in your introduction phase, and they want a price, don't give one! Just comment that you will send them a proposal sheet with all the features outlined, and a price for everything. You don't want to shout out a low number and then deliver something that is way higher. You also don't want to shock them with a big number before they feel like they are getting a great product.Make up a proposal document in a word editor. Personally, I leave the price till the very end. Why? Because by the time they reach the end, you've already discussed all the great features you plan to implement, and how it's the best product they'll ever use, etc etc...so your price comes off as a steal! If you hit them up front with a price, they will read through the document with a negative bias. Think about those commercials on TV. They always go on about their product, then at the end, ask "What would you pay for something like this? $100? $50? How about $20!!". This is not by accident.Scenario: I finished the job way earlier than expectedYou have two options then. You can either polish the hell out of the application, and even throw in a few bonus features (assuming they are in-line with the customer's needs) or you can sit and wait on it until you near your deadline. Why don't you want to turn it in too early? Because you should treat that extra time as a surplus. If you said it is going to take you 3 weeks, and it took you only 1, you have a surplus of 2 weeks. I personally don't want to let them know that I can do a 3 week project in 1 week. Why not? Because that may not always be the case! I may later have a 3 week project that takes all 3 weeks, but if I set a precedent of delivering super early, then the pressure is on for that longer project. It also makes it harder to quote longer times if you keep delivering too early.Feel free to deliver early, but again, don't do it too early. They may also wonder why they paid you for 3 weeks of work if you're done in 1. They may further wonder if the product sucks, or what is wrong with it, if it's done so early, etc.I would just polish the application. Everyone loves polish in their applications. The smallest details are what make an application go from "functional" to "fantastic". And since you are still delivering on time, then they are still going to be very happy with you.Scenario: It's taking way too long to finish this, and the deadline is nearing/here!So this is not a fun scenario to be in, but it'll happen. Sometimes the scope of the project gets out of hand. The best policy here is OPENNESS/HONESTY. Tell them that the project is taking longer than expected, and give a reasonable time for when you think you'll have it done. I typically explain it in a way that makes it sound like it isn't something that I did wrong, but it's just something about the nature of the project. This really goes for any scenario, to be honest. Just continue to stay open and communicative about your progress. This doesn't mean that you should email them every five minutes (unless they want you to), but it does mean that maybe every few days or once a week, give them an update on where you're at, and what's next. They'll be happy to know they are paying for progress, and it'll make it easier to ask for an extension when something goes wrong, because they know that you've been working on it all along.Final tips and thoughts:In general, contract work is really fun and rewarding. It's nice to learn new things all the time, as mandated by the project ,and to challenge yourself to do things you may not have done before. The key is to build a great relationship with your clients for future work, and for recommendations. I am always very honest with them and I never promise something I can't deliver. Again, under promise, over deliver!I hope this has proved helpful!Cheers,samerpaul

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• Are XML Comments Necessary Documentation?

