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• Validate links with php

  - by mike

  Can anyone tell me if its possible to validate a link with php? By validate, I mean check if the link is active and works not just the actual format of the link.

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• Read JSON (text file) into .NET application

  - by Bi

  I have a configuration file in the following JSON format: { "key1": "value1", "key2": "value2", "key3": false, "key4": 10, } The user can set/unset the configuration values using a text editor. I however need to read it in my C# application. Whats the best way to do so for JSON? The above keys are not associated with a class.

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• Briefest way to display TimeSpan value as an elapsed time e.g. 1:45:33

  - by jdk

  I'd like an easy way to display any TimeSpan as an elapsed time without using loops or custom logic e.g. hours : minutes : seconds I'm sure there must be a .NET built-in or format string that applies, however I'm unable to locate it.

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• Thousands separator in .Net/F#

  - by rwallace

  What's the recommended way to print an integer with thousands separator? Best I've come up with so far is let thousands(x:int64) = String.Format("{0:0,0}", x) Which works in most cases, but prints zero as 00.

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• XML Document straight to Stored Proc Mapping in NHibernate

  - by ZekeTheGeek

  Hello. I'm building a mechanism to take XML data from a queue and call stored procs to save the data from the XML document directly to the database. This seems like something that NHibernate could address, but of course most of the information I find discusses going from objects to database instead of another data format (XML, in this case). Is there a way to use NHibernate in this fashion or am I barking up the wrong tree? Thanks.

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• SOAP vs REST (differences)

  - by Abdulaziz

  I have read articles about the differences between SOAP and REST as a web service communication protocol, but I think that the biggest advantage for REST over SOAP are : REST is more dynamic, no need for creating and updating UDDI. REST is not restricted to XML format. REST web services can send plain text, JSON, and also XML. But SOAP is more standardized (Ex; security). So, am I correct in these points? Thanks

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• DirectorySearch.PageSize = 2 doesn't work

  - by Bero

  using (DirectorySearcher srch = new DirectorySearcher(String.Format("(memberOf= {0})",p_Target.DistinguishedName))) { srch.PageSize = 2; SearchResultCollection results = results = srch.FindAll(); int count = results.Count; } count = 3 (THREE) and not 2. Why is that? I don't want to have all results in just one page. I know that PageSize = 2 is silly small but I set that value in this case just for testing purpose (in reality it will be more).

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• Briefest way do display TimeSpan value as an elapsed time e.g. 1:45:33

  - by jdk

  I'd like an easy way to display any TimeSpan as an elapsed time without using loops are custom logic hours : minutes : seconds I'm sure there must be a .NET built-in or format string that applies, however I'm unable to locate it.

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• How to find files older than N days from a given timestamp

  - by JGeZau

  I want to find files older than N days from a given timestamp in format YYYYMMDDHH I can find file older than 2 days with the below command, but this finds files with present time find /path/to/dir -mtime -2 -type f -ls Lets say I give the input timeSamp=2011093009 so I want to find files older than 2 days from 2011093009 Been doing my research, but can't seem to figure it out. ========================================== Found the solution...see below for my Answer.. Thanks

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• php change attribute

  - by Kemrop

  I have an xml file of the following format some title some description I am looking for an efficient way to replace contents of the attributes,be it DOM or simpleXML Example of my function call would be: changeAttribute("collection","collection id","new collection id") Would result in something like some title some description Thanks

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• Web Browser Control &ndash; Specifying the IE Version

  - by Rick Strahl

  I use the Internet Explorer Web Browser Control in a lot of my applications to display document type layout. HTML happens to be one of the most common document formats and displaying data in this format – even in desktop applications, is often way easier than using normal desktop technologies. One issue the Web Browser Control has that it’s perpetually stuck in IE 7 rendering mode by default. Even though IE 8 and now 9 have significantly upgraded the IE rendering engine to be more CSS and HTML compliant by default the Web Browser control will have none of it. IE 9 in particular – with its much improved CSS support and basic HTML 5 support is a big improvement and even though the IE control uses some of IE’s internal rendering technology it’s still stuck in the old IE 7 rendering by default. This applies whether you’re using the Web Browser control in a WPF application, a WinForms app, a FoxPro or VB classic application using the ActiveX control. Behind the scenes all these UI platforms use the COM interfaces and so you’re stuck by those same rules. Rendering Challenged To see what I’m talking about here are two screen shots rendering an HTML 5 doctype page that includes some CSS 3 functionality – rounded corners and border shadows - from an earlier post. One uses IE 9 as a standalone browser, and one uses a simple WPF form that includes the Web Browser control. IE 9 Browser:   Web Browser control in a WPF form: The IE 9 page displays this HTML correctly – you see the rounded corners and shadow displayed. Obviously the latter rendering using the Web Browser control in a WPF application is a bit lacking. Not only are the new CSS features missing but the page also renders in Internet Explorer’s quirks mode so all the margins, padding etc. behave differently by default, even though there’s a CSS reset applied on this page. If you’re building an application that intends to use the Web Browser control for a live preview of some HTML this is clearly undesirable. Feature Delegation via Registry Hacks Fortunately starting with Internet Explore 8 and later there’s a fix for this problem via a registry setting. You can specify a registry key to specify which rendering mode and version of IE should be used by that application. These are not global mind you – they have to be enabled for each application individually. There are two different sets of keys for 32 bit and 64 bit applications. 32 bit: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\MAIN\FeatureControl\FEATURE_BROWSER_EMULATION Value Key: yourapplication.exe 64 bit: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Internet Explorer\MAIN\FeatureControl\FEATURE_BROWSER_EMULATION Value Key: yourapplication.exe The value to set this key to is (taken from MSDN here) as decimal values: 9999 (0x270F) Internet Explorer 9. Webpages are displayed in IE9 Standards mode, regardless of the !DOCTYPE directive. 9000 (0x2328) Internet Explorer 9. Webpages containing standards-based !DOCTYPE directives are displayed in IE9 mode. 8888 (0x22B8) Webpages are displayed in IE8 Standards mode, regardless of the !DOCTYPE directive. 8000 (0x1F40) Webpages containing standards-based !DOCTYPE directives are displayed in IE8 mode. 7000 (0x1B58) Webpages containing standards-based !DOCTYPE directives are displayed in IE7 Standards mode.   The added key looks something like this in the Registry Editor: With this in place my Html Html Help Builder application which has wwhelp.exe as its main executable now works with HTML 5 and CSS 3 documents in the same way that Internet Explorer 9 does. Incidentally I accidentally added an ‘empty’ DWORD value of 0 to my EXE name and that worked as well giving me IE 9 rendering. Although not documented I suspect 0 (or an invalid value) will default to the installed browser. Don’t have a good way to test this but if somebody could try this with IE 8 installed that would be great: What happens when setting 9000 with IE 8 installed? What happens when setting 0 with IE 8 installed? Don’t forget to add Keys for Host Environments If you’re developing your application in Visual Studio and you run the debugger you may find that your application is still not rendering right, but if you run the actual generated EXE from Explorer or the OS command prompt it works. That’s because when you run the debugger in Visual Studio it wraps your application into a debugging host container. For this reason you might want to also add another registry key for yourapp.vshost.exe on your development machine. If you’re developing in Visual FoxPro make sure you add a key for vfp9.exe to see the rendering adjustments in the Visual FoxPro development environment. Cleaner HTML - no more HTML mangling! There are a number of additional benefits to setting up rendering of the Web Browser control to the IE 9 engine (or even the IE 8 engine) beyond the obvious rendering functionality. IE 9 actually returns your HTML in something that resembles the original HTML formatting, as opposed to the IE 7 default format which mangled the original HTML content. If you do the following in the WPF application: private void button2_Click(object sender, RoutedEventArgs e) { dynamic doc = this.webBrowser.Document; MessageBox.Show(doc.body.outerHtml); } you get different output depending on the rendering mode active. With the default IE 7 rendering you get: <BODY><DIV> <H1>Rounded Corners and Shadows - Creating Dialogs in CSS</H1> <DIV class=toolbarcontainer><A class=hoverbutton href="./"><IMG src="../../css/images/home.gif"> Home</A> <A class=hoverbutton href="RoundedCornersAndShadows.htm"><IMG src="../../css/images/refresh.gif"> Refresh</A> </DIV> <DIV class=containercontent> <FIELDSET><LEGEND>Plain Box</LEGEND><!-- Simple Box with rounded corners and shadow --> <DIV style="BORDER-BOTTOM: steelblue 2px solid; BORDER-LEFT: steelblue 2px solid; WIDTH: 550px; BORDER-TOP: steelblue 2px solid; BORDER-RIGHT: steelblue 2px solid" class="roundbox boxshadow"> <DIV style="BACKGROUND: khaki" class="boxcontenttext roundbox">Simple Rounded Corner Box. </DIV></DIV></FIELDSET> <FIELDSET><LEGEND>Box with Header</LEGEND> <DIV style="BORDER-BOTTOM: steelblue 2px solid; BORDER-LEFT: steelblue 2px solid; WIDTH: 550px; BORDER-TOP: steelblue 2px solid; BORDER-RIGHT: steelblue 2px solid" class="roundbox boxshadow"> <DIV class="gridheaderleft roundbox-top">Box with a Header</DIV> <DIV style="BACKGROUND: khaki" class="boxcontenttext roundbox-bottom">Simple Rounded Corner Box. </DIV></DIV></FIELDSET> <FIELDSET><LEGEND>Dialog Style Window</LEGEND> <DIV style="POSITION: relative; WIDTH: 450px" id=divDialog class="dialog boxshadow" jQuery16107208195684204002="2"> <DIV style="POSITION: relative" class=dialog-header> <DIV class=closebox></DIV>User Sign-in <DIV class=closebox jQuery16107208195684204002="3"></DIV></DIV> <DIV class=descriptionheader>This dialog is draggable and closable</DIV> <DIV class=dialog-content><LABEL>Username:</LABEL> <INPUT name=txtUsername value=" "> <LABEL>Password</LABEL> <INPUT name=txtPassword value=" "> <HR> <INPUT id=btnLogin value=Login type=button> </DIV> <DIV class=dialog-statusbar>Ready</DIV></DIV></FIELDSET> </DIV> <SCRIPT type=text/javascript>     $(document).ready(function () {         $("#divDialog")             .draggable({ handle: ".dialog-header" })             .closable({ handle: ".dialog-header",                 closeHandler: function () {                     alert("Window about to be closed.");                     return true;  // true closes - false leaves open                 }             });     }); </SCRIPT> </DIV></BODY> Now lest you think I’m out of my mind and create complete whacky HTML rooted in the last century, here’s the IE 9 rendering mode output which looks a heck of a lot cleaner and a lot closer to my original HTML of the page I’m accessing: <body> <div>         <h1>Rounded Corners and Shadows - Creating Dialogs in CSS</h1>     <div class="toolbarcontainer">         <a class="hoverbutton" href="./"> <img src="../../css/images/home.gif"> Home</a>         <a class="hoverbutton" href="RoundedCornersAndShadows.htm"> <img src="../../css/images/refresh.gif"> Refresh</a>     </div>         <div class="containercontent">     <fieldset>         <legend>Plain Box</legend>                <!-- Simple Box with rounded corners and shadow -->             <div style="border: 2px solid steelblue; width: 550px;" class="roundbox boxshadow">                              <div style="background: khaki;" class="boxcontenttext roundbox">                     Simple Rounded Corner Box.                 </div>             </div>     </fieldset>     <fieldset>         <legend>Box with Header</legend>         <div style="border: 2px solid steelblue; width: 550px;" class="roundbox boxshadow">                          <div class="gridheaderleft roundbox-top">Box with a Header</div>             <div style="background: khaki;" class="boxcontenttext roundbox-bottom">                 Simple Rounded Corner Box.             </div>         </div>     </fieldset>       <fieldset>         <legend>Dialog Style Window</legend>         <div style="width: 450px; position: relative;" id="divDialog" class="dialog boxshadow">             <div style="position: relative;" class="dialog-header">                 <div class="closebox"></div>                 User Sign-in             <div class="closebox"></div></div>             <div class="descriptionheader">This dialog is draggable and closable</div>                    <div class="dialog-content">                             <label>Username:</label>                 <input name="txtUsername" value=" " type="text">                 <label>Password</label>                 <input name="txtPassword" value=" " type="text">                                 <hr/>                                 <input id="btnLogin" value="Login" type="button">                        </div>             <div class="dialog-statusbar">Ready</div>         </div>     </fieldset>     </div> <script type="text/javascript">     $(document).ready(function () {         $("#divDialog")             .draggable({ handle: ".dialog-header" })             .closable({ handle: ".dialog-header",                 closeHandler: function () {                     alert("Window about to be closed.");                     return true;  // true closes - false leaves open                 }             });     }); </script>        </div> </body> IOW, in IE9 rendering mode IE9 is much closer (but not identical) to the original HTML from the page on the Web that we’re reading from. As a side note: Unfortunately, the browser feature emulation can't be applied against the Html Help (CHM) Engine in Windows which uses the Web Browser control (or COM interfaces anyway) to render Html Help content. I tried setting up hh.exe which is the help viewer, to use IE 9 rendering but a help file generated with CSS3 features will simply show in IE 7 mode. Bummer - this would have been a nice quick fix to allow help content served from CHM files to look better. HTML Editing leaves HTML formatting intact In the same vane, if you do any inline HTML editing in the control by setting content to be editable, IE 9’s control does a much more reasonable job of creating usable and somewhat valid HTML. It also leaves the original content alone other than the text your are editing or adding. No longer is the HTML output stripped of excess spaces and reformatted in IEs format. So if I do: private void button3_Click(object sender, RoutedEventArgs e) { dynamic doc = this.webBrowser.Document; doc.body.contentEditable = true; } and then make some changes to the document by typing into it using IE 9 mode, the document formatting stays intact and only the affected content is modified. The created HTML is reasonably clean (although it does lack proper XHTML formatting for things like <br/> <hr/>). This is very different from IE 7 mode which mangled the HTML as soon as the page was loaded into the control. Any editing you did stripped out all white space and lost all of your existing XHTML formatting. In IE 9 mode at least *most* of your original formatting stays intact. This is huge! In Html Help Builder I have supported HTML editing for a long time but the HTML mangling by the Web Browser control made it very difficult to edit the HTML later. Previously IE would mangle the HTML by stripping out spaces, upper casing all tags and converting many XHTML safe tags to its HTML 3 tags. Now IE leaves most of my document alone while editing, and creates cleaner and more compliant markup (with exception of self-closing elements like BR/HR). The end result is that I now have HTML editing in place that's much cleaner and actually capable of being manually edited. Caveats, Caveats, Caveats It wouldn't be Internet Explorer if there weren't some major compatibility issues involved in using this various browser version interaction. The biggest thing I ran into is that there are odd differences in some of the COM interfaces and what they return. I specifically ran into a problem with the document.selection.createRange() function which with IE 7 compatibility returns an expected text range object. When running in IE 8 or IE 9 mode however. I could not retrieve a valid text range with this code where loEdit is the WebBrowser control: loRange = loEdit.document.selection.CreateRange() The loRange object returned (here in FoxPro) had a length property of 0 but none of the other properties of the TextRange or TextRangeCollection objects were available. I figured this was due to some changed security settings but even after elevating the Intranet Security Zone and mucking with the other browser feature flags pertaining to security I had no luck. In the end I relented and used a JavaScript function in my editor document that returns a selection range object: function getselectionrange() { var range = document.selection.createRange(); return range; } and call that JavaScript function from my host applications code: *** Use a function in the document to get around HTML Editing issues loRange = loEdit.document.parentWindow.getselectionrange(.f.) and that does work correctly. This wasn't a big deal as I'm already loading a support script file into the editor page so all I had to do is add the function to this existing script file. You can find out more how to call script code in the Web Browser control from a host application in a previous post of mine. IE 8 and 9 also clamp down the security environment a little more than the default IE 7 control, so there may be other issues you run into. Other than the createRange() problem above I haven't seen anything else that is breaking in my code so far though and that's encouraging at least since it uses a lot of HTML document manipulation for the custom editor I've created (and would love to replace - any PROFESSIONAL alternatives anybody?) Registry Key Installation for your Application It’s important to remember that this registry setting is made per application, so most likely this is something you want to set up with your installer. Also remember that 32 and 64 bit settings require separate settings in the registry so if you’re creating your installer you most likely will want to set both keys in the registry preemptively for your application. I use Tarma Installer for all of my application installs and in Tarma I configure registry keys for both and set a flag to only install the latter key group in the 64 bit version: Because this setting is application specific you have to do this for every application you install unfortunately, but this also means that you can safely configure this setting in the registry because it is after only applied to your application. Another problem with install based installation is version detection. If IE 8 is installed I’d want 8000 for the value, if IE 9 is installed I want 9000. I can do this easily in code but in the installer this is much more difficult. I don’t have a good solution for this at the moment, but given that the app works with IE 7 mode now, IE 9 mode is just a bonus for the moment. If IE 9 is not installed and 9000 is used the default rendering will remain in use.   It sure would be nice if we could specify the IE rendering mode as a property, but I suspect the ActiveX container has to know before it loads what actual version to load up and once loaded can only load a single version of IE. This would account for this annoying application level configuration… Summary The registry feature emulation has been available for quite some time, but I just found out about it today and started experimenting around with it. I’m stoked to see that this is available as I’d pretty much given up in ever seeing any better rendering in the Web Browser control. Now at least my apps can take advantage of newer HTML features. Now if we could only get better HTML Editing support somehow <snicker>… ah can’t have everything.© Rick Strahl, West Wind Technologies, 2005-2011Posted in .NET  FoxPro  Windows  

