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Read jQuery 13. Core methods of adding events and deleting events_jquery

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Release: 2016-05-16 18:03:19
Original
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jQuery's event module relies heavily on its data store (jQuery.data), and you'll find that the dataManager object in my code corresponds to it.
Only bind and unbind methods are provided here. It does not include
1, event namespace (event namespace)
2, event delegation (event delegation)
3, special events such as dom ready
The interface is as follows:

Copy code The code is as follows:

E.bind(el, 'click', fn);
E.bind( el, 'click', fn, data);
E.unbind(el, 'click', fn);
E.unbind(el, 'click');
E.unbind(el) ;

Copy code The code is as follows:

/**
* Event from jQuery
* 2011-06-20 snandy
*
* A number of helper functions used for managing events.
* Many of the ideas behind this code originated from jQuery library (1.6.2).
*
* example
*
* E.bind(el, 'click', fn);
*
* E.bind(el, 'click', fn, data);
*
* E.unbind(el, 'click', fn);
*
* E.unbind(el, 'click');
*
* E.unbind(el);
*
*/
E = function( window ) {
var uuid = 0,
globalCache = {},
doc = window.document,
w3c = !!doc.addEventListener,
expando = 'snandy' ('' Math.random()).replace(/D/g, ''),
addListener = w3c ?
function(el, type, fn) { el.addEventListener(type, fn, false); } :
function(el, type, fn) { el.attachEvent('on' type, fn); },
removeListener = w3c ?
function(el, type, fn) { el.removeEventListener(type, fn, false); } :
function(el, type, fn) { el.detachEvent('on' type, fn); };
dispatch = w3c ?
function( el, type ){
try{
var evt = doc.createEvent('Event');
evt.initEvent( type, true, true );
el.dispatchEvent( evt );
}catch( e ){ alert( e ) };
} :
function( el, type ){
try{
el.fireEvent( 'on' type );
}catch( e ){ alert( e ); }
},
dataManager = {
data : function ( elem, name, data ) {
var getByName = typeof name === "string",
thisCache,
isNode = elem.nodeType,
cache = isNode ? globalCache : elem,
id = isNode ? elem[ expando ] : elem[ expando ] && expando;
if(!id && isNode) {
elem[expando] = id = uuid;
}
if(!cache[id]){
cache[id] = {};
}
thisCache = cache[id];
if(data !== undefined) {
thisCache[name] = data;
}
return getByName ? thisCache[name] : thisCache;
},
removeData : function ( elem, name ) {
var id = elem[expando],
thisCache = globalCache[id];
if(!id || !thisCache){
return;
}
if(typeof name === 'string') {
delete thisCache[name];
}else{
delete globalCache[id];
}
}
};
function returnFalse() {
return false;
}
function returnTrue() {
return true;
}
function now() {
return (new Date).getTime();
}
function isEmptyObject( obj ){
for( var i in obj ){
return false;
}
return true;
}
function addEvent (elem, types, handler, data) {
if ( elem.nodeType === 3 || elem.nodeType === 8 ) {
return;
}
if ( handler === false ) {
handler = returnFalse;
} else if ( !handler ) {
return;
}
var elemData = dataManager.data( elem ),
events = elemData.events,
eventHandle = elemData.handle,
types = types.split(" ");
if ( !events ) {
elemData.events = events = {};
}
if ( !eventHandle ) {
elemData.handle = eventHandle = function ( e ) {
return evtHandle.call( eventHandle.elem, e );
};
}
eventHandle.elem = elem;
var type, i = 0;
while ( type = types[i ] ) {
var handleObj = {handler : handler, data : data},
handlers = events[type];
if ( !handlers ) {
handlers = events[type] = [];
addListener( elem, type, eventHandle );
}
handlers.push( handleObj );
}
elem = null;
}
function evtHandle ( event ) {
event = fixEvent( event || window.event );
var handlers = ((dataManager.data(this, "events") || {})[event.type] || []).slice(0);
event.currentTarget = this;
for( var j = 0, l = handlers.length; j < l; j ) {
var handleObj = handlers[j];
event.handler = handleObj.handler;
event.data = handleObj.data;
event.handleObj = handleObj;
var ret = handleObj.handler.call( this, event );
if( ret !== undefined ) {
if( ret === false ) {
event.preventDefault();
event.stopPropagation();
}
}
if( event.isImmediatePropagationStopped() ) {
break;
}
}
}
function removeEvent( elem, types, handler ) {
// don't do events on text and comment nodes
