context free - Page 15 - Developer IT

How to Use a Free Business Website to Revive Any Ailing Business

In a world where nothing is free, it is difficult to imagine a free business website as a possibility. The popular dictum has always been 'no free lunch.'

Free E-Book - Office 365 (Connect and Collaborate)

MS is offering this free e-book for Office 365 enthusiats - Microsoft Office 365: Connect and Collaborate Virtually Anywhere, Anytime (ISBN 9780735656949), by Katherine Murray, as a free eBook also available in EPUB and MOBI formats. To download PDF version, click here. And EPUB or MOBI version of this eBook, is available here.More Details @ http://blogs.msdn.com/b/microsoft_press/archive/2011/08/17/free-ebook-microsoft-office-365-connect-and-collaborate-virtually-anywhere-anytime.aspx

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Free vouchers to become a certified ADF or WebLogic Implementation Specialist

- by JuergenKress

For all WebLogic & ADF experts, we offer 100 free vouchers worth $195 to become an Oracle certified expert. To receive a WebLogic & ADF voucher please send an e-mail with the screenshot of your WebLogic Server 12c PreSales Specialist or ADF 11g PreSales Specialist certificate to [email protected] including your Name, Company, e-mail and Country with the e-mail subject free WebLogic & ADF voucher! WebLogic ADF Pre-Sales assessment (free online test) Preparation: WebLogic 12c PreSales Specialist (OPN account required – need help?) ADF 11g PreSales Specialist (OPN account required – need help?) Implementation assessment Preparation: WebLogic 12c Implementation Specialist WebLogic Bootcamp training material (Community membership required) WebLogic Knowledge Zone Overview ADF 11g Implementation Specialist ADF 11g bootcamp training material (Community membership required) ADF Knowledge Zone Overview Free vouchers are reserved for partners from Europe, Middle East and Africa. Any other countries please contact your local partner manager! WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: Specialization,ADF certified,WebLogic certification,education,free exam,WebLogic,WebLogic Community,Oracle,OPN,Jürgen Kress

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CoreGraphics taking a while to show on a large view - can i get it to repeat pixels?

- by Andrew

This is my coregraphics code: void drawTopPaperBackground(CGContextRef context, CGRect rect) { CGRect paper3 = CGRectMake(10, 14, 300, rect.size.height - 14); CGRect paper2 = CGRectMake(13, 12, 294, rect.size.height - 12); CGRect paper1 = CGRectMake(16, 10, 288, rect.size.height - 10); //Shadow CGContextSetShadowWithColor(context, CGSizeMake(0,0), 10, [[UIColor colorWithWhite:0 alpha:0.5]CGColor]); CGPathRef path = createRoundedRectForRect(paper3, 0); CGContextSetFillColorWithColor(context, [[UIColor blackColor] CGColor]); CGContextAddPath(context, path); CGContextFillPath(context); //Layers of paper //CGContextSaveGState(context); drawPaper(context, paper3); drawPaper(context, paper2); drawPaper(context, paper1); //CGContextRestoreGState(context); } void drawPaper(CGContextRef context, CGRect rect) { //Shadow CGContextSaveGState(context); CGContextSetShadowWithColor(context, CGSizeMake(0,0), 1, [[UIColor colorWithWhite:0 alpha:0.5]CGColor]); CGPathRef path = createRoundedRectForRect(rect, 0); CGContextSetFillColorWithColor(context, [[UIColor blackColor] CGColor]); CGContextAddPath(context, path); CGContextFillPath(context); //CGContextRestoreGState(context); //Gradient //CGContextSaveGState(context); CGColorRef startColor = [UIColor colorWithWhite:0.92 alpha:1.0].CGColor; CGColorRef endColor = [UIColor colorWithWhite:0.94 alpha:1.0].CGColor; CGRect firstHalf = CGRectMake(rect.origin.x, rect.origin.y, rect.size.width / 2, rect.size.height); CGRect secondHalf = CGRectMake(rect.origin.x + (rect.size.width / 2), rect.origin.y, rect.size.width / 2, rect.size.height); drawVerticalGradient(context, firstHalf, startColor, endColor); drawVerticalGradient(context, secondHalf, endColor, startColor); //CGContextRestoreGState(context); //CGContextSaveGState(context); CGRect redRect = rectForRectWithInset(rect, -1); CGMutablePathRef redPath = createRoundedRectForRect(redRect, 0); //CGContextSaveGState(context); CGContextSetStrokeColorWithColor(context, [[UIColor blackColor] CGColor]); CGContextAddPath(context, path); CGContextClip(context); CGContextAddPath(context, redPath); CGContextSetShadowWithColor(context, CGSizeMake(0, 0), 15.0, [[UIColor colorWithWhite:0 alpha:0.1] CGColor]); CGContextStrokePath(context); CGContextRestoreGState(context); } The view is a UIScrollView, which contains a textview. Every time the user types something and goes onto a new line, I call [self setNeedsDisplay]; and it redraws the code. But when the view starts to get long - around 1000 height, it has very noticeable lag. How can i make this code more efficient? Can i take a line of pixels and make it just repeat that, or stretch it, all the way down?

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Free Access to Resharper Training

- by TATWORTH

There is free access to ReSharper training at http://www.pluralsight-training.net/microsoft/OLT/Course/Toc.aspx?n=resharperfundamentals Starting Tuesday, March 15, 16:00 GMT, Pluralsight provides 48 hours of free access to the full ReSharper course. If you're interested to know what ReSharper can bring to the table for .NET developers, now is just the right time to enjoy this limited-time free access opportunity, with no registration required.

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Making Movies with Free Software

<b>Free Software Magazine: </b>" I'm working on not one, but two animated science-fiction films using free software tools, intended for a free-licensed release on the internet under new distribution models. And, being a writer, I'm going to write about it."

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Sites with free game music loops? [duplicate]

- by Bnhjhvbq7

This question already has an answer here: Where can I find free music for my game? [closed] 13 answers I'm searching for free game loops background music for my game, seams like google is full of those websites but all of them per pay. Where can I download free game loops?

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Keep context-configuration when redeploying via Cargo

- by Björn Pollex

I am using Tomcat 7 to host a web-application that requires a JNDI datasource to be set up. Because this resource is specific to this application, I would like to configure it inside the application-specific context-descriptor in $CATALINA_BASE/conf/[enginename]/[hostname]/. I am also using Cargo from Maven to deploy the web-application to Tomcat. The problem is that when I do a redeploy with Cargo, it first undeploys the application, before deploying it again. When undeploying it, Tomcat deletes the context-descriptor of the application, so it won't work after redeploying. I could of course package the context-descriptor with the application, but I would like to keep any such container-specifics out of the .war. Another alternative is to configure the datasource in the global context-descriptor, but that too seems wrong, because the datasource is supposed to be exclusive to my application. Is my approach fundamentally wrong? What is the best practice here? Is there any way to prevent Tomcat from deleting the descriptor when undeploying?

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The ugly evolution of running a background operation in the context of an ASP.NET app