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• value types in the vm

  - by john.rose

  value types in the vm p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} p.p2 {margin: 0.0px 0.0px 14.0px 0.0px; font: 14.0px Times} p.p3 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times} p.p4 {margin: 0.0px 0.0px 15.0px 0.0px; font: 14.0px Times} p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier} p.p6 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier; min-height: 17.0px} p.p7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p8 {margin: 0.0px 0.0px 0.0px 36.0px; text-indent: -36.0px; font: 14.0px Times; min-height: 18.0px} p.p9 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p10 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; color: #000000} li.li1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} li.li7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} span.s1 {font: 14.0px Courier} span.s2 {color: #000000} span.s3 {font: 14.0px Courier; color: #000000} ol.ol1 {list-style-type: decimal} Or, enduring values for a changing world. Introduction A value type is a data type which, generally speaking, is designed for being passed by value in and out of methods, and stored by value in data structures. The only value types which the Java language directly supports are the eight primitive types. Java indirectly and approximately supports value types, if they are implemented in terms of classes. For example, both Integer and String may be viewed as value types, especially if their usage is restricted to avoid operations appropriate to Object. In this note, we propose a definition of value types in terms of a design pattern for Java classes, accompanied by a set of usage restrictions. We also sketch the relation of such value types to tuple types (which are a JVM-level notion), and point out JVM optimizations that can apply to value types. This note is a thought experiment to extend the JVM’s performance model in support of value types. The demonstration has two phases.  Initially the extension can simply use design patterns, within the current bytecode architecture, and in today’s Java language. But if the performance model is to be realized in practice, it will probably require new JVM bytecode features, changes to the Java language, or both.  We will look at a few possibilities for these new features. An Axiom of Value In the context of the JVM, a value type is a data type equipped with construction, assignment, and equality operations, and a set of typed components, such that, whenever two variables of the value type produce equal corresponding values for their components, the values of the two variables cannot be distinguished by any JVM operation. Here are some corollaries: A value type is immutable, since otherwise a copy could be constructed and the original could be modified in one of its components, allowing the copies to be distinguished. Changing the component of a value type requires construction of a new value. The equals and hashCode operations are strictly component-wise. If a value type is represented by a JVM reference, that reference cannot be successfully synchronized on, and cannot be usefully compared for reference equality. A value type can be viewed in terms of what it doesn’t do. We can say that a value type omits all value-unsafe operations, which could violate the constraints on value types.  These operations, which are ordinarily allowed for Java object types, are pointer equality comparison (the acmp instruction), synchronization (the monitor instructions), all the wait and notify methods of class Object, and non-trivial finalize methods. The clone method is also value-unsafe, although for value types it could be treated as the identity function. Finally, and most importantly, any side effect on an object (however visible) also counts as an value-unsafe operation. A value type may have methods, but such methods must not change the components of the value. It is reasonable and useful to define methods like toString, equals, and hashCode on value types, and also methods which are specifically valuable to users of the value type. Representations of Value Value types have two natural representations in the JVM, unboxed and boxed. An unboxed value consists of the components, as simple variables. For example, the complex number x=(1+2i), in rectangular coordinate form, may be represented in unboxed form by the following pair of variables: /*Complex x = Complex.valueOf(1.0, 2.0):*/ double x_re = 1.0, x_im = 2.0; These variables might be locals, parameters, or fields. Their association as components of a single value is not defined to the JVM. Here is a sample computation which computes the norm of the difference between two complex numbers: double distance(/*Complex x:*/ double x_re, double x_im,         /*Complex y:*/ double y_re, double y_im) {     /*Complex z = x.minus(y):*/     double z_re = x_re - y_re, z_im = x_im - y_im;     /*return z.abs():*/     return Math.sqrt(z_re*z_re + z_im*z_im); } A boxed representation groups component values under a single object reference. The reference is to a ‘wrapper class’ that carries the component values in its fields. (A primitive type can naturally be equated with a trivial value type with just one component of that type. In that view, the wrapper class Integer can serve as a boxed representation of value type int.) The unboxed representation of complex numbers is practical for many uses, but it fails to cover several major use cases: return values, array elements, and generic APIs. The two components of a complex number cannot be directly returned from a Java function, since Java does not support multiple return values. The same story applies to array elements: Java has no ’array of structs’ feature. (Double-length arrays are a possible workaround for complex numbers, but not for value types with heterogeneous components.) By generic APIs I mean both those which use generic types, like Arrays.asList and those which have special case support for primitive types, like String.valueOf and PrintStream.println. Those APIs do not support unboxed values, and offer some problems to boxed values. Any ’real’ JVM type should have a story for returns, arrays, and API interoperability. The basic problem here is that value types fall between primitive types and object types. Value types are clearly more complex than primitive types, and object types are slightly too complicated. Objects are a little bit dangerous to use as value carriers, since object references can be compared for pointer equality, and can be synchronized on. Also, as many Java programmers have observed, there is often a performance cost to using wrapper objects, even on modern JVMs. Even so, wrapper classes are a good starting point for talking about value types. If there were a set of structural rules and restrictions which would prevent value-unsafe operations on value types, wrapper classes would provide a good notation for defining value types. This note attempts to define such rules and restrictions. Let’s Start Coding Now it is time to look at some real code. Here is a definition, written in Java, of a complex number value type. @ValueSafe public final class Complex implements java.io.Serializable {     // immutable component structure:     public final double re, im;     private Complex(double re, double im) {         this.re = re; this.im = im;     }     // interoperability methods:     public String toString() { return "Complex("+re+","+im+")"; }     public List<Double> asList() { return Arrays.asList(re, im); }     public boolean equals(Complex c) {         return re == c.re && im == c.im;     }     public boolean equals(@ValueSafe Object x) {         return x instanceof Complex && equals((Complex) x);     }     public int hashCode() {         return 31*Double.valueOf(re).hashCode()                 + Double.valueOf(im).hashCode();     }     // factory methods:     public static Complex valueOf(double re, double im) {         return new Complex(re, im);     }     public Complex changeRe(double re2) { return valueOf(re2, im); }     public Complex changeIm(double im2) { return valueOf(re, im2); }     public static Complex cast(@ValueSafe Object x) {         return x == null ? ZERO : (Complex) x;     }     // utility methods and constants:     public Complex plus(Complex c)  { return new Complex(re+c.re, im+c.im); }     public Complex minus(Complex c) { return new Complex(re-c.re, im-c.im); }     public double abs() { return Math.sqrt(re*re + im*im); }     public static final Complex PI = valueOf(Math.PI, 0.0);     public static final Complex ZERO = valueOf(0.0, 0.0); } This is not a minimal definition, because it includes some utility methods and other optional parts.  The essential elements are as follows: The class is marked as a value type with an annotation. The class is final, because it does not make sense to create subclasses of value types. The fields of the class are all non-private and final.  (I.e., the type is immutable and structurally transparent.) From the supertype Object, all public non-final methods are overridden. The constructor is private. Beyond these bare essentials, we can observe the following features in this example, which are likely to be typical of all value types: One or more factory methods are responsible for value creation, including a component-wise valueOf method. There are utility methods for complex arithmetic and instance creation, such as plus and changeIm. There are static utility constants, such as PI. The type is serializable, using the default mechanisms. There are methods for converting to and from dynamically typed references, such as asList and cast. The Rules In order to use value types properly, the programmer must avoid value-unsafe operations.  A helpful Java compiler should issue errors (or at least warnings) for code which provably applies value-unsafe operations, and should issue warnings for code which might be correct but does not provably avoid value-unsafe operations.  No such compilers exist today, but to simplify our account here, we will pretend that they do exist. A value-safe type is any class, interface, or type parameter marked with the @ValueSafe annotation, or any subtype of a value-safe type.  If a value-safe class is marked final, it is in fact a value type.  All other value-safe classes must be abstract.  The non-static fields of a value class must be non-public and final, and all its constructors must be private. Under the above rules, a standard interface could be helpful to define value types like Complex.  Here is an example: @ValueSafe public interface ValueType extends java.io.Serializable {     // All methods listed here must get redefined.     // Definitions must be value-safe, which means     // they may depend on component values only.     List<? extends Object> asList();     int hashCode();     boolean equals(@ValueSafe Object c);     String toString(); } //@ValueSafe inherited from supertype: public final class Complex implements ValueType { … The main advantage of such a conventional interface is that (unlike an annotation) it is reified in the runtime type system.  It could appear as an element type or parameter bound, for facilities which are designed to work on value types only.  More broadly, it might assist the JVM to perform dynamic enforcement of the rules for value types. Besides types, the annotation @ValueSafe can mark fields, parameters, local variables, and methods.  (This is redundant when the type is also value-safe, but may be useful when the type is Object or another supertype of a value type.)  Working forward from these annotations, an expression E is defined as value-safe if it satisfies one or more of the following: The type of E is a value-safe type. E names a field, parameter, or local variable whose declaration is marked @ValueSafe. E is a call to a method whose declaration is marked @ValueSafe. E is an assignment to a value-safe variable, field reference, or array reference. E is a cast to a value-safe type from a value-safe expression. E is a conditional expression E0 ? E1 : E2, and both E1 and E2 are value-safe. Assignments to value-safe expressions and initializations of value-safe names must take their values from value-safe expressions. A value-safe expression may not be the subject of a value-unsafe operation.  In particular, it cannot be synchronized on, nor can it be compared with the “==” operator, not even with a null or with another value-safe type. In a program where all of these rules are followed, no value-type value will be subject to a value-unsafe operation.  Thus, the prime axiom of value types will be satisfied, that no two value type will be distinguishable as long as their component values are equal. More Code To illustrate these rules, here are some usage examples for Complex: Complex pi = Complex.valueOf(Math.PI, 0); Complex zero = pi.changeRe(0);  //zero = pi; zero.re = 0; ValueType vtype = pi; @SuppressWarnings("value-unsafe")   Object obj = pi; @ValueSafe Object obj2 = pi; obj2 = new Object();  // ok List<Complex> clist = new ArrayList<Complex>(); clist.add(pi);  // (ok assuming List.add param is @ValueSafe) List<ValueType> vlist = new ArrayList<ValueType>(); vlist.add(pi);  // (ok) List<Object> olist = new ArrayList<Object>(); olist.add(pi);  // warning: "value-unsafe" boolean z = pi.equals(zero); boolean z1 = (pi == zero);  // error: reference comparison on value type boolean z2 = (pi == null);  // error: reference comparison on value type boolean z3 = (pi == obj2);  // error: reference comparison on value type synchronized (pi) { }  // error: synch of value, unpredictable result synchronized (obj2) { }  // unpredictable result Complex qq = pi; qq = null;  // possible NPE; warning: “null-unsafe" qq = (Complex) obj;  // warning: “null-unsafe" qq = Complex.cast(obj);  // OK @SuppressWarnings("null-unsafe")   Complex empty = null;  // possible NPE qq = empty;  // possible NPE (null pollution) The Payoffs It follows from this that either the JVM or the java compiler can replace boxed value-type values with unboxed ones, without affecting normal computations.  Fields and variables of value types can be split into their unboxed components.  Non-static methods on value types can be transformed into static methods which take the components as value parameters. Some common questions arise around this point in any discussion of value types. Why burden the programmer with all these extra rules?  Why not detect programs automagically and perform unboxing transparently?  The answer is that it is easy to break the rules accidently unless they are agreed to by the programmer and enforced.  Automatic unboxing optimizations are tantalizing but (so far) unreachable ideal.  In the current state of the art, it is possible exhibit benchmarks in which automatic unboxing provides the desired effects, but it is not possible to provide a JVM with a performance model that assures the programmer when unboxing will occur.  This is why I’m writing this note, to enlist help from, and provide assurances to, the programmer.  Basically, I’m shooting for a good set of user-supplied “pragmas” to frame the desired optimization. Again, the important thing is that the unboxing must be done reliably, or else programmers will have no reason to work with the extra complexity of the value-safety rules.  There must be a reasonably stable performance model, wherein using a value type has approximately the same performance characteristics as writing the unboxed components as separate Java variables. There are some rough corners to the present scheme.  Since Java fields and array elements are initialized to null, value-type computations which incorporate uninitialized variables can produce null pointer exceptions.  One workaround for this is to require such variables to be null-tested, and the result replaced with a suitable all-zero value of the value type.  That is what the “cast” method does above. Generically typed APIs like List<T> will continue to manipulate boxed values always, at least until we figure out how to do reification of generic type instances.  Use of such APIs will elicit warnings until their type parameters (and/or relevant members) are annotated or typed as value-safe.  Retrofitting List<T> is likely to expose flaws in the present scheme, which we will need to engineer around.  