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  • Used HDD/ran DiskSmartView/40,000 Power-on-hours?? should i trust it w/ my data, or take it back and bitch?

    - by David Lindsay
    I just bought a used hard drive from a University Surplus Store. Decided to run DiskSmartView to make sure it wasn't ready to fail. 40,000 power-on-hours I don't know if I feel like trusting my data to something that used. I really dont know if thats unreasonably old, but when i compare it to the POH reading i get when testing my other hdds its more than 3x older (my others have 2110 hours, 6150 hours, etc.. It's a Western Digital, so that gives me a little bit of hope(WDC WD4000KD-00NAB0). I could sure use someone else's opinion here. Thanks, DAVE

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  • How to assign more then one open action to one file system

    - by Martin
    All operating system I use apart form Windows have a “Open with…” options for there Explorer, Finder, whatever. This is very useful as often more then one program can handle a given file extension. With the exception on zip file I generally have not seen such a function on Window. However since there is an exceptions it is possible. The questions I have is: How can a “Open with…” can be archived with windows? Is there perhaps a tool which can do it?

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  • Windows Azure Recipe: Big Data

    - by Clint Edmonson
    As the name implies, what we’re talking about here is the explosion of electronic data that comes from huge volumes of transactions, devices, and sensors being captured by businesses today. This data often comes in unstructured formats and/or too fast for us to effectively process in real time. Collectively, we call these the 4 big data V’s: Volume, Velocity, Variety, and Variability. These qualities make this type of data best managed by NoSQL systems like Hadoop, rather than by conventional Relational Database Management System (RDBMS). We know that there are patterns hidden inside this data that might provide competitive insight into market trends.  The key is knowing when and how to leverage these “No SQL” tools combined with traditional business such as SQL-based relational databases and warehouses and other business intelligence tools. Drivers Petabyte scale data collection and storage Business intelligence and insight Solution The sketch below shows one of many big data solutions using Hadoop’s unique highly scalable storage and parallel processing capabilities combined with Microsoft Office’s Business Intelligence Components to access the data in the cluster. Ingredients Hadoop – this big data industry heavyweight provides both large scale data storage infrastructure and a highly parallelized map-reduce processing engine to crunch through the data efficiently. Here are the key pieces of the environment: Pig - a platform for analyzing large data sets that consists of a high-level language for expressing data analysis programs, coupled with infrastructure for evaluating these programs. Mahout - a machine learning library with algorithms for clustering, classification and batch based collaborative filtering that are implemented on top of Apache Hadoop using the map/reduce paradigm. Hive - data warehouse software built on top of Apache Hadoop that facilitates querying and managing large datasets residing in distributed storage. Directly accessible to Microsoft Office and other consumers via add-ins and the Hive ODBC data driver. Pegasus - a Peta-scale graph mining system that runs in parallel, distributed manner on top of Hadoop and that provides algorithms for important graph mining tasks such as Degree, PageRank, Random Walk with Restart (RWR), Radius, and Connected Components. Sqoop - a tool designed for efficiently transferring bulk data between Apache Hadoop and structured data stores such as relational databases. Flume - a distributed, reliable, and available service for efficiently collecting, aggregating, and moving large log data amounts to HDFS. Database – directly accessible to Hadoop via the Sqoop based Microsoft SQL Server Connector for Apache Hadoop, data can be efficiently transferred to traditional relational data stores for replication, reporting, or other needs. Reporting – provides easily consumable reporting when combined with a database being fed from the Hadoop environment. Training These links point to online Windows Azure training labs where you can learn more about the individual ingredients described above. Hadoop Learning Resources (20+ tutorials and labs) Huge collection of resources for learning about all aspects of Apache Hadoop-based development on Windows Azure and the Hadoop and Windows Azure Ecosystems SQL Azure (7 labs) Microsoft SQL Azure delivers on the Microsoft Data Platform vision of extending the SQL Server capabilities to the cloud as web-based services, enabling you to store structured, semi-structured, and unstructured data. See my Windows Azure Resource Guide for more guidance on how to get started, including links web portals, training kits, samples, and blogs related to Windows Azure.

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  • How to best migrate one Windows 2008 R2 / SharePoint / Exchange / Terminal Services (All-in-one) int

    - by MadBoy
    Hello, My client has one machine with Windows 2008 R2 and everything on it. By everything I mean AD, DNS, SharePoint 2010 Standard, Exchange 2010 Standard, Terminal Services, Office 2010 and a bunch of additional apps. Everything stands on I7 x 2 and 36gb ram for 7 people total. I've decided that we should virtualize it and split things into 4 VM's and keep host only with Hyper-V installed to host all the machines. What problems should I expect? What good advices can you give. My plan is that when i move everything to VM's i will move vm's to safe place and format the host as it has a lot of really bad things happening on it. But this also means that everything will be wiped from current solution so I have to be sure that Exchange etc will work when host gets wiped. MadBoy

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  • Redirect one input from one terminal to another

    - by Niki Yoshiuchi
    I have sshed into a linux box and I'm using dvtm and bash (although I have also tried this with Gnu screen and bash). I have two terminals, current /dev/pts/29 and /dev/pts/130. I want to redirect the input from one to the other. From what I understand, in /dev/pts/130 I can type: cat </dev/pts/29 And then when I type in /dev/pts/29 the characters I type should show up in /dev/pts/130. However what ends up happening is that every other character I type gets redirected. For example, if I type "hello" I get this: /dev/pts/29 | /dev/pts/130 $ | $ cat </dev/pts/29 $ el | hlo This is really frustrating as I need to do this in order to redirect the io of a process running in gdb (I've tried both run /dev/pts/# and set inferior-tty /dev/pts/# and both resulted in the aforementioned behavior). Am I doing something wrong, or is this a bug in bash/screen/dvtm?

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  • Master Data Management

    - by Logicalj
    I am looking for a very flexible, easy to integrate and dynamic application with as many features as possible for Master Data Management. As Master Data Management is used to Manage Operational Data, Analytical Data and Master Data so, I want guidance about "What is exactly expected from Master Data Management and What are the Basic and Challenging Scenarios to be covered or resolved in Master Data Management". Please guide me with all the possible aspects of Master Data Management like Data Cleansing, Data Management and Start Data Analyzing, etc.

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  • What is the architectural name for the set of data that enables UI choices?

    - by Richard Collette
    I have separate service methods that fetch business object data and the data for UI selection input such as radio buttons, check-boxes, combo-boxes, etc. I want to name my service methods that fetch the selection data appropriately. I am assuming that Model and ViewModel would not be part of the name because the selection data is but a portion of the Model or ViewModel. What might this set of data be named such that I can name my service method?