- by Jeff

If you’re one of the two people who has followed my blog for many years, you know that I’ve been going at POP Forums now for over almost 15 years. Publishing it as an open source app has been a big help because it helps me understand how people want to use it, and having it translated to six languages is pretty sweet. Despite this warm and fuzzy group hug, there has been an ugly hack hiding in there for years. One of the things we find ourselves wanting to do is hide some kind of regular process inside of an ASP.NET application that runs periodically. The motivation for this has always been that a lot of people simply don’t have a choice, because they’re running the app on shared hosting, or don’t otherwise have access to a box that can run some kind of regular background service. In POP Forums, I “solved” this problem years ago by hiding some static timers in an HttpModule. Truthfully, this works well as long as you don’t run multiple instances of the app, which in the cloud world, is always a possibility. With the arrival of WebJobs in Azure, I’m going to solve this problem. This post isn’t about that. The other little hacky problem that I “solved” was spawning a background thread to queue emails to subscribed users of the forum. This evolved quite a bit over the years, starting with a long running page to mail users in real-time, when I had only a few hundred. By the time it got into the thousands, or tens of thousands, I needed a better way. What I did is launched a new thread that read all of the user data in, then wrote a queued email to the database (as in, the entire body of the email, every time), with the properly formatted opt-out link. It was super inefficient, but it worked. Then I moved my biggest site using it, CoasterBuzz, to an Azure Website, and it stopped working. So let’s start with the first stupid thing I was doing. The new thread was simply created with delegate code inline. As best I can tell, Azure Websites are more aggressive about garbage collection, because that thread didn’t queue even one message. When the calling server response went out of scope, so went the magic background thread. Duh, all I had to do was move the thread to a private static variable in the class. That’s the way I was able to keep stuff running from the HttpModule. (And yes, I know this is still prone to failure, particularly if the app recycles. For as infrequently as it’s used, I have not, however, experienced this.) It was still failing, but this time I wasn’t sure why. It would queue a few dozen messages, then die. Running in Azure, I had to turn on the application logging and FTP in to see what was going on. That led me to a helper method I was using as delegate to build the unsubscribe links. The idea here is that I didn’t want yet another config entry to describe the base URL, appended with the right path that would match the routing table. No, I wanted the app to figure it out for you, so I came up with this little thing: public static string FullUrlHelper(this Controller controller, string actionName, string controllerName, object routeValues = null) { var helper = new UrlHelper(controller.Request.RequestContext); var requestUrl = controller.Request.Url; if (requestUrl == null) return String.Empty; var url = requestUrl.Scheme + "://"; url += requestUrl.Host; url += (requestUrl.Port != 80 ? ":" + requestUrl.Port : ""); url += helper.Action(actionName, controllerName, routeValues); return url; } And yes, that should have been done with a string builder. This is useful for sending out the email verification messages, too. As clever as I thought I was with this, I was using a delegate in the admin controller to format these unsubscribe links for tens of thousands of users. I passed that delegate into a service class that did the email work: Func<User, string> unsubscribeLinkGenerator = user => this.FullUrlHelper("Unsubscribe", AccountController.Name, new { id = user.UserID, key = _profileService.GetUnsubscribeHash(user) }); _mailingListService.MailUsers(subject, body, htmlBody, unsubscribeLinkGenerator); Cool, right? Actually, not so much. If you look back at the helper, this delegate then will depend on the controller context to learn the routing and format for the URL. As you might have guessed, those things were turning null after a few dozen formatted links, when the original request to the admin controller went away. That this wasn’t already happening on my dedicated server is surprising, but again, I understand why the Azure environment might be eager to reclaim a thread after servicing the request. It’s already inefficient that I’m building the entire email for every user, but going back to check the routing table for the right link every time isn’t a win either. I put together a little hack to look up one generic URL, and use that as the basis for a string format. If you’re wondering why I didn’t just use the curly braces up front, it’s because they get URL formatted: var baseString = this.FullUrlHelper("Unsubscribe", AccountController.Name, new { id = "--id--", key = "--key--" }); baseString = baseString.Replace("--id--", "{0}").Replace("--key--", "{1}"); Func unsubscribeLinkGenerator = user => String.Format(baseString, user.UserID, _profileService.GetUnsubscribeHash(user)); _mailingListService.MailUsers(subject, body, htmlBody, unsubscribeLinkGenerator); And wouldn’t you know it, the new solution works just fine. It’s still kind of hacky and inefficient, but it will work until this somehow breaks too.

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How can I make a custom layout / change header background color … with Tex, Latex, ConTeXt ?

- by harobed

Hi, currently I produce dynamically this document http://download.stephane-klein.info/exemple_document.png with Python Report Labs… to produce pdf documents. Now, I would like try to produce this document with Tex / Latex / ConTeXt… I've some questions : how can I make the layout ? how can I make header background color ? how can I define my custom title (with blue box) ? what is the better choice for my project : Latex or ConTeXt ? What package I need to use ? geometry ? fancyhdr ? Have you some example ? some resource ? Yesterday, I've read many many documentation… and I don't found a solution / example for my questions. Thanks for your help, Stephane

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How can I use the paid version of my app as a "key" to the free version?

- by Bryan Denny

Let's say for example that I have some Android app that does X. The free version has ads or basic features. I want to have a paid version that removes the ads and adds extra features. How can I use the paid app as a "license key" to unlock the features in the free app? So the user would install the free app, then install the paid app to get the extra features, but they would still run the free app (which would now be unlocked). What's the best approach to doing this?

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How to add icons to the android context menu?

- by Avinash

How to add icons to the android context menu?

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If free() knows the length of my array, why can't I ask for it in my own code?

- by Chris Cooper

I know that it's a common convention to pass the length of dynamically allocated arrays to functions that manipulate them: void initializeAndFree(int* anArray, int length); int main(){ int arrayLength = 0; scanf("%d", &arrayLength); int* myArray = (int*)malloc(sizeof(int)*arrayLength); initializeAndFree(myArray, arrayLength); } void initializeAndFree(int* anArray, int length){ int i = 0; for (i = 0; i < length; i++) { anArray[i] = 0; } free(anArray); } but if there's no way for me to get the length of the allocated memory from a pointer, how does free() "automagically" know what to deallocate? Why can't I get in on the magic, as a C programmer? Where does free() get its free (har-har) knowledge from?

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Can a function/class know the context from where it is being invoked or instantiated?

- by vrode

Let's take this class as example and assume that get_context() returns the source of the call: class A { public function __construct( ) { if( get_class( get_context( ) ) == B ) { return true; } else { return false; } } } class B { function __construct( ) { $a = new A( ); } } $a = new B( ); // returns true, as B is the invoking class of A $a = new A( ); // returns false, as B is invoked outside of any class So, my questions are: 1) can a function know the context that calls it? 2) can a object know context from where it has been instantiated? Or am I dreaming up new features not implementable in PHP?

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Can my thread help the OS decide when to context switch it out?

- by WilliamKF

I am working on a threaded application on Linux in C++ which attempts to be real time, doing an action on a heartbeat, or as close to it as possible. In practice, I find the OS is swapping out my thread and causing delays of up to a tenth of a second while it is switched out, causing the heartbeat to be irregular. Is there a way my thread can hint to the OS that now is a good time to context switch it out? I could make this call right after doing a heartbeat, and thus minimize the delay due to an ill timed context switch.

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Free internet radio station server software with remote broadcasting?

- by Zachary Brown

I am in the process of creating an internet radio station, but the two djs I have for it are not able to be in one place. I need for them to be able to login to a web based broadcasting session that still has full functionality. They need to be able to broadcast thier live shows with talk and music. The music will be stroed on the server. I have checked out the Broadwave media streaming server from NCH, but ti does not have the ability to login as a dj from a remote computer. I don't have any money for this, so I need it to be free. If this is not possible, I need it to be cheap!

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HELP! Free space not reclaimed after online resizing ext4 in Ubuntu 9.10

- by TiansHUo

My root partition was filling up, with only 500 mbs left, I wanted to resize my root partition from 20 Gb to 40Gb So I resized my partition by using these steps: Using Gparted to resize another partition to give space for the EXT4 Using fdisk, deleting the root partition (on /dev/sda2), and creating it again using the new size resize2fs /dev/sda2 Updating grub2 But now the problem is that although I can boot in my new partition and the new partition shows it is 40Gb, but the free size was still 500mb. So I booted from a LiveCD and checked with e2fsck -p /dev/sda2, it reported clean. So I added the -f flag (force check), still, the drive is full.

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Hosting the Razor Engine for Templating in Non-Web Applications