Here are a couple of first approaches: public interface java.util.List<@ValueSafe T> extends Collection<T> { … public interface java.util.List<T extends Object|ValueType> extends Collection<T> { … (The second approach would require disjunctive types, in which value-safety is “contagious” from the constituent types.) With more transformations, the return value types of methods can also be unboxed.  This may require significant bytecode-level transformations, and would work best in the presence of a bytecode representation for multiple value groups, which I have proposed elsewhere under the title “Tuples in the VM”. But for starters, the JVM can apply this transformation under the covers, to internally compiled methods.  This would give a way to express multiple return values and structured return values, which is a significant pain-point for Java programmers, especially those who work with low-level structure types favored by modern vector and graphics processors.  The lack of multiple return values has a strong distorting effect on many Java APIs. Even if the JVM fails to unbox a value, there is still potential benefit to the value type.  Clustered computing systems something have copy operations (serialization or something similar) which apply implicitly to command operands.  When copying JVM objects, it is extremely helpful to know when an object’s identity is important or not.  If an object reference is a copied operand, the system may have to create a proxy handle which points back to the original object, so that side effects are visible.  Proxies must be managed carefully, and this can be expensive.  On the other hand, value types are exactly those types which a JVM can “copy and forget” with no downside. Array types are crucial to bulk data interfaces.  (As data sizes and rates increase, bulk data becomes more important than scalar data, so arrays are definitely accompanying us into the future of computing.)  Value types are very helpful for adding structure to bulk data, so a successful value type mechanism will make it easier for us to express richer forms of bulk data. Unboxing arrays (i.e., arrays containing unboxed values) will provide better cache and memory density, and more direct data movement within clustered or heterogeneous computing systems.  They require the deepest transformations, relative to today’s JVM.  There is an impedance mismatch between value-type arrays and Java’s covariant array typing, so compromises will need to be struck with existing Java semantics.  It is probably worth the effort, since arrays of unboxed value types are inherently more memory-efficient than standard Java arrays, which rely on dependent pointer chains. It may be sufficient to extend the “value-safe” concept to array declarations, and allow low-level transformations to change value-safe array declarations from the standard boxed form into an unboxed tuple-based form.  Such value-safe arrays would not be convertible to Object[] arrays.  Certain connection points, such as Arrays.copyOf and System.arraycopy might need additional input/output combinations, to allow smooth conversion between arrays with boxed and unboxed elements. Alternatively, the correct solution may have to wait until we have enough reification of generic types, and enough operator overloading, to enable an overhaul of Java arrays. Implicit Method Definitions The example of class Complex above may be unattractively complex.  I believe most or all of the elements of the example class are required by the logic of value types. If this is true, a programmer who writes a value type will have to write lots of error-prone boilerplate code.  On the other hand, I think nearly all of the code (except for the domain-specific parts like plus and minus) can be implicitly generated. Java has a rule for implicitly defining a class’s constructor, if no it defines no constructors explicitly.  Likewise, there are rules for providing default access modifiers for interface members.  Because of the highly regular structure of value types, it might be reasonable to perform similar implicit transformations on value types.  Here’s an example of a “highly implicit” definition of a complex number type: public class Complex implements ValueType {  // implicitly final     public double re, im;  // implicitly public final     //implicit methods are defined elementwise from te fields:     //  toString, asList, equals(2), hashCode, valueOf, cast     //optionally, explicit methods (plus, abs, etc.) would go here } In other words, with the right defaults, a simple value type definition can be a one-liner.  The observant reader will have noticed the similarities (and suitable differences) between the explicit methods above and the corresponding methods for List<T>. Another way to abbreviate such a class would be to make an annotation the primary trigger of the functionality, and to add the interface(s) implicitly: public @ValueType class Complex { … // implicitly final, implements ValueType (But to me it seems better to communicate the “magic” via an interface, even if it is rooted in an annotation.) Implicitly Defined Value Types So far we have been working with nominal value types, which is to say that the sequence of typed components is associated with a name and additional methods that convey the intention of the programmer.  A simple ordered pair of floating point numbers can be variously interpreted as (to name a few possibilities) a rectangular or polar complex number or Cartesian point.  The name and the methods convey the intended meaning. But what if we need a truly simple ordered pair of floating point numbers, without any further conceptual baggage?  Perhaps we are writing a method (like “divideAndRemainder”) which naturally returns a pair of numbers instead of a single number.  Wrapping the pair of numbers in a nominal type (like “QuotientAndRemainder”) makes as little sense as wrapping a single return value in a nominal type (like “Quotient”).  What we need here are structural value types commonly known as tuples. For the present discussion, let us assign a conventional, JVM-friendly name to tuples, roughly as follows: public class java.lang.tuple.$DD extends java.lang.tuple.Tuple {      double $1, $2; } Here the component names are fixed and all the required methods are defined implicitly.  The supertype is an abstract class which has suitable shared declarations.  The name itself mentions a JVM-style method parameter descriptor, which may be “cracked” to determine the number and types of the component fields. The odd thing about such a tuple type (and structural types in general) is it must be instantiated lazily, in response to linkage requests from one or more classes that need it.  The JVM and/or its class loaders must be prepared to spin a tuple type on demand, given a simple name reference, $xyz, where the xyz is cracked into a series of component types.  (Specifics of naming and name mangling need some tasteful engineering.) Tuples also seem to demand, even more than nominal types, some support from the language.  (This is probably because notations for non-nominal types work best as combinations of punctuation and type names, rather than named constructors like Function3 or Tuple2.)  At a minimum, languages with tuples usually (I think) have some sort of simple bracket notation for creating tuples, and a corresponding pattern-matching syntax (or “destructuring bind”) for taking tuples apart, at least when they are parameter lists.  Designing such a syntax is no simple thing, because it ought to play well with nominal value types, and also with pre-existing Java features, such as method parameter lists, implicit conversions, generic types, and reflection.  That is a task for another day. Other Use Cases Besides complex numbers and simple tuples there are many use cases for value types.  Many tuple-like types have natural value-type representations. These include rational numbers, point locations and pixel colors, and various kinds of dates and addresses. Other types have a variable-length ‘tail’ of internal values. The most common example of this is String, which is (mathematically) a sequence of UTF-16 character values. Similarly, bit vectors, multiple-precision numbers, and polynomials are composed of sequences of values. Such types include, in their representation, a reference to a variable-sized data structure (often an array) which (somehow) represents the sequence of values. The value type may also include ’header’ information. Variable-sized values often have a length distribution which favors short lengths. In that case, the design of the value type can make the first few values in the sequence be direct ’header’ fields of the value type. In the common case where the header is enough to represent the whole value, the tail can be a shared null value, or even just a null reference. Note that the tail need not be an immutable object, as long as the header type encapsulates it well enough. This is the case with String, where the tail is a mutable (but never mutated) character array. Field types and their order must be a globally visible part of the API.  The structure of the value type must be transparent enough to have a globally consistent unboxed representation, so that all callers and callees agree about the type and order of components  that appear as parameters, return types, and array elements.  This is a trade-off between efficiency and encapsulation, which is forced on us when we remove an indirection enjoyed by boxed representations.  A JVM-only transformation would not care about such visibility, but a bytecode transformation would need to take care that (say) the components of complex numbers would not get swapped after a redefinition of Complex and a partial recompile.  Perhaps constant pool references to value types need to declare the field order as assumed by each API user. This brings up the delicate status of private fields in a value type.  It must always be possible to load, store, and copy value types as coordinated groups, and the JVM performs those movements by moving individual scalar values between locals and stack.  If a component field is not public, what is to prevent hostile code from plucking it out of the tuple using a rogue aload or astore instruction?  Nothing but the verifier, so we may need to give it more smarts, so that it treats value types as inseparable groups of stack slots or locals (something like long or double). My initial thought was to make the fields always public, which would make the security problem moot.  But public is not always the right answer; consider the case of String, where the underlying mutable character array must be encapsulated to prevent security holes.  I believe we can win back both sides of the tradeoff, by training the verifier never to split up the components in an unboxed value.  Just as the verifier encapsulates the two halves of a 64-bit primitive, it can encapsulate the the header and body of an unboxed String, so that no code other than that of class String itself can take apart the values. Similar to String, we could build an efficient multi-precision decimal type along these lines: public final class DecimalValue extends ValueType {     protected final long header;     protected private final BigInteger digits;     public DecimalValue valueOf(int value, int scale) {         assert(scale >= 0);         return new DecimalValue(((long)value << 32) + scale, null);     }     public DecimalValue valueOf(long value, int scale) {         if (value == (int) value)             return valueOf((int)value, scale);         return new DecimalValue(-scale, new BigInteger(value));     } } Values of this type would be passed between methods as two machine words. Small values (those with a significand which fits into 32 bits) would be represented without any heap data at all, unless the DecimalValue itself were boxed. (Note the tension between encapsulation and unboxing in this case.  It would be better if the header and digits fields were private, but depending on where the unboxing information must “leak”, it is probably safer to make a public revelation of the internal structure.) Note that, although an array of Complex can be faked with a double-length array of double, there is no easy way to fake an array of unboxed DecimalValues.  (Either an array of boxed values or a transposed pair of homogeneous arrays would be reasonable fallbacks, in a current JVM.)  Getting the full benefit of unboxing and arrays will require some new JVM magic. Although the JVM emphasizes portability, system dependent code will benefit from using machine-level types larger than 64 bits.  For example, the back end of a linear algebra package might benefit from value types like Float4 which map to stock vector types.  This is probably only worthwhile if the unboxing arrays can be packed with such values. More Daydreams A more finely-divided design for dynamic enforcement of value safety could feature separate marker interfaces for each invariant.  An empty marker interface Unsynchronizable could cause suitable exceptions for monitor instructions on objects in marked classes.  More radically, a Interchangeable marker interface could cause JVM primitives that are sensitive to object identity to raise exceptions; the strangest result would be that the acmp instruction would have to be specified as raising an exception. @ValueSafe public interface ValueType extends java.io.Serializable,         Unsynchronizable, Interchangeable { … public class Complex implements ValueType {     // inherits Serializable, Unsynchronizable, Interchangeable, @ValueSafe     … It seems possible that Integer and the other wrapper types could be retro-fitted as value-safe types.  This is a major change, since wrapper objects would be unsynchronizable and their references interchangeable.  It is likely that code which violates value-safety for wrapper types exists but is uncommon.  It is less plausible to retro-fit String, since the prominent operation String.intern is often used with value-unsafe code. We should also reconsider the distinction between boxed and unboxed values in code.  The design presented above obscures that distinction.  As another thought experiment, we could imagine making a first class distinction in the type system between boxed and unboxed representations.  Since only primitive types are named with a lower-case initial letter, we could define that the capitalized version of a value type name always refers to the boxed representation, while the initial lower-case variant always refers to boxed.  For example: complex pi = complex.valueOf(Math.PI, 0); Complex boxPi = pi;  // convert to boxed myList.add(boxPi); complex z = myList.get(0);  // unbox Such a convention could perhaps absorb the current difference between int and Integer, double and Double. It might also allow the programmer to express a helpful distinction among array types. As said above, array types are crucial to bulk data interfaces, but are limited in the JVM.  Extending arrays beyond the present limitations is worth thinking about; for example, the Maxine JVM implementation has a hybrid object/array type.  Something like this which can also accommodate value type components seems worthwhile.  On the other hand, does it make sense for value types to contain short arrays?  And why should random-access arrays be the end of our design process, when bulk data is often sequentially accessed, and it might make sense to have heterogeneous streams of data as the natural “jumbo” data structure.  These considerations must wait for another day and another note. More Work It seems to me that a good sequence for introducing such value types would be as follows: Add the value-safety restrictions to an experimental version of javac. Code some sample applications with value types, including Complex and DecimalValue. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. A staggered roll-out like this would decouple language changes from bytecode changes, which is always a convenient thing. A similar investigation should be applied (concurrently) to array types.  In this case, it seems to me that the starting point is in the JVM: Add an experimental unboxing array data structure to a production JVM, perhaps along the lines of Maxine hybrids.  No bytecode or language support is required at first; everything can be done with encapsulated unsafe operations and/or method handles. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. That’s enough musing me for now.  Back to work!