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  • One to many too much data returned - MySQL

    - by Evan McPeters
    I have 2 related MySQL tables in a one to many relationship. Customers: cust_id, cust_name, cust_notes Orders: order_id, cust_id, order_comments So, if I do a standard join to get all customers and their orders via PHP, I return something like: Jack Black, jack's notes, comments about jack's 1st order Jack Black, jack's notes, comments about jack's 2nd order Simon Smith, simon's notes, comments about simon's 1st order Simon Smith, simon's notes, comments about simon's 2nd order The problem is that *cust_notes* is a text field and can be quite large (a couple of thousand words). So, it seems like returning that field for every order is inneficient. I could use *GROUP_CONCAT* and JOINS to return all *order_comments* on a single row BUT order_comments is a large text field too, so it seems like that could create a problem. Should I just use two separate queries, one for the customers table and one for the orders table? Is there a better way?

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  • hibernate foreign key mapping many-to-one

    - by Lily
    I have been working on it for quite a while, but still can't figure out what's wrong with my code. Each Service has multiple profiles, but each profile only has one Service. Service { Long service_id; // primary key ... getter/setter } Profile { Long profile_id; // primary key Long service_id; // foreign key ... getter and setter } in Profile.hbm.xml. I add < many-to-one name="service_id" class="com.mot.diva.dto.Service" column="SERVICE_ID" cascade="save-update"> < /many-to-one> Is it the correct way to map it?

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  • Laravel 4 showing all field from one to one relationship in

    - by rivai04
    I'm trying to show all field of the chosen row from one to one relationship... Route Route::get('relasi-pasien', function() { $pasien = PasienIri::where('no_ipd', '=', '100')->first(); foreach($pasien->keadaanumum as $temp) { echo'<li> Name : '.$temp->name. 'Tekdar: '.$temp->tekdar. 'Nadi : '.$temp->nadi. '</li>'; } }); Relation at PasienIri's model public function keadaanumum() { return $this->hasOne('KeadaanUmum', 'no_ipd'); } Relation at KeadaanUmum's Model public function pasieniri() { return $this->belongsTo('PasienIri', 'no_ipd'); } When I used that way, it showed error: 'Trying to get property of non-object' But if I just trying to show only one of the field, it works, showing one field: Route::get('relasi-pasien', function() { $pasien = PasienIri::where('no_ipd', '=', '100')->first(); return $pasien->keadaanumum->name; }); anyone could help me to show all field with one to one relationship or I really have to change it to one to many relationship? cause if I change it to one to many relationship, it works

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  • nHibernate one-to-many inserts but doesnt update

    - by user210713
    Instead of getting into code, I have a simple question. Default behavior for a simple one-to-many is that it inserts the child record then updates the foreign key column with the parent key. Has anyone ever had a one-to-many where the child object gets inserted but not updated resulting in a row in my table with a null in the foreign key column? I want the default behaviour for a standard one-to-many. I don't want to have to add the parent as a property to the child. Thanks.

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  • PHP or C# script to parse CSV table values to fill in one-to-many table

    - by Yaaqov
    I'm looking for an example of how to split-out comma-delimited data in a field of one table, and fill in a second table with those individual elements, in order to make a one-to-many relational database schema. This is probably really simple, but let me give an example: I'll start with everything in one table, Widgets, which has a "state" field to contain states that have that widget: Table: WIDGET =============================== | id | unit | states | =============================== |1 | abc | AL,AK,CA | ------------------------------- |2 | lmn | VA,NC,SC,GA,FL | ------------------------------- |3 | xyz | KY | =============================== Now, what I'd like to create via code is a second table to be joined to WIDGET called *Widget_ST* that has widget id, widget state id, and widget state name fields, for example Table: WIDGET_ST ============================== | w_id | w_st_id | w_st_name | ------------------------------ |1 | 1 | AL | |1 | 2 | AK | |1 | 3 | CA | |2 | 1 | VA | |2 | 2 | NC | |2 | 1 | SC | |2 | 2 | GA | |2 | 1 | FL | |3 | 1 | KY | ============================== I am learning C# and PHP, so responses in either language would be great. Thanks.

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  • Slow performance of MySQL database on one server and fast on another one, with similar configurations

    - by Alon_A
    We have a web application that run on two servers of GoDaddy. We experince slow preformance on our production server, although it has stronger hardware then the testing one, and it is dedicated. I'll start with the configurations. Testing: CentOS Linux 5.8, Linux 2.6.18-028stab101.1 on i686 Intel(R) Xeon(R) CPU L5609 @ 1.87GHz, 8 cores 60 GB total, 6.03 GB used Apache/2.2.3 (CentOS) MySQL 5.5.21-log PHP Version 5.3.15 Production: CentOS Linux 6.2, Linux 2.6.18-028stab101.1 on x86_64 Intel(R) Xeon(R) CPU L5410 @ 2.33GHz, 8 cores 120 GB total, 2.12 GB used Apache/2.2.15 (CentOS) MySQL 5.5.27-log - MySQL Community Server (GPL) by Remi PHP Version 5.3.15 We are running the same code on both servers. The Problem We have some function that executes ~30000 PDO-exec commands. On our testing server it takes about 1.5-2 minutes to complete and our production server it can take more then 15 minutes to complete. As you can see here, from qcachegrind: Researching the problem, we've checked the live graphs on phpMyAdmin and discovered that the MySQL server on our testing server was preforming at steady level of 1000 execution statements per 2 seconds, while the slow production MySQL server was only 250 executions statements per 2 seconds and not steady at all, jumping from 0 to 250 every seconds. You can clearly see it in the graphs: Testing server: Production server: You can see here the comparison between both of the configuration of the MySQL servers.Left is the fast testing and right is the slow production. The differences are highlighted, but I cant find anything that can cause such a behavior difference, as the configs are mostly the same. Maybe you can see something that I cant see. Note that our tables are all InnoDB, so the MyISAM difference is (probably) not relevant. Maybe it is the MySQL Community Server (GPL) that is installed on the production server that can cause the slow performance? Or maybe it needs to be configured differently for 64bit ? I'm currently out of ideas...

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  • www-data can upload a file but cant move it after the upload action

    - by user70058
    I am currently running Apache and PHP on Ubuntu. I have a page where a user is supposed to upload a profile image. The action on the backend is supposed to work like this: Upload file to user directory -- WORKS! Refer to the uploaded file and create a thumbnail in directory thumbs -- DOES NOT WORK www-data has write access to directory thumbs. My guess is that www-data for some reason does not have proper access to the file that was uploaded. UPLOADED FILE PERMISSIONS -rw-r--r-- 1 www-data www-data 47057 Feb 8 23:24 0181c6e0973eb19cb0d98521a6fe1d9e71cd6daa.jpg THUMBS DIRECTORY PERMISSIONS drwxr-sr-x 2 www-data www-data 4096 Feb 8 23:23 thumbs Im at lost here. I'm new to Ubuntu as well. Any help would be greatly appreciated!