  - by Bob Horn

  I used to be a fan of requiring XML comments for documentation. I've since changed my mind for two main reasons: Like good code, methods should be self-explanatory. In practice, most XML comments are useless noise that provide no additional value. Many times we simply use GhostDoc to generate generic comments, and this is what I mean by useless noise: /// <summary> /// Gets or sets the unit of measure. /// </summary> /// <value> /// The unit of measure. /// </value> public string UnitOfMeasure { get; set; } To me, that's obvious. Having said that, if there were special instructions to include, then we should absolutely use XML comments. I like this excerpt from this article: Sometimes, you will need to write comments. But, it should be the exception not the rule. Comments should only be used when they are expressing something that cannot be expressed in code. If you want to write elegant code, strive to eliminate comments and instead write self-documenting code. Am I wrong to think we should only be using XML comments when the code isn't enough to explain itself on its own? I believe this is a good example where XML comments make pretty code look ugly. It takes a class like this... public class RawMaterialLabel : EntityBase { public long Id { get; set; } public string ManufacturerId { get; set; } public string PartNumber { get; set; } public string Quantity { get; set; } public string UnitOfMeasure { get; set; } public string LotNumber { get; set; } public string SublotNumber { get; set; } public int LabelSerialNumber { get; set; } public string PurchaseOrderNumber { get; set; } public string PurchaseOrderLineNumber { get; set; } public DateTime ManufacturingDate { get; set; } public string LastModifiedUser { get; set; } public DateTime LastModifiedTime { get; set; } public Binary VersionNumber { get; set; } public ICollection<LotEquipmentScan> LotEquipmentScans { get; private set; } } ... And turns it into this: /// <summary> /// Container for properties of a raw material label /// </summary> public class RawMaterialLabel : EntityBase { /// <summary> /// Gets or sets the id. /// </summary> /// <value> /// The id. /// </value> public long Id { get; set; } /// <summary> /// Gets or sets the manufacturer id. /// </summary> /// <value> /// The manufacturer id. /// </value> public string ManufacturerId { get; set; } /// <summary> /// Gets or sets the part number. /// </summary> /// <value> /// The part number. /// </value> public string PartNumber { get; set; } /// <summary> /// Gets or sets the quantity. /// </summary> /// <value> /// The quantity. /// </value> public string Quantity { get; set; } /// <summary> /// Gets or sets the unit of measure. /// </summary> /// <value> /// The unit of measure. /// </value> public string UnitOfMeasure { get; set; } /// <summary> /// Gets or sets the lot number. /// </summary> /// <value> /// The lot number. /// </value> public string LotNumber { get; set; } /// <summary> /// Gets or sets the sublot number. /// </summary> /// <value> /// The sublot number. /// </value> public string SublotNumber { get; set; } /// <summary> /// Gets or sets the label serial number. /// </summary> /// <value> /// The label serial number. /// </value> public int LabelSerialNumber { get; set; } /// <summary> /// Gets or sets the purchase order number. /// </summary> /// <value> /// The purchase order number. /// </value> public string PurchaseOrderNumber { get; set; } /// <summary> /// Gets or sets the purchase order line number. /// </summary> /// <value> /// The purchase order line number. /// </value> public string PurchaseOrderLineNumber { get; set; } /// <summary> /// Gets or sets the manufacturing date. /// </summary> /// <value> /// The manufacturing date. /// </value> public DateTime ManufacturingDate { get; set; } /// <summary> /// Gets or sets the last modified user. /// </summary> /// <value> /// The last modified user. /// </value> public string LastModifiedUser { get; set; } /// <summary> /// Gets or sets the last modified time. /// </summary> /// <value> /// The last modified time. /// </value> public DateTime LastModifiedTime { get; set; } /// <summary> /// Gets or sets the version number. /// </summary> /// <value> /// The version number. /// </value> public Binary VersionNumber { get; set; } /// <summary> /// Gets the lot equipment scans. /// </summary> /// <value> /// The lot equipment scans. /// </value> public ICollection<LotEquipmentScan> LotEquipmentScans { get; private set; } }

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• ASP.Net MVC Interview Questions and Answers

