用法和$.Callbacks完全一致， 但只是實現了add , remove , fire , empty, has和帶參數的構造函數功能， $.Callbacks 還有disable,disabled, fireWith , fired , lock, locked 方法
程式碼如下：
// Simulate jQuery.Callbacks object
function MyCallbacks( options )
{
var ops = { once: false, memory: false, unique: false, stopOnFalse: false };
if ( typeof options === 'string' && options.trim() !== '' )
{
var opsArray = options.split( /\s+/ );
for ( var i = 0; i < options.length; i++ )
{
if ( opsArray[i] === 'once' )
ops.once = true;
else if ( opsArray[i] === 'memory' )
ops.memory = true;
else if ( opsArray[i] === 'unique' )
ops.unique = true;
else if ( opsArray[i] === 'stopOnFalse' )
ops.stopOnFalse = true;
}
}
var ar = [];
var lastArgs = null;
var firedTimes = 0;
function hasName( name )
{
var h = false;
if ( typeof name === 'string'
&& name !== null
&& name.trim() !== ''
&& ar.length > 0 )
{
for ( var i = 0; i < ar.length; i++ )
{
if ( ar[i].name === name )
{
h = true;
break;
}
}
}
return h;
}
// add a function
this.add = function ( fn )
{
if ( typeof fn === 'function' )
{
if ( ops.unique )
{
// check whether it had been added before
if ( fn.name !== '' && hasName( fn.name ) )
{
return this;
}
}
ar.push( fn );
if ( ops.memory )
{
// after added , call it immediately
fn.call( this, lastArgs );
}
}
return this;
};
// remove a function
this.remove = function ( fn )
{
if ( typeof ( fn ) === 'function'
&& fn.name !== ''
&& ar.length > 0 )
{
for ( var i = 0; i < ar.length; i++ )
{
if ( ar[i].name === fn.name )
{
ar.splice( i, 1 );
}
}
}
return this;
};
// remove all functions
this.empty = function ()
{
ar.length = 0;
return this;
};
// check whether it includes a specific function
this.has = function ( fn )
{
var f = false;
if ( typeof ( fn ) === 'function'
&& fn.name !== ''
&& ar.length > 0 )
{
for ( var i = 0; i < ar.length; i++ )
{
if ( ar[i].name === fn.name )
{
f = true;
break;
}
}
}
return f;
};
// 逐一調用其中包含的函數
this.fire = function ( args )
{
if ( ops.once &&firedTimes > 0 )
{
返回此信息;
}
var r;
, ( var i = 0; i < ar.length; i )
if ( ops.stopOnFalse && r === false )
{
}
}
}
被解僱次數 ;
}
以這裡回來給
測試函數如下：（注意fn1 fn2是匿名函數，fn2回傳false，fn3是有「名稱」函數）
複製程式碼
程式碼如下：
🎜>
1 . 測試add & fire
var cb=new MyCallbacks();
cb.add(fn1)
cb.add(fn2)
cb.add(fn3)
cb.fire('hello')
輸出：
fn1 hello
fn2 hello
fn3 hello
2.測試remove
var cb=new MyCallbacks();
cb.add(fn1)
cb.add(fn2)
cb.add(fn3)
cb.remove(fn1)
cb.fire('hello')
cb.remove(fn3)
cb.fire('hello')
輸出：
fn1 hello
fn2 hello
fn3 hello
----------------------------
fn1 hello
fn2 hello
2.測試has
var cb=new MyCallbacks();
cb.add(fn1)
cb.add(fn2)
cb.add(fn3)
cb.has(fn1)
cb.has(fn3)
輸出：
false
---------------
true
3.測試帶參數的建構子 : once
var cb=new MyCallbacks('once')
cb.add(fn1)
cb.fire('hello')
cb.fire('hello')
cb.add(fn2)
cb.fire('hello')
輸出：
hello
-------------------
------------------
------------------------------
4.測試帶參數的建構子 : memory
var cb=new MyCallbacks('memory')
cb.add(fn1)
cb.fire('hello') // 輸出 : fn1 hello
cb.add(fn2) // 輸出 : fn2 hello
cb.fire('hello')
輸出 :
fn1 hello
fn2 hello
5.測試帶參數的建構子 : stopOnFalse
var cb=new MyCallbacks('stopOnFalse')
cb.add(fn1)
cb.add(fn2)
cb.add(fn3)
cb.fire('hello')
輸出：
fn1 hello
fn2 hello
6.測試帶參數的建構子 :unique
var cb=new MyCallbacks('unique')
b.add(fn3)
b.add(fn3)
cb.fire('hello')
輸出：
fn3 hello
7. 測試帶組合參數的建構子：四個設定參數可以隨意組合，一下只測試全部組合的情況， 不然要寫16個測試用例 T_T
var cb=new MyCallbacks('once memory unique stopOnFalse')
cb.add(fn1) // 輸出： fn1
cb.add(fn2) // 輸出： fn2
cb.add(fn3) // 輸出： fn3
cb.fire('hello')
輸出：
fn1 hello
fn2 hello
cb.fire('hello') // 輸出：沒有輸出
以下是官方API 文件：
Description: A multi-purpose callbacks list object that provides a powerful way to manage callback lists.The $.Callbacks() function is internally used to provide the base functionality behind the jeryDe $. ) components. It can be used as a similar base to define functionality for new components.