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• iPhone SDK vs Windows Phone 7 Series SDK Challenge, Part 1: Hello World!

  In this series, I will be taking sample applications from the iPhone SDK and implementing them on Windows Phone 7 Series.  My goal is to do as much of an apples-to-apples comparison as I can.  This series will be written to not only compare and contrast how easy or difficult it is to complete tasks on either platform, how many lines of code, etc., but Id also like it to be a way for iPhone developers to either get started on Windows Phone 7 Series development, or for developers in general to learn the platform. Heres my methodology: Run the iPhone SDK app in the iPhone Simulator to get a feel for what it does and how it works, without looking at the implementation Implement the equivalent functionality on Windows Phone 7 Series using Silverlight. Compare the two implementations based on complexity, functionality, lines of code, number of files, etc. Add some functionality to the Windows Phone 7 Series app that shows off a way to make the scenario more interesting or leverages an aspect of the platform, or uses a better design pattern to implement the functionality. You can download Microsoft Visual Studio 2010 Express for Windows Phone CTP here, and the Expression Blend 4 Beta here. Hello World! Of course no first post would be allowed if it didnt focus on the hello world scenario.  The iPhone SDK follows that tradition with the Your First iPhone Application walkthrough.  I will say that the developer documentation for iPhone is pretty good.  There are plenty of walkthoughs and they break things down into nicely sized steps and do a good job of bringing the user along.  As expected, this application is quite simple.  It comprises of a text box, a label, and a button.  When you push the button, the label changes to Hello plus the  word you typed into the text box.  Makes perfect sense for a starter application.  Theres not much to this but it covers a few basic elements: Laying out basic UI Handling user input Hooking up events Formatting text     So, lets get started building a similar app for Windows Phone 7 Series! Implementing the UI: UI in Silverlight (and therefore Windows Phone 7) is defined in XAML, which is a declarative XML language also used by WPF on the desktop.  For anyone thats familiar with similar types of markup, its relatively straightforward to learn, but has a lot of power in it once you get it figured out.  Well talk more about that. This UI is very simple.  When I look at this, I note a couple of things: Elements are arranged vertically They are all centered So, lets create our Application and then start with the UI.  Once you have the the VS 2010 Express for Windows Phone tool running, create a new Windows Phone Project, and call it Hello World: Once created, youll see the designer on one side and your XAML on the other: Now, we can create our UI in one of three ways: Use the designer in Visual Studio to drag and drop the components Use the designer in Expression Blend 4 to drag and drop the components Enter the XAML by hand in either of the above Well start with (1), then kind of move to (3) just for instructional value. To develop this UI in the designer: First, delete all of the markup between inside of the Grid element (LayoutRoot).  You should be left with just this XAML for your MainPage.xaml (i shortened all the xmlns declarations below for brevity): 1: <phoneNavigation:PhoneApplicationPage 2: x:Class="HelloWorld.MainPage" 3: xmlns="...[snip]" 4: FontFamily="{StaticResource PhoneFontFamilyNormal}" 5: FontSize="{StaticResource PhoneFontSizeNormal}" 6: Foreground="{StaticResource PhoneForegroundBrush}"> 7:   8: <Grid x:Name="LayoutRoot" Background="{StaticResource PhoneBackgroundBrush}"> 9:   10: </Grid> 11:   12: </phoneNavigation:PhoneApplicationPage> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Well be adding XAML at line 9, so thats the important part. Now, Click on the center area of the phone surface Open the Toolbox and double click StackPanel Double click TextBox Double click TextBlock Double click Button That will create the necessary UI elements but they wont be arranged quite right.  Well fix it in a second.    Heres the XAML that we end up with: 1: <StackPanel Height="100" HorizontalAlignment="Left" Margin="10,10,0,0" Name="stackPanel1" VerticalAlignment="Top" Width="200"> 2: <TextBox Height="32" Name="textBox1" Text="TextBox" Width="100" /> 3: <TextBlock Height="23" Name="textBlock1" Text="TextBlock" /> 4: <Button Content="Button" Height="70" Name="button1" Width="160" /> 5: </StackPanel> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The designer does its best at guessing what we want, but in this case we want things to be a bit simpler. So well just clean it up a bit.  We want the items to be centered and we want them to have a little bit of a margin on either side, so heres what we end up with.  Ive also made it match the values and style from the iPhone app: 1: <StackPanel Margin="10"> 2: <TextBox Name="textBox1" HorizontalAlignment="Stretch" Text="You" TextAlignment="Center"/> 3: <TextBlock Name="textBlock1" HorizontalAlignment="Center" Margin="0,100,0,0" Text="Hello You!" /> 4: <Button Name="button1" HorizontalAlignment="Center" Margin="0,150,0,0" Content="Hello"/> 5: </StackPanel> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Now lets take a look at what weve done there. Line 1: We removed all of the formatting from the StackPanel, except for Margin, as thats all we need.  Since our parent element is a Grid, by default the StackPanel will be sized to fit in that space.  The Margin says that we want to reserve 10 pixels on each side of the StackPanel. Line 2: Weve set the HorizontalAlignment of the TextBox to Stretch, which says that it should fill its parents size horizontally.  We want to do this so the TextBox is always full-width.  We also set TextAlignment to Center, to center the text. Line 3: In contrast to the TextBox above, we dont care how wide the TextBlock is, just so long as it is big enough for its text.  Thatll happen automatically, so we just set its Horizontal alignment to Center.  We also set a Margin above the TextBlock of 100 pixels to bump it down a bit, per the iPhone UI. Line 4: We do the same things here as in Line 3. Heres how the UI looks in the designer: Believe it or not, were almost done! Implementing the App Logic Now, we want the TextBlock to change its text when the Button is clicked.  In the designer, double click the Button to be taken to the Event Handler for the Buttons Click event.  In that event handler, we take the Text property from the TextBox, and format it into a string, then set it into the TextBlock.  Thats it! 1: private void button1_Click(object sender, RoutedEventArgs e) 2: { 3: string name = textBox1.Text; 4:   5: // if there isn't a name set, just use "World" 6: if (String.IsNullOrEmpty(name)) 7: { 8: name = "World"; 9: } 10:   11: // set the value into the TextBlock 12: textBlock1.Text = String.Format("Hello {0}!", name); 13:   14: } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } We use the String.Format() method to handle the formatting for us.    Now all thats left is to test the app in the Windows Phone Emulator and verify it does what we think it does! And it does! Comparing against the iPhone Looking at the iPhone example, there are basically three things that you have to touch as the developer: 1) The UI in the Nib file 2) The app delegate 3) The view controller Counting lines is a bit tricky here, but to try to keep this even, Im going to only count lines of code that I could not have (or would not have) generated with the tooling.  Meaning, Im not counting XAML and Im not counting operations that happen in the Nib file with the XCode designer tool.  So in the case of the above, even though I modified the XAML, I could have done all of those operations using the visual designer tool.  And normally I would have, but the XAML is more instructive (and less steps!).  Im interested in things that I, as the developer have to figure out in code.  Im also not counting lines that just have a curly brace on them, or lines that are generated for me (e.g. method names that are generated for me when I make a connection, etc.) So, by that count, heres what I get from the code listing for the iPhone app found here: HelloWorldAppDelegate.h: 6 HelloWorldAppDelegate.m: 12 MyViewController.h: 8 MyViewController.m: 18 Which gives me a grand total of about 44 lines of code on iPhone.  I really do recommend looking at the iPhone code for a comparison to the above. Now, for the Windows Phone 7 Series application, the only code I typed was in the event handler above Main.Xaml.cs: 4 So a total of 4 lines of code on Windows Phone 7.  And more importantly, the process is just A LOT simpler.  For example, I was surprised that the User Interface Designer in XCode doesnt automatically create instance variables for me and wire them up to the corresponding elements.  I assumed I wouldnt have to write this code myself (and risk getting it wrong!).  I dont need to worry about view controllers or anything.  I just write my code.  This blog post up to this point has covered almost every aspect of this apps development in a few pages.  The iPhone tutorial has 5 top level steps with 2-3 sub sections of each. Now, its worth pointing out that the iPhone development model uses the Model View Controller (MVC) pattern, which is a very flexible and powerful pattern that enforces proper separation of concerns.  But its fairly complex and difficult to understand when you first walk up to it.  Here at Microsoft weve dabbled in MVC a bit, with frameworks like MFC on Visual C++ and with the ASP.NET MVC framework now.  Both are very powerful frameworks.  But one of the reasons weve stayed away from MVC with client UI frameworks is that its difficult to tool.  We havent seen the type of value that beats double click, write code! for the broad set of scenarios. Another thing to think about is how many of those lines of code were focused on my apps functionality?.  Or, the converse of How many lines of code were boilerplate plumbing?  In both examples, the actual number of functional code lines is similar.  I count most of them in MyViewController.m, in the changeGreeting method.  Its about 7 lines of code that do the work of taking the value from the TextBox and putting it into the label.  Versus 4 on the Windows Phone 7 side.  But, unfortunately, on iPhone I still have to write that other 37 lines of code, just to get there. 10% of the code, 1 file instead of 4, its just much simpler. Making Some Tweaks It turns out, I can actually do this application with ZERO  lines of code, if Im willing to change the spec a bit. The data binding functionality in Silverlight is incredibly powerful.  And what I can do is databind the TextBoxs value directly to the TextBlock.  Take some time looking at this XAML below.  Youll see that I have added another nested StackPanel and two more TextBlocks.  Why?  Because thats how I build that string, and the nested StackPanel will lay things out Horizontally for me, as specified by the Orientation property. 1: <StackPanel Margin="10"> 2: <TextBox Name="textBox1" HorizontalAlignment="Stretch" Text="You" TextAlignment="Center"/> 3: <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="0,100,0,0" > 4: <TextBlock Text="Hello " /> 5: <TextBlock Name="textBlock1" Text="{Binding ElementName=textBox1, Path=Text}" /> 6: <TextBlock Text="!" /> 7: </StackPanel> 8: <Button Name="button1" HorizontalAlignment="Center" Margin="0,150,0,0" Content="Hello" Click="button1_Click" /> 9: </StackPanel> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Now, the real action is there in the bolded TextBlock.Text property: Text="{Binding ElementName=textBox1, Path=Text}" .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } That does all the heavy lifting.  It sets up a databinding between the TextBox.Text property on textBox1 and the TextBlock.Text property on textBlock1. As I change the text of the TextBox, the label updates automatically. In fact, I dont even need the button any more, so I could get rid of that altogether.  And no button means no event handler.  No event handler means no C# code at all.  Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• Rails requires Rubygems but I have the gems