- by Rick Strahl

Microsoft’s new Razor HTML Rendering Engine that is currently shipping with ASP.NET MVC previews can be used outside of ASP.NET. Razor is an alternative view engine that can be used instead of the ASP.NET Page engine that currently works with ASP.NET WebForms and MVC. It provides a simpler and more readable markup syntax and is much more light weight in terms of functionality than the full blown WebForms Page engine, focusing only on features that are more along the lines of a pure view engine (or classic ASP!) with focus on expression and code rendering rather than a complex control/object model. Like the Page engine though, the parser understands .NET code syntax which can be embedded into templates, and behind the scenes the engine compiles markup and script code into an executing piece of .NET code in an assembly. Although it ships as part of the ASP.NET MVC and WebMatrix the Razor Engine itself is not directly dependent on ASP.NET or IIS or HTTP in any way. And although there are some markup and rendering features that are optimized for HTML based output generation, Razor is essentially a free standing template engine. And what’s really nice is that unlike the ASP.NET Runtime, Razor is fairly easy to host inside of your own non-Web applications to provide templating functionality. Templating in non-Web Applications? Yes please! So why might you host a template engine in your non-Web application? Template rendering is useful in many places and I have a number of applications that make heavy use of it. One of my applications – West Wind Html Help Builder - exclusively uses template based rendering to merge user supplied help text content into customizable and executable HTML markup templates that provide HTML output for CHM style HTML Help. This is an older product and it’s not actually using .NET at the moment – and this is one reason I’m looking at Razor for script hosting at the moment. For a few .NET applications though I’ve actually used the ASP.NET Runtime hosting to provide templating and mail merge style functionality and while that works reasonably well it’s a very heavy handed approach. It’s very resource intensive and has potential issues with versioning in various different versions of .NET. The generic implementation I created in the article above requires a lot of fix up to mimic an HTTP request in a non-HTTP environment and there are a lot of little things that have to happen to ensure that the ASP.NET runtime works properly most of it having nothing to do with the templating aspect but just satisfying ASP.NET’s requirements. The Razor Engine on the other hand is fairly light weight and completely decoupled from the ASP.NET runtime and the HTTP processing. Rather it’s a pure template engine whose sole purpose is to render text templates. Hosting this engine in your own applications can be accomplished with a reasonable amount of code (actually just a few lines with the tools I’m about to describe) and without having to fake HTTP requests. It’s also much lighter on resource usage and you can easily attach custom properties to your base template implementation to easily pass context from the parent application into templates all of which was rather complicated with ASP.NET runtime hosting. Installing the Razor Template Engine You can get Razor as part of the MVC 3 (RC and later) or Web Matrix. Both are available as downloadable components from the Web Platform Installer Version 3.0 (!important – V2 doesn’t show these components). If you already have that version of the WPI installed just fire it up. You can get the latest version of the Web Platform Installer from here: http://www.microsoft.com/web/gallery/install.aspx Once the platform Installer 3.0 is installed install either MVC 3 or ASP.NET Web Pages. Once installed you’ll find a System.Web.Razor assembly in C:\Program Files\Microsoft ASP.NET\ASP.NET Web Pages\v1.0\Assemblies\System.Web.Razor.dll which you can add as a reference to your project. Creating a Wrapper The basic Razor Hosting API is pretty simple and you can host Razor with a (large-ish) handful of lines of code. I’ll show the basics of it later in this article. However, if you want to customize the rendering and handle assembly and namespace includes for the markup as well as deal with text and file inputs as well as forcing Razor to run in a separate AppDomain so you can unload the code-generated assemblies and deal with assembly caching for re-used templates little more work is required to create something that is more easily reusable. For this reason I created a Razor Hosting wrapper project that combines a bunch of this functionality into an easy to use hosting class, a hosting factory that can load the engine in a separate AppDomain and a couple of hosting containers that provided folder based and string based caching for templates for an easily embeddable and reusable engine with easy to use syntax. If you just want the code and play with the samples and source go grab the latest code from the Subversion Repository at: http://www.west-wind.com:8080/svn/articles/trunk/RazorHosting/ or a snapshot from: http://www.west-wind.com/files/tools/RazorHosting.zip Getting Started Before I get into how hosting with Razor works, let’s take a look at how you can get up and running quickly with the wrapper classes provided. It only takes a few lines of code. The easiest way to use these Razor Hosting Wrappers is to use one of the two HostContainers provided. One is for hosting Razor scripts in a directory and rendering them as relative paths from these script files on disk. The other HostContainer serves razor scripts from string templates… Let’s start with a very simple template that displays some simple expressions, some code blocks and demonstrates rendering some data from contextual data that you pass to the template in the form of a ‘context’. Here’s a simple Razor template: @using System.Reflection Hello @Context.FirstName! Your entry was entered on: @Context.Entered @{ // Code block: Update the host Windows Form passed in through the context Context.WinForm.Text = "Hello World from Razor at " + DateTime.Now.ToString(); } AppDomain Id: @AppDomain.CurrentDomain.FriendlyName Assembly: @Assembly.GetExecutingAssembly().FullName Code based output: @{ // Write output with Response object from code string output = string.Empty; for (int i = 0; i < 10; i++) { output += i.ToString() + " "; } Response.Write(output); } Pretty easy to see what’s going on here. The only unusual thing in this code is the Context object which is an arbitrary object I’m passing from the host to the template by way of the template base class. I’m also displaying the current AppDomain and the executing Assembly name so you can see how compiling and running a template actually loads up new assemblies. Also note that as part of my context I’m passing a reference to the current Windows Form down to the template and changing the title from within the script. It’s a silly example, but it demonstrates two-way communication between host and template and back which can be very powerful. The easiest way to quickly render this template is to use the RazorEngine<TTemplateBase> class. The generic parameter specifies a template base class type that is used by Razor internally to generate the class it generates from a template. The default implementation provided in my RazorHosting wrapper is RazorTemplateBase. Here’s a simple one that renders from a string and outputs a string: var engine = new RazorEngine<RazorTemplateBase>(); // we can pass any object as context - here create a custom context var context = new CustomContext() { WinForm = this, FirstName = "Rick", Entered = DateTime.Now.AddDays(-10) }; string output = engine.RenderTemplate(this.txtSource.Text new string[] { "System.Windows.Forms.dll" }, context); if (output == null) this.txtResult.Text = "*** ERROR:\r\n" + engine.ErrorMessage; else this.txtResult.Text = output; Simple enough. This code renders a template from a string input and returns a result back as a string. It creates a custom context and passes that to the template which can then access the Context’s properties. Note that anything passed as ‘context’ must be serializable (or MarshalByRefObject) – otherwise you get an exception when passing the reference over AppDomain boundaries (discussed later). Passing a context is optional, but is a key feature in being able to share data between the host application and the template. Note that we use the Context object to access FirstName, Entered and even the host Windows Form object which is used in the template to change the Window caption from within the script! In the code above all the work happens in the RenderTemplate method which provide a variety of overloads to read and write to and from strings, files and TextReaders/Writers. Here’s another example that renders from a file input using a TextReader: using (reader = new StreamReader("templates\\simple.csHtml", true)) { result = host.RenderTemplate(reader, new string[] { "System.Windows.Forms.dll" }, this.CustomContext); } RenderTemplate() is fairly high level and it handles loading of the runtime, compiling into an assembly and rendering of the template. If you want more control you can use the lower level methods to control each step of the way which is important for the HostContainers I’ll discuss later. Basically for those scenarios you want to separate out loading of the engine, compiling into an assembly and then rendering the template from the assembly. Why? So we can keep assemblies cached. In the code above a new assembly is created for each template rendered which is inefficient and uses up resources. Depending on the size of your templates and how often you fire them you can chew through memory very quickly. This slighter lower level approach is only a couple of extra steps: // we can pass any object as context - here create a custom context var context = new CustomContext() { WinForm = this, FirstName = "Rick", Entered = DateTime.Now.AddDays(-10) }; var engine = new RazorEngine<RazorTemplateBase>(); string assId = null; using (StringReader reader = new StringReader(this.txtSource.Text)) { assId = engine.ParseAndCompileTemplate(new string[] { "System.Windows.Forms.dll" }, reader); } string