Observable-more.js
资源名称:ext-3.0.0.zip [点击查看]
上传用户:shuoshiled
上传日期:2018-01-28
资源大小:10124k
文件大小:6k
源码类别:
中间件编程
开发平台:
JavaScript
- /*! * Ext JS Library 3.0.0 * Copyright(c) 2006-2009 Ext JS, LLC * licensing@extjs.com * http://www.extjs.com/license */ /**
- * @class Ext.util.Observable
- */
- Ext.apply(Ext.util.Observable.prototype, function(){
- // this is considered experimental (along with beforeMethod, afterMethod, removeMethodListener?)
- // allows for easier interceptor and sequences, including cancelling and overwriting the return value of the call
- // private
- function getMethodEvent(method){
- var e = (this.methodEvents = this.methodEvents ||
- {})[method], returnValue, v, cancel, obj = this;
- if (!e) {
- this.methodEvents[method] = e = {};
- e.originalFn = this[method];
- e.methodName = method;
- e.before = [];
- e.after = [];
- var makeCall = function(fn, scope, args){
- if (!Ext.isEmpty(v = fn.apply(scope || obj, args))) {
- if (Ext.isObject(v)) {
- returnValue = !Ext.isEmpty(v.returnValue) ? v.returnValue : v;
- cancel = !!v.cancel;
- }
- else
- if (v === false) {
- cancel = true;
- }
- else {
- returnValue = v;
- }
- }
- };
- this[method] = function(){
- var args = Ext.toArray(arguments);
- returnValue = v = undefined;
- cancel = false;
- Ext.each(e.before, function(b){
- makeCall(b.fn, b.scope, args);
- if (cancel) {
- return returnValue;
- }
- });
- if (!Ext.isEmpty(v = e.originalFn.apply(obj, args))) {
- returnValue = v;
- }
- Ext.each(e.after, function(a){
- makeCall(a.fn, a.scope, args);
- if (cancel) {
- return returnValue;
- }
- });
- return returnValue;
- };
- }
- return e;
- }
- return {
- // these are considered experimental
- // allows for easier interceptor and sequences, including cancelling and overwriting the return value of the call
- // adds an "interceptor" called before the original method
- beforeMethod: function(method, fn, scope){
- getMethodEvent.call(this, method).before.push({
- fn: fn,
- scope: scope
- });
- },
- // adds a "sequence" called after the original method
- afterMethod: function(method, fn, scope){
- getMethodEvent.call(this, method).after.push({
- fn: fn,
- scope: scope
- });
- },
- removeMethodListener: function(method, fn, scope){
- var e = getMethodEvent.call(this, method), found = false;
- Ext.each(e.before, function(b, i, arr){
- if (b.fn == fn && b.scope == scope) {
- arr.splice(i, 1);
- found = true;
- return false;
- }
- });
- if (!found) {
- Ext.each(e.after, function(a, i, arr){
- if (a.fn == fn && a.scope == scope) {
- arr.splice(i, 1);
- return false;
- }
- });
- }
- },
- /**
- * Relays selected events from the specified Observable as if the events were fired by <tt><b>this</b></tt>.
- * @param {Object} o The Observable whose events this object is to relay.
- * @param {Array} events Array of event names to relay.
- */
- relayEvents: function(o, events){
- var me = this;
- function createHandler(ename){
- return function(){
- return me.fireEvent.apply(me, [ename].concat(Ext.toArray(arguments)));
- };
- }
- Ext.each(events, function(ename){
- me.events[ename] = me.events[ename] || true;
- o.on(ename, createHandler(ename), me);
- });
- },
- /**
- * Used to enable bubbling of events
- * @param {Object} events
- */
- enableBubble: function(events){
- var me = this;
- events = Ext.isArray(events) ? events : Ext.toArray(arguments);
- Ext.each(events, function(ename){
- ename = ename.toLowerCase();
- var ce = me.events[ename] || true;
- if (typeof ce == "boolean") {
- ce = new Ext.util.Event(me, ename);
- me.events[ename] = ce;
- }
- ce.bubble = true;
- });
- }
- };
- }());
- /**
- * Starts capture on the specified Observable. All events will be passed
- * to the supplied function with the event name + standard signature of the event
- * <b>before</b> the event is fired. If the supplied function returns false,
- * the event will not fire.
- * @param {Observable} o The Observable to capture
- * @param {Function} fn The function to call
- * @param {Object} scope (optional) The scope (this object) for the fn
- * @static
- */
- Ext.util.Observable.capture = function(o, fn, scope){
- o.fireEvent = o.fireEvent.createInterceptor(fn, scope);
- };
- /**
- * Sets observability on the passed class constructor.<p>
- * <p>This makes any event fired on any instance of the passed class also fire a single event through
- * the <i>class</i> allowing for central handling of events on many instances at once.</p>
- * <p>Usage:</p><pre><code>
- Ext.util.Observable.observeClass(Ext.data.Connection);
- Ext.data.Connection.on('beforerequest', function(con, options) {
- console.log("Ajax request made to " + options.url);
- });</code></pre>
- * @param {Function} c The class constructor to make observable.
- * @static
- */
- Ext.util.Observable.observeClass = function(c){
- Ext.apply(c, new Ext.util.Observable());
- c.prototype.fireEvent = function(){
- return (c.fireEvent.apply(c, arguments) !== false) &&
- (Ext.util.Observable.prototype.fireEvent.apply(this, arguments) !== false);
- };
- };