  - by Samir R. Bhogayta

  About ASP.Net MVC The ASP.Net MVC is the framework provided by Microsoft that lets you develop the applications that follows the principles of Model-View-Controller (MVC) design pattern. The .Net programmers new to MVC thinks that it is similar to WebForms Model (Normal ASP.Net), but it is far different from the WebForms programming.  This article will tell you how to quick learn the basics of MVC along with some frequently asked interview questions and answers on ASP.Net MVC 1. What is ASP.Net MVC The ASP.Net MVC is the framework provided by Microsoft to achieve     separation of concerns that leads to easy maintainability of the     application. Model is supposed to handle data related activity View deals with user interface related work Controller is meant for managing the application flow by communicating between Model and View. Normal 0 false false false EN-US X-NONE X-NONE 2. Why to use ASP.Net MVC The strength of MVC (i.e. ASP.Net MVC) listed below will answer this question MVC reduces the dependency between the components; this makes your code more testable. MVC does not recommend use of server controls, hence the processing time required to generate HTML response is drastically reduced. The integration of java script libraries like jQuery, Microsoft MVC becomes easy as compared to Webforms approach. 3. What do you mean by Razor The Razor is the new View engine introduced in MVC 3.0. The View engine is responsible for processing the view files [e.g. .aspx, .cshtml] in order to generate HTML response. The previous versions of MVC were dependent on ASPX view engine.  4. Can we use ASPX view engine in latest versions of MVC Yes. The Recommended way is to prefer Razor View 5. What are the benefits of Razor View?      The syntax for server side code is simplified      The length of code is drastically reduced      Razor syntax is easy to learn and reduces the complexity Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} 6. What is the extension of Razor View file? .cshtml (for c#) and .vbhtml (for vb) 7. How to create a Controller in MVC Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Create a simple class and extend it from Controller class. The bare minimum requirement for a class to become a controller is to inherit it from ControllerBase is the class that is required to inherit to create the controller but Controller class inherits from ControllerBase. 8. How to create an Action method in MVC Add a simple method inside a controller class with ActionResult return type. 9. How to access a view on the server    The browser generates the request in which the information like Controller name, Action Name and Parameters are provided, when server receives this URL it resolves the Name of Controller and Action, after that it calls the specified action with provided parameters. Action normally does some processing and returns the ViewResult by specifying the view name (blank name searches according to naming conventions).   10. What is the default Form method (i.e. GET, POST) for an action method GET. To change this you can add an action level attribute e.g [HttpPost] Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} 11. What is a Filter in MVC? When user (browser) sends a request to server an action method of a controller gets invoked; sometimes you may require executing a custom code before or after action method gets invoked, this custom code is called as Filter. 12. What are the different types of Filters in MVC? a. Authorization filter b. Action filter c. Result filter d. Exception filter [Do not forget the order mentioned above as filters gets executed as per above mentioned sequence] 13. Explain the use of Filter with an example? Suppose you are working on a MVC application where URL is sent in an encrypted format instead of a plain text, once encrypted URL is received by server it will ignore action parameters because of URL encryption. To solve this issue you can create global action filter by overriding OnActionExecuting method of controller class, in this you can extract the action parameters from the encrypted URL and these parameters can be set on filterContext to send plain text parameters to the actions.     14. What is a HTML helper? A HTML helper is a method that returns string; return string usually is the HTML tag. The standard HTML helpers (e.g. Html.BeginForm(),Html.TextBox()) available in MVC are lightweight as it does not rely on event model or view state as that of in ASP.Net server controls.

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• Introducing Oracle Multitenant

