/**
* Custom event engine, DOM event listener abstraction layer, synthetic DOM
* events.
* @module event
*/
/**
* Return value from all subscribe operations
* @class EventHandle
* @constructor
* @param evt {Event.Custom} the custom event
* @param sub {Subscriber} the subscriber
*/
var onsubscribeType = "_event:onsub",
AFTER = 'after',
CONFIGS = [
'broadcast',
'bubbles',
'context',
'configured',
'currentTarget',
'defaultFn',
'details',
'emitFacade',
'fireOnce',
'host',
'preventable',
'preventedFn',
'queuable',
'silent',
'stoppedFn',
'target',
'type'
],
YUI3_SIGNATURE = 9;
Y.EventHandle = function(evt, sub) {
/**
* The custom event
* @type Event.Custom
*/
this.evt = evt;
/**
* The subscriber object
* @type Subscriber
*/
this.sub = sub;
};
Y.EventHandle.prototype = {
/**
* Detaches this subscriber
* @method detach
*/
detach: function() {
if (this.evt) {
// Y.log('EventHandle.detach: ' + this.sub, 'info', 'Event');
this.evt._delete(this.sub);
}
}
};
/**
* The Event.Custom class lets you define events for your application
* that can be subscribed to by one or more independent component.
*
* @param {String} type The type of event, which is passed to the callback
* when the event fires
* @param o configuration object
* @class Event.Custom
* @constructor
*/
Y.CustomEvent = function(type, o) {
// if (arguments.length > 2) {
// this.log('CustomEvent context and silent are now in the config', 'warn', 'Event');
// }
o = o || {};
this.id = Y.stamp(this);
/**
* The type of event, returned to subscribers when the event fires
* @property type
* @type string
*/
this.type = type;
/**
* The context the the event will fire from by default. Defaults to the YUI
* instance.
* @property context
* @type object
*/
this.context = Y;
this.logSystem = (type == "yui:log");
/**
* If 0, this event does not broadcast. If 1, the YUI instance is notified
* every time this event fires. If 2, the YUI instance and the YUI global
* (if event is enabled on the global) are notified every time this event
* fires.
* @property broadcast
* @type int
*/
this.broadcast = 0;
/**
* By default all custom events are logged in the debug build, set silent
* to true to disable debug outpu for this event.
* @property silent
* @type boolean
*/
this.silent = this.logSystem;
// this.queuable = !(this.logSystem);
this.queuable = false;
/**
* The subscribers to this event
* @property subscribers
* @type Subscriber{}
*/
this.subscribers = {};
/*
* The publisher has configured this event
* @property configured
* @type boolean
* @default true
*/
// this.configured = true;
/**
* 'After' subscribers
* @property afters
* @type Subscriber{}
*/
this.afters = {};
/**
* This event has fired if true
*
* @property fired
* @type boolean
* @default false;
*/
this.fired = false;
/**
* This event should only fire one time if true, and if
* it has fired, any new subscribers should be notified
* immediately.
*
* @property fireOnce
* @type boolean
* @default false;
*/
this.fireOnce = false;
/**
* Flag for stopPropagation that is modified during fire()
* 1 means to stop propagation to bubble targets. 2 means
* to also stop additional subscribers on this target.
* @property stopped
* @type int
*/
this.stopped = 0;
/**
* Flag for preventDefault that is modified during fire().
* if it is not 0, the default behavior for this event
* @property prevented
* @type int
*/
this.prevented = 0;
/**
* Specifies the host for this custom event. This is used
* to enable event bubbling
* @property host
* @type Event.Target
*/
this.host = null;
/**
* The default function to execute after event listeners
* have fire, but only if the default action was not
* prevented.
* @property defaultFn
* @type Function
*/
this.defaultFn = null;
/**
* The function to execute if a subscriber calls
* stopPropagation or stopImmediatePropagation
* @property stoppedFn
* @type Function
*/
this.stoppedFn = null;
/**
* The function to execute if a subscriber calls
* preventDefault
* @property preventedFn
* @type Function
*/
this.preventedFn = null;
/**
* Specifies whether or not this event's default function
* can be cancelled by a subscriber by executing preventDefault()
* on the event facade
* @property preventable
* @type boolean
* @default true
*/
this.preventable = true;
/**
* Specifies whether or not a subscriber can stop the event propagation
* via stopPropagation(), stopImmediatePropagation(), or halt()
* @property bubbles
* @type boolean
* @default true
*/
this.bubbles = true;
/**
* Supports multiple options for listener signatures in order to
* port YUI 2 apps.
* @property signature
* @type int
* @default 9
*/
this.signature = YUI3_SIGNATURE;
/**
* If set to true, the custom event will deliver an EventFacade object
* that is similar to a DOM event object.