  - by fogonthedowns

  Update I notice that which ruby and whereis ruby are different locations which ruby /opt/local/bin/ruby whereis ruby /usr/bin/ruby I recently upgraded ruby to ruby 1.8.7 (2009-06-12 patchlevel 174) [i686-darwin10] and I think I broke rails. When I attempt to load rails. I get an odd message. Please help! $ ruby script/server Rails requires RubyGems = 1.3.2. Please install RubyGems and try again: http://rubygems.rubyforge.org $ rails -v Rails 3.0.0.beta $ gem -v 1.3.6 $ which gem /usr/bin/gem $ whereis gem /usr/bin/gem $ which rails /usr/bin/rails $ whereis rails /usr/bin/rails $ /usr/bin/gem -v 1.3.6 $ /usr/bin/rails -v Rails 3.0.0.beta $ ruby script/console Rails requires RubyGems >= 1.3.2. Please install RubyGems and try again: http://rubygems.rubyforge.org $ gem list rails *** LOCAL GEMS *** rails (3.0.0.beta, 2.3.5, 2.2.2, 1.2.6) $ gem list *** LOCAL GEMS *** abstract (1.0.0) actionmailer (3.0.0.beta, 2.3.5, 2.2.2, 1.3.6) actionpack (3.0.0.beta, 2.3.5, 2.2.2, 1.13.6) actionwebservice (1.2.6) activemerchant (1.4.1) activemodel (3.0.0.beta) activerecord (3.0.0.beta, 2.3.5, 2.2.2, 1.15.6) activerecord-tableless (0.1.0) activeresource (3.0.0.beta, 2.3.5, 2.2.2) activesupport (3.0.0.beta, 2.3.5, 2.2.2, 1.4.4) acts_as_ferret (0.4.3) arel (0.2.pre) authlogic (2.1.3) builder (2.1.2) bundler (0.9.3) calendar_date_select (1.15) capistrano (2.5.2) cgi_multipart_eof_fix (2.5.0) chronic (0.2.3) columnize (0.3.1) compass (0.8.17) daemons (1.0.10) dnssd (0.6.0) erubis (2.6.5) fastercsv (1.5.0) fastthread (1.0.1) fcgi (0.8.7) ferret (0.11.6) flay (1.4.0) flog (2.4.0) gbarcode (0.98.16) gem_plugin (0.2.3) git (1.2.5) haml (2.2.15) haml-edge (2.3.100) highline (1.5.0) hoe (2.4.0) hpricot (0.6.164) i18n (0.3.3) javan-whenever (0.3.7) jeweler (1.4.0) jscruggs-metric_fu (1.1.5) json_pure (1.2.0) libxml-ruby (1.1.2) linecache (0.43) mail (2.1.2) mechanize (0.9.3) memcache-client (1.7.8) mime-types (1.16) mislav-will_paginate (2.3.11) mocha (0.9.7) mojombo-chronic (0.3.0) mongrel (1.1.5) needle (1.3.0) net-scp (1.0.1) net-sftp (2.0.1, 1.1.1) net-ssh (2.0.4, 1.1.4) net-ssh-gateway (1.0.0) nifty-generators (0.3.0) nokogiri (1.4.0) openrain-action_mailer_tls (1.1.3) passenger (2.2.5) polyglot (0.2.9) prawn (0.6.3) prawn-core (0.6.3) prawn-format (0.2.3) prawn-layout (0.3.2) prawn-security (0.1.1) rack (1.1.0, 1.0.1) rack-mount (0.4.5) rack-test (0.5.3) rails (3.0.0.beta, 2.3.5, 2.2.2, 1.2.6) railties (3.0.0.beta) rake (0.8.7, 0.8.3) rake-compiler (0.6.0) RedCloth (4.1.1) reek (1.2.6) relevance-rcov (0.9.2.1) rmagick (2.12.2) roodi (2.1.0) rsl-stringex (1.0.3) rspec (1.2.9) rspec-rails (1.2.9) ruby-debug (0.10.3) ruby-debug-base (0.10.3) ruby-openid (2.1.2) ruby-yadis (0.3.4) ruby2ruby (1.2.4) ruby_parser (2.0.4) rubyforge (2.0.3) rubygems-update (1.3.6, 1.3.5) rubynode (0.1.5) searchlogic (2.3.9) sexp_processor (3.0.3) spree (0.9.4) sqlite3-ruby (1.2.5, 1.2.4) termios (0.9.4) test-unit (2.0.5) text-format (1.0.0) text-hyphen (1.0.0) thor (0.13.0) tlsmail (0.0.1) topfunky-gruff (0.3.5) treetop (1.4.3) tzinfo (0.3.16) xmpp4r (0.4)

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• Splitting a raidctl mirror safely

  - by milkfilk

  I have a Sun T5220 server with the onboard LSI card and two disks that were in a RAID 1 mirror. The data is not important right now but we had a failed disk and are trying to understand how to do this for real if we had to recover from a failure. The initial situation looked like this: # raidctl -l c1t0d0 Volume Size Stripe Status Cache RAID Sub Size Level Disk ---------------------------------------------------------------- c1t0d0 136.6G N/A DEGRADED OFF RAID1 0.1.0 136.6G GOOD N/A 136.6G FAILED Green light on the 0.0.0 disk. Find / lights up the 0.1.0 disk. So I know I have a bad drive and which one it is. Server still boots obviously. First, we tried putting a new disk in. This disk came from an unknown source. Format would not see it, cfgadm -al would not see it so raidctl -l would not see it. I figure it's bad. We tried another disk from another spare server: # raidctl -c c1t1d0 c1t0d0 (where t1 is my good disk - 0.1.0) Disk has occupied space. Also the different syntax options don't change anything: # raidctl -C "0.1.0 0.0.0" -r 1 1 Disk has occupied space. # raidctl -C "0.1.0 0.0.0" 1 Disk has occupied space. Ok. Maybe this is because the disk from the spare server had a RAID 1 on it already. Aha, I can see another volume in raidctl: # raidctl -l Controller: 1 Volume:c1t1d0 (this is my server's root mirror) Volume:c1t132d0 (this is the foreign root mirror) Disk: 0.0.0 Disk: 0.1.0 ... No problem. I don't care about the data, I'll just delete the foreign mirror. # raidctl -d c1t132d0 (warning about data deletion but it works) At this point, /usr/bin/ binaries freak out. By that I mean, ls -l /usr/bin/which shows 1.4k but cat /usr/bin/which gives me a newline. Great, I just blew away the binaries (ie: binaries in mem still work)? I bounce the box. It all comes back fine. WTF. Anyway, back to recreating my mirror. # raidctl -l Controller: 1 Volume:c1t1d0 (this is my server's root mirror) Disk: 0.0.0 Disk: 0.1.0 ... Man says that you can delete a mirror and it will split it. Ok, I'll delete the root mirror. # raidctl -d c1t0d0 Array in use. (this might not be the exact error) I googled this and found of course you can't do this (even with -f) while booted off the mirror. Ok. I boot cdrom -s and deleted the volume. Now I have one disk that has a type of "LSI-Logical-Volume" on c1t1d0 (where my data is) and a brand new "Hitachi 146GB" on c1t0d0 (what I'm trying to mirror to): (booted off the CD) # raidctl -c c1t1d0 c1t0d0 (man says it's source destination for mirroring) Illegal Array Layout. # raidctl -C "0.1.0 0.0.0" -r 1 1 (alt syntax per man) Illegal Array Layout. # raidctl -C "0.1.0 0.0.0" 1 (assumes raid1, no help) Illegal Array Layout. Same size disks, same manufacturer but I did delete the volume instead of throwing in a blank disk and waiting for it to resync. Maybe this was a critical error. I tried selecting the type in format for my good disk to be a plain 146gb disk but it resets the partition table which I'm pretty sure would wipe the data (bad if this was production). Am I boned? Anyone have experience with breaking and resyncing a mirror? There's nothing on Google about "Illegal Array Layout" so here's my contrib to the search gods.