  - by OracleMultitenant

  0 0 1 1142 6510 Oracle Corporation 54 15 7637 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-language:JA;} The First Database Designed for the Cloud Today Oracle announced the general availability (GA) of Oracle Database 12c, the first database designed for the Cloud. Oracle Multitenant, new with Oracle Database 12c, is a key component of this – a new architecture for consolidating databases and simplifying operations in the Cloud. With this, the inaugural post in the Multitenant blog, my goal is to start the conversation about Oracle Multitenant. We are very proud of this new architecture, which we view as a major advance for Oracle. Customers, partners and analysts who have had previews are very excited about its capabilities and its flexibility. This high level review of Oracle Multitenant will touch on our design considerations and how we re-architected our database for the cloud. I’ll briefly describe our new multitenant architecture and explain it’s key benefits. Finally I’ll mention some of the major use cases we see for Oracle Multitenant. Industry Trends We always start by talking to our customers about the pressures and challenges they’re facing and what trends they’re seeing in the industry. Some things don’t change. They face the same pressures and the same requirements as ever: Pressure to do more with less; be faster, leaner, cheaper, and deliver services 24/7. Big companies have achieved scale. Now they want to realize economies of scale. As ever, DBAs are faced with the challenges of patching and upgrading large numbers of databases, and provisioning new ones.  Requirements are familiar: Performance, scalability, reliability and high availability are non-negotiable. They need ever more security in this threatening climate. There’s no time to stop and retool with new applications. What’s new are the trends. These are the techniques to use to respond to these pressures within the constraints of the requirements. With the advent of cloud computing and availability of massively powerful servers – even engineered systems such as Exadata – our customers want to consolidate many applications into fewer larger servers. There’s a move to standardized services – even self-service. Consolidation Consolidation is not new; companies have tried various different approaches to consolidation of databases in the cloud. One approach is to partition a powerful server between several virtual machines, one per application. A downside of this is that you have the resource and management overheads of OS and RDBMS per VM – that is, per application. Another is that you have replaced physical sprawl with virtual sprawl and virtual sprawl is still expensive to manage. In the dedicated database model, we have a single physical server supporting multiple databases, one per application. So there’s a shared OS overhead, but RDBMS process and memory overhead are replicated per application. Let's think about our traditional Oracle Database architecture. Every time we create a database, be it a production database, a development or a test database, what do we do? We create a set of files, we allocate a bunch of memory for managing the data, and we kick off a series of background processes. This is replicated for every one of the databases that we create. As more and more databases are fired up, these replicated overheads quickly consume the available server resources and this limits the number of applications we can run on any given server. In Oracle Database 11g and earlier the highest degree of consolidation could be achieved by what we call schema consolidation. In this model we have one big server with one big database. Individual applications are installed in separate schemas or table-owners. Database overheads are shared between all applications, which affords maximum consolidation. The shortcomings are that application changes are often required. There is no tenant isolation. One bad apple can spoil the whole batch. New Architecture & Benefits In Oracle Database 12c, we have a new multitenant architecture, featuring pluggable databases. This delivers all the resource utilization advantages of schema consolidation with none of the downsides. There are two parts to the term “pluggable database”: "pluggable", which is new, and "database", which is familiar.  Before we get to the exciting new stuff let’s discuss what hasn’t changed. A pluggable database is a fully functional Oracle database. It’s not watered down in any way. From the perspective of an application or an end user it hasn’t changed at all. This is very important because it means that no application changes are required to adopt this new architecture. There are many thousands of applications built on Oracle databases and they are all ready to run on Oracle Multitenant. So we have these self-contained pluggable databases (PDBs), and as their name suggests, they are plugged into a multitenant container database (CDB). The CDB behaves as a single database from the operations point of view. Very much as we had with the schema consolidation model, we only have a single set of Oracle background processes and a single, shared database memory requirement. This gives us very high consolidation density, which affords maximum reduction in capital expenses (CapEx). By performing management operations at the CDB level – “managing many as one” – we can achieve great reductions in operating expenses (OpEx) as well, but we retain granular control where appropriate. Furthermore, the “pluggability” capability gives us portability and this adds a tremendous amount of agility. We can simply unplug a PDB from one CDB and plug it into another CDB, for example to move it from one SLA tier to another. I'll explore all these new capabilities in much more detail in a future posting.  Use Cases We can identify a number of use cases for Oracle Multitenant. Here are a few of the major ones. 0 0 1 113 650 Oracle Corporation 5 1 762 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-language:JA;} Development / Testing where individual engineers need rapid provisioning and recycling of private copies of a few "master test databases" Consolidation of disparate applications using fewer, more powerful servers Software as a Service deploying separate copies of identical applications to individual tenants Database as a Service typically self-service provisioning of databases on the private cloud Application Distribution from ISV / Installation by Customer Eliminating many typical installation steps (create schema, import seed data, import application code PL/SQL…) - just plug in a PDB! High volume data distribution literally via disk drives in envelopes distributed by truck! - distribution of things like GIS or MDM master databases …various others! Benefits Previous approaches to consolidation have involved a trade-off between reductions in Capital Expenses (CapEx) and Operating Expenses (OpEx), and they’ve usually come at the expense of agility. With Oracle Multitenant you can have your cake and eat it: Minimize CapEx More Applications per server Minimize OpEx Manage many as one Standardized procedures and services Rapid provisioning Maximize Agility Cloning for development and testing Portability through pluggability Scalability with RAC Ease of Adoption Applications run unchanged It’s a pure deployment choice. Neither the database backend nor the application needs to be changed. In future postings I’ll explore various aspects in more detail. However, if you feel compelled to devour everything you can about Oracle Multitenant this very minute, have no fear. Visit the Multitenant page on OTN and explore the various resources we have available there. Among these, Oracle Distinguished Product Manager Bryn Llewellyn has written an excellent, thorough, and exhaustively detailed White Paper about Oracle Multitenant, which is available here.  Follow me  I tweet @OraclePDB #OracleMultitenant