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  • Syncing Data with a Server using Silverlight and HTTP Polling Duplex

    - by dwahlin
    Many applications have the need to stay in-sync with data provided by a service. Although web applications typically rely on standard polling techniques to check if data has changed, Silverlight provides several interesting options for keeping an application in-sync that rely on server “push” technologies. A few years back I wrote several blog posts covering different “push” technologies available in Silverlight that rely on sockets or HTTP Polling Duplex. We recently had a project that looked like it could benefit from pushing data from a server to one or more clients so I thought I’d revisit the subject and provide some updates to the original code posted. If you’ve worked with AJAX before in Web applications then you know that until browsers fully support web sockets or other duplex (bi-directional communication) technologies that it’s difficult to keep applications in-sync with a server without relying on polling. The problem with polling is that you have to check for changes on the server on a timed-basis which can often be wasteful and take up unnecessary resources. With server “push” technologies, data can be pushed from the server to the client as it changes. Once the data is received, the client can update the user interface as appropriate. Using “push” technologies allows the client to listen for changes from the data but stay 100% focused on client activities as opposed to worrying about polling and asking the server if anything has changed. Silverlight provides several options for pushing data from a server to a client including sockets, TCP bindings and HTTP Polling Duplex.  Each has its own strengths and weaknesses as far as performance and setup work with HTTP Polling Duplex arguably being the easiest to setup and get going.  In this article I’ll demonstrate how HTTP Polling Duplex can be used in Silverlight 4 applications to push data and show how you can create a WCF server that provides an HTTP Polling Duplex binding that a Silverlight client can consume.   What is HTTP Polling Duplex? Technologies that allow data to be pushed from a server to a client rely on duplex functionality. Duplex (or bi-directional) communication allows data to be passed in both directions.  A client can call a service and the server can call the client. HTTP Polling Duplex (as its name implies) allows a server to communicate with a client without forcing the client to constantly poll the server. It has the benefit of being able to run on port 80 making setup a breeze compared to the other options which require specific ports to be used and cross-domain policy files to be exposed on port 943 (as with sockets and TCP bindings). Having said that, if you’re looking for the best speed possible then sockets and TCP bindings are the way to go. But, they’re not the only game in town when it comes to duplex communication. The first time I heard about HTTP Polling Duplex (initially available in Silverlight 2) I wasn’t exactly sure how it was any better than standard polling used in AJAX applications. I read the Silverlight SDK, looked at various resources and generally found the following definition unhelpful as far as understanding the actual benefits that HTTP Polling Duplex provided: "The Silverlight client periodically polls the service on the network layer, and checks for any new messages that the service wants to send on the callback channel. The service queues all messages sent on the client callback channel and delivers them to the client when the client polls the service." Although the previous definition explained the overall process, it sounded as if standard polling was used. Fortunately, Microsoft’s Scott Guthrie provided me with a more clear definition several years back that explains the benefits provided by HTTP Polling Duplex quite well (used with his permission): "The [HTTP Polling Duplex] duplex support does use polling in the background to implement notifications – although the way it does it is different than manual polling. It initiates a network request, and then the request is effectively “put to sleep” waiting for the server to respond (it doesn’t come back immediately). The server then keeps the connection open but not active until it has something to send back (or the connection times out after 90 seconds – at which point the duplex client will connect again and wait). This way you are avoiding hitting the server repeatedly – but still get an immediate response when there is data to send." After hearing Scott’s definition the light bulb went on and it all made sense. A client makes a request to a server to check for changes, but instead of the request returning immediately, it parks itself on the server and waits for data. It’s kind of like waiting to pick up a pizza at the store. Instead of calling the store over and over to check the status, you sit in the store and wait until the pizza (the request data) is ready. Once it’s ready you take it back home (to the client). This technique provides a lot of efficiency gains over standard polling techniques even though it does use some polling of its own as a request is initially made from a client to a server. So how do you implement HTTP Polling Duplex in your Silverlight applications? Let’s take a look at the process by starting with the server. Creating an HTTP Polling Duplex WCF Service Creating a WCF service that exposes an HTTP Polling Duplex binding is straightforward as far as coding goes. Add some one way operations into an interface, create a client callback interface and you’re ready to go. The most challenging part comes into play when configuring the service to properly support the necessary binding and that’s more of a cut and paste operation once you know the configuration code to use. To create an HTTP Polling Duplex service you’ll need to expose server-side and client-side interfaces and reference the System.ServiceModel.PollingDuplex assembly (located at C:\Program Files (x86)\Microsoft SDKs\Silverlight\v4.0\Libraries\Server on my machine) in the server project. For the demo application I upgraded a basketball simulation service to support the latest polling duplex assemblies. The service simulates a simple basketball game using a Game class and pushes information about the game such as score, fouls, shots and more to the client as the game changes over time. Before jumping too far into the game push service, it’s important to discuss two interfaces used by the service to communicate in a bi-directional manner. The first is called IGameStreamService and defines the methods/operations that the client can call on the server (see Listing 1). The second is IGameStreamClient which defines the callback methods that a server can use to communicate with a client (see Listing 2).   [ServiceContract(Namespace = "Silverlight", CallbackContract = typeof(IGameStreamClient))] public interface IGameStreamService { [OperationContract(IsOneWay = true)] void GetTeamData(); } Listing 1. The IGameStreamService interface defines server operations that can be called on the server.   [ServiceContract] public interface IGameStreamClient { [OperationContract(IsOneWay = true)] void ReceiveTeamData(List<Team> teamData); [OperationContract(IsOneWay = true, AsyncPattern=true)] IAsyncResult BeginReceiveGameData(GameData gameData, AsyncCallback callback, object state); void EndReceiveGameData(IAsyncResult result); } Listing 2. The IGameStreamClient interfaces defines client operations that a server can call.   The IGameStreamService interface is decorated with the standard ServiceContract attribute but also contains a value for the CallbackContract property.  This property is used to define the interface that the client will expose (IGameStreamClient in this example) and use to receive data pushed from the service. Notice that each OperationContract attribute in both interfaces sets the IsOneWay property to true. This means that the operation can be called and passed data as appropriate, however, no data will be passed back. Instead, data will be pushed back to the client as it’s available.  Looking through the IGameStreamService interface you can see that the client can request team data whereas the IGameStreamClient interface allows team and game data to be received by the client. One interesting point about the IGameStreamClient interface is the inclusion of the AsyncPattern property on the BeginReceiveGameData operation. I initially created this operation as a standard one way operation and it worked most of the time. However, as I disconnected clients and reconnected new ones game data wasn’t being passed properly. After researching the problem more I realized that because the service could take up to 7 seconds to return game data, things were getting hung up. By setting the AsyncPattern property to true on the BeginReceivedGameData operation and providing a corresponding EndReceiveGameData operation I was able to get around this problem and get everything running properly. I’ll provide more details on the implementation of these two methods later in this post. Once the interfaces were created I moved on to the game service class. The first order of business was to create a class that implemented the IGameStreamService interface. Since the service can be used by multiple clients wanting game data I added the ServiceBehavior attribute to the class definition so that I could set its InstanceContextMode to InstanceContextMode.Single (in effect creating a Singleton service object). Listing 3 shows the game service class as well as its fields and constructor.   [ServiceBehavior(ConcurrencyMode = ConcurrencyMode.Multiple, InstanceContextMode = InstanceContextMode.Single)] public class GameStreamService : IGameStreamService { object _Key = new object(); Game _Game = null; Timer _Timer = null; Random _Random = null; Dictionary<string, IGameStreamClient> _ClientCallbacks = new Dictionary<string, IGameStreamClient>(); static AsyncCallback _ReceiveGameDataCompleted = new AsyncCallback(ReceiveGameDataCompleted); public GameStreamService() { _Game = new Game(); _Timer = new Timer { Enabled = false, Interval = 2000, AutoReset = true }; _Timer.Elapsed += new ElapsedEventHandler(_Timer_Elapsed); _Timer.Start(); _Random = new Random(); }} Listing 3. The GameStreamService implements the IGameStreamService interface which defines a callback contract that allows the service class to push data back to the client. By implementing the IGameStreamService interface, GameStreamService must supply a GetTeamData() method which is responsible for supplying information about the teams that are playing as well as individual players.  GetTeamData() also acts as a client subscription method that tracks clients wanting to receive game data.  Listing 4 shows the GetTeamData() method. public void GetTeamData() { //Get client callback channel var context = OperationContext.Current; var sessionID = context.SessionId; var currClient = context.GetCallbackChannel<IGameStreamClient>(); context.Channel.Faulted += Disconnect; context.Channel.Closed += Disconnect; IGameStreamClient client; if (!_ClientCallbacks.TryGetValue(sessionID, out client)) { lock (_Key) { _ClientCallbacks[sessionID] = currClient; } } currClient.ReceiveTeamData(_Game.GetTeamData()); //Start timer which when fired sends updated score information to client if (!_Timer.Enabled) { _Timer.Enabled = true; } } Listing 4. The GetTeamData() method subscribes a given client to the game service and returns. The key the line of code in the GetTeamData() method is the call to GetCallbackChannel<IGameStreamClient>().  This method is responsible for accessing the calling client’s callback channel. The callback channel is defined by the IGameStreamClient interface shown earlier in Listing 2 and used by the server to communicate with the client. Before passing team data back to the client, GetTeamData() grabs the client’s session ID and checks if it already exists in the _ClientCallbacks dictionary object used to track clients wanting callbacks from the server. If the client doesn’t exist it adds it into the collection. It then pushes team data from the Game class back to the client by calling ReceiveTeamData().  Since the service simulates a basketball game, a timer is then started if it’s not already enabled which is then used to randomly send data to the client. When the timer fires, game data is pushed down to the client. Listing 5 shows the _Timer_Elapsed() method that is called when the timer fires as well as the SendGameData() method used to send data to the client. void _Timer_Elapsed(object sender, ElapsedEventArgs e) { int interval = _Random.Next(3000, 7000); lock (_Key) { _Timer.Interval = interval; _Timer.Enabled = false; } SendGameData(_Game.GetGameData()); } private void SendGameData(GameData gameData) { var cbs = _ClientCallbacks.Where(cb => ((IContextChannel)cb.Value).State == CommunicationState.Opened); for (int i = 0; i < cbs.Count(); i++) { var cb = cbs.ElementAt(i).Value; try { cb.BeginReceiveGameData(gameData, _ReceiveGameDataCompleted, cb); } catch (TimeoutException texp) { //Log timeout error } catch (CommunicationException cexp) { //Log communication error } } lock (_Key) _Timer.Enabled = true; } private static void ReceiveGameDataCompleted(IAsyncResult result) { try { ((IGameStreamClient)(result.AsyncState)).EndReceiveGameData(result); } catch (CommunicationException) { // empty } catch (TimeoutException) { // empty } } LIsting 5. _Timer_Elapsed is used to simulate time in a basketball game. When _Timer_Elapsed() fires the SendGameData() method is called which iterates through the clients wanting to be notified of changes. As each client is identified, their respective BeginReceiveGameData() method is called which ultimately pushes game data down to the client. Recall that this method was defined in the client callback interface named IGameStreamClient shown earlier in Listing 2. Notice that BeginReceiveGameData() accepts _ReceiveGameDataCompleted as its second parameter (an AsyncCallback delegate defined in the service class) and passes the client callback as the third parameter. The initial version of the sample application had a standard ReceiveGameData() method in the client callback interface. However, sometimes the client callbacks would work properly and sometimes they wouldn’t which was a little baffling at first glance. After some investigation I realized that I needed to implement an asynchronous pattern for client callbacks to work properly since 3 – 7 second delays are occurring as a result of the timer. Once I added the BeginReceiveGameData() and ReceiveGameDataCompleted() methods everything worked properly since each call was handled in an asynchronous manner. The final task that had to be completed to get the server working properly with HTTP Polling Duplex was adding configuration code into web.config. In the interest of brevity I won’t post all of the code here since the sample application includes everything you need. However, Listing 6 shows the key configuration code to handle creating a custom binding named pollingDuplexBinding and associate it with the service’s endpoint.   <bindings> <customBinding> <binding name="pollingDuplexBinding"> <binaryMessageEncoding /> <pollingDuplex maxPendingSessions="2147483647" maxPendingMessagesPerSession="2147483647" inactivityTimeout="02:00:00" serverPollTimeout="00:05:00"/> <httpTransport /> </binding> </customBinding> </bindings> <services> <service name="GameService.GameStreamService" behaviorConfiguration="GameStreamServiceBehavior"> <endpoint address="" binding="customBinding" bindingConfiguration="pollingDuplexBinding" contract="GameService.IGameStreamService"/> <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" /> </service> </services>   Listing 6. Configuring an HTTP Polling Duplex binding in web.config and associating an endpoint with it. Calling the Service and Receiving “Pushed” Data Calling the service and handling data that is pushed from the server is a simple and straightforward process in Silverlight. Since the service is configured with a MEX endpoint and exposes a WSDL file, you can right-click on the Silverlight project and select the standard Add Service Reference item. After the web service proxy is created you may notice that the ServiceReferences.ClientConfig file only contains an empty configuration element instead of the normal configuration elements created when creating a standard WCF proxy. You can certainly update the file if you want to read from it at runtime but for the sample application I fed the service URI directly to the service proxy as shown next: var address = new EndpointAddress("http://localhost.:5661/GameStreamService.svc"); var binding = new PollingDuplexHttpBinding(); _Proxy = new GameStreamServiceClient(binding, address); _Proxy.ReceiveTeamDataReceived += _Proxy_ReceiveTeamDataReceived; _Proxy.ReceiveGameDataReceived += _Proxy_ReceiveGameDataReceived; _Proxy.GetTeamDataAsync(); This code creates the proxy and passes the endpoint address and binding to use to its constructor. It then wires the different receive events to callback methods and calls GetTeamDataAsync().  Calling GetTeamDataAsync() causes the server to store the client in the server-side dictionary collection mentioned earlier so that it can receive data that is pushed.  As the server-side timer fires and game data is pushed to the client, the user interface is updated as shown in Listing 7. Listing 8 shows the _Proxy_ReceiveGameDataReceived() method responsible for handling the data and calling UpdateGameData() to process it.   Listing 7. The Silverlight interface. Game data is pushed from the server to the client using HTTP Polling Duplex. void _Proxy_ReceiveGameDataReceived(object sender, ReceiveGameDataReceivedEventArgs e) { UpdateGameData(e.gameData); } private void UpdateGameData(GameData gameData) { //Update Score this.tbTeam1Score.Text = gameData.Team1Score.ToString(); this.tbTeam2Score.Text = gameData.Team2Score.ToString(); //Update ball visibility if (gameData.Action != ActionsEnum.Foul) { if (tbTeam1.Text == gameData.TeamOnOffense) { AnimateBall(this.BB1, this.BB2); } else //Team 2 { AnimateBall(this.BB2, this.BB1); } } if (this.lbActions.Items.Count > 9) this.lbActions.Items.Clear(); this.lbActions.Items.Add(gameData.LastAction); if (this.lbActions.Visibility == Visibility.Collapsed) this.lbActions.Visibility = Visibility.Visible; } private void AnimateBall(Image onBall, Image offBall) { this.FadeIn.Stop(); Storyboard.SetTarget(this.FadeInAnimation, onBall); Storyboard.SetTarget(this.FadeOutAnimation, offBall); this.FadeIn.Begin(); } Listing 8. As the server pushes game data, the client’s _Proxy_ReceiveGameDataReceived() method is called to process the data. In a real-life application I’d go with a ViewModel class to handle retrieving team data, setup data bindings and handle data that is pushed from the server. However, for the sample application I wanted to focus on HTTP Polling Duplex and keep things as simple as possible.   Summary Silverlight supports three options when duplex communication is required in an application including TCP bindins, sockets and HTTP Polling Duplex. In this post you’ve seen how HTTP Polling Duplex interfaces can be created and implemented on the server as well as how they can be consumed by a Silverlight client. HTTP Polling Duplex provides a nice way to “push” data from a server while still allowing the data to flow over port 80 or another port of your choice.   Sample Application Download

