ExtJs event mechanism basic code model and process analysis_extjs

The purpose of code implementation: trigger an event when using a certain attribute of a custom class.
The effect of this program: Click the input button, and a script prompt input box will pop up for the user to enter his name. After confirmation, the name entered by the user will be displayed in the name text box of the page, and the page title will become consistent with the name. , and then a script prompt input box will pop up for the user to enter their gender. After the input is completed and OK is clicked, the gender entered by the user will be displayed in the gender text box on the page.

Copy code The code is as follows:

.org/1999/xhtml">


< link rel="stylesheet" type="text/css" href="ext-all.css" />







Name:

Gender:

Copy code The code is as follows:

Ext.namespace("Ext.dojochina");

//Define a class
Ext.dojochina.Person = function(){
//Add event methods to the class
this.addEvents(
"namechange",
"sexchange"
) ;
} ;

//The Person class inherits from Observable
Ext.extend(Ext.dojochina.Person, Ext.util.Observable, {
name:"",
sex:"",
//Attributes
setName:function(_name){

if(this.name != _name){
// Set a new name for the object
this.name = _name ;
//Initiate an event named namechange, followed by the three parameters passed
this.fireEvent("namechange" , this , this. name , _name) ;


}
},
setSex:function(_sex){

if(this.sex != _sex){
this .sex = _sex ;
//Same as above
this.fireEvent("sexchange" , this , this.sex , _sex) ;

}
},
getName:function( ){
return this.name;
}
}) ;

It can be concluded from the above representative code that if a class wants to bind an event, The most basic and common programming process is as follows:


1. When declaring an object, you need to use the following method to declare the event name to be bound;

Copy code The code is as follows:

this.addEvents(
"namechange",
"sexchange "

2. Inherit the custom class from Ext.util.Observable, and implement the attribute that wants to trigger the event name defined in 1 (or in other words is the method);

Copy code The code is as follows:

setName:function(_name){
if(this.name != _name){
//Set a new name for the object
this.name = _name;
/ / Fire an event named namechange, followed by the three passed parameters
this.fireEvent("namechange" , this , this.name , _name) ;
}
},

Note here: this.fireEvent("namechange", this, this.name, _name); is the most intuitive entrance to trigger events. When the method is executed here, an event named namechange will be fired.

3 Implement the processing logic after the event is triggered.

Copy code The code is as follows:

_person.on("namechange " , function(_person , _old , _new){
txt_name.dom.value = _new ;
alert(_person.getName());
}) ;

here on is a built-in method of Extjs. When an event named namechange is triggered, the function function will be executed. The parameters of the function here are determined by this.fireEvent("namechange", this, this.name, in JS. _name) ; The next three parameters are passed.
Okay, the simplest and classic event triggering mechanism program code design process of EXTJS is like this, and the code execution process is a reverse process. Welcome to communicate with the majority of EXTJS enthusiasts, my QQ: 1213145055.

The author of this article: Wang Chongan, blog address: http://www.cnblogs.com/wangchongan