output = engine.RenderTemplateFromAssembly(assId, context); if (output == null) this.txtResult.Text = "*** ERROR:\r\n" + engine.ErrorMessage; else this.txtResult.Text = output; The difference here is that you can capture the assembly – or rather an Id to it – and potentially hold on to it to render again later assuming the template hasn’t changed. The HostContainers take advantage of this feature to cache the assemblies based on certain criteria like a filename and file time step or a string hash that if not change indicate that an assembly can be reused. Note that ParseAndCompileTemplate returns an assembly Id rather than the assembly itself. This is done so that that the assembly always stays in the host’s AppDomain and is not passed across AppDomain boundaries which would cause load failures. We’ll talk more about this in a minute but for now just realize that assemblies references are stored in a list and are accessible by this ID to allow locating and re-executing of the assembly based on that id. Reuse of the assembly avoids recompilation overhead and creation of yet another assembly that loads into the current AppDomain. You can play around with several different versions of the above code in the main sample form: Using Hosting Containers for more Control and Caching The above examples simply render templates into assemblies each and every time they are executed. While this works and is even reasonably fast, it’s not terribly efficient. If you render templates more than once it would be nice if you could cache the generated assemblies for example to avoid re-compiling and creating of a new assembly each time. Additionally it would be nice to load template assemblies into a separate AppDomain optionally to be able to be able to unload assembli es and also to protect your host application from scripting attacks with malicious template code. Hosting containers provide also provide a wrapper around the RazorEngine<T> instance, a factory (which allows creation in separate AppDomains) and an easy way to start and stop the container ‘runtime’. The Razor Hosting samples provide two hosting containers: RazorFolderHostContainer and StringHostContainer. The folder host provides a simple runtime environment for a folder structure similar in the way that the ASP.NET runtime handles a virtual directory as it’s ‘application' root. Templates are loaded from disk in relative paths and the resulting assemblies are cached unless the template on disk is changed. The string host also caches templates based on string hashes – if the same string is passed a second time a cached version of the assembly is used. Here’s how HostContainers work. I’ll use the FolderHostContainer because it’s likely the most common way you’d use templates – from disk based templates that can be easily edited and maintained on disk. The first step is to create an instance of it and keep it around somewhere (in the example it’s attached as a property to the Form): RazorFolderHostContainer Host = new RazorFolderHostContainer(); public RazorFolderHostForm() { InitializeComponent(); // The base path for templates - templates are rendered with relative paths // based on this path. Host.TemplatePath = Path.Combine(Environment.CurrentDirectory, TemplateBaseFolder); // Add any assemblies you want reference in your templates Host.ReferencedAssemblies.Add("System.Windows.Forms.dll"); // Start up the host container Host.Start(); } Next anytime you want to render a template you can use simple code like this: private void RenderTemplate(string fileName) { // Pass the template path via the Context var relativePath = Utilities.GetRelativePath(fileName, Host.TemplatePath); if (!Host.RenderTemplate(relativePath, this.Context, Host.RenderingOutputFile)) { MessageBox.Show("Error: " + Host.ErrorMessage); return; } this.webBrowser1.Navigate("file://" + Host.RenderingOutputFile); } You can also render the output to a string instead of to a file: string result = Host.RenderTemplateToString(relativePath,context); Finally if you want to release the engine and shut down the hosting AppDomain you can simply do: Host.Stop(); Stopping the AppDomain and restarting it (ie. calling Stop(); followed by Start()) is also a nice way to release all resources in the AppDomain. The FolderBased domain also supports partial Rendering based on root path based relative paths with the same caching characteristics as the main templates. From within a template you can call out to a partial like this: @RenderPartial(@"partials\PartialRendering.cshtml", Context) where partials\PartialRendering.cshtml is a relative to the template root folder. The folder host example lets you load up templates from disk and display the result in a Web Browser control which demonstrates using Razor HTML output from templates that contain HTML syntax which happens to me my target scenario for Html Help Builder. The Razor Engine Wrapper Project The project I created to wrap Razor hosting has a fair bit of code and a number of classes associated with it. Most of the components are internally used and as you can see using the final RazorEngine<T> and HostContainer classes is pretty easy. The classes are extensible and I suspect developers will want to build more customized host containers for their applications. Host containers are the key to wrapping up all functionality – Engine, BaseTemplate, AppDomain Hosting, Caching etc in a logical piece that is ready to be plugged into an application. When looking at the code there are a couple of core features provided: Core Razor Engine Hosting This is the core Razor hosting which provides the basics of loading a template, compiling it into an assembly and executing it. This is fairly straightforward, but without a host container that can cache assemblies based on some criteria templates are recompiled and re-created each time which is inefficient (although pretty fast). The base engine wrapper implementation also supports hosting the Razor runtime in a separate AppDomain for security and the ability to unload it on demand. Host Containers The engine hosting itself doesn’t provide any sort of ‘runtime’ service like picking up files from disk, caching assemblies and so forth. So my implementation provides two HostContainers: RazorFolderHostContainer and RazorStringHostContainer. The FolderHost works off a base directory and loads templates based on relative paths (sort of like the ASP.NET runtime does off a virtual). The HostContainers also deal with caching of template assemblies – for the folder host the file date is tracked and checked for updates and unless the template is changed a cached assembly is reused. The StringHostContainer similiarily checks string hashes to figure out whether a particular string template was previously compiled and executed. The HostContainers also act as a simple startup environment and a single reference to easily store and reuse in an application. TemplateBase Classes The template base classes are the base classes that from which the Razor engine generates .NET code. A template is parsed into a class with an Execute() method and the class is based on this template type you can specify. RazorEngine<TBaseTemplate> can receive this type and the HostContainers default to specific templates in their base implementations. Template classes are customizable to allow you to create templates that provide application specific features and interaction from the template to your host application. How does the RazorEngine wrapper work? You can browse the source code in the links above or in the repository or download the source, but I’ll highlight some key features here. Here’s part of the RazorEngine implementation that can be used to host the runtime and that demonstrates the key code required to host the Razor runtime. The RazorEngine class is implemented as a generic class to reflect the Template base class type: public class RazorEngine<TBaseTemplateType> : MarshalByRefObject where TBaseTemplateType : RazorTemplateBase The generic type is used to internally provide easier access to the template type and assignments on it as part of the template processing. The class also inherits MarshalByRefObject to allow execution over AppDomain boundaries – something that all the classes discussed here need to do since there is much interaction between the host and the template. The first two key methods deal with creating a template assembly: /// <summary> /// Creates an instance of the RazorHost with various options applied. /// Applies basic namespace imports and the name of the class to generate /// </summary> /// <param name="generatedNamespace"></param> /// <param name="generatedClass"></param> /// <returns></returns> protected RazorTemplateEngine CreateHost(string generatedNamespace, string generatedClass) { Type baseClassType = typeof(TBaseTemplateType); RazorEngineHost host = new RazorEngineHost(new CSharpRazorCodeLanguage()); host.DefaultBaseClass = baseClassType.FullName; host.DefaultClassName = generatedClass; host.DefaultNamespace = generatedNamespace; host.NamespaceImports.Add("System"); host.NamespaceImports.Add("System.Text"); host.NamespaceImports.Add("System.Collections.Generic"); host.NamespaceImports.Add("System.Linq"); host.NamespaceImports.Add("System.IO"); return new RazorTemplateEngine(host); } /// <summary> /// Parses and compiles a markup template into an assembly and returns /// an assembly name. The name is an ID that can be passed to /// ExecuteTemplateByAssembly which picks up a cached instance of the /// loaded assembly. /// /// </summary> /// <param name="namespaceOfGeneratedClass">The namespace of the class to generate from the template</param> /// <param name="generatedClassName">The name of the class to generate from the template</param> /// <param name="ReferencedAssemblies">Any referenced assemblies by dll name only. Assemblies must be in execution path of host or in GAC.</param> /// <param name="templateSourceReader">Textreader that loads the template</param> /// <remarks> /// The actual assembly isn't returned here to allow for cross-AppDomain /// operation. If the assembly was returned it would fail for cross-AppDomain /// calls. /// </remarks> /// <returns>An assembly Id. The Assembly is cached in memory and can be used with RenderFromAssembly.