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  • Nhibernate one-to-many with table per subclass

    - by Wayne
    I am customizing N2CMS's database structure, and met with an issue. The two classes are listed below. public class Customer : ContentItem { public IList<License> Licenses { get; set; } } public class License : ContentItem { public Customer Customer { get; set; } } The nhibernate mapping are as follows. <class name="N2.ContentItem,N2" table="n2item"> <cache usage="read-write" /> <id name="ID" column="ID" type="Int32" unsaved-value="0" access="property"> <generator class="native" /> </id> <discriminator column="Type" type="String" /> </class> <subclass name="My.Customer,My" extends="N2.ContentItem,N2" discriminator-value="Customer"> <join table="Customer"> <key column="ItemID" /> <bag name="Licenses" generic="true" inverse="true"> <key column="CustomerID" /> <one-to-many class="My.License,My"/> </bag> </join> </subclass> <subclass name="My.License,My" extends="N2.ContentItem,N2" discriminator-value="License"> <join table="License" fetch="select"> <key column="ItemID" /> <many-to-one name="Customer" column="CustomerID" class="My.Customer,My" not-null="false" /> </join> </subclass> Then, when get an instance of Customer, the customer.Licenses is always empty, but actually there are licenses in the database for the customer. When I check the nhibernate log file, I find that the SQL query is like: SELECT licenses0_.CustomerID as CustomerID1_, licenses0_.ID as ID1_, licenses0_.ID as ID2_0_, licenses0_1_.CustomerID as CustomerID7_0_, FROM n2item licenses0_ inner join License licenses0_1_ on licenses0_.ID = licenses0_1_.ItemID WHERE licenses0_.CustomerID = 12 /* @p0 */ It seems that nhibernate believes that the CustomerID is in the 'n2item' table. I don't know why, but to make it work, I think the SQL should be something like this. SELECT licenses0_.ID as ID1_, licenses0_.ID as ID2_0_, licenses0_1_.CustomerID as CustomerID7_0_, FROM n2item licenses0_ inner join License licenses0_1_ on licenses0_.ID = licenses0_1_.ItemID WHERE licenses0_1_.CustomerID = 12 /* @p0 */ Could any one point out what's wrong with my mappings? And how can I get the correct licenses of one customer? Thanks in advance.

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  • Oracle Enterprise Data Quality Adds Global Address Verification Capabilities for Greater Accuracy and Broader Location Coverage

    - by Mala Narasimharajan
    Data quality – has many flavors to it.  Product, Customer – you name the data domain and there’s data quality associated with it.  Address verification and data quality are a little different.  in that there is a tremendous amount of variation as well as nuance attached to it.  Specifically, what makes address verification challenging is that more often than not, addresses are incomplete, riddled with misspellings, incorrect postal codes are assigned to locations or non-address items are present.  Almost all data has locations, and accurate locations power a wealth of business processes: Customer Relationship Management, data quality, delivery of materials, goods or services, fraud detection, insurance risk assessment, data analytics, store and territory planning, and much more. Oracle Address Verification Server provides location-based services as well as deeper parsing and analysis capabilities for Oracle Enterprise Data Quality.  Specifically, Pre-integrated with the EDQ platform, Oracle Address Verification Server provides robust parsing, validation, as well as specialized location information for over 240 countries – all populated countries on Earth.  Oracle Enterprise Data Quality (EDQ) is a data quality platform, dedicated to address the distinct challenges of customer and product data quality, and performs advanced data profiling to identify and measure poor quality data and identify rule requirements, as well as semantic and pattern-based recognition to accurately parse and standardize data that is poorly structured.   EDQ is integrated with Oracle Master Data Management, including Oracle Customer Hub and Oracle Product Hub, as well as Oracle Data Integrator Enterprise Edition and Oracle CRM.  Address Verification Server provides key address verification services for Oracle CRM and Oracle Customer Hub.  In addition, Address Verification Server provides greater accuracy when handling address data due to its expanded sources and extensible knowledge repository, solid parsing across locales and countries as well as  adept handling of extraneous data in address fields.  For more information on Oracle Address Verification Server visit:  http://bit.ly/GMUE4H and http://bit.ly/GWf7U6

