zeroxs/amf3cpp

amf3cpp

C++ implementation of the Action Message Format (AMF3)

License

This project is licensed under the MIT license. See LICENSE

Documentation

Include files within your project to use. Makes use of C++11 functionality. Compiles on both Windows and Linux.

To create an AMF3Object:

amf3object obj;
obj["command"] = "test";//set 'command' key to string 'test'

amf3object & data = obj["data"];//set 'data' key to new amf3object
data["something"] = 1;//set 'something' key to integer value of 1
data["thing"] = 1.5f;//set 'thing' key to double (AMF3Number type) value of 1.5

To create an AMF3Array: (supports both dense and associative arrays)

Dense:

amf3array arr;

amf3object o;
o["key"] = "this will go into the array";

arr.Add(o);

printf("%s", arr[0]["key"].c_str());

Associative:

amf3object o;
o["key"] = "this will be referenced by key in the array";

arr.Add("second", o);

printf("%s", arr["second"]["key"].c_str());

Can also access elements through C++11 ranged based for loop:

for (auto object : arr)
{
  printf("%s", object["key"].c_str());
}

To serialize an object (and potentially send it over a socket):

amf3object object;
object["key"] = "some data";

char buffer[100];
auto length = 0;

amf3writer writer(buffer);

writer.Write(object);

length = writer.position;

To deserialize an object:

//buffer from the serialize example

amf3parser cparser(buffer);

amf3object temp = cparser.ReadNextObject();

printf("%s\n", temp["key"].c_str());//prints out "some data"

Notes

When nesting objects together, care should be taken with how you insert objects. Reusing objects and inserting them multiple times will not create new objects but instead create references.

amf3array arr;

amf3object o;
o["key"] = "this will go into the array";
arr.Add(o);

o["key"] = "this will go into the array1";
arr.Add(o);

o["key"] = "this will go into the array2";
arr.Add(o);

for (auto object : arr)
{
  printf("%s", object["key"].c_str());//this will print "this will go into the array2" x3 times
}

The solution is to do o = amf3object() when you wish to reuse a variable. This will not clear the original data.

amf3array arr;

amf3object o;
o["key"] = "this will go into the array";
arr.Add(o);

o = amf3object();
o["key"] = "this will go into the array1";
arr.Add(o);

o = amf3object();
o["key"] = "this will go into the array2";
arr.Add(o);

for (auto object : arr)
{
  printf("%s\n", object["key"].c_str());//this will print all 3 unique lines correctly
}

The amf3object class is really an encapsulating class that maintains the meta-data of the object. A true amf3object that contains associative keys and data can be checked through the member variable type (enum Amf3TypeCode). Likewise can be used to check if there is any other sort of value inside the container.

if (object.type == Amf3TypeCode::Object){}

Storing an array as a root object (serializing an array as the base container) is as easy as just setting an object to the array variable:

amf3object container;
amf3array arr;

amf3object o;
o["key"] = "value";
arr.Add(o);

container = arr;

char buffer[100];
auto length = 0;

amf3writer writer(buffer);

If receiving an object like such, accessing the underlying array is just as easy:

amf3parser cparser(buffer);

amf3object obj = cparser.ReadNextObject();

amf3array & arr = obj;
for (auto object : arr)
{
  printf("%s\n", object["key"].c_str());
}

This library does not have Amf3 object types: Xml, ByteArray, Date, or LegacyXmlDocument implemented yet.