</returns> public string ParseAndCompileTemplate( string namespaceOfGeneratedClass, string generatedClassName, string[] ReferencedAssemblies, TextReader templateSourceReader) { RazorTemplateEngine engine = CreateHost(namespaceOfGeneratedClass, generatedClassName); // Generate the template class as CodeDom GeneratorResults razorResults = engine.GenerateCode(templateSourceReader); // Create code from the codeDom and compile CSharpCodeProvider codeProvider = new CSharpCodeProvider(); CodeGeneratorOptions options = new CodeGeneratorOptions(); // Capture Code Generated as a string for error info // and debugging LastGeneratedCode = null; using (StringWriter writer = new StringWriter()) { codeProvider.GenerateCodeFromCompileUnit(razorResults.GeneratedCode, writer, options); LastGeneratedCode = writer.ToString(); } CompilerParameters compilerParameters = new CompilerParameters(ReferencedAssemblies); // Standard Assembly References compilerParameters.ReferencedAssemblies.Add("System.dll"); compilerParameters.ReferencedAssemblies.Add("System.Core.dll"); compilerParameters.ReferencedAssemblies.Add("Microsoft.CSharp.dll"); // dynamic support! // Also add the current assembly so RazorTemplateBase is available compilerParameters.ReferencedAssemblies.Add(Assembly.GetExecutingAssembly().CodeBase.Substring(8)); compilerParameters.GenerateInMemory = Configuration.CompileToMemory; if (!Configuration.CompileToMemory) compilerParameters.OutputAssembly = Path.Combine(Configuration.TempAssemblyPath, "_" + Guid.NewGuid().ToString("n") + ".dll"); CompilerResults compilerResults = codeProvider.CompileAssemblyFromDom(compilerParameters, razorResults.GeneratedCode); if (compilerResults.Errors.Count > 0) { var compileErrors = new StringBuilder(); foreach (System.CodeDom.Compiler.CompilerError compileError in compilerResults.Errors) compileErrors.Append(String.Format(Resources.LineX0TColX1TErrorX2RN, compileError.Line, compileError.Column, compileError.ErrorText)); this.SetError(compileErrors.ToString() + "\r\n" + LastGeneratedCode); return null; } AssemblyCache.Add(compilerResults.CompiledAssembly.FullName, compilerResults.CompiledAssembly); return compilerResults.CompiledAssembly.FullName; } Think of the internal CreateHost() method as setting up the assembly generated from each template. Each template compiles into a separate assembly. It sets up namespaces, and assembly references, the base class used and the name and namespace for the generated class. ParseAndCompileTemplate() then calls the CreateHost() method to receive the template engine generator which effectively generates a CodeDom from the template – the template is turned into .NET code. The code generated from our earlier example looks something like this: //------------------------------------------------------------------------------ // <auto-generated> // This code was generated by a tool. // Runtime Version:4.0.30319.1 // // Changes to this file may cause incorrect behavior and will be lost if // the code is regenerated. // </auto-generated> //------------------------------------------------------------------------------ namespace RazorTest { using System; using System.Text; using System.Collections.Generic; using System.Linq; using System.IO; using System.Reflection; public class RazorTemplate : RazorHosting.RazorTemplateBase { #line hidden public RazorTemplate() { } public override void Execute() { WriteLiteral("Hello "); Write(Context.FirstName); WriteLiteral("! Your entry was entered on: "); Write(Context.Entered); WriteLiteral("\r\n\r\n"); // Code block: Update the host Windows Form passed in through the context Context.WinForm.Text = "Hello World from Razor at " + DateTime.Now.ToString(); WriteLiteral("\r\nAppDomain Id:\r\n "); Write(AppDomain.CurrentDomain.FriendlyName); WriteLiteral("\r\n \r\nAssembly:\r\n "); Write(Assembly.GetExecutingAssembly().FullName); WriteLiteral("\r\n\r\nCode based output: \r\n"); // Write output with Response object from code string output = string.Empty; for (int i = 0; i < 10; i++) { output += i.ToString() + " "; } } } } Basically the template’s body is turned into code in an Execute method that is called. Internally the template’s Write method is fired to actually generate the output. Note that the class inherits from RazorTemplateBase which is the generic parameter I used to specify the base class when creating an instance in my RazorEngine host: var engine = new RazorEngine<RazorTemplateBase>(); This template class must be provided and it must implement an Execute() and Write() method. Beyond that you can create any class you chose and attach your own properties. My RazorTemplateBase class implementation is very simple: public class RazorTemplateBase : MarshalByRefObject, IDisposable { /// <summary> /// You can pass in a generic context object /// to use in your template code /// </summary> public dynamic Context { get; set; } /// <summary> /// Class that generates output. Currently ultra simple /// with only Response.Write() implementation. /// </summary> public RazorResponse Response { get; set; } public object HostContainer {get; set; } public object Engine { get; set; } public RazorTemplateBase() { Response = new RazorResponse(); } public virtual void Write(object value) { Response.Write(value); } public virtual void WriteLiteral(object value) { Response.Write(value); } /// <summary> /// Razor Parser implements this method /// </summary> public virtual void Execute() {} public virtual void Dispose() { if (Response != null) { Response.Dispose(); Response = null; } } } Razor fills in the Execute method when it generates its subclass and uses the Write() method to output content. As you can see I use a RazorResponse() class here to generate output. This isn’t necessary really, as you could use a StringBuilder or StringWriter() directly, but I prefer using Response object so I can extend the Response behavior as needed. The RazorResponse class is also very simple and merely acts as a wrapper around a TextWriter: public class RazorResponse : IDisposable { /// <summary> /// Internal text writer - default to StringWriter() /// </summary> public TextWriter Writer = new StringWriter(); public virtual void Write(object value) { Writer.Write(value); } public virtual void WriteLine(object value) { Write(value); Write("\r\n"); } public virtual void WriteFormat(string format, params object[] args) { Write(string.Format(format, args)); } public override string ToString() { return Writer.ToString(); } public virtual void Dispose() { Writer.Close(); } public virtual void SetTextWriter(TextWriter writer) { // Close original writer if (Writer != null) Writer.Close(); Writer = writer; } } The Rendering Methods of RazorEngine At this point I’ve talked about the assembly generation logic and the template implementation itself. What’s left is that once you’ve generated the assembly is to execute it. The code to do this is handled in the various RenderXXX methods of the RazorEngine class. Let’s look at the lowest level one of these which is RenderTemplateFromAssembly() and a couple of internal support methods that handle instantiating and invoking of the generated template method: public string RenderTemplateFromAssembly( string assemblyId, string generatedNamespace, string generatedClass, object context, TextWriter outputWriter) { this.SetError(); Assembly generatedAssembly = AssemblyCache[assemblyId]; if (generatedAssembly == null) { this.SetError(Resources.PreviouslyCompiledAssemblyNotFound); return null; } string className = generatedNamespace + "." + generatedClass; Type type; try { type = generatedAssembly.GetType(className); } catch (Exception ex) { this.SetError(Resources.UnableToCreateType + className + ": " + ex.Message); return null; } // Start with empty non-error response (if we use a writer) string result = string.Empty; using(TBaseTemplateType instance = InstantiateTemplateClass(type)) { if (instance == null) return null; if (outputWriter != null) instance.Response.SetTextWriter(outputWriter); if (!InvokeTemplateInstance(instance, context)) return null; // Capture string output if implemented and return // otherwise null is returned if (outputWriter == null) result = instance.Response.ToString(); } return result; } protected virtual TBaseTemplateType InstantiateTemplateClass(Type type) { TBaseTemplateType instance = Activator.CreateInstance(type) as TBaseTemplateType; if (instance == null) { SetError(Resources.CouldnTActivateTypeInstance + type.FullName); return null; } instance.Engine = this; // If a HostContainer was set pass that to the template too instance.HostContainer = this.HostContainer; return instance; } /// <summary> /// Internally executes an instance of the template, /// captures errors on execution and returns true or false /// </summary> /// <param name="instance">An instance of the generated template</param> /// <returns>true or false - check ErrorMessage for errors</returns> protected virtual bool InvokeTemplateInstance(TBaseTemplateType instance, object context) { try { instance.Context = context; instance.Execute(); } catch (Exception ex) { this.SetError(Resources.TemplateExecutionError + ex.Message); return false; } finally { // Must make sure Response is closed instance.Response.Dispose(); } return true; } The RenderTemplateFromAssembly method basically requires the namespace and class to instantate and creates an instance of the class using InstantiateTemplateClass(). It then invokes the method with InvokeTemplateInstance(). These two methods are broken out because they are re-used by various other rendering methods and also to allow subclassing and providing additional configuration tasks to set properties and pass values to templates at execution time. In the default mode instantiation sets the Engine and HostContainer (discussed later) so the template can call back into the template engine, and the context is set when the template method is invoked. The various RenderXXX methods use similar code although they create the assemblies first. If you’re after potentially cashing assemblies the method is the one to call and that’s exactly what the two HostContainer classes do. More on that in a minute, but before we get into HostContainers let’s talk about AppDomain hosting and the like. Running Templates in their own