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  • JavaScript Collection of one-line Useful Functions

    - by Wilq32
    This is a question to put as many interesting and useful JavaScript functions written in one line as we can. I made this question because I'm curious how many people around like the art of one-Line programming in JavaScript, and I want to see their progress in action. Put variations of each code inside comments.

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  • Making Spring Data JPA work with DataNucleus (GAE) (Spring Boot)

    - by xybrek
    There are several hints that Spring Data works with Google App Engine like: http://tommysiu.blogspot.com/2014/01/spring-data-on-gae-part-1.html http://blog.eisele.net/2009/07/spring-300m3-on-google-appengine-with.html Much of the examples are not "Spring Boot" so I've been trying to retrofit things with it. However, I've been stuck with this error for days and days: [INFO] Caused by: java.lang.NullPointerException [INFO] at org.datanucleus.api.jpa.metamodel.SingularAttributeImpl.isVersion(SingularAttributeImpl.java:79) [INFO] at org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation.findVersionAttribute(JpaMetamodelEntityInformation.java:102) [INFO] at org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation.<init>(JpaMetamodelEntityInformation.java:79) [INFO] at org.springframework.data.jpa.repository.support.JpaEntityInformationSupport.getMetadata(JpaEntityInformationSupport.java:65) [INFO] at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getEntityInformation(JpaRepositoryFactory.java:149) [INFO] at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository(JpaRepositoryFactory.java:88) [INFO] at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository(JpaRepositoryFactory.java:68) [INFO] at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:158) [INFO] at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.initAndReturn(RepositoryFactoryBeanSupport.java:224) [INFO] at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:210) [INFO] at org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet(JpaRepositoryFactoryBean.java:92) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$6.run(AbstractAutowireCapableBeanFactory.java:1602) [INFO] at java.security.AccessController.doPrivileged(Native Method) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1599) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1549) [INFO] ... 40 more Where, I'm trying to use Spring Data JPA with DataNucleus/AppEngine: @Configuration @ComponentScan @EnableJpaRepositories @EnableTransactionManagement class JpaApplicationConfig { private static final Logger logger = Logger .getLogger(JpaApplicationConfig.class.getName()); @Bean public EntityManagerFactory entityManagerFactory() { logger.info("Loading Entity Manager..."); return Persistence .createEntityManagerFactory("transactions-optional"); } @Bean public PlatformTransactionManager transactionManager() { logger.info("Loading Transaction Manager..."); final JpaTransactionManager txManager = new JpaTransactionManager(); txManager.setEntityManagerFactory(entityManagerFactory()); return txManager; } } I've tested Persistence.createEntityManagerFactory("transactions-optional"); to see if the app can persist using this EMF, well, it does, so I am sure that this EMF works fine. The problem is the "wiring" up with the Spring Data JPA, can anybody help?

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  • Parse and read data frame in C?

    - by user253656
    I am writing a program that reads the data from the serial port on Linux. The data are sent by another device with the following frame format: |start | Command | Data | CRC | End | |0x02 | 0x41 | (0-127 octets) | | 0x03| ---------------------------------------------------- The Data field contains 127 octets as shown and octet 1,2 contains one type of data; octet 3,4 contains another data. I need to get these data I know how to write and read data to and from a serial port in Linux, but it is just to write and read a simple string (like "ABD") My issue is that I do not know how to parse the data frame formatted as above so that I can: get the data in octet 1,2 in the Data field get the data in octet 3,4 in the Data field get the value in CRC field to check the consistency of the data Here the sample snip code that read and write a simple string from and to a serial port in Linux: int writeport(int fd, char *chars) { int len = strlen(chars); chars[len] = 0x0d; // stick a <CR> after the command chars[len+1] = 0x00; // terminate the string properly int n = write(fd, chars, strlen(chars)); if (n < 0) { fputs("write failed!\n", stderr); return 0; } return 1; } int readport(int fd, char *result) { int iIn = read(fd, result, 254); result[iIn-1] = 0x00; if (iIn < 0) { if (errno == EAGAIN) { printf("SERIAL EAGAIN ERROR\n"); return 0; } else { printf("SERIAL read error %d %s\n", errno, strerror(errno)); return 0; } } return 1; } Does anyone please have some ideas? Thanks all.

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  • How to maintain an ordered table with Core Data (or SQL) with insertions/deletions?

    - by Jean-Denis Muys
    This question is in the context of Core Data, but if I am not mistaken, it applies equally well to a more general SQL case. I want to maintain an ordered table using Core Data, with the possibility for the user to: reorder rows insert new lines anywhere delete any existing line What's the best data model to do that? I can see two ways: 1) Model it as an array: I add an int position property to my entity 2) Model it as a linked list: I add two one-to-one relations, next and previous from my entity to itself 1) makes it easy to sort, but painful to insert or delete as you then have to update the position of all objects that come after 2) makes it easy to insert or delete, but very difficult to sort. In fact, I don't think I know how to express a Sort Descriptor (SQL ORDER BY clause) for that case. Now I can imagine a variation on 1): 3) add an int ordering property to the entity, but instead of having it count one-by-one, have it count 100 by 100 (for example). Then inserting is as simple as finding any number between the ordering of the previous and next existing objects. The expensive renumbering only has to occur when the 100 holes have been filled. Making that property a float rather than an int makes it even better: it's almost always possible to find a new float midway between two floats. Am I on the right track with solution 3), or is there something smarter?