if( elem.nodeType === 3 || elem.nodeType === 8 ) {
return;
}
if( handler === false ) {
handler = returnFalse;
}
var type, origType, i = 0, j,
elemData = dataManager.data( elem ),
events = elemData && elemData.events;
if( !elemData || !events ) {
return;
}
// Unbind all events for the element
if( !types ) {
types = types || "";
for ( type in events ) {
removeEvent( elem, type );
}
return;
}
// Handle multiple events separated by a space
// jQuery(...).unbind("mouseover mouseout", fn);
types = types.split(" ");
while( (type = types[ i ]) ) {
origType = type;
handleObj = null;
eventType = events[ type ];
if( !eventType ) {
continue;
}
if( !handler ) {
for ( j = 0; j < eventType.length; j ) {
handleObj = eventType[ j ];
removeEvent( elem, origType, handleObj.handler );
eventType.splice( j--, 1 );
}
continue;
}
for( j = 0; j < eventType.length; j ) {
handleObj = eventType[ j ];
if( handler === handleObj.handler ) {
// remove the given handler for the given type
eventType.splice( j--, 1 );
}
}
}
// remove generic event handler if no more handlers exist
if ( eventType.length === 0 ) {
delete events[ origType ];
}
// Remove the expando if it's no longer used
if ( isEmptyObject( events ) ) {
var handle = elemData.handle;
if ( handle ) {
handle.elem = null;
}
delete elemData.events;
delete elemData.handle;
if ( isEmptyObject( elemData ) ) {
dataManager.removeData( elem, 'events' );
}
}
}
function Event( src ) {
this.originalEvent = src;
this.type = src.type;
this.timeStamp = now();
}
Event.prototype = {
preventDefault: function() {
this.isDefaultPrevented = returnTrue;
var e = this.originalEvent;
if( e.preventDefault ) {
e.preventDefault();
}
e.returnValue = false;
},
stopPropagation: function() {
this.isPropagationStopped = returnTrue;
var e = this.originalEvent;
if( e.stopPropagation ) {
e.stopPropagation();
}
e.cancelBubble = true;
},
stopImmediatePropagation: function() {
this.isImmediatePropagationStopped = returnTrue;
this.stopPropagation();
},
isDefaultPrevented: returnFalse,
isPropagationStopped: returnFalse,
isImmediatePropagationStopped: returnFalse
};
function fixEvent( evt ) {
var props = "altKey attrChange attrName bubbles button cancelable charCode clientX clientY ctrlKey currentTarget data detail eventPhase fromElement handler keyCode layerX layerY metaKey newValue offsetX offsetY originalTarget pageX pageY prevValue relatedNode relatedTarget screenX screenY shiftKey srcElement target toElement view wheelDelta which".split(" "),
len = props.length;
var originalEvent = evt;
evt = new Event(originalEvent);
for(var i = len, prop; i;) {
prop = props[ --i ];
evt[ prop ] = originalEvent[ prop ];
}
if(!evt.target) {
evt.target = evt.srcElement || document;
}
if( evt.target.nodeType === 3 ) {
evt.target = evt.target.parentNode;
}
if( !evt.relatedTarget && evt.fromElement ) {
evt.relatedTarget = evt.fromElement === evt.target ? evt.toElement : evt.fromElement;
}
if( evt.pageX == null && evt.clientX != null ) {
var doc = document.documentElement, body = document.body;
evt.pageX = evt.clientX (doc && doc.scrollLeft || body && body.scrollLeft || 0) - (doc && doc.clientLeft || body && body.clientLeft || 0);
evt.pageY = evt.clientY (doc && doc.scrollTop || body && body.scrollTop || 0) - (doc && doc.clientTop || body && body.clientTop || 0);
}
if( !evt.which && ((evt.charCode || evt.charCode === 0) ? evt.charCode : evt.keyCode) ) {
evt.which = evt.charCode || evt.keyCode;
}
if( !evt.metaKey && evt.ctrlKey ) {
evt.metaKey = evt.ctrlKey;
}
if( !evt.which && evt.button !== undefined ) {
evt.which = (evt.button & 1 ? 1 : ( evt.button & 2 ? 3 : ( evt.button & 4 ? 2 : 0 ) ));
}
return evt;
}
function bind ( el, type, fn, data ) {
var handler;
if( typeof type === "object" ) {
for( var key in type ) {
bind(el, key, type[key], data);
}
return;
}
handler = fn;
addEvent( el, type, handler, data );
}
function unbind ( el, type, fn ) {
if( typeof type === "object" ) {
for ( var key in type ) {
unbind( el, key, type[key] );
}
}else {
removeEvent( el, type, fn );
}
}
return {
data : dataManager.data,
removeData : dataManager.removeData,
bind : bind,
unbind : unbind
};
}(this);
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