AppDomain With the RazorEngine class above, when a template is parsed into an assembly and executed the assembly is created (in memory or on disk – you can configure that) and cached in the current AppDomain. In .NET once an assembly has been loaded it can never be unloaded so if you’re loading lots of templates and at some time you want to release them there’s no way to do so. If however you load the assemblies in a separate AppDomain that new AppDomain can be unloaded and the assemblies loaded in it with it. In order to host the templates in a separate AppDomain the easiest thing to do is to run the entire RazorEngine in a separate AppDomain. Then all interaction occurs in the other AppDomain and no further changes have to be made. To facilitate this there is a RazorEngineFactory which has methods that can instantiate the RazorHost in a separate AppDomain as well as in the local AppDomain. The host creates the remote instance and then hangs on to it to keep it alive as well as providing methods to shut down the AppDomain and reload the engine. Sounds complicated but cross-AppDomain invocation is actually fairly easy to implement. Here’s some of the relevant code from the RazorEngineFactory class. Like the RazorEngine this class is generic and requires a template base type in the generic class name: public class RazorEngineFactory<TBaseTemplateType> where TBaseTemplateType : RazorTemplateBase Here are the key methods of interest: /// <summary> /// Creates an instance of the RazorHost in a new AppDomain. This /// version creates a static singleton that that is cached and you /// can call UnloadRazorHostInAppDomain to unload it. /// </summary> /// <returns></returns> public static RazorEngine<TBaseTemplateType> CreateRazorHostInAppDomain() { if (Current == null) Current = new RazorEngineFactory<TBaseTemplateType>(); return Current.GetRazorHostInAppDomain(); } public static void UnloadRazorHostInAppDomain() { if (Current != null) Current.UnloadHost(); Current = null; } /// <summary> /// Instance method that creates a RazorHost in a new AppDomain. /// This method requires that you keep the Factory around in /// order to keep the AppDomain alive and be able to unload it. /// </summary> /// <returns></returns> public RazorEngine<TBaseTemplateType> GetRazorHostInAppDomain() { LocalAppDomain = CreateAppDomain(null); if (LocalAppDomain == null) return null; /// Create the instance inside of the new AppDomain /// Note: remote domain uses local EXE's AppBasePath!!! RazorEngine<TBaseTemplateType> host = null; try { Assembly ass = Assembly.GetExecutingAssembly(); string AssemblyPath = ass.Location; host = (RazorEngine<TBaseTemplateType>) LocalAppDomain.CreateInstanceFrom(AssemblyPath, typeof(RazorEngine<TBaseTemplateType>).FullName).Unwrap(); } catch (Exception ex) { ErrorMessage = ex.Message; return null; } return host; } /// <summary> /// Internally creates a new AppDomain in which Razor templates can /// be run. /// </summary> /// <param name="appDomainName"></param> /// <returns></returns> private AppDomain CreateAppDomain(string appDomainName) { if (appDomainName == null) appDomainName = "RazorHost_" + Guid.NewGuid().ToString("n"); AppDomainSetup setup = new AppDomainSetup(); // *** Point at current directory setup.ApplicationBase = AppDomain.CurrentDomain.BaseDirectory; AppDomain localDomain = AppDomain.CreateDomain(appDomainName, null, setup); return localDomain; } /// <summary> /// Allow unloading of the created AppDomain to release resources /// All internal resources in the AppDomain are released including /// in memory compiled Razor assemblies. /// </summary> public void UnloadHost() { if (this.LocalAppDomain != null) { AppDomain.Unload(this.LocalAppDomain); this.LocalAppDomain = null; } } The static CreateRazorHostInAppDomain() is the key method that startup code usually calls. It uses a Current singleton instance to an instance of itself that is created cross AppDomain and is kept alive because it’s static. GetRazorHostInAppDomain actually creates a cross-AppDomain instance which first creates a new AppDomain and then loads the RazorEngine into it. The remote Proxy instance is returned as a result to the method and can be used the same as a local instance. The code to run with a remote AppDomain is simple: private RazorEngine<RazorTemplateBase> CreateHost() { if (this.Host != null) return this.Host; // Use Static Methods - no error message if host doesn't load this.Host = RazorEngineFactory<RazorTemplateBase>.CreateRazorHostInAppDomain(); if (this.Host == null) { MessageBox.Show("Unable to load Razor Template Host", "Razor Hosting", MessageBoxButtons.OK, MessageBoxIcon.Exclamation); } return this.Host; } This code relies on a local reference of the Host which is kept around for the duration of the app (in this case a form reference). To use this you’d simply do: this.Host = CreateHost(); if (host == null) return; string result = host.RenderTemplate( this.txtSource.Text, new string[] { "System.Windows.Forms.dll", "Westwind.Utilities.dll" }, this.CustomContext); if (result == null) { MessageBox.Show(host.ErrorMessage, "Template Execution Error", MessageBoxButtons.OK, MessageBoxIcon.Exclamation); return; } this.txtResult.Text = result; Now all templates run in a remote AppDomain and can be unloaded with simple code like this: RazorEngineFactory<RazorTemplateBase>.UnloadRazorHostInAppDomain(); this.Host = null; One Step further – Providing a caching ‘Runtime’ Once we can load templates in a remote AppDomain we can add some additional functionality like assembly caching based on application specific features. One of my typical scenarios is to render templates out of a scripts folder. So all templates live in a folder and they change infrequently. So a Folder based host that can compile these templates once and then only recompile them if something changes would be ideal. Enter host containers which are basically wrappers around the RazorEngine<t> and RazorEngineFactory<t>. They provide additional logic for things like file caching based on changes on disk or string hashes for string based template inputs. The folder host also provides for partial rendering logic through a custom template base implementation. There’s a base implementation in RazorBaseHostContainer, which provides the basics for hosting a RazorEngine, which includes the ability to start and stop the engine, cache assemblies and add references: public abstract class RazorBaseHostContainer<TBaseTemplateType> : MarshalByRefObject where TBaseTemplateType : RazorTemplateBase, new() { public RazorBaseHostContainer() { UseAppDomain = true; GeneratedNamespace = "__RazorHost"; } /// <summary> /// Determines whether the Container hosts Razor /// in a separate AppDomain. Seperate AppDomain /// hosting allows unloading and releasing of /// resources. /// </summary> public bool UseAppDomain { get; set; } /// <summary> /// Base folder location where the AppDomain /// is hosted. By default uses the same folder /// as the host application. /// /// Determines where binary dependencies are /// found for assembly references. /// </summary> public string BaseBinaryFolder { get; set; } /// <summary> /// List of referenced assemblies as string values. /// Must be in GAC or in the current folder of the host app/ /// base BinaryFolder /// </summary> public List<string> ReferencedAssemblies = new List<string>(); /// <summary> /// Name of the generated namespace for template classes /// </summary> public string GeneratedNamespace {get; set; } /// <summary> /// Any error messages /// </summary> public string ErrorMessage { get; set; } /// <summary> /// Cached instance of the Host. Required to keep the /// reference to the host alive for multiple uses. /// </summary> public RazorEngine<TBaseTemplateType> Engine; /// <summary> /// Cached instance of the Host Factory - so we can unload /// the host and its associated AppDomain. /// </summary> protected RazorEngineFactory<TBaseTemplateType> EngineFactory; /// <summary> /// Keep track of each compiled assembly /// and when it was compiled. /// /// Use a hash of the string to identify string /// changes. /// </summary> protected Dictionary<int, CompiledAssemblyItem> LoadedAssemblies = new Dictionary<int, CompiledAssemblyItem>(); /// <summary> /// Call to start the Host running. Follow by a calls to RenderTemplate to /// render individual templates. Call Stop when done. /// </summary> /// <returns>true or false - check ErrorMessage on false </returns> public virtual bool Start() { if (Engine == null) { if (UseAppDomain) Engine = RazorEngineFactory<TBaseTemplateType>.CreateRazorHostInAppDomain(); else Engine = RazorEngineFactory<TBaseTemplateType>.CreateRazorHost(); Engine.Configuration.CompileToMemory = true; Engine.HostContainer = this; if (Engine == null) { this.ErrorMessage = EngineFactory.ErrorMessage; return false; } } return true; } /// <summary> /// Stops the Host and releases the host AppDomain and cached /// assemblies. /// </summary> /// <returns>true or false</returns> public bool Stop() { this.LoadedAssemblies.Clear(); RazorEngineFactory<RazorTemplateBase>.UnloadRazorHostInAppDomain(); this.Engine = null; return true; } … } This base class provides most of the mechanics to host the runtime, but no application specific implementation for rendering. There are rendering functions but they just call the engine directly and provide no caching – there’s no context to decide how to cache and reuse templates. The key methods are Start and Stop and their main purpose is to start a new AppDomain (optionally) and shut it down when requested. The RazorFolderHostContainer – Folder Based Runtime Hosting Let’s look at the more application specific RazorFolderHostContainer implementation which is defined like this: public class RazorFolderHostContainer : RazorBaseHostContainer<RazorTemplateFolderHost> Note that a customized RazorTemplateFolderHost class template is used for this implementation that supports partial rendering in form of a RenderPartial() method that’s available to templates. The folder host’s features are: Render templates based on a Template Base Path (a ‘virtual’ if you will) Cache compiled assemblies based on the relative path and file time stamp File changes on templates cause templates to be recompiled into new assemblies Support for partial rendering using base folder relative pathing As shown in the startup examples earlier host containers require some startup code with a HostContainer tied to a persistent property (like a Form property): // The base path for templates - templates are rendered with relative paths // based on this path. HostContainer.TemplatePath = Path.Combine(Environment.CurrentDirectory, TemplateBaseFolder); // Default output rendering disk location HostContainer.RenderingOutputFile = Path.Combine(HostContainer.TemplatePath, "__Preview.htm"); // Add any assemblies you want reference in your templates HostContainer.ReferencedAssemblies.Add("System.Windows.Forms.dll"); // Start up the host container HostContainer.Start(); Once that’s done, you can render templates with the host container: // Pass the template path for full filename seleted with OpenFile Dialog // relativepath is: subdir\file.cshtml or file.cshtml or ..