Blackbox is an embeddable Cocoa HTTP server -- sort of: strictly speaking, it's a set of classes that wraps the terrific CocoaHTTPServer project, which deserves all of the credit for the code that does the heavy-lifting. Blackbox allows you to associate HTTP resources with Cocoa "responder" objects (kind of like Twisted Web does for Python) rather than files on your filesystem.

With Blackbox, you can create personal file sharers in a snap, write applications that communicate with each other over HTTP, and easily create web control interfaces for headless applications.

Want a demo? Check out this (old) video, which shows how you can build a small personal web server in under 15 minutes with Blackbox. (Note: don't rely on the API demonstrated in the video; the project works more or less the same way, but the method names have changed considerably since the video was created).

Documentation is forthcoming, but not yet available. :) Here are the basics though:

You create your server by alloc/init'ing a BBServer object, which inherits most of its functionality from the HTTPServer class (part of CocoaHTTPServer). See HTTPServer.h for configuration options (ie, server port, Bonjour service name/type, etc.). Once your server is configured to your liking, set it into motion with the start: method.

When a request comes in, Blackbox looks for the appropriate "responder" object to handle the request. A responder (in this context) is any Objective-C object that conforms to the BBResponder protocol (in BBResponder.h) -- currently, this is only the handleRequest: method. You associate responders with URL paths using BBServer's setResponder:forPath: method.

For example, if I wanted the object myObject to handle any calls below /coolbeans, I would do this:

[myServer setResponder:myObject forPath:@"/coolbeans"];

Now, requests to /coolbeans, /coolbeans/yummy, and /coolbeans/photos/garbanzo.jpg would all be directed to myObject's handleRequest: method. You respond to a request using either the setResponseBody: or setResponseString: method of the provided BBRequest object. You use the BBRequest object to get information (ie, POST params) out of the request, and to change other properties of the response, including content type and HTTP status code -- see BBRequest.h for more details. The response is sent when your responder's handleRequest: method returns.

Requests to paths without an associated responder object are tacitly ignored by default, and given a response of "200 OK." If you'd like, you can set a "catch-all" responder using the setDefaultResponder: method.

If you want to play around with it, start with the Blackbox Demo app, included in the project. Please note that the demo application links against the SystemConfiguration framework; this is not necessary to use Blackbox, the framework is only used to get the computer name to display as the placeholder text for "Bonjour Name." This value is obtained automatically if you set the Bonjour name to an empty string (@"").

If you're using Blackbox on 10.6+, you can also use blocks to respond to requests rather than having dedicated responder objects:

[myServer setHandlerForPath:@"/coolbeans" handler:^(BBRequest *theRequest){
	// do stuff with theRequest
}];

Note, however, that block handlers are always processed before responders. It is generally inadvisable to use a mixed environment of responder objects and block handlers, but if you do, it is strongly recommended that handlers and responders not share common path prefixes. For example:

[myServer setHandlerForPath:@"/generic" handler:^{...}];
[myServer setResponder:myObj forPath:@"/generic/specific"];

In the above, requests made to /generic/specific would in fact be handled by the block handler, not the myObj responder, because /generic/specific does indeed fall underneath /generic, and the handlers are searched for a match first. For this reason, setting a default handler (with setDefaultHandler:, like setDefaultResponder:) will prevent any responder from ever being used.

Currently the only known project that uses Blackbox is Bowtie -- my themeable iTunes controller -- which uses Blackbox to communicate with Bowtie for iPhone and other remote clients.

Do you use Blackbox in your project? Drop me a note at [email protected], and I'll add you to this list!

Blackbox is licensed under the MIT license, excerpted below.

Copyright (C) 2010 Matt Patenaude.

Permission is hereby granted, free of charge, to any person obtaining a copy
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copies of the Software, and to permit persons to whom the Software is
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The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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THE SOFTWARE.

This project is a wrapper around the CocoaHTTPServer project, by Deusty Designs.

Copyright (c) 2006, Deusty Designs, LLC
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