* @property emitFacade
* @type boolean
* @default false
*/
this.emitFacade = false;
this.applyConfig(o, true);
this.log("Creating " + this.type);
// Only add subscribe events for events that are not generated by
// Event.Custom
if (type !== onsubscribeType) {
/**
* Custom events provide a custom event that fires whenever there is
* a new subscriber to the event. This provides an opportunity to
* handle the case where there is a non-repeating event that has
* already fired has a new subscriber.
*
* @event subscribeEvent
* @type Event.Custom
* @param {Function} fn The function to execute
* @param {Object} obj An object to be passed along when the event
* fires
* @param {boolean|Object} override If true, the obj passed in becomes
* the execution context of the listener.
* if an object, that object becomes the
* the execution context.
*/
this.subscribeEvent = new Y.CustomEvent(onsubscribeType, {
context: this,
silent: true
});
}
};
Y.CustomEvent.prototype = {
_YUI_EVENT: true,
/**
* Apply configuration properties. Only applies the CONFIG whitelist
* @method applyConfig
* @param o hash of properties to apply
* @param force {boolean} if true, properties that exist on the event
* will be overwritten.
*/
applyConfig: function(o, force) {
if (o) {
Y.mix(this, o, force, CONFIGS);
}
},
_subscribe: function(fn, context, args, when) {
if (!fn) {
Y.error("Invalid callback for CE: " + this.type);
}
var se = this.subscribeEvent, s;
if (se) {
se.fire.apply(se, args);
}
s = new Y.Subscriber(fn, context, args, when);
if (this.fireOnce && this.fired) {
// this._notify(s);
// setTimeout(Y.rbind(this._notify, this, s), 0);
Y.later(0, this, this._notify, s);
}
if (when == AFTER) {
this.afters[s.id] = s;
} else {
this.subscribers[s.id] = s;
}
return new Y.EventHandle(this, s);
},
/**
* Listen for this event
* @method subscribe
* @param {Function} fn The function to execute
* @param {Object} context Specifies the value of the
* 'this' keyword in the listener.
* @param args* 0..n params to provide to the listener
* @return {EventHandle} unsubscribe handle
*/
subscribe: function(fn, context) {
return this._subscribe(fn, context, arguments, true);
},
/**
* Listen for this event after the normal subscribers have been notified and
* the default behavior has been applied. If a normal subscriber prevents the
* default behavior, it also prevents after listeners from firing.
* @method after
* @param {Function} fn The function to execute
* @param {Object} context Specifies the value of the
* 'this' keyword in the listener.
* @param args* 0..n params to provide to the listener
* @return {EventHandle} unsubscribe handle
*/
after: function(fn, context) {
return this._subscribe(fn, context, arguments, AFTER);
},
/**
* Unsubscribes subscribers.
* @method unsubscribe
* @param {Function} fn The subscribed function to remove, if not supplied
* all will be removed
* @param {Object} context The context object passed to subscribe.
* @return {boolean} True if the subscriber was found and detached.
*/
unsubscribe: function(fn, context) {
// if arg[0] typeof unsubscribe handle
if (fn && fn.detach) {
return fn.detach();
}
if (!fn) {
return this.unsubscribeAll();
}
var found = false, subs = this.subscribers, i, s;
for (i in subs) {
if (subs.hasOwnProperty(i)) {
s = subs[i];
if (s && s.contains(fn, context)) {
this._delete(s);
found = true;
}
}
}
return found;
},
_getFacade: function(args) {
var ef = this._facade, o;
if (!ef) {
ef = new Y.EventFacade(this, this.currentTarget);
}
// if the first argument is an object literal, apply the
// properties to the event facade
o = args && args[0];
if (Y.Lang.isObject(o, true) && !o._yuifacade) {
Y.mix(ef, o, true);
}
// update the details field with the arguments
ef.details = this.details;
ef.target = this.target;
ef.currentTarget = this.currentTarget;
ef.stopped = 0;
ef.prevented = 0;
this._facade = ef;
return this._facade;
},
/**
* Notify a single subscriber
* @method _notify
* @param s {Subscriber} the subscriber
* @param args {Array} the arguments array to apply to the listener
* @private
*/
_notify: function(s, args, ef) {
this.log(this.type + "->" + ": " + s);
var ret, ct;
// emit an EventFacade if this is that sort of event
// if (this.emitFacade && (!args[0] || !args[0]._yuifacade)) {
if (this.emitFacade) {
// @TODO object literal support to fire makes it possible for
// config info to be passed if we wish.
if (!ef) {
ef = this._getFacade(args);
args[0] = ef;
}
}
// The default context should be the object/element that
// the listener was bound to.