\file.cshtml var relativePath = Utilities.GetRelativePath(fileName, HostContainer.TemplatePath); if (!HostContainer.RenderTemplate(relativePath, Context, HostContainer.RenderingOutputFile)) { MessageBox.Show("Error: " + HostContainer.ErrorMessage); return; } webBrowser1.Navigate("file://" + HostContainer.RenderingOutputFile); The most critical task of the RazorFolderHostContainer implementation is to retrieve a template from disk, compile and cache it and then deal with deciding whether subsequent requests need to re-compile the template or simply use a cached version. Internally the GetAssemblyFromFileAndCache() handles this task: /// <summary> /// Internally checks if a cached assembly exists and if it does uses it /// else creates and compiles one. Returns an assembly Id to be /// used with the LoadedAssembly list. /// </summary> /// <param name="relativePath"></param> /// <param name="context"></param> /// <returns></returns> protected virtual CompiledAssemblyItem GetAssemblyFromFileAndCache(string relativePath) { string fileName = Path.Combine(TemplatePath, relativePath).ToLower(); int fileNameHash = fileName.GetHashCode(); if (!File.Exists(fileName)) { this.SetError(Resources.TemplateFileDoesnTExist + fileName); return null; } CompiledAssemblyItem item = null; this.LoadedAssemblies.TryGetValue(fileNameHash, out item); string assemblyId = null; // Check for cached instance if (item != null) { var fileTime = File.GetLastWriteTimeUtc(fileName); if (fileTime <= item.CompileTimeUtc) assemblyId = item.AssemblyId; } else item = new CompiledAssemblyItem(); // No cached instance - create assembly and cache if (assemblyId == null) { string safeClassName = GetSafeClassName(fileName); StreamReader reader = null; try { reader = new StreamReader(fileName, true); } catch (Exception ex) { this.SetError(Resources.ErrorReadingTemplateFile + fileName); return null; } assemblyId = Engine.ParseAndCompileTemplate(this.ReferencedAssemblies.ToArray(), reader); // need to ensure reader is closed if (reader != null) reader.Close(); if (assemblyId == null) { this.SetError(Engine.ErrorMessage); return null; } item.AssemblyId = assemblyId; item.CompileTimeUtc = DateTime.UtcNow; item.FileName = fileName; item.SafeClassName = safeClassName; this.LoadedAssemblies[fileNameHash] = item; } return item; } This code uses a LoadedAssembly dictionary which is comprised of a structure that holds a reference to a compiled assembly, a full filename and file timestamp and an assembly id. LoadedAssemblies (defined on the base class shown earlier) is essentially a cache for compiled assemblies and they are identified by a hash id. In the case of files the hash is a GetHashCode() from the full filename of the template. The template is checked for in the cache and if not found the file stamp is checked. If that’s newer than the cache’s compilation date the template is recompiled otherwise the version in the cache is used. All the core work defers to a RazorEngine<T> instance to ParseAndCompileTemplate(). The three rendering specific methods then are rather simple implementations with just a few lines of code dealing with parameter and return value parsing: /// <summary> /// Renders a template to a TextWriter. Useful to write output into a stream or /// the Response object. Used for partial rendering. /// </summary> /// <param name="relativePath">Relative path to the file in the folder structure</param> /// <param name="context">Optional context object or null</param> /// <param name="writer">The textwriter to write output into</param> /// <returns></returns> public bool RenderTemplate(string relativePath, object context, TextWriter writer) { // Set configuration data that is to be passed to the template (any object) Engine.TemplatePerRequestConfigurationData = new RazorFolderHostTemplateConfiguration() { TemplatePath = Path.Combine(this.TemplatePath, relativePath), TemplateRelativePath = relativePath, }; CompiledAssemblyItem item = GetAssemblyFromFileAndCache(relativePath); if (item == null) { writer.Close(); return false; } try { // String result will be empty as output will be rendered into the // Response object's stream output. However a null result denotes // an error string result = Engine.RenderTemplateFromAssembly(item.AssemblyId, context, writer); if (result == null) { this.SetError(Engine.ErrorMessage); return false; } } catch (Exception ex) { this.SetError(ex.Message); return false; } finally { writer.Close(); } return true; } /// <summary> /// Render a template from a source file on disk to a specified outputfile. /// </summary> /// <param name="relativePath">Relative path off the template root folder. Format: path/filename.cshtml</param> /// <param name="context">Any object that will be available in the template as a dynamic of this.Context</param> /// <param name="outputFile">Optional - output file where output is written to. If not specified the /// RenderingOutputFile property is used instead /// </param> /// <returns>true if rendering succeeds, false on failure - check ErrorMessage</returns> public bool RenderTemplate(string relativePath, object context, string outputFile) { if (outputFile == null) outputFile = RenderingOutputFile; try { using (StreamWriter writer = new StreamWriter(outputFile, false, Engine.Configuration.OutputEncoding, Engine.Configuration.StreamBufferSize)) { return RenderTemplate(relativePath, context, writer); } } catch (Exception ex) { this.SetError(ex.Message); return false; } return true; } /// <summary> /// Renders a template to string. Useful for RenderTemplate /// </summary> /// <param name="relativePath"></param> /// <param name="context"></param> /// <returns></returns> public string RenderTemplateToString(string relativePath, object context) { string result = string.Empty; try { using (StringWriter writer = new StringWriter()) { // String result will be empty as output will be rendered into the // Response object's stream output. However a null result denotes // an error if (!RenderTemplate(relativePath, context, writer)) { this.SetError(Engine.ErrorMessage); return null; } result = writer.ToString(); } } catch (Exception ex) { this.SetError(ex.Message); return null; } return result; } The idea is that you can create custom host container implementations that do exactly what you want fairly easily. Take a look at both the RazorFolderHostContainer and RazorStringHostContainer classes for the basic concepts you can use to create custom implementations. Notice also that you can set the engine’s PerRequestConfigurationData() from the host container: // Set configuration data that is to be passed to the template (any object) Engine.TemplatePerRequestConfigurationData = new RazorFolderHostTemplateConfiguration() { TemplatePath = Path.Combine(this.TemplatePath, relativePath), TemplateRelativePath = relativePath, }; which when set to a non-null value is passed to the Template’s InitializeTemplate() method. This method receives an object parameter which you can cast as needed: public override void InitializeTemplate(object configurationData) { // Pick up configuration data and stuff into Request object RazorFolderHostTemplateConfiguration config = configurationData as RazorFolderHostTemplateConfiguration; this.Request.TemplatePath = config.TemplatePath; this.Request.TemplateRelativePath = config.TemplateRelativePath; } With this data you can then configure any custom properties or objects on your main template class. It’s an easy way to pass data from the HostContainer all the way down into the template. The type you use is of type object so you have to cast it yourself, and it must be serializable since it will likely run in a separate AppDomain. This might seem like an ugly way to pass data around – normally I’d use an event delegate to call back from the engine to the host, but since this is running over AppDomain boundaries events get really tricky and passing a template instance back up into the host over AppDomain boundaries doesn’t work due to serialization issues. So it’s easier to pass the data from the host down into the template using this rather clumsy approach of set and forward. It’s ugly, but it’s something that can be hidden in the host container implementation as I’ve done here. It’s also not something you have to do in every implementation so this is kind of an edge case, but I know I’ll need to pass a bunch of data in some of my applications and this will be the easiest way to do so. Summing Up Hosting the Razor runtime is something I got jazzed up about quite a bit because I have an immediate need for this type of templating/merging/scripting capability in an application I’m working on. I’ve also been using templating in many apps and it’s always been a pain to deal with. The Razor engine makes this whole experience a lot cleaner and more light weight and with these wrappers I can now plug .NET based templating into my code literally with a few lines of code. That’s something to cheer about… I hope some of you will find this useful as well… Resources The examples and code require that you download the Razor runtimes. Projects are for Visual Studio 2010 running on .NET 4.0 Platform Installer 3.0 (install WebMatrix or MVC 3 for Razor Runtimes) Latest Code in Subversion Repository Download Snapshot of the Code Documentation (CHM Help File) © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET .NET

