I failed to find an AMF library for Node, and I’m not hugely surprised; Flash is rather out of favour with today’s JavaScript gurus. Secretly pleased that I couldn’t find anything, I set about writing my own. It is also the first time I’ve put an open source project on Github.

See node-amf on Github

The current state of node-amf is that it’s not ready for production. I am experiencing errors in the pack and unpack functions which are taken from the excellent php.js project. I hope to hear from the authors to rectify this.

[UPDATE] Now using this BinaryParser class instead of the pack/unpack functions.

The examples in the Git repository are for a simple HTTP gateway – This is the standard way you’d use AMF to talk to PHP, for example. The next step is to see if it’s possible to work with persistent sockets carrying AMF packets. That could be pretty cool.

So what’s the problem?

If your PHP developers  have to start work before your Flash developers, you may find yourself with a back end, but no front end, so how do you test everything works? Moreover, how do you develop the back end at all if you can’t send and receive requests from your AMF gateway?

I wrote a simple command line tool for testing AMF calls, so I thought I’d share it with you here:
Download the amf command line program, requires PHP 5.2 with the json extension enabled.

It’s a fairly crude tool, and cannot support class mapping, but it’s currently helping us out very nicely. If you like it, or would like to see any improvements, please post a comment.

Usage:

Download and make sure you can execute the program

> wget http://lab.publicreative.com/wp-content/uploads/2009/03/amf.tgz
> tar -xvzf amf.tgz
> chmod u+x amf

For each service you want to test, create a file containing three lines.
1. The URL of your AMF service gateway
2. The method you want to call, <service>.<method>
3. The arguments to post to the service as a JSON array. This may go onto multiple lines

Here’s the bundled example in example_test.txt

http://mydomain.com/my/amf/gateway
MyServiceClass.MyMethod
[
  "Arguments in JSON format",
  "always as an array",
  { "objects": "are also legal" }
]

To execute this test, pipe the file into the amf program as stdin, e.g.
> cat example_test.txt | ./amf

You should see the deserialized arguments you are about to post, then a hex dump of the request packet, and then hopefully the response, followed by the deserialized response data.