/**
* Simple event bindings for form state
*
* In general, access through CFState.events() not directly.
*
* @since 1.5.3
*
* @param state {CFState} State object to subscribe to
* @constructor
*/
function CFEvents(state) {
var events = {};
/**
* Attach an event (add_action)
*
* @since 1.5.3
*
* @param id {String} Any string, but generally input ID
* @param callback {Function} The callback function
*/
this.subscribe = function (id, callback) {
if (!hasEvents(id)) {
events[id] = [];
}
events[id].push(callback);
};
/**
* Trigger an event (do_action)
*
* @since 1.5.3
*
* @param id {String} Any string, but generally input ID
* @param value {*} The value to pass to callback
*/
this.trigger = function (id, value) {
if (!hasEvents(id)) {
return;
}
events[id].forEach(function (callback) {
if(typeof value === 'undefined'){
value = state.getState(id);
}
callback(id, value);
});
};
this.emit = function (eventName, payload) {
if (!hasEvents(eventName)) {
return;
}
events[eventName].forEach(function (callback) {
callback(payload,eventName);
});
};
/**
* Detach a bound event (remove_action)
*
* @since 1.5.3
*
* @param id {String} Any string, but generally input ID
* @param callback {Function|null} The callback function you wish to detatch or null to detach all events.
*/
this.detach = function(id,callback){
if( hasEvents(id)){
if( null === callback ){
delete events[id];
}else{
for (var key in events[id]) {
if (callback === key) {
events[id].splice(key, 1);
}
}
}
}
};
/**
* Check if there are events attatched to an identifier
*
* @since 1.5.23
*
*
* @param id {String} Identifying string
* @returns {boolean}
*/
function hasEvents(id) {
return events.hasOwnProperty(id);
}
}
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