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Ext.util.DelayedTask

Hierarchy

Ext.Base
Ext.util.DelayedTask

Files

The DelayedTask class provides a convenient way to "buffer" the execution of a method, performing setTimeout where a new timeout cancels the old timeout. When called, the task will wait the specified time period before executing. If durng that time period, the task is called again, the original call will be cancelled. This continues so that the function is only called a single time for each iteration.

This method is especially useful for things like detecting whether a user has finished typing in a text field. An example would be performing validation on a keypress. You can use this class to buffer the keypress events for a certain number of milliseconds, and perform only if they stop for that amount of time.

Using Ext.util.DelayedTask is very simple:

//create the delayed task instance with our callback
var task = Ext.create('Ext.util.DelayedTask', function() {
    console.log('callback!');
});

task.delay(1500); //the callback function will now be called after 1500ms

task.cancel(); //the callback function will never be called now, unless we call delay() again

Example

//create a textfield where we can listen to text
var field = Ext.create('Ext.field.Text', {
    xtype: 'textfield',
    label: 'Length: 0'
});

//add the textfield into a fieldset
Ext.Viewport.add({
    xtype: 'formpanel',
    items: [{
        xtype: 'fieldset',
        items: [field],
        instructions: 'Type into the field and watch the count go up after 500ms.'
    }]
});

//create our delayed task with a function that returns the fields length as the fields label
var task = Ext.create('Ext.util.DelayedTask', function() {
    field.setLabel('Length: ' + field.getValue().length);
});

// Wait 500ms before calling our function. If the user presses another key
// during that 500ms, it will be cancelled and we'll wait another 500ms.
field.on('keyup', function() {
    task.delay(500);
});

Available since: 1.1.0

Defined By

Config options

Ext.util.DelayedTask
view source
: Objectprivate

Available since: 2.0.0

Ext.util.DelayedTask
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: Objectprivate

Available since: 2.0.0

Ext.util.DelayedTask
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: Objectprivate

Available since: 2.0.0

Ext.util.DelayedTask
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: Objectprivate

Available since: 2.0.0

Ext.util.DelayedTask
view source
: Objectprivate

Available since: 2.0.0

Properties

Defined By

Instance properties

Get the reference to the current class from which this object was instantiated. ...

Get the reference to the current class from which this object was instantiated. Unlike statics, this.self is scope-dependent and it's meant to be used for dynamic inheritance. See statics for a detailed comparison

Ext.define('My.Cat', {
    statics: {
        speciesName: 'Cat' // My.Cat.speciesName = 'Cat'
    },

    constructor: function() {
        alert(this.self.speciesName); / dependentOL on 'this'
    },

    clone: function() {
        return new this.self();
    }
});


Ext.define('My.SnowLeopard', {
    extend: 'My.Cat',
    statics: {
        speciesName: 'Snow Leopard'         // My.SnowLeopard.speciesName = 'Snow Leopard'
    }
});

var cat = new My.Cat();                     // alerts 'Cat'
var snowLeopard = new My.SnowLeopard();     // alerts 'Snow Leopard'

var clone = snowLeopard.clone();
alert(Ext.getClassName(clone));             // alerts 'My.SnowLeopard'

Available since: 2.0.0

Defined By

Static properties

...

Defaults to: []

Available since: 2.0.0

Methods

Defined By

Instance methods

Ext.util.DelayedTask
view source
new( fn, scope, args ) : Ext.util.DelayedTask
The parameters to this constructor serve as defaults and are not required. ...

The parameters to this constructor serve as defaults and are not required.

Available since: 1.1.0

Parameters

  • fn : Function

    The default function to call.

  • scope : Object

    The default scope (The this reference) in which the function is called. If not specified, this will refer to the browser window.

  • args : Array

    The default Array of arguments.

Returns

Ext.util.DelayedTask
view source
( config )private
Changes the value into an array if it isn't one. ...

Changes the value into an array if it isn't one.

Available since: 2.0.0

Parameters

Call the original method that was previously overridden with override Ext.define('My.Cat', { constructor: functi...

