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A collection of middleware packages that many websites frequently need. Provides examples of how to write middleware

This solution compiles optional NuGet package that enhance the OWIN Framework by providing useful tools and default implementations of some standard types of middleware.

These middleware components are designed to get you off the ground, and were never intended to be full featured. Full featured middleware for things like identification, authorization, output caching, rendering etc should be separate projects, and there should be choice and diversity among offerings from different authors. This is the whole point of creating this open architecture for middleware interoperability,

The main reason why this project exists is chicken and egg. Developers don't want to target their packages at this framework if nobody is using it, and nobody wants to use the framework unless there is a decent amount of middleware available.

As well as making this set of middleware available, the framework was deliberately designed so that middleware developers can support it without requiring application developers to use it. This is because middleware developers only have to implement the very simple IMiddlewareT interface for their middleware to work with the OWIN Framework, and implementing this interface does not change how the middleware is used for application developers that choose not to use the OWIN Framework.

Middleware devlopers of the world, please go ahead and implement IMiddlewareobject in your middleware so that application developers can configure it using the Owin Framework if they choose to.

Each project in this solution has its own readem file with detailed information about what the middleware provides and how it can be configured. In addition most of these middleware also impelement the ISelfDocumenting interface which can provide detailed documentation at run-time.

Briefly, the middleware in this solution is:


The AnalysisReporter middleware extracts analytics from middleware that implements IAnalysable and formats it into JSON, HTML, plain text etc.


The Dart middleware provides back-end support for including a UI written in the Dart programming language. It does this by detecting if the browser supports Dart and rewriting the request URL. You will probably want StaticFiles middleware to run after this one unless you plan to generate the content dynamically.


The DefaultDocument middleware will rewrite requests for the root of your web site so that they return a specific document.


The Documenter middleware will extract documentation from Middleware that implements ISelfDocumenting and present this in HTML.


The ExceptionReporter middleware will wrap the downstream middleware in a try/catch block and report exception details. It also allows you to return specific responses by throwing HttpException in your middleware (for example to permenant redirect).


The Less middleware will handle requests for CSS files. If a file exists with the requested name it is served as a static file. If a file exists with a .less file extension it will compile this on the fly into CSS and return this to the browser. It is recommended that you put the OutputCache middleware in front of this one to avoid re-compiling the less on eac request.


The NotFound middleware will always return a 404 response. Put this at the end of your Middleware pipeline to catch all requests not already handled.


The OutputCache middleware will capture responses to requests and replay these responses from cache instead of rendering them again through the OWIN pipeline. You have full control over what is cached and for how long. This improves the performance and scaleability of your web site.


The RouteVisualizer middleware will generate an SVG visualization of the OWIN pipeline. This lets you see how your OWIN pipeline is configured.


The StaticFiles middleware will map paths in the URL to the same relative file path, and if the file exists will return its contents. You can configure how each file type is handled. This provides the ability to deploy content in files and have those files requestable from the browser.


The Versioning middleware will modify html before it is returned to the browser, and insert a version number into the URLs of static assets. When these assets are requested by the browser this middleware removes the version number from the request URL and adds response headers telling the browser to cache the asset. This has the effect of transparently versioning static assets and caching them on the broswer.