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• CodePlex Daily Summary for Sunday, November 03, 2013

  CodePlex Daily Summary for Sunday, November 03, 2013Popular ReleasesuComponents: uComponents v6.0.0: This release of uComponents will compile against and support the new API in Umbraco v6.1.0. What's new in uComponents v6.0.0? New DataTypesImage Point XML DropDownList XPath Templatable List New features / Resolved issuesThe following workitems have been implemented and/or resolved: 14781 14805 14808 14818 14854 14827 14868 14859 14790 14853 14790 DataType Grid 14788 14810 14873 14833 14864 14855 / 14860 14816 14823 Drag & Drop support for rows Su...SmartStore.NET - Free ASP.NET MVC Ecommerce Shopping Cart Solution: SmartStore.NET 1.2.1: New FeaturesAdded option Limit to current basket subtotal to HadSpentAmount discount rule Items in product lists can be labelled as NEW for a configurable period of time Product templates can optionally display a discount sign when discounts were applied Added the ability to set multiple favicons depending on stores and/or themes Plugin management: multiple plugins can now be (un)installed in one go Added a field for the HTML body id to store entity (Developer) New property 'Extra...WPF Extended DataGrid: WPF Extended DataGrid 2.0.0.9 binaries: Fixed issue with ICollectionView containg null values (AutoFilter issue)Community TFS Build Extensions: October 2013: The October 2013 release contains Scripts - a new addition to our delivery. These are a growing library of PowerShell scripts to use with VS2013. See our documentation for more on scripting. VS2010 Activities(target .NET 4.0) VS2012 Activities (target .NET 4.5) VS2013 Activities (target .NET 4.5.1) Community TFS Build Manager VS2012 Community TFS Build Manager VS2013 The Community TFS Build Managers for VS2010, 2012 and 2013 can also be found in the Visual Studio Gallery where upda...WMI Inventory Client: WMI Inventory Client: WMI Inventory Client ?????????????? ?????????????? ?? WMISuperSocket, an extensible socket server framework: SuperSocket 1.6 stable: Changes included in this release: Process level isolation SuperSocket ServerManager (include server and client) Connect to client from server side initiatively Client certificate validation New configuration attributes "textEncoding", "defaultCulture", and "storeLocation" (certificate node) Many bug fixes http://docs.supersocket.net/v1-6/en-US/New-Features-and-Breaking-ChangesFile System Explorer: Beta 1: Try me and please give feedback via Discussions and issues Installation: Download the zip file Unblock it Unzip to a suitable location Just run Filesystemexplorer.exe Enjoy Updates: V1.1 Beta: Fixed some low level file search issuesBarbaTunnel: BarbaTunnel 8.1: Check Version History for more information about this release.Mugen MVVM Toolkit: Mugen MVVM Toolkit 2.1: v 2.1 Added the 'Should' class instead of the 'Validate' class. The 'Validate' class is now obsolete. Added 'Toolkit.Annotations' to support the Mugen MVVM Toolkit ReSharper plugin. Updated JetBrains annotations within the project. Added the 'GlobalSettings.DefaultActivationPolicy' property to represent the default activation policy. Removed the 'GetSettings' method from the 'ViewModelBase' class. Instead of it, the 'GlobalSettings.DefaultViewModelSettings' property is used. Updated...SharePoint User Permission Check: SP User Permission Check: Modified Current.Web.Title in output label.TFS Event Workflows: TFS Event Workflows 0.10.41576.0 - TFS 2012-2013: Supports TFS 2012 and TFS 2013 For a TFS 2010 version look at https://tfseventworkflows.codeplex.com/releases/view/102444 New Features multiple application tiers storage of workflows, configurations and activities in the version control support for async execution in TFS job agent selection of collection/project filters in config file simple disable in config file simplified configurationCrowd CMS: Crowd CMS FREE - Official Release: This is the original source files for Crowd CMS Free (v1.0.0) and is the latest stable release which has been bug-tested and fixed.Sea Dragon AJAX Viewer Web Part: Sea Dragon Ajax Web Part: The Seadragon Viewer WSP and companion literature. There are three seperate guides that explain how to get up