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• Crash in audio resampler with some audio rates - FFMPEG PHP ( Solved! )

  - by Olaf Erlandsen

  i have a problem with this command( FFMPEG PHP ): Command: ffmpeg -i 62f76f050494f0ed6a5997967c00c0c0.wmv -ss 0 -t 99 -y -ar 44100 -async 44100 -r 29.970 -ac 2 -qscale 5 -f flv 62f76f050494f0ed6a5997967c00c0c0.flv Output: FFmpeg version 0.6.5, Copyright (c) 2000-2010 the FFmpeg developers built on Jan 29 2012 17:52:15 with gcc 4.4.5 20110214 (Red Hat 4.4.5-6) configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 --mandir=/usr/share/man --incdir=/usr/include --disable-avisynth --extra-cflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -fPIC' --enable-avfilter --enable-avfilter-lavf --enable-libdc1394 --enable-libdirac --enable-libfaac --enable-libfaad --enable-libfaadbin --enable-libgsm --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libx264 --enable-gpl --enable-nonfree --enable-postproc --enable-pthreads --enable-shared --enable-swscale --enable-vdpau --enable-version3 --enable-x11grab libavutil 50.15. 1 / 50.15. 1 libavcodec 52.72. 2 / 52.72. 2 libavformat 52.64. 2 / 52.64. 2 libavdevice 52. 2. 0 / 52. 2. 0 libavfilter 1.19. 0 / 1.19. 0 libswscale 0.11. 0 / 0.11. 0 libpostproc 51. 2. 0 / 51. 2. 0 [asf @ 0xe81670]max_analyze_duration reached Input #0, asf, from '/var/www/resources/tmp/62f76f050494f0ed6a5997967c00c0c0.wmv': Metadata: WMFSDKVersion : 12.0.7601.17514 WMFSDKNeeded : 0.0.0.0000 IsVBR : 0 Duration: 00:00:50.87, bitrate: 2467 kb/s Stream #0.0: Audio: wmapro, 44100 Hz, stereo, flt, 256 kb/s Stream #0.1: Video: vc1, yuv420p, 950x460 [PAR 1:1 DAR 95:46], 25 fps, 25 tbr, 1k tbn, 25 tbc Output #0, flv, to '/var/www/resources/media/62f76f050494f0ed6a5997967c00c0c0.flv': Metadata: encoder : Lavf52.64.2 Stream #0.0: Video: flv, yuv420p, 950x460 [PAR 1:1 DAR 95:46], q=2-31, 200 kb/s, 1k tbn, 29.97 tbc Stream #0.1: Audio: libmp3lame, 11025 Hz, stereo, s16, 64 kb/s Stream mapping: Stream #0.1 -> #0.0 Stream #0.0 -> #0.1 Press [q] to stop encoding frame= 72 fps= 0 q=5.0 size= 0kB time=10.91 bitrate= 0.0kbits/s Multiple frames in a packet from stream 0 Warning, using s16 intermediate sample format for resampling frame= 141 fps=139 q=5.0 size= 103kB time=8.15 bitrate= 103.2kbits/s frame= 220 fps=144 q=5.0 size= 875kB time=10.92 bitrate= 656.6kbits/s frame= 290 fps=143 q=5.0 size= 1525kB time=13.74 bitrate= 909.1kbits/s frame= 356 fps=141 q=5.0 size= 2153kB time=15.99 bitrate=1103.1kbits/s frame= 427 fps=141 q=5.0 size= 2847kB time=18.70 bitrate=1247.0kbits/s frame= 497 fps=141 q=5.0 size= 3771kB time=21.16 bitrate=1460.0kbits/s frame= 575 fps=142 q=5.0 size= 4695kB time=24.61 bitrate=1563.0kbits/s frame= 639 fps=141 q=5.0 size= 5301kB time=26.80 bitrate=1620.2kbits/s frame= 703 fps=139 q=5.0 size= 5829kB time=29.36 bitrate=1626.2kbits/s frame= 774 fps=139 q=5.0 size= 6659kB time=32.39 bitrate=1684.0kbits/s frame= 842 fps=139 q=5.0 size= 7915kB time=35.27 bitrate=1838.6kbits/s frame= 911 fps=139 q=5.0 size= 9011kB time=37.98 bitrate=1943.4kbits/s frame= 975 fps=138 q=5.0 size= 9788kB time=40.59 bitrate=1975.3kbits/s frame= 1041 fps=138 q=5.0 size= 10904kB time=43.83 bitrate=2037.9kbits/s frame= 1115 fps=138 q=5.0 size= 11795kB time=46.24 bitrate=2089.8kbits/s frame= 1183 fps=138 q=5.0 size= 12678kB time=48.74 bitrate=2130.7kbits/s frame= 1247 fps=137 q=5.0 size= 13964kB time=51.36 bitrate=2227.5kbits/s frame= 1271 fps=136 q=5.0 Lsize= 15865kB time=58.86 bitrate=2208.1kbits/s video:15366kB audio:462kB global headers:0kB muxing overhead 0.238956% Problem: Warning, using s16 intermediate sample format for resampling I've also tried changing the parameter From -ar 44100 to -ar 11025 Thanks! Solution: Read this link: http://en.wikipedia.org/wiki/MP3#Bit_rate

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• Command-line video editing in Linux (cut, join and preview)

  - by sdaau

  I have rather simple editing needs - I need to cut up some videos, maybe insert some PNGs in between them, and join these videos (don't need transitions, effects, etc.). Basically, pitivi would do what I want - except, I use 640x480 30 fps AVI's from a camera, and as soon as I put in over a couple of minutes of that kind of material, pitivi starts freezing on preview, and thus becomes unusable. So, I started looking for a command line tool for Linux; I guess only ffmpeg (command line - Using ffmpeg to cut up video - Super User) and mplayer (Sam - Edit video file with mencoder under linux) are so far candidates, but I cannot find examples of the use I have in mind.   Basically, I'd imagine there's an encoder and player tools (like ffmpeg vs ffplay; or mencoder vs mplayer) - such that, to begin with, the edit sequence could be specified directly on the command line, preferably with frame resolution - a pseudocode would look like: videnctool -compose --file=vid1.avi --start=00:00:30:12 --end=00:01:45:00 --file=vid2.avi --start=00:05:00:00 --end=00:07:12:25 --file=mypicture.png --duration=00:00:02:00 --file=vid3.avi --start=00:02:00:00 --end=00:02:45:10 --output=editedvid.avi ... or, it could have a "playlist" text file, like: vid1.avi 00:00:30:12 00:01:45:00 vid2.avi 00:05:00:00 00:07:12:25 mypicture.png - 00:00:02:00 vid3.avi 00:02:00:00 00:02:45:10 ... so it could be called with videnctool -compose --playlist=playlist.txt --output=editedvid.avi The idea here would be that all of the videos are in the same format - allowing the tool to avoid transcoding, and just do a "raw copy" instead (as in mencoder's copy codec: "-oac copy -ovc copy") - or in lack of that, uncompressed audio/video would be OK (although it would eat a bit of space). In the case of the still image, the tool would use the encoding set by the video files.   The thing is, I can so far see that mencoder and ffmpeg can operate on individual files; e.g. cut a single section from a single file, or join files (mencoder also has Edit Decision Lists (EDL), which can be used to do frame-exact cutting - so you can define multiple cut regions, but it's again attributed to a single file). Which implies I have to work on cutting pieces first from individual files first (each of which would demand own temporary file on disk), and then joining them in a final video file. I would then imagine, that there is a corresponding player tool, which can read the same command line option format / playlist file as the encoding tool - except it will not generate an output file, but instead play the video; e.g. in pseudocode: vidplaytool --playlist=playlist.txt --start=00:01:14 --end=00:03:13 ... and, given there's enough memory, it would generate a low-res video preview in RAM, and play it back in a window, while offering some limited interaction ( like mplayer's keyboard shortcuts for play, pause, rewind, step frame). Of course, I'd imagine the start and end times to refer to the entire playlist, and include any file that may end up in that region in the playlist. Thus, the end result of all this would be: command line operation; no temporary files while doing the editing - and also no temporary files (nor transcoding) when rendering final output... which I myself think would be nice. So, while I think that all of the above may be a bit of a stretch - does there exist anything that would approximate the workflow described above?

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• How to automate org-refile for multiple todo

  - by lawlist

  I'm looking to automate org-refile so that it will find all of the matches and re-file them to a specific location (but not archive). I found a fully automated method of archiving multiple todo, and I am hopeful to find or create (with some help) something similar to this awesome function (but for a different heading / location other than archiving): https://github.com/tonyday567/jwiegley-dot-emacs/blob/master/dot-org.el (defun org-archive-done-tasks () (interactive) (save-excursion (goto-char (point-min)) (while (re-search-forward "\* \\(None\\|Someday\\) " nil t) (if (save-restriction (save-excursion (org-narrow-to-subtree) (search-forward ":LOGBOOK:" nil t))) (forward-line) (org-archive-subtree) (goto-char (line-beginning-position)))))) I also found this (written by aculich), which is a step in the right direction, but still requires repeating the function manually: http://stackoverflow.com/questions/7509463/how-to-move-a-subtree-to-another-subtree-in-org-mode-emacs ;; I also wanted a way for org-refile to refile easily to a subtree, so I wrote some code and generalized it so that it will set an arbitrary immediate target anywhere (not just in the same file). ;; Basic usage is to move somewhere in Tree B and type C-c C-x C-m to mark the target for refiling, then move to the entry in Tree A that you want to refile and type C-c C-w which will immediately refile into the target location you set in Tree B without prompting you, unless you called org-refile-immediate-target with a prefix arg C-u C-c C-x C-m. ;; Note that if you press C-c C-w in rapid succession to refile multiple entries it will preserve the order of your entries even if org-reverse-note-order is set to t, but you can turn it off to respect the setting of org-reverse-note-order with a double prefix arg C-u C-u C-c C-x C-m. (defvar org-refile-immediate nil "Refile immediately using `org-refile-immediate-target' instead of prompting.") (make-local-variable 'org-refile-immediate) (defvar org-refile-immediate-preserve-order t "If last command was also `org-refile' then preserve ordering.") (make-local-variable 'org-refile-immediate-preserve-order) (defvar org-refile-immediate-target nil) "Value uses the same format as an item in `org-refile-targets'." (make-local-variable 'org-refile-immediate-target) (defadvice org-refile (around org-immediate activate) (if (not org-refile-immediate) ad-do-it ;; if last command was `org-refile' then preserve ordering (let ((org-reverse-note-order (if (and org-refile-immediate-preserve-order (eq last-command 'org-refile)) nil org-reverse-note-order))) (ad-set-arg 2 (assoc org-refile-immediate-target (org-refile-get-targets))) (prog1 ad-do-it (setq this-command 'org-refile))))) (defadvice org-refile-cache-clear (after org-refile-history-clear activate) (setq org-refile-targets (default-value 'org-refile-targets)) (setq org-refile-immediate nil) (setq org-refile-immediate-target nil) (setq org-refile-history nil)) ;;;###autoload (defun org-refile-immediate-target (&optional arg) "Set current entry as `org-refile' target. Non-nil turns off `org-refile-immediate', otherwise `org-refile' will immediately refile without prompting for target using most recent entry in `org-refile-targets' that matches `org-refile-immediate-target' as the default." (interactive "P") (if (equal arg '(16)) (progn (setq org-refile-immediate-preserve-order (not org-refile-immediate-preserve-order)) (message "Order preserving is turned: %s" (if org-refile-immediate-preserve-order "on" "off"))) (setq org-refile-immediate (unless arg t)) (make-local-variable 'org-refile-targets) (let* ((components (org-heading-components)) (level (first components)) (heading (nth 4 components)) (string (substring-no-properties heading))) (add-to-list 'org-refile-targets (append (list (buffer-file-name)) (cons :regexp (format "^%s %s$" (make-string level ?*) string)))) (setq org-refile-immediate-target heading)))) (define-key org-mode-map "\C-c\C-x\C-m" 'org-refile-immediate-target) It sure would be helpful if aculich, or some other maven, could please create a variable similar to (setq org-archive-location "~/0.todo.org::* Archived Tasks") so users can specify the file and heading, which is already a part of the org-archive-subtree functionality. I'm doing a search and mark because I don't have the wherewithal to create something like org-archive-location for this setup. EDIT: One step closer -- almost home free . . . (defun lawlist-auto-refile () (interactive) (beginning-of-buffer) (re-search-forward "\* UNDATED") (org-refile-immediate-target) ;; cursor must be on a heading to work. (save-excursion (re-search-backward "\* UNDATED") ;; must be written in such a way so that sub-entries of * UNDATED are not searched; or else infinity loop. (while (re-search-backward "\* \\(None\\|Someday\\) " nil t) (org-refile) ) ) )

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• how to use ajax with json in ruby on rails

  - by rafik860

  I am implemeting a facebook application in rails using facebooker plugin, therefore it is very important to use this architecture if i want to update multiple DOM in my page. if my code works in a regular rails application it would work in my facebook application. i am trying to use ajax to let the user know that the comment was sent, and update the comments bloc. migration: class CreateComments < ActiveRecord::Migration def self.up create_table :comments do |t| t.string :body t.timestamps end end def self.down drop_table :comments end end controller: class CommentsController < ApplicationController def index @comments=Comment.all end def create @comment=Comment.create(params[:comment]) if request.xhr? @comments=Comment.all render :json=>{:ids_to_update=>[:all_comments,:form_message], :all_comments=>render_to_string(:partial=>"comments" ), :form_message=>"Your comment has been added." } else redirect_to comments_url end end end view: <script> function update_count(str,message_id) { len=str.length; if (len < 200) { $(message_id).innerHTML="<span style='color: green'>"+ (200-len)+" remaining</span>"; } else { $(message_id).innerHTML="<span style='color: red'>"+ "Comment too long. Only 200 characters allowed.</span>"; } } function update_multiple(json) { for( var i=0; i<json["ids_to_update"].length; i++ ) { id=json["ids_to_update"][i]; $(id).innerHTML=json[id]; } } </script> <div id="all_comments" > <%= render :partial=>"comments/comments" %> </div> Talk some trash: <br /> <% remote_form_for Comment.new, :url=>comments_url, :success=>"update_multiple(request)" do |f|%> <%= f.text_area :body, :onchange=>"update_count(this.getValue(),'remaining');" , :onkeyup=>"update_count(this.getValue(),'remaining');" %> <br /> <%= f.submit 'Post'%> <% end %> <p id="remaining" >&nbsp;</p> <p id="form_message" >&nbsp;</p> <br><br> <br> if i try to do alert(json) in the first line of the update_multiple function , i got an [object Object]. if i try to do alert(json["ids_to_update"][0]) in the first line of the update_multiple function , there is no dialog box displayed. however the comment got saved but nothing is updated. it seems like the object sent by rails is nil or cant be parsed by JSON.parse(json). questions: 1.how can javascript and rails know that i am dealing with json objects?deos ROR sent it a object format or a text format?how can it check that the json object has been sent 2.how can i see what is the returned json?do i have to parse it?how? 2.how can i debug this problem? 3.how can i get it to work?