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  • Passing parameters between Silverlight and ASP.NET – Part 1

    - by mohanbrij
    While working with Silverlight applications, we may face some scenarios where we may need to embed Silverlight as a component, like for e.g in Sharepoint Webpars or simple we can have the same with ASP.NET. The biggest challenge comes when we have to pass the parameters from ASP.NET to Silverlight components or back from Silverlight to ASP.NET. We have lots of ways we can do this, like using InitParams, QueryStrings, using HTML objects in Silverlight, etc. All these different techniques have some advantages or disadvantages or limitations. Lets see one by one why we should choose one and what are the ways to achieve the same. 1. InitParams: Lets start with InitParams, Start your Visual Studio 2010 IDE, and Create a Silverlight Application, give any name. Now go to the ASP.NET WebProject which is used to Host the Silverlight XAP component. You will find lots of different tags are used by Silverlight object as <params> tags. To use InitParams, Silverlight provides us with a tag called InitParams which we can use to pass parameters to Silverlight object from ASP.NET. 1: <object data="data:application/x-silverlight-2," type="application/x-silverlight-2" width="100%" height="100%"> 2: <param name="source" value="ClientBin/SilverlightApp.xap"/> 3: <param name="onError" value="onSilverlightError" /> 4: <param name="background" value="white" /> 5: <param name="minRuntimeVersion" value="4.0.50826.0" /> 6: <param name="initparams" id="initParams" runat="server" value=""/> 7: <param name="autoUpgrade" value="true" /> 8: <a href="http://go.microsoft.com/fwlink/?LinkID=149156&v=4.0.50826.0" style="text-decoration:none"> 9: <img src="http://go.microsoft.com/fwlink/?LinkId=161376" alt="Get Microsoft Silverlight" style="border-style:none"/> 10: </a> 11: </object> Here in the code above I have included a initParam as a param tag (line 6), now in the page load I will add a line 1: initParams.Attributes.Add("value", "key1=Brij, key2=Mohan"); This basically add a value parameter inside the initParam. So thats all we need in our ASP.NET side, now coming to the Silverlight Code open the code behind of App.xaml and add the following lines of code. 1: private string firstKey, secondKey; 2: private void Application_Startup(object sender, StartupEventArgs e) 3: { 4: if (e.InitParams.ContainsKey("key1")) 5: this.firstKey = e.InitParams["key1"]; 6: if (e.InitParams.ContainsKey("key2")) 7: this.secondKey = e.InitParams["key2"]; 8: this.RootVisual = new MainPage(firstKey, secondKey); 9: } This code fetch the init params and pass it to our MainPage.xaml constructor, in the MainPage.xaml we can use these variables according to our requirement, here in this example I am simply displaying the variables in a Message Box. 1: public MainPage(string param1, string param2) 2: { 3: InitializeComponent(); 4: MessageBox.Show("Welcome, " + param1 + " " + param2); 5: } This will give you a sample output as Limitations: Depending on the browsers you have some limitation on the overall string length of the parameters you can pass. To get more details on this limitation, you can refer to this link :http://www.boutell.com/newfaq/misc/urllength.html 2. QueryStrings To show this example I am taking the scenario where we have a default.aspx page and we are going to the SIlverlightTestPage.aspx, and we have to work with the parameters which was passed by default.aspx in the SilverlightTestPage.aspx Silverlight Component. So first I will add a new page in my application which contains a button with ID =btnNext, and on click of the button I will redirect my page to my SilverlightTestAppPage.aspx with the required query strings. Code of Default.aspx 1: protected void btnNext_Click(object sender, EventArgs e) 2: { 3: Response.Redirect("~/SilverlightAppTestPage.aspx?FName=Brij" + "&LName=Mohan"); 4: } Code of MainPage.xaml.cs 1: public partial class MainPage : UserControl 2: { 3: public MainPage() 4: { 5: InitializeComponent(); 6: this.Loaded += new RoutedEventHandler(MainPage_Loaded); 7: } 8: 9: void MainPage_Loaded(object sender, RoutedEventArgs e) 10: { 11: IDictionary<string, string> qString = HtmlPage.Document.QueryString; 12: string firstName = string.Empty; 13: string lastName = string.Empty; 14: foreach (KeyValuePair<string, string> keyValuePair in qString) 15: { 16: string key = keyValuePair.Key; 17: string value = keyValuePair.Value; 18: if (key == "FName") 19: firstName = value; 20: else if (key == "LName") 21: lastName = value; 22: } 23: MessageBox.Show("Welcome, " + firstName + " " + lastName); 24: } 25: } Set the Startup page as Default.aspx, now run the application. This will give you the following output: Since here also you are using the Query Strings to pass your parameters, so you are depending on the browser capabilities of the length of the query strings it can pass. Here also you can refer the limitation which I have mentioned in my previous example for the length of parameters you can use.   3. Using HtmlPage.Document Silverlight to ASP.NET <—> ASP.NET to Silverlight: To show this I setup a sample Silverlight Application with Buttons Get Data and Set Data with the Data Text Box. In ASP.NET page I kep a TextBox to Show how the values passed to and From Silverlight to ASP.NET reflects back. My page with Silverlight control looks like this. When I Say Get Data it pulls the data from ASP.NET to Silverlight Control Text Box, and When I say Set data it basically Set the Value from Silverlight Control TextBox to ASP.NET TextBox. Now let see the code how it is doing. This is my ASP.NET Source Code. Here I have just created a TextBox named : txtData 1: <body> 2: <form id="form1" runat="server" style="height:100%"> 3: <div id="silverlightControlHost"> 4: ASP.NET TextBox: <input type="text" runat="server" id="txtData" value="Some Data" /> 5: <object data="data:application/x-silverlight-2," type="application/x-silverlight-2" width="100%" height="100%"> 6: <param name="source" value="ClientBin/SilverlightApplication1.xap"/> 7: <param name="onError" value="onSilverlightError" /> 8: <param name="background" value="white" /> 9: <param name="minRuntimeVersion" value="4.0.50826.0" /> 10: <param name="autoUpgrade" value="true" /> 11: <a href="http://go.microsoft.com/fwlink/?LinkID=149156&v=4.0.50826.0" style="text-decoration:none"> 12: <img src="http://go.microsoft.com/fwlink/?LinkId=161376" alt="Get Microsoft Silverlight" style="border-style:none"/> 13: </a> 14: </object><iframe id="_sl_historyFrame" style="visibility:hidden;height:0px;width:0px;border:0px"></iframe> 15: </div> 16: </form> 17: </body> My actual logic for getting and setting the data lies in my Silverlight Control, this is my XAML code with TextBox and Buttons. 1: <Grid x:Name="LayoutRoot" Background="White" Height="100" Width="450" VerticalAlignment="Top"> 2: <Grid.ColumnDefinitions> 3: <ColumnDefinition Width="110" /> 4: <ColumnDefinition Width="110" /> 5: <ColumnDefinition Width="110" /> 6: <ColumnDefinition Width="110" /> 7: </Grid.ColumnDefinitions> 8: <TextBlock Text="Silverlight Text Box: " Grid.Column="0" VerticalAlignment="Center"></TextBlock> 9: <TextBox x:Name="DataText" Width="100" Grid.Column="1" Height="20"></TextBox> 10: <Button x:Name="GetData" Width="100" Click="GetData_Click" Grid.Column="2" Height="30" Content="Get Data"></Button> 11: <Button x:Name="SetData" Width="100" Click="SetData_Click" Grid.Column="3" Height="30" Content="Set Data"></Button> 12: </Grid> Now we have to write few lines of Button Events for Get Data and Set Data which basically make use of Windows.System.Browser namespace. 1: private void GetData_Click(object sender, RoutedEventArgs e) 2: { 3: DataText.Text = HtmlPage.Document.GetElementById("txtData").GetProperty("value").ToString(); 4: } 5:  6: private void SetData_Click(object sender, RoutedEventArgs e) 7: { 8: HtmlPage.Document.GetElementById("txtData").SetProperty("value", DataText.Text); 9: } That’s it so when we run this application my Form will look like this. 4. Using Object Serialization. This is a useful when we want to pass Objects of Data from our ASP.NET application to Silverlight Controls and back. This technique basically uses the above technique I mentioned in Pint 3 above. Since this itself is a length topic so details of this I am going to cover in Part 2 of this Post with Sample Code Example very soon.