and running: - Seadragon Viewer Web Part Installation Guide Creating Deep Zoom Images for Seadragon Viewer Bringing it all together These guides are currently very basic and are offered as guides for getting full usage out Seadragon. Please post any suggestions for further documentation in the discussions forumProject Nonnon: 2013_10_30: ----------==========----------==========----------==========---------- "No news is good news." ----------==========----------==========----------==========---------- Change Log 2013/10/30 BUGFIX win32/explorer.c n_explorer_path_get() : comment OLD : typo NEW : fixed Felis Win8 or latert : Link Maker OLD : not function in some cases NEW : fixed Nyaurism Formatter : byte count label : when resized OLD : text will be broken NEW : fixed NEW_FEATURE win...NAudio: NAudio 1.7: full release notes available at http://mark-dot-net.blogspot.co.uk/2013/10/naudio-17-release-notes.htmlFormula Calculation Toolkit: FCT Library: Alfa release for Formula Calculation Toolkit.WebExtras: v1.3.0 Beta: Enh: Adding support for Bootstrap 3.x Enh: Adding support for Gumby 2.5.x Enh: Adding a new string extension Remove() to remove occurences of given string Enh: Adding a ToDictionary() for name value collections Enh: The dataTable sort extension is now a little more intelligent and robust Enh: General under the hood code enhancements Fix: Hyperlink extensions now handle MVC Areas Fix: Marking JsFunc as serializable otherwise when using the ASP.NET State Server, the object does no...DirectX Tool Kit: October 2013: October 28, 2013 Updated for Visual Studio 2013 and Windows 8.1 SDK RTM Added DGSLEffect, DGSLEffectFactory, VertexPositionNormalTangentColorTexture, and VertexPositionNormalTangentColorTextureSkinning Model loading and effect factories support loading skinned models MakeSpriteFont now has a smooth vs. sharp antialiasing option: /sharp Model loading from CMOs now handles UV transforms for texture coordinates A number of small fixes for EffectFactory Minor code and project cleanup ...ExtJS based ASP.NET Controls: FineUI v4.0beta1: +2013-10-28 v4.0 beta1 +?????Collapsed???????????????。 -????：window/group_panel.aspx??，???????，???????，?????????。 +??????SelectedNodeIDArray???????????????。 -????：tree/checkbox/tree_checkall.aspx??，?????，?????，????????????。 -??TimerPicker???????（????、????ing）。 -??????????????????????（???）。 -?????????????，??type=text/css（??~`）。 -MsgTarget???MessageTarget，???None。 -FormOffsetRight?????20px??5px。 -?Web.config?PageManager??FormLabelAlign???。 -ToolbarPosition??Left/Right。 -??Web.conf...CODE Framework: 4.0.31028.0: See change notes in the documentation section for details on what's new. Note: If you download the class reference help file with, you have to right-click the file, pick "Properties", and then unblock the file, as many browsers flag the file as blocked during download (for security reasons) and thus hides all content.New Projects.NET Site Storage: Write .NET code to use an abstract storage system that can work with a variety of storage, such as local file system and Azure blob.Asp.net Mvc Ajax Infinite Scroll: Asp.net Mvc 4 Ajax Json Infinite Scrollblueblue: tetCar: CArCSharp Generic Data Access: Yet another generic data access for .NETDotNet Manuals: DotNet Manuals aims to provide developers an easy way to create, manage and distribute manuals and various documentation for their applications and libraries.EIB Watcher .Net Library: .Net Library for EIB/NKX bus accessopenGamification: This intends to become an open source gamification framework based on TypeScript.PaginaWebCursoNetAcc: aSimple Person Manager: The application accepts POST requests with JSON data about a Person, stored the values in Azure Table Storage and accepts GET requests to retrieve it back.Stock Track: If you have a small retail store with simple stock management and tracking requirements, this program might work for you. Stock Track easily categorises your ptrapawebapp: testVisualStateManager: This is a simple, but quite powerful mechanism allowing you to separate the application UI from application logic in Windows Forms.Yet Another VirtualBox ToolSet: This is going to be another VirtualBox Toolset.Zodinet: Co ca ngua

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