| Index: pkg/shelf/README.md
|
| diff --git a/pkg/shelf/README.md b/pkg/shelf/README.md
|
| deleted file mode 100644
|
| index b138204853965a3173230594b1027013f9595d83..0000000000000000000000000000000000000000
|
| --- a/pkg/shelf/README.md
|
| +++ /dev/null
|
| @@ -1,133 +0,0 @@
|
| -## Web Server Middleware for Dart
|
| -
|
| -## Introduction
|
| -
|
| -**Shelf** makes it easy to create and compose **web servers** and **parts of web
|
| -servers**. How?
|
| -
|
| -* Expose a small set of simple types.
|
| -* Map server logic into a simple function: a single argument for the request,
|
| -the response is the return value.
|
| -* Trivially mix and match synchronous and asynchronous processing.
|
| -* Flexibliity to return a simple string or a byte stream with the same model.
|
| -
|
| -## Example
|
| -
|
| -See `example/example_server.dart`
|
| -
|
| -```dart
|
| -import 'package:shelf/shelf.dart' as shelf;
|
| -import 'package:shelf/shelf_io.dart' as io;
|
| -
|
| -void main() {
|
| - var handler = const shelf.Pipeline().addMiddleware(shelf.logRequests())
|
| - .addHandler(_echoRequest);
|
| -
|
| - io.serve(handler, 'localhost', 8080).then((server) {
|
| - print('Serving at http://${server.address.host}:${server.port}');
|
| - });
|
| -}
|
| -
|
| -shelf.Response _echoRequest(shelf.Request request) {
|
| - return new shelf.Response.ok('Request for "${request.url}"');
|
| -}
|
| -```
|
| -
|
| -## Handlers and Middleware
|
| -
|
| -A [handler][] is any function that handles a [shelf.Request][] and returns a
|
| -[shelf.Response][]. It can either handle the request itself--for example, a
|
| -static file server that looks up the requested URI on the filesystem--or it can
|
| -do some processing and forward it to another handler--for example, a logger that
|
| -prints information about requests and responses to the command line.
|
| -
|
| -[handler]: http://www.dartdocs.org/documentation/shelf/latest/index.html#shelf/shelf@id_Handler
|
| -
|
| -[shelf.Request]: http://www.dartdocs.org/documentation/shelf/latest/index.html#shelf/shelf.Request
|
| -
|
| -[shelf.Response]: http://www.dartdocs.org/documentation/shelf/latest/index.html#shelf/shelf.Response
|
| -
|
| -The latter kind of handler is called "[middleware][]", since it sits in the
|
| -middle of the server stack. Middleware can be thought of as a function that
|
| -takes a handler and wraps it in another handler to provide additional
|
| -functionality. A Shelf application is usually composed of many layers of
|
| -middleware with one or more handlers at the very center; the [shelf.Pipeline][]
|
| -class makes this sort of application easy to construct.
|
| -
|
| -[middleware]: http://www.dartdocs.org/documentation/shelf/latest/index.html#shelf/shelf@id_Middleware
|
| -
|
| -[shelf.Pipeline]: http://www.dartdocs.org/documentation/shelf/latest/index.html#shelf/shelf.Pipeline
|
| -
|
| -Some middleware can also take multiple handlers and call one or more of them for
|
| -each request. For example, a routing middleware might choose which handler to
|
| -call based on the request's URI or HTTP method, while a cascading middleware
|
| -might call each one in sequence until one returns a successful response.
|
| -
|
| -## Adapters
|
| -
|
| -An adapter is any code that creates [shelf.Request][] objects, passes them to a
|
| -handler, and deals with the resulting [shelf.Response][]. For the most part,
|
| -adapters forward requests from and responses to an underlying HTTP server;
|
| -[shelf_io.serve][] is this sort of adapter. An adapter might also synthesize
|
| -HTTP requests within the browser using `window.location` and `window.history`,
|
| -or it might pipe requests directly from an HTTP client to a Shelf handler.
|
| -
|
| -[shelf_io.serve]: http://www.dartdocs.org/documentation/shelf/latest/index.html#shelf/shelf-io@id_serve
|
| -
|
| -When implementing an adapter, some rules must be followed. The adapter must not
|
| -pass the `url` or `scriptName` parameters to [new shelf.Request][]; it should
|
| -only pass `requestedUri`. If it passes the `context` parameter, all keys must
|
| -begin with the adapter's package name followed by a period. If multiple headers
|
| -with the same name are received, the adapter must collapse them into a single
|
| -header separated by commas as per [RFC 2616 section 4.2][].
|
| -
|
| -[new shelf.Request]: http://www.dartdocs.org/documentation/shelf/latest/index.html#shelf/shelf.Request@id_Request-
|
| -
|
| -[RFC 2616 section 4.2]: http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html
|
| -
|
| -An adapter must handle all errors from the handler, including the handler
|
| -returning a `null` response. It should print each error to the console if
|
| -possible, then act as though the handler returned a 500 response. The adapter
|
| -may include body data for the 500 response, but this body data must not include
|
| -information about the error that occurred. This ensures that unexpected errors
|
| -don't result in exposing internal information in production by default; if the
|
| -user wants to return detailed error descriptions, they should explicitly include
|
| -middleware to do so.
|
| -
|
| -An adapter should include information about itself in the Server header of the
|
| -response by default. If the handler returns a response with the Server header
|
| -set, that must take precedence over the adapter's default header.
|
| -
|
| -An adapter should include the Date header with the time the handler returns a
|
| -response. If the handler returns a response with the Date header set, that must
|
| -take precedence.
|
| -
|
| -An adapter should ensure that asynchronous errors thrown by the handler don't
|
| -cause the application to crash, even if they aren't reported by the future
|
| -chain. Specifically, these errors shouldn't be passed to the root zone's error
|
| -handler; however, if the adapter is run within another error zone, it should
|
| -allow these errors to be passed to that zone. The following function can be used
|
| -to capture only errors that would otherwise be top-leveled:
|
| -
|
| -```dart
|
| -/// Run [callback] and capture any errors that would otherwise be top-leveled.
|
| -///
|
| -/// If [this] is called in a non-root error zone, it will just run [callback]
|
| -/// and return the result. Otherwise, it will capture any errors using
|
| -/// [runZoned] and pass them to [onError].
|
| -catchTopLevelErrors(callback(), void onError(error, StackTrace stackTrace)) {
|
| - if (Zone.current.inSameErrorZone(Zone.ROOT)) {
|
| - return runZoned(callback, onError: onError);
|
| - } else {
|
| - return callback();
|
| - }
|
| -}
|
| -```
|
| -
|
| -## Inspiration
|
| -
|
| -* [Connect](http://www.senchalabs.org/connect/) for NodeJS.
|
| - * Read [this great write-up](http://howtonode.org/connect-it) to understand
|
| - the overall philosophy of all of these models.
|
| -* [Rack](http://rack.github.io/) for Ruby.
|
| -* [WSGI](http://legacy.python.org/dev/peps/pep-3333/) for Python.
|
|
|