diffusion/src/node_modules/control/registration.js

Diffusion JavaScript client

var Services = require('services/services');

var Emitter = require('events/emitter');
var Result = require('events/result');

var CloseReason = require('client/close-reason');

var ResponseHandlerState = {
    REGISTERING : 0,
    ACTIVE : 1,
    CLOSED : 2
};

function responseHandler(internal, adapter, deregistration) {
    var state = ResponseHandlerState.REGISTERING;
    var close;

    return {
        onDiscard : function(cid, err) {
            if (err instanceof CloseReason) {
                adapter.close();
            } else {
                adapter.close(err);
            }

            state = ResponseHandlerState.CLOSED;
        },
        onOpen : function(cid) {
            close = function close() {
                var emitter = new Emitter();
                var result = new Result(emitter);

                if (state !== ResponseHandlerState.CLOSED) {
                    deregistration(cid, function(err) {
                        if (err) {
                            internal.getConversationSet().discard(cid, err);
                            emitter.error(err);
                        } else {
                            internal.getConversationSet().respondIfPresent(cid, ResponseHandlerState.CLOSED);
                            emitter.emit('complete');
                        }
                    });
                } else {
                    emitter.error(new Error('Handler already closed'));
                }

                return result;
            };
        },
        onResponse : function(cid, response) {
            switch (response) {
                case ResponseHandlerState.ACTIVE:
                    adapter.active(close, cid);
                    state = response;
                    return false;
                case ResponseHandlerState.CLOSED:
                    adapter.close();
                    state = response;
                    return true;
                default:
                    return adapter.respond(response);
            }
        }
    };
}

function registrationCallback(conversationSet, cid, emitter) {
    return function(err) {
        if (err) {
            conversationSet.discard(cid, err);
            emitter.error(err);
        } else {
            conversationSet.respondIfPresent(cid, ResponseHandlerState.ACTIVE);
            emitter.emit('complete');
        }
    };
}

function registerHandler(internal, params, adapter, reg, dereg) {
    var conversationSet = internal.getConversationSet();
    var serviceLocator = internal.getServiceLocator();

    var registration = serviceLocator.obtain(reg);
    var deregistration = serviceLocator.obtain(dereg);

    var cid = conversationSet.newConversation(responseHandler(internal, adapter, function(cid, callback) {
        deregistration.send(params, callback);
    }));

    var emitter = new Emitter();
    var result = new Result(emitter);

    registration.send({ params : params, cid : cid }, registrationCallback(conversationSet, cid, emitter));

    return result;
}

module.exports.responseHandler = responseHandler;

module.exports.registrationCallback = registrationCallback;

module.exports.registerHandler = registerHandler;

module.exports.registerMessageHandler = function registerMessageHandler(internal, params, adapter) {
    return registerHandler(internal, params, adapter,
                                  Services.MESSAGE_RECEIVER_CONTROL_REGISTRATION,
                                  Services.MESSAGE_RECEIVER_CONTROL_DEREGISTRATION);
};

module.exports.registerRequestHandler = function registerMessageHandler(internal, params, adapter) {
    return registerHandler(internal, params, adapter,
                                  Services.MESSAGING_RECEIVER_CONTROL_REGISTRATION,
                                  Services.MESSAGING_RECEIVER_CONTROL_DEREGISTRATION);
};

module.exports.registerServerHandler = function registerServerHandler(internal, params, adapter) {
    return registerHandler(internal, params, adapter,
            Services.SERVER_CONTROL_REGISTRATION,
            Services.SERVER_CONTROL_DEREGISTRATION);
};

module.exports.registerTopicHandler = function registerTopicHandler(internal, params, adapter) {
    return registerHandler(internal, params, adapter,
        Services.TOPIC_CONTROL_REGISTRATION,
        Services.TOPIC_CONTROL_DEREGISTRATION);
};

module.exports.ResponseHandlerState = ResponseHandlerState;