Call the original method that was previously overridden with override

Ext.define('My.Cat', {
    constructor: function() {
        alert("I'm a cat!");
    }
});

My.Cat.override({
    constructor: function() {
        alert("I'm going to be a cat!");

        var instance = this.callOverridden();

        alert("Meeeeoooowwww");

        return instance;
    }
});

var kitty = new My.Cat(); // alerts "I'm going to be a cat!"
                          // alerts "I'm a cat!"
                          // alerts "Meeeeoooowwww"

Available since: 2.0.0

Parameters

  • args : Array/Arguments

    The arguments, either an array or the arguments object from the current method, for example: this.callOverridden(arguments)

Returns

  • Object

    Returns the result of calling the overridden method

Call the "parent" method of the current method. ...

Call the "parent" method of the current method. That is the method previously overridden by derivation or by an override (see Ext.define).

 Ext.define('My.Base', {
     constructor: function (x) {
         this.x = x;
     },

     statics: {
         method: function (x) {
             return x;
         }
     }
 });

 Ext.define('My.Derived', {
     extend: 'My.Base',

     constructor: function () {
         this.callParent([21]);
     }
 });

 var obj = new My.Derived();

 alert(obj.x);  // alerts 21

This can be used with an override as follows:

 Ext.define('My.DerivedOverride', {
     override: 'My.Derived',

     constructor: function (x) {
         this.callParent([x*2]); // calls original My.Derived constructor
     }
 });

 var obj = new My.Derived();

 alert(obj.x);  // now alerts 42

This also works with static methods.

 Ext.define('My.Derived2', {
     extend: 'My.Base',

     statics: {
         method: function (x) {
             return this.callParent([x*2]); // calls My.Base.method
         }
     }
 });

 alert(My.Base.method(10);     // alerts 10
 alert(My.Derived2.method(10); // alerts 20

Lastly, it also works with overridden static methods.

 Ext.define('My.Derived2Override', {
     override: 'My.Derived2',

     statics: {
         method: function (x) {
             return this.callParent([x*2]); // calls My.Derived2.method
         }
     }
 });

 alert(My.Derived2.method(10); // now alerts 40

Available since: 2.0.0

Parameters

  • args : Array/Arguments

    The arguments, either an array or the arguments object from the current method, for example: this.callParent(arguments)

Returns

  • Object

    Returns the result of calling the parent method

Ext.util.DelayedTask
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( )
Cancel the last queued timeout ...

Cancel the last queued timeout

Available since: 1.1.0

Fires

    Ext.util.DelayedTask
    view source
    ( delay, newFn, newScope, newArgs )
    Cancels any pending timeout and queues a new one. ...

    Cancels any pending timeout and queues a new one.

    Available since: 1.1.0

    Parameters

    • delay : Number

      The milliseconds to delay

    • newFn : Function

      Overrides the original function passed when instantiated.

    • newScope : Object

      Overrides the original scope passed when instantiated. Remember that if no scope is specified, this will refer to the browser window.

    • newArgs : Array

      Overrides the original args passed when instantiated.

    Fires

      Ext.util.DelayedTask
      view source
      ( ) : Object
      Returns the value of args. ...

      Returns the value of args.

      Available since: 2.0.0

      Returns

      ...

      Available since: 2.0.0

      Parameters

      ...

      Available since: 2.0.0

      Ext.util.DelayedTask
      view source
      ( ) : Object
      Returns the value of delay. ...

      Returns the value of delay.

      Available since: 2.0.0

      Returns

      Ext.util.DelayedTask
      view source
      ( ) : Object
      Returns the value of fn. ...

      Returns the value of fn.

      Available since: 2.0.0

      Returns

      Returns the initial configuration passed to constructor. ...

      Returns the initial configuration passed to constructor.

      Available since: 2.0.0

      Parameters

      • name : String (optional)

        When supplied, value for particular configuration option is returned, otherwise the full config object is returned.

      Returns

      Ext.util.DelayedTask
      view source
      ( ) : Object
      Returns the value of interval. ...

      Returns the value of interval.

      Available since: 2.0.0

      Returns

      Ext.util.DelayedTask
      view source
      ( ) : Object
      Returns the value of scope. ...

      Returns the value of scope.

      Available since: 2.0.0

      Returns

      ...

      Available since: 2.0.0

      Parameters

      ( instanceConfig ) : Objectchainableprotected
      Initialize configuration for this class. ...