建構子 ： jQuery.Callbacks( flags )
flags
Type: String
An optional list of space-separated flags that change how the callback list behaves.
Possible flags:
once: Encosurce the call list list like a Deferred).
memory: Keeps track of previous values and will call any callback added after the list has been fired right away with the latest "memorized" values (like a Deferred).<
stopOnFalse: Interrupts callings when a callback returns false.
By default a callback list will act like an event default a callback list will act like like 2000 月multiple times.
利用Callbacks 實現發布訂閱模式 pub/sub: (官方文件)
jQuery.Topic = function ( id )
{
方法,
topic = id && topic[id];
{
topic = {
訂閱：callbacks.add,
取消訂閱：callbacks.remove
};
} {
為主題[id] = topic;
🎜> 回主體;
} ;
使用
複製程式碼
複製程式碼
if ( typeof options === 'string' && options.trim() !== '' )
{
var opsArray = options.split( /\s+/ );
for ( var i = 0; i < options.length; i++ )
{
if ( opsArray[i] === 'once' )
ops.once = true;
else if ( opsArray[i] === 'memory' )
ops.memory = true;
else if ( opsArray[i] === 'unique' )
ops.unique = true;
else if ( opsArray[i] === 'stopOnFalse' )
ops.stopOnFalse = true;
}
}
function hasName( name )
{
var h = false;
if ( typeof name === 'string'
&& name !== null
&& name.trim() !== ''
&& ar.length > 0 )
{
for ( var i = 0; i < ar.length; i++ )
{
if ( ar[i].name === name )
{
h = true;
break;
}
}
}
return h;
}
// add a function
this.add = function ( fn )
{
if ( typeof fn === 'function' )
{
if ( ops.unique )
{
// check whether it had been added before
if ( fn.name !== '' && hasName( fn.name ) )
{
return this;
}
}
ar.push( fn );
if ( ops.memory )
{
// after added , call it immediately
fn.call( this, lastArgs );
}
}
return this;
};
// remove a function
this.remove = function ( fn )
{
if ( typeof ( fn ) === 'function'
&& fn.name !== ''
&& ar.length > 0 )
{
for ( var i = 0; i < ar.length; i++ )
{
if ( ar[i].name === fn.name )
{
ar.splice( i, 1 );
}
}
}
return this;
};
// remove all functions
this.empty = function ()
{
ar.length = 0;
return this;
};
// check whether it includes a specific function
this.has = function ( fn )
{
var f = false;
if ( typeof ( fn ) === 'function'
&& fn.name !== ''
&& ar.length > 0 )
{
for ( var i = 0; i < ar.length; i++ )
{
if ( ar[i].name === fn.name )
{
f = true;
break;
}
}
}
return f;
};
this.disable = function ()
{
_disabled = true;
return this;
};
this.disabled = function ()
{
return _disabled;
};
this.fired = function ()
{
return firedTimes > 0;
};
function _fire( context, args )
{
if ( _disabled || ops.once && firedTimes > 0 || _locked )
{
return;
}
if ( ar.length > 0 )
{
var r;
for ( var i = 0; i < ar.length; i++ )
{
r = ar[i].call( context, args );
if ( ops.stopOnFalse && r === false )
{
break;
}
}
}
firedTimes++;
if ( ops.memory )
{
lastArgs = args;
}
};
this.fireWith = function ( context, args )
{
context = context || this;
_fire( context, args );
return this;
};
this.fire = function ( args )
{
_fire( this, args );
return this;
};
this.lock = function ()
{
_locked = true;
return this;
};
this.locked = function ()
{
return _locked;
};
};
// ファクトリ メソッドとしてグローバルに公開
window.callbacks = function ( options )
{
return new Callbacks( options );
};
} )( window );