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• libvirt upgrade caused vms to not see drives (boot media not found)

  - by bias

  I upgraded to Ubuntu 12.04.1 and now libvirt (via open nebula) successfully runs vms but they aren't finding the 2 drives (specifically, the boot drive). One is "hd" the other is "cdrom". The machine boots but fails and displays something like "boot media not found hd" (this was in a vnc terminal and I didn't copy the output anywhere so that's not the verbatim message). I tried constructing a new disk using the new version of qemu (via vmbuilder) and this new machine has the same problem as the old machine. In case it matters (I can't see why it would) I'm using open nebula to manage the machines. There's nothing relevant in any of the logs: syslog, libvirtd, oned. Which is to say nothing interesting/anomalous is reported when the machine is brought up. Versions libvirt 0.9.8-2ubuntu17.4 qemu-kvm 1.0+noroms-0ubuntu14.3 The libvirt xml config portions (relavent) <os> <type arch='x86_64' machine='pc-1.0'>hvm</type> <boot dev='hd'/> </os> ... <devices> <emulator>/usr/bin/kvm</emulator> <disk type='file' device='disk'> <driver name='qemu' type='qcow2'/> <source file='/var/lib/one//203/images/disk.0'/> <target dev='sda' bus='scsi'/> <alias name='scsi0-0-0'/> <address type='drive' controller='0' bus='0' unit='0'/> </disk> <disk type='file' device='cdrom'> <driver name='qemu' type='raw'/> <source file='/var/lib/one//203/images/disk.1'/> <target dev='sdc' bus='scsi'/> <readonly/> <alias name='scsi0-0-2'/> <address type='drive' controller='0' bus='0' unit='2'/> </disk> <controller type='scsi' index='0'> <alias name='scsi0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </controller> <memballoon model='virtio'> <alias name='balloon0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </memballoon> ... </devices> The libvirt/qemu log contains 2012-11-25 22:19:24.328+0000: starting up LC_ALL=C PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/sbin:/sbin:/bin QEMU_AUDIO_DRV=none /usr/bin/kvm -S -M pc-1.0 -enable-kvm -m 256 -smp 1,sockets=1,cores=1,threads=1 -name one-204 -uuid 4be6c276-19e8-bdc2-e9c9-9ca5352f2be3 -nodefconfig -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/one-204.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown -device lsi,id=scsi0,bus=pci.0,addr=0x5 -drive file=/var/lib/one//204/images/disk.0,if=none,id=drive-scsi0-0-0,format=qcow2 -device scsi-disk,bus=scsi0.0,scsi-id=0,drive=drive-scsi0-0-0,id=scsi0-0-0,bootindex=1 -drive file=/var/lib/one//204/images/disk.1,if=none,media=cdrom,id=drive-scsi0-0-2,readonly=on,format=raw -device scsi-disk,bus=scsi0.0,scsi-id=2,drive=drive-scsi0-0-2,id=scsi0-0-2 -netdev tap,fd=18,id=hostnet0 -device rtl8139,netdev=hostnet0,id=net0,mac=02:00:c0:a8:00:68,bus=pci.0,addr=0x3 -netdev tap,fd=19,id=hostnet1 -device rtl8139,netdev=hostnet1,id=net1,mac=02:00:ad:f0:1b:94,bus=pci.0,addr=0x4 -usb -vnc 0.0.0.0:204 -vga cirrus -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6 kvm: -device rtl8139,netdev=hostnet0,id=net0,mac=02:00:c0:a8:00:68,bus=pci.0,addr=0x3: pci_add_option_rom: failed to find romfile "pxe-rtl8139.rom" kvm: -device rtl8139,netdev=hostnet1,id=net1,mac=02:00:ad:f0:1b:94,bus=pci.0,addr=0x4: pci_add_option_rom: failed to find romfile "pxe-rtl8139.rom"

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• Installing XP through USB-flash disc

  - by Crazy Buddy

  I don't know whether this could be asked here... So, Pardon me for this. Probably, this is based on My laptop and a contradiction to this question asked already here... I tried to format my "government-provided" laptop (No CD-drive). I thought those IT guys are proving that they're too smart..! I have the Windows XP CD right now. I didn't like to stick with some home-made OS from our Government. So, I used another laptop to format the govt. thing and tried to install XP (As I didn't have enough bills to invest on Windows 7 or 8). Case 1: First, I allowed WinSetupFromUSB 1.0 beta 8 to deal with the flash disk. I wondered for the first time that XP text-screen appeared. Using the first part, I formatted my laptop. It started to copy files, entered into the next part, and completed the installation. I started my PC for the first time. XP splash screen appeared. Suddenly, a blue screen flashed and disappeared (I can't even read what it says). Rebooted and arrived at the screen, "Start Windows Normally". It happens and happens still - like an infinite loop :-) Case 2: Next, I used Rufus 1.2.0 to transfer files to my Flash and it screwed everything out. Even if I used Flash to boot, it arrives to the same screen "Start Windows normally". It doesn't show any response of Flash being inserted. Then I recognized that, It's simply copies everything to the flash disk. Case 3: Then, I started with Novicorp WinToFlash (giving utmost priority to this site). I booted with the disk. I entered into the first part - "Text mode". Some lines started running like that "Press F6 if you..." like that. The last thing I saw was, "Setup is starting Windows..." Suddenly a blue screen appeared like this captured one. I've a suspicion that the same screen appears again & again in first case. Man, I'm dead. Case 4: For the sake of my last hope, I used WinSetupFromUSB 0.1.1. I was shocked on arriving at a screen which says something "GRUB4DOS" like that and some commands like {command line, reboot, halt, \find menu.lst} and when I go inside those "find" options, I see "Error:15 - File not found". Googling provided some commands to mount SETUPLDR.BIN file in the "grub" thing which also proved unsuccessful... Some sites say that Factory reset uses only some function keys. A guy said that it's F11 for lenovo. Screw him. It's all a waste-of-time. But, I think SE would help me out. Is our government IT guys doin' this to me? Are they Soooo smart to spark some blue screen in front of me to freak me out? Any suggestions or new (useful) USB transferring things would be appreciated. It's very urgent. So, It'd be better if you guys pay some attention in debugging and help me out..? Thanks for your time guys :-)

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• The Complete List of iPad Tips, Tricks, and Tutorials

  - by Ross

  The Apple iPad is the latest new toy, and we’ve put together a comprehensive list of every tip, trick, and tutorial that we could find to help you get the most out of it—and we’re even giving one away to one lucky reader. So read on! Note: We’ll be keeping this page updated as we find more great articles, so you should bookmark this page for future reference. Want Your Own iPad? How-To Geek is Giving One Away! All you have to do to enter is become a fan of our Facebook page, and we’ll pick a random fan to win the prize. Win an iPad on the How-To Geek Facebook Fan Page Disable the “clicking sound” on the iPad Keyboard Does the clicking sound when you tap the iPad keyboard bother you? Thankfully it’s easy to disable with a couple of taps. How to disable the “clicking sound” on your iPad’s keyboard Enable and add bookmarks to the Safari Bookmarks Bar on your iPad By default, Safari doesn’t display the Bookmarks Bar. This tip shows you how to change that. How to enable and add bookmarks to the Safari Bookmarks Bar on your iPad Clear the Cache, History and Cookies in Safari for the iPad You’re probably used to clearing this kind of data right from within the browser. Not so with Safari on the iPad – but here’s how you can. How to clear the cache, history and cookies in Safari for iPad How to add more Apps to your iPad Dock The iPad has four icons in its ‘dock’. Did you know it can hold 6? How to add more Apps to your iPad Dock Convert PDF files to ePub files to read on your iPad with iBooks ePub is the format that iBooks are in. So for those of you with large eBook collections in PDF, here’s how you convert them to read in iBooks. How to convert PDF files to ePub files to read on your iPad with iBooks How to force your iPad to restart Has an app caused your iPad to freeze up, and you can’t escape? This tip shows you how to force your iPad to restart. How to force your iPad to restart How to export Keynote for iPad presentations to your Mac or PC Exporting Keynote presentations from your iPad to your Mac or PC isn’t as straight forward as you might have expected. This tutorial shows you how. How to export Keynote for iPad presentations to your Mac or PC How to import presentations to Keynote on your iPad Having trouble getting your presentations onto your iPad? How to import presentations to Keynote on your iPad How to import documents to Pages on your iPad This guide shows you how to transfer documents (MS Word or Pages) from your Mac/PC to your iPad. How to import documents to Pages on your iPad How to insert photos in a Pages document using iPad and share it as a PDF Want to spice up that doc with a picture you just took? This tutorial will show you how – and how to export that document as a PDF. How to insert photos in a Pages document using iPad and share it as a PDF How to lock your iPad If you have kids or co-workers/friends who think it’s funny to mess with your iPad – lock it. How to lock your iPad How to remove the “Sent from my iPad” signature from outgoing email on your iPad Does everyone need to know you just sent that email from your iPad? Probably not. This guide shows you how to remove the “Sent from my iPad” signature and replace it with your own (or none). How to remove the “Sent from my iPad” signature from outgoing email on your iPad How To Sync Multiple Calendars to the iPad With Google Sync This tutorial will show you a workaround on how to sync multiple calendars on your iPad using Google Sync. How to Sync Multiple Calendars to the iPad With Google Sync How to determine the MAC address of your iPad If your network restricts connections via MAC address – this guide will show you how to determine what yours is. How to determine the MAC address of your iPad How to take a screenshot of your iPad Do you need to take a screenshot of your iPad? This quick tip shows you how to do just that. How to take a screenshot of your iPad How to delete apps from your iPod Touch, iPhone or iPad Anyone who had an iPod Touch or iPhone before they had an iPad won’t need this tutorial. But if you’re new to the experience, this one will help. How to delete apps from your iPod Touch, iPhone or iPad How to determine the iPad ECID on Windows and Mac iPadintosh shows us how to determine the iPad’s ECID code – something you’ll want to have come Jailbreak time. How to grab the iPad ECID in Windows or OS X iPad Apps: Twitter and social networking essentials Enggadget has you covered with reviews of the first slew of iPad specific Twitter and other social networking apps. iPad Apps: Twitter and social networking essentials What does your website look like on an iPad? iPad Peek is a web based tool that allows you to enter any given URL, and it will display that page the same way Safari on the iPad does. Great for web site owners who don’t have access to an iPad. iPadPeek Stream Music and Videos to your iPad Gizmodo reviews the iPad app StreamToMe, which allows you to stream media from your Mac to your iPad across your local network. Their feelings in a nutshell – worth the $3, but not perfect. Review: StreamToMe for the iPad Apple iPad : Change links in Google Reader to point to full HTML webpage How to change links in Safari for iPad so that Google Reader points to a full HTML webpage How to connect an iPad to your existing wireless keyboard This video will show you how to connect your iPad to a wireless keyboard if you’re having any problems – and from the sound of things, quite a few folks are. via TUAW How to get started with the iPad Mashable has a very entry-level guide that will help you set up your iPad for the first time. Mashable’s Guide to Setting up the iPad Essential iPad Apps Downloadsquad gives mini-reviews to 8 iPad apps that you should install as soon as you get your iPad. iPad App Buyers Guide: Essential Apps you should get on day one Videos: The Official iPad Guided Tours From none other than Apple! Great getting started videos for all the included iPad apps. The Official iPad Guided Tours The Official iPad Manual When you buy an iPad, you don’t get a manual. But that’s not to say there isn’t one. Apple provides a 150 guide for your iPad in PDF format. The Official iPad Manual (pdf) How to print from your iPad Sure, it’s actually just an App (PrintCentral – $9.99 USD), but as of right now, it’s the only way. PrintCentral How to make your own iPad Wallpaper A perfectly detailed tutorial on how to make your own wallpaper for your iPad. The author also provides a really nice sample wallpaper, published under the Attribution-Noncommercial 2.0 Generic license. How to make your own iPad Wallpaper Got any more tips? Share them in the comments, and we’ll update the post with the links, or just the tip itself. Similar Articles Productive Geek Tips Want an iPad? How-To Geek is Giving One Away!Why Wait? Amazing New Add-on Turns Your iPhone into an iPad! [Comic]Clear the Auto-Complete Email Address Cache in OutlookAsk the Readers: Share Your Tips for Defeating Viruses and MalwareStupid Geek Tricks: Tile or Cascade Multiple Windows in Windows 7 TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Are You Blocked On Gtalk? Find out Discover Latest Android Apps On AppBrain The Ultimate Guide For YouTube Lovers Will it Blend? iPad Edition Penolo Lets You Share Sketches On Twitter Visit Woolyss.com for Old School Games, Music and Videos