ct = (args && Y.Lang.isObject(args[0]) && args[0].currentTarget);
ret = s.notify(ct || this.context, args, this);
if (false === ret || this.stopped > 1) {
this.log(this.type + " cancelled by subscriber");
return false;
}
return true;
},
/**
* Logger abstraction to centralize the application of the silent flag
* @method log
* @param msg {string} message to log
* @param cat {string} log category
*/
log: function(msg, cat) {
if (!this.silent) {
Y.log(this.id + ': ' + msg, cat || "info", "event");
}
},
/**
* Notifies the subscribers. The callback functions will be executed
* from the context specified when the event was created, and with the
* following parameters:
* <ul>
* <li>The type of event</li>
* <li>All of the arguments fire() was executed with as an array</li>
* <li>The custom object (if any) that was passed into the subscribe()
* method</li>
* </ul>
* @method fire
* @param {Object*} arguments an arbitrary set of parameters to pass to
* the handler.
* @return {boolean} false if one of the subscribers returned false,
* true otherwise
*/
fire: function() {
var es = Y.Env._eventstack,
subs, s, args, i, ef, q, queue, ce, hasSub,
ret = true;
if (es) {
// var b = this.bubbles, h = this.host;
// if (b && h) {
// b = (h._yuievt.targets.length);
// }
// es.silent = (es.silent || this.silent);
// queue this event if the current item in the queue bubbles
// if (b && this.queuable && this.type != es.next.type) {
if (this.queuable && this.type != es.next.type) {
this.log('queue ' + this.type);
es.queue.push([this, arguments]);
return true;
}
} else {
Y.Env._eventstack = {
// id of the first event in the stack
id: this.id,
next: this,
silent: this.silent,
logging: (this.type === 'yui:log'),
stopped: 0,
prevented: 0,
queue: []
};
es = Y.Env._eventstack;
}
if (this.fireOnce && this.fired) {
this.log('fireOnce event: ' + this.type + ' already fired');
} else {
// var subs = this.subscribers.slice(), len=subs.length,
subs = Y.merge(this.subscribers);
args = Y.Array(arguments, 0, true);
this.stopped = 0;
this.prevented = 0;
this.target = this.target || this.host;
this.currentTarget = this.host || this.currentTarget;
this.fired = true;
this.details = args.slice(); // original arguments in the details
// this.log("Firing " + this + ", " + "args: " + args);
this.log("Firing " + this.type);
hasSub = false;
es.lastLogState = es.logging;
ef = null;
if (this.emitFacade) {
// this.fire({
// foo: 1
// bar: 2
// }
// this.fire({
// bar: 2
// } // foo is still 1 unless we create a new facade
this._facade = null;
ef = this._getFacade(args);
args[0] = ef;
}
for (i in subs) {
if (subs.hasOwnProperty(i)) {
if (!hasSub) {
es.logging = (es.logging || (this.type === 'yui:log'));
hasSub = true;
}
// stopImmediatePropagation
if (this.stopped == 2) {
break;
}
s = subs[i];
if (s && s.fn) {
ret = this._notify(s, args, ef);
if (false === ret) {
this.stopped = 2;
}
}
}
}
es.logging = (es.lastLogState);
// bubble if this is hosted in an event target and propagation has not been stopped
// @TODO check if we need to worry about defaultFn order
if (this.bubbles && this.host && !this.stopped) {
es.stopped = 0;
es.prevented = 0;
ret = this.host.bubble(this);
this.stopped = Math.max(this.stopped, es.stopped);
this.prevented = Math.max(this.prevented, es.prevented);
}
// execute the default behavior if not prevented
// @TODO need context
if (this.defaultFn && !this.prevented) {
this.defaultFn.apply(this.host || this, args);
}
// process after listeners. If the default behavior was
// prevented, the after events don't fire.
