Channel.prototype.subscribe = function()

in src/common/channel.js [154:192]

• 30 lines of code
• 10 McCabe index (conditional complexity)

Channel.prototype.subscribe = function (eventListenerOrFunction, eventListener) {
    checkSubscriptionArgument(eventListenerOrFunction);
    var handleEvent, guid;

    if (eventListenerOrFunction && typeof eventListenerOrFunction === 'object') {
        // Received an EventListener object implementing the handleEvent interface
        handleEvent = eventListenerOrFunction.handleEvent;
        eventListener = eventListenerOrFunction;
    } else {
        // Received a function to handle event
        handleEvent = eventListenerOrFunction;
    }

    if (this.state === 2) {
        handleEvent.apply(eventListener || this, this.fireArgs);
        return;
    }

    guid = eventListenerOrFunction.observer_guid;
    if (typeof eventListener === 'object') {
        handleEvent = utils.close(eventListener, handleEvent);
    }

    if (!guid) {
        // First time any channel has seen this subscriber
        guid = '' + nextGuid++;
    }
    handleEvent.observer_guid = guid;
    eventListenerOrFunction.observer_guid = guid;

    // Don't add the same handler more than once.
    if (!this.handlers[guid]) {
        this.handlers[guid] = handleEvent;
        this.numHandlers++;
        if (this.numHandlers === 1) {
            this.onHasSubscribersChange && this.onHasSubscribersChange();
        }
    }
};