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• Creating packages in code - Package Configurations

  Continuing my theme of building various types of packages in code, this example shows how to building a package with package configurations. Incidentally it shows you how to add a variable, and a connection too. It covers the five most common configurations: Configuration File Indirect Configuration File SQL Server Indirect SQL Server Environment Variable  For a general overview try the SQL Server Books Online Package Configurations topic. The sample uses a a simple helper function ApplyConfig to create or update a configuration, although in the example we will only ever create. The most useful knowledge is the configuration string (Configuration.ConfigurationString) that you need to set. Configuration Type Configuration String Description Configuration File The full path and file name of an XML configuration file. The file can contain one or more configuration and includes the target path and new value to set. Indirect Configuration File An environment variable the value of which contains full path and file name of an XML configuration file as per the Configuration File type described above. SQL Server A three part configuration string, with each part being quote delimited and separated by a semi-colon. -- The first part is the connection manager name. The connection tells you which server and database to look for the configuration table. -- The second part is the name of the configuration table. The table is of a standard format, use the Package Configuration Wizard to help create an example, or see the sample script files below. The table contains one or more rows or configuration items each with a target path and new value. -- The third and final part is the optional filter name. A configuration table can contain multiple configurations, and the filter is  literal value that can be used to group items together and act as a filter clause when configurations are being read. If you do not need a filter, just leave the value empty. Indirect SQL Server An environment variable the value of which is the three part configuration string as per the SQL Server type described above. Environment Variable An environment variable the value of which is the value to set in the package. This is slightly different to the other examples as the configuration definition in the package also includes the target information. In our ApplyConfig function this is the only example that actually supplies a target value for the Configuration.PackagePath property. The path is an XPath style path for the target property, \Package.Variables[User::Variable].Properties[Value], the equivalent of which can be seen in the screenshot below, with the object being our variable called Variable, and the property to set is the Value property of that variable object. The configurations as seen when opening the generated package in BIDS: The sample code creates the package, adds a variable and connection manager, enables configurations, and then adds our example configurations. The package is then saved to disk, useful for checking the package and testing, before finally executing, just to prove it is valid. There are some external resources used here, namely some environment variables and a table, see below for more details. namespace Konesans.Dts.Samples { using System; using Microsoft.SqlServer.Dts.Runtime; public class PackageConfigurations { public void CreatePackage() { // Create a new package Package package = new Package(); package.Name = "ConfigurationSample"; // Add a variable, the target for our configurations package.Variables.Add("Variable", false, "User", 0); // Add a connection, for SQL configurations // Add the SQL OLE-DB connection ConnectionManager connectionManagerOleDb = package.Connections.Add("OLEDB"); connectionManagerOleDb.Name = "SQLConnection"; connectionManagerOleDb.ConnectionString = "Provider=SQLOLEDB.1;Data Source=(local);Initial Catalog=master;Integrated Security=SSPI;"; // Add our example configurations, first must enable package setting package.EnableConfigurations = true; // Direct configuration file, see sample file this.ApplyConfig(package, "Configuration File", DTSConfigurationType.ConfigFile, "C:\\Temp\\XmlConfig.dtsConfig", string.Empty); // Indirect configuration file, the emvironment variable XmlConfigFileEnvironmentVariable // contains the path to the configuration file, e.g. C:\Temp\XmlConfig.dtsConfig this.ApplyConfig(package, "Indirect Configuration File", DTSConfigurationType.IConfigFile, "XmlConfigFileEnvironmentVariable", string.Empty); // Direct SQL Server configuration, uses the SQLConnection package connection to read // configurations from the [dbo].[SSIS Configurations] table, with a filter of "SampleFilter" this.ApplyConfig(package, "SQL Server", DTSConfigurationType.SqlServer, "\"SQLConnection\";\"[dbo].[SSIS Configurations]\";\"SampleFilter\";", string.Empty); // Indirect SQL Server configuration, the environment variable "SQLServerEnvironmentVariable" // contains the configuration string e.g. "SQLConnection";"[dbo].[SSIS Configurations]";"SampleFilter"; this.ApplyConfig(package, "Indirect SQL Server", DTSConfigurationType.ISqlServer, "SQLServerEnvironmentVariable", string.Empty); // Direct environment variable, the value of the EnvironmentVariable environment variable is // applied to the target property, the value of the "User::Variable" package variable this.ApplyConfig(package, "EnvironmentVariable", DTSConfigurationType.EnvVariable, "EnvironmentVariable", "\\Package.Variables[User::Variable].Properties[Value]"); #if DEBUG // Save package to disk, DEBUG only new Application().SaveToXml(String.Format(@"C:\Temp\{0}.dtsx", package.Name), package, null); Console.WriteLine(@"C:\Temp\{0}.dtsx", package.Name); #endif // Execute package package.Execute(); // Basic check for warnings foreach (DtsWarning warning in package.Warnings) { Console.WriteLine("WarningCode : {0}", warning.WarningCode); Console.WriteLine(" SubComponent : {0}", warning.SubComponent); Console.WriteLine(" Description : {0}", warning.Description); Console.WriteLine(); } // Basic check for errors foreach (DtsError error in package.Errors) { Console.WriteLine("ErrorCode : {0}", error.ErrorCode); Console.WriteLine(" SubComponent : {0}", error.SubComponent); Console.WriteLine(" Description : {0}", error.Description); Console.WriteLine(); } package.Dispose(); } /// <summary> /// Add or update an package configuration. /// </summary> /// <param name="package">The package.</param> /// <param name="name">The configuration name.</param> /// <param name="type">The type of configuration</param> /// <param name="setting">The configuration setting.</param> /// <param name="target">The target of the configuration, leave blank if not required.</param> internal void ApplyConfig(Package package, string name, DTSConfigurationType type, string setting, string target) { Configurations configurations = package.Configurations; Configuration configuration; if (configurations.Contains(name)) { configuration = configurations[name]; } else { configuration = configurations.Add(); } configuration.Name = name; configuration.ConfigurationType = type; configuration.ConfigurationString = setting; configuration.PackagePath = target; } } } The following table lists the environment variables required for the full example to work along with some sample values. Variable Sample value EnvironmentVariable 1 SQLServerEnvironmentVariable "SQLConnection";"[dbo].[SSIS Configurations]";"SampleFilter"; XmlConfigFileEnvironmentVariable C:\Temp\XmlConfig.dtsConfig Sample code, package and configuration file. ConfigurationApplication.cs ConfigurationSample.dtsx XmlConfig.dtsConfig

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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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• Using Unity – Part 2

  - by nmarun

  In the first part of this series, we created a simple project and learned how to implement IoC pattern using Unity. In this one, I’ll show how you can instantiate other types that implement our IProduct interface. One place where this one would want to use this feature is to create mock types for testing purposes. Alright, let’s dig in. I added another class – Product2.cs  to the ProductModel project. 1: public class Product2 : IProduct 2: { 3: public string Name { get; set;} 4: public Category Category { get; set; } 5: public DateTime MfgDate { get;set; } 6:  7: public Product2() 8: { 9: Name = "Canon Digital Rebel XTi"; 10: Category = new Category {Name = "Electronics", SubCategoryName = "Digital Cameras"}; 11: MfgDate = DateTime.Now; 12: } 13:  14: public string WriteProductDetails() 15: { 16: return string.Format("Name: {0}<br/>Category: {1}<br/>Mfg Date: {2}", 17: Name, Category, MfgDate.ToShortDateString()); 18: } 19: } Highlights of this class are that it implements IProduct interface and it has some different properties than the Product class. The Category class looks like below: 1: public class Category 2: { 3: public string Name { get; set; } 4: public string SubCategoryName { get; set; } 5:  6: public override string ToString() 7: { 8: return string.Format("{0} - {1}", Name, SubCategoryName); 9: } 10: } We’ll go to our web.config file to add the configuration information about this new class – Product2 that we created. Let’s first add a typeAlias element. 1: <typeAlias alias="Product2" type="ProductModel.Product2, ProductModel"/> That’s all that is needed for us to get an instance of Product2 in our application. I have a new button added to the .aspx page and the click event of this button is where all the magic happens: 1: private IUnityContainer unityContainer; 2: protected void Page_Load(object sender, EventArgs e) 3: { 4: unityContainer = Application["UnityContainer"] as IUnityContainer; 5: 6: if (unityContainer == null) 7: { 8: productDetailsLabel.Text = "ERROR: Unity Container not populated in Global.asax.<p />"; 9: } 10: else 11: { 12: if (!IsPostBack) 13: { 14: IProduct productInstance = unityContainer.Resolve<IProduct>(); 15: productDetailsLabel.Text = productInstance.WriteProductDetails(); 16: } 17: } 18: } 19:  20: protected void Product2Button_Click(object sender, EventArgs e) 21: { 22: unityContainer.RegisterType<IProduct, Product2>(); 23: IProduct product2Instance = unityContainer.Resolve<IProduct>(); 24: productDetailsLabel.Text = product2Instance.WriteProductDetails(); 25: } The unityContainer instance is set in the Page_Load event. Line 22 in the click event of the Product2Button registers a type mapping in the container. In English, this means that when unityContainer tries to resolve for IProduct, it gets an instance of Product2. Once this code runs, following output is rendered: There’s another way of doing this. You can resolve an instance of the requested type with a name from the container. We’ll have to update the container element of our web.config file to include the following: 1: <container name="unityContainer"> 2: <types> 3: <type type="IProduct" mapTo="Product"/> 4: <!-- Named mapping for IProduct to Product --> 5: <type type="IProduct" mapTo="Product" name="LegacyProduct" /> 6: <!-- Named mapping for IProduct to Product2 --> 7: <type type="IProduct" mapTo="Product2" name="NewProduct" /> 8: </types> 9: </container> I’ve added a Dropdownlist and a button to the design page: 1: <asp:DropDownList ID="ModelTypesList" runat="server"> 2: <asp:ListItem Text="Legacy Product" Value="LegacyProduct" /> 3: <asp:ListItem Text="New Product" Value="NewProduct" /> 4: </asp:DropDownList> 5: <br /> 6: <asp:Button ID="SelectedModelButton" Text="Get Selected Instance" runat="server" 7: onclick="SelectedModelButton_Click" /> 1: protected void SelectedModelButton_Click(object sender, EventArgs e) 2: { 3: // get the selected value: LegacyProduct or NewProduct 4: string modelType = ModelTypesList.SelectedValue; 5: // pass the modelType to the Resolve method 6: IProduct customModel = unityContainer.Resolve<IProduct>(modelType); 7: productDetailsLabel.Text = customModel.WriteProductDetails(); 8: } Pretty straight forward right? The only thing to note here is that the values in the dropdownlist item need to match the name attribute of the type. Depending on what you select, you’ll get an instance of either the Product class or the Product2 class and the corresponding WriteProductDetails() method is called. Now you see, how either of these methods can be used to create mock objects your the test project. See the code here. I’ll continue to share more of Unity in the next blog.

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