https://github.com/sile/erl-amf

An Erlang library to encode/decode AMF
https://github.com/sile/erl-amf

amf erlang

Last synced: 8 days ago
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An Erlang library to encode/decode AMF

• Host: GitHub
• URL: https://github.com/sile/erl-amf
• Owner: sile
• Created: 2013-04-03T13:59:08.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2018-03-11T10:30:39.000Z (over 6 years ago)
• Last Synced: 2024-05-01T23:47:16.456Z (7 months ago)
• Topics: amf, erlang
• Language: Erlang
• Size: 1.05 MB
• Stars: 5
• Watchers: 3
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# ErlAMF

[![hex.pm version](https://img.shields.io/hexpm/v/amf.svg)](https://hex.pm/packages/amf)

[![Build Status](https://travis-ci.org/sile/amf.svg?branch=master)](https://travis-ci.org/sile/erl-amf)

[![Code Coverage](https://codecov.io/gh/sile/amf/branch/master/graph/badge.svg)](https://codecov.io/gh/sile/erl-amf/branch/master)

[![License: MIT](https://img.shields.io/badge/license-MIT-blue.svg)](LICENSE)

ErlAMF is an AMF(Action Message Format) encoding/deconding library written in Erlang.

[EDoc Documentation](https://hexdocs.pm/amf/)

## Usage

### Build

ErlAMF uses [rebar3](https://github.com/erlang/rebar3) as build tool.

```sh

# build

$ git clone git://github.com/sile/erl-amf.git

$ cd erl-amf

$ rebar3 compile

# run unit tests

$ rebar3 eunit

```

### Examples

```erlang

$ erl -pa ebin

%%%

%%% Encode and Decode

%%%

%%% AMF3 encode

1> {ok, IoList} = amf:encode(amf3, [1,2,3]).

{ok,[9,7,[1],[[4,1],[4,2],[4,3]]]}

%% AMF3 decode

2> amf:decode(amf3, list_to_binary(IoList)).

{ok,[1,2,3],<<>>}

%%%

%%% AMF values

%%%

%% Load records

%% (Records are defined in "erl-amf/include/amf.hrl")

3> rr(amf).

[amf_array,amf_avmplus_object,amf_byte_array,amf_date,

 amf_dictionary,amf_exception,amf_object,amf_vector,amf_xml,

 amf_xml_document]

%% Anonymous object

4> amf:object([{<<"one">>, 1}, {<<"two">>, 2}]).

#amf_object{class = undefined,dynamic = true,

            sealed_fields = [],

            members = [{<<"one">>,1},{<<"two">>,2}]}

5> amf:encode(amf0, v(4)).

{ok,[3,

     [<<0,3>>, <<"one">>,

      [0,<<63,240,0,0,0,0,0,0>>],

      <<0,3>>, <<"two">>,

      [0,<<64,0,0,0,0,0,0,0>>]],

      0,0,9]}

%% Date

6> amf:encode(amf0, amf:date(now())).

{ok,[11,<<66,115,221,102,242,183,208,0,0,0>>]}

%%%

%%% Error

%%%

%% The encode/2(and decode/2) function returns an amf_exception() instance as error reason

7> amf:encode(amf0, can_not_encode).

{error,#amf_exception{type = unsupported,

                      message = {value,can_not_encode}}}

8> amf:decode(amf0, <<>>).

{error,#amf_exception{type = partial,

                      message = {marker,<<>>}}}

```

## Mapping between Erlang Values and AMF types(markers)

Erlang ValueAMF0 MarkerAMF3 Marker

10numberinteger

10.5numberdouble

truebooleantrue

falsebooleanfalse

nullnullnull

undefinedundefinedundefined

<<"string">>string | long-stringstring

movieclip

recordset

unsupported

amf:date(now())datedate

amf:xml(<<"xml">>)xml

amf:xml_document(<<"xml">>)xml-documentxml-doc

amf:byte_array(<<"bytes">>)byte-array

amf:vector(int, [-1,2,-3])vector-int

amf:vector(uint, [1,2,3])vector-uint

amf:vector(double, [-1.0,2.0,-3.0])vector-double

amf:vector(<<"type_name">>, [1,<<"2">>,[3]])vector-object

[1,2,3]strict-arrayarray (only dense element)

amf:array([{<<"key">>, <<"value">>}])ecma-arrayarray (only associative element)

amf:array([1,2,3], [{<<"key">>, <<"value">>}])array (mixed)

amf:object([{<<"key">>, <<"value">>}])objectobject (anonymous)

amf:typed_object(<<"type">>, [{<<"key">>, <<"value">>}])typed-objectobject (typed)

amf:dictionary([{1,2}, {true, false}])dictionary

amf:avmplus_object([1,2,3])avmplus-object

## Limitations

ErlAMF doesn't support following features:

* Circular reference objects

* flash.utils.IExternalizable interface

* No Object/Trait/String reference is used in encoding process

* Special double value (e.g. NaN, Infinity)

## Reference

* [AMF0 Specification](http://download.macromedia.com/pub/labs/amf/amf0_spec_121207.pdf)

* [AMF3 Specification](http://wwwimages.adobe.com/www.adobe.com/content/dam/Adobe/en/devnet/amf/pdf/amf-file-format-spec.pdf)