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AMF (Action Message Format) is a binary data serialization protocol. Simply put, it transforms objects in memory into a binary string, and can reverse this binary string into an object in memory. It can be used just likeJSON, and this library has been build to provide a similar API to that exposed by theJSON functionality inJavaScript.

The purpose of this library is to provide a consistent and symmetric implementation of theAMF specification in bothPHP &JavaScript.

Well, it's up to you.JSON is perfectly suited to the web, however it does have some shortcomings which are addressed byAMF. For starters,JSON cannot handle complex object graphs with circular references; additionally, it cannot serialize dates & byte arrays - you would need to do some additional work to support these inJSON (convert date to unix timestamp, byte arrays to base64).

Hells no.JSON is great;AMF can simply provide you with some additional functionality which could help you build your web app.

To begin using this library, you will need to install it viaComposer:

bower install -S infomaniac-amf.js#latest

This will download the repository for you and make the library available for inclusion. For convenience, a filedist/amf.js has been compiled for you with all of its dependencies, uglified and browserified. The file is a mere43kb.

<scriptsrc="bower_components/infomaniac-amf.js/dist/amf.js"type="text/javascript"></script>

Here is a simple example of encoding an object toAMF:

vardata={any:'data',you:'like!'};varencodedData=AMF.stringify(data);console.log(encodedData);

This will produce a binary string which represents your given data.

If you were to inspect the HTTP traffic of a page that producesAMF data, using a tool such asCharles Proxy, you would see the following output:

To decode this string, simply do the following:

vardata={any:'data',you:'like!'};varencodedData=AMF.stringify(data);console.log(AMF.parse(encodedData));

If you were toconsole.log this data, it would look identical to the input data given to theAMF.stringify function.

Object{any:"data",you:"like!"}

AMF allows you to encode an object and retain some metadata about it; for example, when serializing an instance of a class (notObject) the library will retain the class' fully qualified namespace name and use it to reconstruct an object of that type upon decoding.

Consider the following class:

varPerson=function(){this.name='Bob';this._classMapping='Person';};

If we encode an instance of this object, by default its class type will be ignored and when the data is decoded, the resulting value will be a plain PHPObject instance.

varPerson=function(){this._classMapping='Person';};vardata=newPerson();data.name="Bob";varencodedData=AMF.stringify(data);console.log(AMF.parse(encodedData));

...will produce...

Object{name:"Bob"}

In order to retain the class type inAMF, you will need to add the following:

1. an additional flag to theAMF.stringify function call
2. define a_classMapping variable on the object(s) being encododed, and
3. register a "class alias" usingAMF.registerClassAlias to associate the_classMapping value to its related class type

varPerson=function(){this._classMapping='Person';};vardata=newPerson();data.name="Bob";varencodedData=AMF.stringify(data,AMF.CLASS_MAPPING);AMF.registerClassAlias('Person',Person);console.log(AMF.parse(encodedData));

Now, when this data is decoded, the library will attempt to create a new instance of thePerson class and set its public propertyname to"Bob".

Person{_classMapping:"Person",name:"Bob"}

TheAMF spec allows for the serialization of several different data-types.

Here is a link to the latest specification:AMF3 Spec - January 2013

This library implements10 of the18 data-types described in the specification. The reason for the support of only asubset of these types can be seen in two lights:utility andlimitation. Here is an exhaustive list of the data-types available:

This project is licensed under theMIT license.

While writing this library, I used several libraries to validate my progress, and to help me come unstuck. I would like to extend a special thanks to the following libraries and individuals:

• SabreAMF
• AmfPhp
• Charles Proxy's wonderful AMF implementation
• Arseny Vakhrushev (neoxic) for his patience, guidance, advice and help
• Robert Cesaric,Grant McMullin andAndre Venter for their insight and advice
• My esteemed colleagues atZando