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Define Servlet Context in WAR-File

- by er4z0r

Hi, How can I tell e.g. Tomcat to use a specific context path when given my WAR-File? Example: I have a war file created by maven build and the resulting name of the file is rather long. So I do not want the tomcat manager application to use the filename of the war as the context. Supplying a context.xml in META-INF did not produce the desired results I also found this in the documentation for the path attribute of Context: The value of this field must not be set except when statically defining a Context in server.xml, as it will be inferred from the filenames used for either the .xml context file or the docBase. So it does not seem to be the right way to tell the application-server what the path for my WAR should be. Any more hints?

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Getting invalid context errors

- by Andrew

I don't have much code thus far, only this to start: UIGraphicsBeginImageContextWithOptions(bounds.size, NO, 0); CGContextRef context = UIGraphicsGetCurrentContext(); CGMutablePathRef outerPath; CGMutablePathRef highlightPath; CGRect outerRect = rectForRectWithInset(bounds, 1); CGRect highlightRect = CGRectMake(outerRect.origin.x, outerRect.origin.y + 1, outerRect.size.width, outerRect.size.height); And then the problematic bit, which when commented out, the error goes away: CGContextSaveGState(context); CGContextAddPath(context, highlightPath); CGContextSetFillColorWithColor(context, [[UIColor colorWithWhite:1.0 alpha:0.05]CGColor]); CGContextFillPath(context); CGContextRestoreGState(context); Below that is simply: UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext();

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Django template context not working with imported class

- by Andy Hume

I'm using Django's templating on appengine, and am having a problem whereby a class I'm importing from another package is not correctly being made available to the template context. Broadly speaking, this is the code. The prop1 is not available in the template in the first example below, but is in the second. MyClass is identical in both cases. This does not work: from module import MyClass context = MyClass() self.response.out.write(template.render(path, context)) This does: class MyClass(object): def __init__(self): self.prop1 = "prop1" context = MyClass() self.response.out.write(template.render(path, context)) If I log the context in the above code I get: <module.MyClass object at 0x107b1e450> when it's imported, and: <__main__.MyClass object at 0x103759390> when it's defined in the same file. Any clues as to what might cause this kind of behaviour?

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Convert .3GP and .3G2 Files to AVI / MPEG for Free

- by DigitalGeekery

3GP and .3G2 are common video capture formats used on many mobile phones, but they may not be supported by your favorite media player. Today we’ll show you a quick and easy way to convert those files to AVI or MPG format with the free Windows application, Pazera Free 3GP to AVI Converter. Download the Pazera Free 3GP to AVI Converter. You’ll have to unzip the download folder, but there is no need to install the application. Just double-click the 3gptoavi.exe file to run the application. To add your 3GP or 3G2 files to the queue to be converted, click on the Add files button at the top left. Browse for your file, and click Open. Your video will be added to the Queue. You can add multiple files to the queue and convert them all at one time. Most users will find it preferable to use one of the pre-configured profiles for their conversion settings. To load a profile, choose one from the Profile drop down list and then click the Load button. You will see the profile update the settings in the panels at the bottom of the application. We tested Pazera Free 3GP to AVI Converter with 3GP files recorded on a Motorola Droid, and found the AVI H.264 Very High Q. profile to return the best results for AVI output, and the MPG – DVD NTSC: MPEG-2 the best results for MPG output. Other profiles produced smaller file sizes, but at a cost of reduced quality video output. More advanced users may tweak video and audio settings to their liking in the lower panels. Click on the AVI button under Output file format / Video settings to adjust settings AVI… Or the MPG button to adjust the settings for MPG output. By default, the converted file will be output to the same location as the input directory. You can change it by clicking the text box input radio button and browsing for a different folder. When you’ve chosen your settings, click Convert to begin the conversion process. A conversion output box will open and display the progress. When finished, click Close. Now you’re ready to enjoy your video in your favorite media player. Pazera Free 3GP to AVI Converter isn’t the most robust media conversion tool, but it does what it is intended to do. It handles the task of 3GP to AVI / MPG conversion very well. It’s easy enough for the beginner to manage without much trouble, but also has enough options to please more experienced users. Download Pazera Free 3GP to AVI Converter Similar Articles Productive Geek Tips How To Convert Video Files to MP3 with VLCEasily Change Audio File Formats with XRECODEConvert PDF Files to Word Documents and Other FormatsConvert Video and Remove Commercials in Windows 7 Media Center with MCEBuddy 1.1Compress Large Video Files with DivX / Xvid and AutoGK 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 Install, Remove and HIDE Fonts in Windows 7 Need Help with Your Home Network? Awesome Lyrics Finder for Winamp & Windows Media Player Download Videos from Hulu Pixels invade Manhattan Convert PDF files to ePub to read on your iPad

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Extract Audio from a Video File with Pazera Free Audio Extractor

- by DigitalGeekery

Have you ever wanted to extract some or all of the audio from a video file? Today we’ll take a look at Pazera Free Audio Extractor. A simple audio converter that specializes in that very task. Download the Pazera Free Audio Extractor. (See download link below) You’ll need to unzip the download folder, but there is no need to install the application. Simply double-click the AudioExtractor.exe file to run the application. To add your video files to the queue to be converted, click on the Add files button at the top left. You can add multiple files to the queue and convert them all at one time. Browse for your video file, and click Open. Your video will be added to the Queue for processing. Under Output directory you can choose to output to a folder of your choice. Outputting to the same folder as the input folder is the default. Pazera Free Audio Extractor includes pre-configured profiles that will simplify the process of choosing conversion settings. To load a profile, choose one from the Profile drop down list and then click the Load button. You can choose to output to MP3, AAC, AC3, WMA, FLAC, OGG or WAV file format. You will see the profile update the Audio settings in the panels at the lower left of the application. If you wish, you may also select your own custom settings. Advanced Settings The Advanced settings can be used if you want to extract only a portion of the the audio, such as a clip of dialog or a song from a movie. To extract only a portion of the audio, set the start time by selecting the Start time offset check box, then entering the time in the video clip where the audio begins. To set the end time, begin by selecting the Duration check box. Now, you can either select the Duration radio button and enter the amount of time for which you would like to extract the audio, or you can select the End time offset radio button and enter the time in the video clip where the audio ends. When you are ready to convert, click the CONVERT button on the menu at the top of the screen. An output box will open and display the conversion progress. When finished, click Close. Now you are ready to enjoy your audio clip. Pazera Free Audio Extractor is a basic audio tool that is easy enough for everyone to use. It runs on Windows only and supports most common video formats including AVI, FLV, MP4, MPG, MOV, 3GP, and WMV. Download Free Audio Extractor 1.3 Similar Articles Productive Geek Tips Eufony Free Audio Player – Resource Gentle Audio PlayerConvert .3GP and .3G2 Files to AVI / MPEG for FreeTurn Off Auto-Play of Audio and Video CDs and DVDs in UbuntuHow to Make/Edit a movie with Windows Movie Maker in Windows VistaEasily Change Audio File Formats with XRECODE 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 Use Printflush to Solve Printing Problems Icelandic Volcano Webcams Open Multiple Links At One Go NachoFoto Searches Images in Real-time Office 2010 Product Guides Google Maps Place marks – Pizza, Guns or Strip Clubs

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How expensive is a context switch? Is it better to implement a manual task switch than to rely on OS

- by Vilx-

The title says it all. Imagine I have two (three, four, whatever) tasks that have to run in parallel. Now, the easy way to do this would be to create separate threads and forget about it. But on a plain old single-core CPU that would mean a lot of context switching - and we all know that context switching is big, bad, slow, and generally simply Evil. It should be avoided, right? On that note, if I'm writing the software from ground up anyway, I could go the extra mile and implement my own task-switching. Split each task in parts, save the state inbetween, and then switch among them within a single thread. Or, if I detect that there are multiple CPU cores, I could just give each task to a separate thread and all would be well. The second solution does have the advantage of adapting to the number of available CPU cores, but will the manual task-switch really be faster than the one in the OS core? Especially if I'm trying to make the whole thing generic with a TaskManager and an ITask, etc?

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iphone encode problem with ffmpeg

- by samantha

Hi, I need to encode a video from image. I use ffmpeg and compiling rigth. My problem is that when i try to opne video with quicktime on iphone, this give me a message "this movie format is not supported". I create a file mp4 with this parameter on context: context-time_base.num = 1; context-time_base.den = 15; context-codec_type = CODEC_TYPE_VIDEO; context-codec_id = CODEC_ID_H264; context-bit_rate = 1000000; context-width = width; context-height = height; context-keyint_min = 10; context-i_quant_factor = 0.71; context-bit_rate_tolerance = 20000; context-rc_max_rate = 100000; context-rc_buffer_size = 8835000; context-qcompress = 0.6; context-qmin = 10; context-qmax = 30; context-max_qdiff = 4; context-gop_size = 30; context->time_base.num = 1; context-time_base.den = 30; context-sample_aspect_ratio = av_d2q(1, 255); context-profile = 30; context-pix_fmt = PIX_FMT_YUV420P; context-flags |= CODEC_FLAG_LOOP_FILTER; where is my mistake?? thanks

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