      Initialize configuration for this class. a typical example:

      Ext.define('My.awesome.Class', {
          // The default config
          config: {
              name: 'Awesome',
              isAwesome: true
          },
      
          constructor: function(config) {
              this.initConfig(config);
          }
      });
      
      var awesome = new My.awesome.Class({
          name: 'Super Awesome'
      });
      
      alert(awesome.getName()); // 'Super Awesome'
      

      Available since: 2.0.0

      Parameters

      Returns

      • Object

        mixins The mixin prototypes as key - value pairs

      Fires

        ( names, callback, scope )private
        ...

        Available since: 2.0.0

        Parameters

        Ext.util.DelayedTask
        view source
        ( args )
        Sets the value of args. ...

        Sets the value of args.

        Available since: 2.0.0

        Parameters

        ( config, applyIfNotSet ) : Ext.Basechainableprivate
        ...

        Available since: 2.0.0

        Parameters

        Returns

        Ext.util.DelayedTask
        view source
        ( delay )
        Sets the value of delay. ...

        Sets the value of delay.

        Available since: 2.0.0

        Parameters

        Ext.util.DelayedTask
        view source
        ( fn )
        Sets the value of fn. ...

        Sets the value of fn.

        Available since: 2.0.0

        Parameters

        Ext.util.DelayedTask
        view source
        ( interval )
        Sets the value of interval. ...

        Sets the value of interval.

        Available since: 2.0.0

        Parameters

        Ext.util.DelayedTask
        view source
        ( scope )
        Sets the value of scope. ...

        Sets the value of scope.

        Available since: 2.0.0

        Parameters

        Get the reference to the class from which this object was instantiated. ...

        Get the reference to the class from which this object was instantiated. Note that unlike self, this.statics() is scope-independent and it always returns the class from which it was called, regardless of what this points to during run-time

        Ext.define('My.Cat', {
            statics: {
                totalCreated: 0,
                speciesName: 'Cat' // My.Cat.speciesName = 'Cat'
            },
        
            constructor: function() {
                var statics = this.statics();
        
                alert(statics.speciesName);     // always equals to 'Cat' no matter what 'this' refers to
                                                // equivalent to: My.Cat.speciesName
        
                alert(this.self.speciesName);   // dependent on 'this'
        
                statics.totalCreated++;
            },
        
            clone: function() {
                var cloned = new this.self;                      // dependent on 'this'
        
                cloned.groupName = this.statics().speciesName;   // equivalent to: My.Cat.speciesName
        
                return cloned;
            }
        });
        
        
        Ext.define('My.SnowLeopard', {
            extend: 'My.Cat',
        
            statics: {
                speciesName: 'Snow Leopard'     // My.SnowLeopard.speciesName = 'Snow Leopard'
            },
        
            constructor: function() {
                this.callParent();
            }
        });
        
        var cat = new My.Cat();                 // alerts 'Cat', then alerts 'Cat'
        
        var snowLeopard = new My.SnowLeopard(); // alerts 'Cat', then alerts 'Snow Leopard'
        
        var clone = snowLeopard.clone();
        alert(Ext.getClassName(clone));         // alerts 'My.SnowLeopard'
        alert(clone.groupName);                 // alerts 'Cat'
        
        alert(My.Cat.totalCreated);             // alerts 3
        

        Available since: 2.0.0

        Returns

        Ext.util.DelayedTask
        view source
        ( newInterval, oldInterval )private
        Clears the old interval ...

        Clears the old interval

        Available since: 2.0.0

        Parameters

        Defined By

        Static methods

        ( config, fullMerge )privatestatic
        ...

        Available since: 2.0.0

        Parameters

        ( members )chainableprivatestatic
        ...

        Available since: 2.0.0

        Parameters

        ( name, member )chainableprivatestatic
        ...

        Available since: 2.0.0

        Parameters

        ( members )chainablestatic
        Add methods / properties to the prototype of this class. ...

        Add methods / properties to the prototype of this class.

        Ext.define('My.awesome.Cat', {
            constructor: function() {
                ...
            }
        });
        
         My.awesome.Cat.implement({
             meow: function() {
                alert('Meowww...');
             }
         });
        
         var kitty = new My.awesome.Cat;
         kitty.meow();
        

        Available since: 2.0.0

        Parameters

        ( members ) : Ext.Basechainablestatic
        Add / override static properties of this class. ...

        Add / override static properties of this class.

