HOWTO WRITE an APPLICATION above AGL FRAMEWORK

version: 1
Date:    30 mai 2016
Author:  José Bollo

Writing an HTML5 application

Developpers of HTML5 applications (client side) can easyly create applications for AGL framework using their prefered HTML framework.

Developpers can also create powerful server side plugins to improve their application. This server side plugin should return the mime-type application/json and can be accessed either by HTTP or by Websockets.

In a near future, the JSON-RPC protocol will be available together with the current x-afb-json1 protocol.

Two examples of HTML5 applications are given:

Writing a Qt application

Writing Qt applications is also possible because Qt offers APIs to make HTTP queries and to connect using WebSockets.

It is even possible to write a QML application. It is demontrated by the sample application token-websock:

Writing a C application

C applications can use the binder afb-daemon through a websocket connection.

The library libafbwsc is made for C clients that want to connect to the afb-daemon binder.

The program afb-client-demo is the C program that use the provided library libafbwsc. Its source code is here src/afb-client-demo.c.

The current implementation use libsystemd and file descriptors. This may be changed in the future to also support secure sockets and being less dependant of libsystemd.

Handling sessions within applications

Exchanging tokens

Applications are communicating with their binder afb-daemon using a network connection or a kind of network connection (unix domain socket isn’t currently implemented but could be used in near future). Also, HTTP protocol is not a connected protocol. It means that the socket connection can not be used to authenticate a client.

For this reason, the binder should authenticate the application by using a commonly shared secret named token.

At start, the framework communicate a common secret to both the binder and its client: the application. When the application

Handling sessions