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  • Pre-filtering and shaping OData feeds using WCF Data Services and the Entity Framework - Part 1

    - by rajbk
    The Open Data Protocol, referred to as OData, is a new data-sharing standard that breaks down silos and fosters an interoperative ecosystem for data consumers (clients) and producers (services) that is far more powerful than currently possible. It enables more applications to make sense of a broader set of data, and helps every data service and client add value to the whole ecosystem. WCF Data Services (previously known as ADO.NET Data Services), then, was the first Microsoft technology to support the Open Data Protocol in Visual Studio 2008 SP1. It provides developers with client libraries for .NET, Silverlight, AJAX, PHP and Java. Microsoft now also supports OData in SQL Server 2008 R2, Windows Azure Storage, Excel 2010 (through PowerPivot), and SharePoint 2010. Many other other applications in the works. * This post walks you through how to create an OData feed, define a shape for the data and pre-filter the data using Visual Studio 2010, WCF Data Services and the Entity Framework. A sample project is attached at the bottom of Part 2 of this post. Pre-filtering and shaping OData feeds using WCF Data Services and the Entity Framework - Part 2 Create the Web Application File –› New –› Project, Select “ASP.NET Empty Web Application” Add the Entity Data Model Right click on the Web Application in the Solution Explorer and select “Add New Item..” Select “ADO.NET Entity Data Model” under "Data”. Name the Model “Northwind” and click “Add”.   In the “Choose Model Contents”, select “Generate Model From Database” and click “Next”   Define a connection to your database containing the Northwind database in the next screen. We are going to expose the Products table through our OData feed. Select “Products” in the “Choose your Database Object” screen.   Click “Finish”. We are done creating our Entity Data Model. Save the Northwind.edmx file created. Add the WCF Data Service Right click on the Web Application in the Solution Explorer and select “Add New Item..” Select “WCF Data Service” from the list and call the service “DataService” (creative, huh?). Click “Add”.   Enable Access to the Data Service Open the DataService.svc.cs class. The class is well commented and instructs us on the next steps. public class DataService : DataService< /* TODO: put your data source class name here */ > { // This method is called only once to initialize service-wide policies. public static void InitializeService(DataServiceConfiguration config) { // TODO: set rules to indicate which entity sets and service operations are visible, updatable, etc. // Examples: // config.SetEntitySetAccessRule("MyEntityset", EntitySetRights.AllRead); // config.SetServiceOperationAccessRule("MyServiceOperation", ServiceOperationRights.All); config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2; } } Replace the comment that starts with “/* TODO:” with “NorthwindEntities” (the entity container name of the Model we created earlier).  WCF Data Services is initially locked down by default, FTW! No data is exposed without you explicitly setting it. You have explicitly specify which Entity sets you wish to expose and what rights are allowed by using the SetEntitySetAccessRule. The SetServiceOperationAccessRule on the other hand sets rules for a specified operation. Let us define an access rule to expose the Products Entity we created earlier. We use the EnititySetRights.AllRead since we want to give read only access. Our modified code is shown below. public class DataService : DataService<NorthwindEntities> { public static void InitializeService(DataServiceConfiguration config) { config.SetEntitySetAccessRule("Products", EntitySetRights.AllRead); config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2; } } We are done setting up our ODataFeed! Compile your project. Right click on DataService.svc and select “View in Browser” to see the OData feed. To view the feed in IE, you must make sure that "Feed Reading View" is turned off. You set this under Tools -› Internet Options -› Content tab.   If you navigate to “Products”, you should see the Products feed. Note also that URIs are case sensitive. ie. Products work but products doesn’t.   Filtering our data OData has a set of system query operations you can use to perform common operations against data exposed by the model. For example, to see only Products in CategoryID 2, we can use the following request: /DataService.svc/Products?$filter=CategoryID eq 2 At the time of this writing, supported operations are $orderby, $top, $skip, $filter, $expand, $format†, $select, $inlinecount. Pre-filtering our data using Query Interceptors The Product feed currently returns all Products. We want to change that so that it contains only Products that have not been discontinued. WCF introduces the concept of interceptors which allows us to inject custom validation/policy logic into the request/response pipeline of a WCF data service. We will use a QueryInterceptor to pre-filter the data so that it returns only Products that are not discontinued. To create a QueryInterceptor, write a method that returns an Expression<Func<T, bool>> and mark it with the QueryInterceptor attribute as shown below. [QueryInterceptor("Products")] public Expression<Func<Product, bool>> OnReadProducts() { return o => o.Discontinued == false; } Viewing the feed after compilation will only show products that have not been discontinued. We also confirm this by looking at the WHERE clause in the SQL generated by the entity framework. SELECT [Extent1].[ProductID] AS [ProductID], ... ... [Extent1].[Discontinued] AS [Discontinued] FROM [dbo].[Products] AS [Extent1] WHERE 0 = [Extent1].[Discontinued] Other examples of Query/Change interceptors can be seen here including an example to filter data based on the identity of the authenticated user. We are done pre-filtering our data. In the next part of this post, we will see how to shape our data. Pre-filtering and shaping OData feeds using WCF Data Services and the Entity Framework - Part 2 Foot Notes * http://msdn.microsoft.com/en-us/data/aa937697.aspx † $format did not work for me. The way to get a Json response is to include the following in the  request header “Accept: application/json, text/javascript, */*” when making the request. This is easily done with most JavaScript libraries.

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