        Ext.define('My.cool.Class', {
            ...
        });
        
        My.cool.Class.addStatics({
            someProperty: 'someValue',      // My.cool.Class.someProperty = 'someValue'
            method1: function() { ... },    // My.cool.Class.method1 = function() { ... };
            method2: function() { ... }     // My.cool.Class.method2 = function() { ... };
        });
        

        Available since: 2.0.0

        Parameters

        Returns

        ( xtype )chainableprivatestatic
        ...

        Available since: 2.0.0

        Parameters

        ( fromClass, members ) : Ext.Basechainableprivatestatic
        Borrow another class' members to the prototype of this class. ...

        Borrow another class' members to the prototype of this class.

        Ext.define('Bank', {
            money: '$$$',
            printMoney: function() {
                alert('$$$$$$$');
            }
        });
        
        Ext.define('Thief', {
            ...
        });
        
        Thief.borrow(Bank, ['money', 'printMoney']);
        
        var steve = new Thief();
        
        alert(steve.money); // alerts '$$$'
        steve.printMoney(); // alerts '$$$$$$$'
        

        Available since: 2.0.0

        Parameters

        • fromClass : Ext.Base

          The class to borrow members from

        • members : Array/String

          The names of the members to borrow

        Returns

        ( args )privatestatic
        ...

        Available since: 2.0.0

        Parameters

        Create a new instance of this Class. ...

        Create a new instance of this Class.

        Ext.define('My.cool.Class', {
            ...
        });
        
        My.cool.Class.create({
            someConfig: true
        });
        

        All parameters are passed to the constructor of the class.

        Available since: 2.0.0

        Returns

        ( alias, origin )static
        Create aliases for existing prototype methods. ...

        Create aliases for existing prototype methods. Example:

        Ext.define('My.cool.Class', {
            method1: function() { ... },
            method2: function() { ... }
        });
        
        var test = new My.cool.Class();
        
        My.cool.Class.createAlias({
            method3: 'method1',
            method4: 'method2'
        });
        
        test.method3(); // test.method1()
        
        My.cool.Class.createAlias('method5', 'method3');
        
        test.method5(); // test.method3() -> test.method1()
        

        Available since: 2.0.0

        Parameters

        ( parent )privatestatic
        ...

        Available since: 2.0.0

        Parameters

        Get the current class' name in string format. ...

        Get the current class' name in string format.

        Ext.define('My.cool.Class', {
            constructor: function() {
                alert(this.self.getName()); // alerts 'My.cool.Class'
            }
        });
        
        My.cool.Class.getName(); // 'My.cool.Class'
        

        Available since: 2.0.0

        Returns

        ...

        Available since: 2.0.0

        ( name, mixinClass )privatestatic
        Used internally by the mixins pre-processor ...

        Used internally by the mixins pre-processor

        Available since: 2.0.0

        Parameters

        ( fn, scope )chainableprivatestatic
        ...

        Available since: 2.0.0

        Parameters

        ( members ) : Ext.Basechainabledeprecatedstatic
        Override members of this class. ...

        Override members of this class. Overridden methods can be invoked via callParent.

        Ext.define('My.Cat', {
            constructor: function() {
                alert("I'm a cat!");
            }
        });
        
        My.Cat.override({
            constructor: function() {
                alert("I'm going to be a cat!");
        
                var instance = this.callParent(arguments);
        
                alert("Meeeeoooowwww");
        
                return instance;
            }
        });
        
        var kitty = new My.Cat(); // alerts "I'm going to be a cat!"
                                  // alerts "I'm a cat!"
                                  // alerts "Meeeeoooowwww"
        

        As of 4.1, direct use of this method is deprecated. Use Ext.define instead:

        Ext.define('My.CatOverride', {
            override: 'My.Cat',
            constructor: function() {
                alert("I'm going to be a cat!");
        
                var instance = this.callParent(arguments);
        
                alert("Meeeeoooowwww");
        
                return instance;
            }
        });
        

        The above accomplishes the same result but can be managed by the Ext.Loader which can properly order the override and its target class and the build process can determine whether the override is needed based on the required state of the target class (My.Cat).

        Available since: 2.0.0

        This method has been deprecated since 4.1.0

        Please use Ext.define instead

        Parameters

        • members : Object

          The properties to add to this class. This should be specified as an object literal containing one or more properties.

        Returns

        ...

        Available since: 2.0.0