if (!this.prevented && this.stopped < 2) {
subs = Y.merge(this.afters);
for (i in subs) {
if (subs.hasOwnProperty(i)) {
if (!hasSub) {
es.logging = (es.logging || (this.type === 'yui:log'));
hasSub = true;
}
// stopImmediatePropagation
if (this.stopped == 2) {
break;
}
s = subs[i];
if (s && s.fn) {
ret = this._notify(s, args, ef);
if (false === ret) {
this.stopped = 2;
}
}
}
}
}
}
if (es.id === this.id) {
// console.log('clearing stack: ' + es.id + ', ' + this);
// reset propragation properties while processing the rest of the queue
// process queued events
queue = es.queue;
while (queue.length) {
// q[0] = the event, q[1] = arguments to fire
q = queue.pop();
ce = q[0];
// Y.log('firing queued event ' + ce.type + ', from ' + this);
es.stopped = 0;
es.prevented = 0;
// set up stack to allow the next item to be processed
es.next = ce;
ret = ce.fire.apply(ce, q[1]);
}
Y.Env._eventstack = null;
}
return (ret !== false);
},
/**
* Removes all listeners
* @method unsubscribeAll
* @return {int} The number of listeners unsubscribed
*/
unsubscribeAll: function() {
var subs = this.subscribers, i, l=0;
for (i in subs) {
if (subs.hasOwnProperty(i)) {
this._delete(subs[i]);
l++;
}
}
this.subscribers={};
return l;
},
/**
* @method _delete
* @param subscriber object
* @private
*/
_delete: function(s) {
if (s) {
delete s.fn;
delete s.context;
delete this.subscribers[s.id];
delete this.afters[s.id];
}
},
/**
* @method toString
*/
toString: function() {
// return "{ CE '" + this.type + "' " + "id: " + this.id +
// ", host: " + (this.host && Y.stamp(this.host) + " }");
return this.type;
},
/**
* Stop propagation to bubble targets
* @method stopPropagation
*/
stopPropagation: function() {
this.stopped = 1;
Y.Env._eventstack.stopped = 1;
if (this.stoppedFn) {
this.stoppedFn.call(this.host || this, this);
}
},
/**
* Stops propagation to bubble targets, and prevents any remaining
* subscribers on the current target from executing.
* @method stopImmediatePropagation
*/
stopImmediatePropagation: function() {
this.stopped = 2;
Y.Env._eventstack.stopped = 2;
if (this.stoppedFn) {
this.stoppedFn.call(this.host || this, this);
}
},
/**
* Prevents the execution of this event's defaultFn
* @method preventDefault
*/
preventDefault: function() {
if (this.preventable) {
this.prevented = 1;
Y.Env._eventstack.prevented = 1;
}
if (this.preventedFn) {
this.preventedFn.call(this.host || this, this);
}
}
};
/////////////////////////////////////////////////////////////////////
/**
* Stores the subscriber information to be used when the event fires.
* @param {Function} fn The wrapped function to execute
* @param {Object} context The value of the keyword 'this' in the listener
* @param {Array} args* 0..n additional arguments to supply the listener
*
* @class Subscriber
* @constructor
*/
Y.Subscriber = function(fn, context, args) {
/**
* The callback that will be execute when the event fires
* This is wrapped by Y.rbind if obj was supplied.
* @property fn
* @type Function
*/
this.fn = fn;
/**
* Optional 'this' keyword for the listener
* @property context
* @type Object
*/
this.context = context;
/**
* Unique subscriber id
* @property id
* @type String
*/
this.id = Y.stamp(this);
/**
* Optional additional arguments supplied to subscribe(). If present,
* these will be appended to the arguments supplied to fire()
* @property args
* @type Array
*/
// this.args = args;
/**
* }
* fn bound to obj with additional arguments applied via Y.rbind
* @property wrappedFn
* @type Function
*/
this.wrappedFn = fn;
if (context) {
/*
var a = (args) ? Y.Array(args) : [];
a.unshift(fn, context);
// a.unshift(fn);
m = Y.rbind.apply(Y, a);
*/
this.wrappedFn = Y.rbind.apply(Y, args);
}
};
Y.Subscriber.prototype = {
/**
* Executes the subscriber.
* @method notify
* @param defaultContext The execution context if not overridden
* by the subscriber
* @param args {Array} Arguments array for the subscriber
* @param ce {Event.Custom} The custom event that sent the notification
*/
notify: function(defaultContext, args, ce) {
var c = this.context || defaultContext, ret = true,
f = function() {
switch (ce.signature) {
case 0:
ret = this.fn.call(c, ce.type, args, this.context);
break;
case 1:
ret = this.fn.call(c, args[0] || null, this.context);
break;
default:
ret = this.wrappedFn.apply(c, args || []);
}
};
// Ease debugging by only catching errors if we will not re-throw
// them.
if (Y.config.throwFail) {
f.call(this);
} else {
try {
f.call(this);
} catch(e) {
Y.error(this + ' failed: ' + e.message, e);
}
}
return ret;
},
/**
* Returns true if the fn and obj match this objects properties.
* Used by the unsubscribe method to match the right subscriber.
*
* @method contains
* @param {Function} fn the function to execute
* @param {Object} context optional 'this' keyword for the listener
* @return {boolean} true if the supplied arguments match this
* subscriber's signature.
*/
contains: function(fn, context) {
if (context) {
return ((this.fn == fn) && this.context == context);
} else {
return (this.fn == fn);
}
},
/**
* @method toString
*/
toString: function() {
return "Subscriber " + this.id;
}
};