rest_dart

A library for automating much of the minutia of creating a rest interface. This mostly means automatically sending the correct error messages when a request is invalid, and some automatic header handling, such as:

• Automatic 204 messages when a resource returns no data but is still succesful.
• Automatic 404 messages when a requested resource does not exist.
• Automatic 405 errors when a method is not valid for a resource.
• Automatic 406 errors when requested content type is not available, or is not a valid content type.
• Automatic 415 errors when a submitted content type is not supported, or is not a valid content type.
• Automatic handling of the OPTIONS method, and automatic Allow header generation.
• Automatic setting of content-length and contnt-type headers.
• Provides a custom x-processing-time header that automatically contains how long it took for the server to generate a response.

TODO:

• The error handling outputs the errors as JSON. This needs to be more flexible, and overridable.
• Add support for variable URL prefixes. Currently assumes running right under the host name/ip.
• Change rest event handlers to be generic functions instead of classes.
• Sets VERY generous Access-Control-Allow-Origin and Access-Control-Allow-Methods to allow cross-domain testing (this will be chagned to be mroe secure in the future).
• Per-resource/method content typing.

Usage!

// Import the package
import 'package:rest_dart/rest_dart.dart';

// Create the server object.
RestServer rest = new RestServer();

// If you don't add a content type, the server will throw an error on the first request.
rest.AddDefaultContentType(new ContentType("application", "json", charset: "utf-8"));

// Create a REST resource, along with the regex for recognizing its path.
RestResource resource = new RestResource(r'^/?$');

// Create a method handler
Future DeleteHandler(ContentType type, String path, Map<String, String> args) {
  return new Future.sync(() {
    return "test";
  });
}

// Add the method handler to the resource 
resource.SetMethodHandler("DELETE", DeleteHandler);

// Add the resource to the server,
rest.AddResource(resource);

// Start the server. This handles creating the HTTP server as well.
rest.Start("127.0.0.1",8080);

// Begin requesting from the server!

Errors

So, if something goes wrong and you need to send an error message back to the user, just throw a RestException!

RestException(this.Code, this.Message, [this.InnerException = null]);

This will cause the server to send back the HTTP code you specify, and be presented with your message. Make sure to throw it through a future, so that it can be caught by the higher-up logic:

Future DeleteHandler(ContentType type, String path, Map<String, String> args) {
  return new Future.sync(() {
    throw new RestException(500,"I don't like you");
  });
}