ExtJS preguntas y respuestas de entrevista

Pregunta 6. Extjs Ajax implementation?

A typical Ext JS Ajax implementation: an HTML text field and button element that posts data in the text field to a Web server when the button is clicked.

Pregunta 7. Do you have any advice for developers using ExtJS for the first time?

ExtJS can be used by Web Application developers who are familiar with HTML but may have little or no experience with JavaScript application development. If you are starting to build a new web application, or you are revamping an existing application, then take your time to understand the basics of the library including.

Pregunta 8. How to access DOM element using EXTJS?

The Element API is fundamental to the entire Ext library.
Using traditional Javascript, selecting a DOM node by ID is done like this:
var myDiv = document.getElementById('myDiv');
Using Extjs:
Ext.onReady(function() {
var myDiv = Ext.get('myDiv');
});

Pregunta 9. What is the purpose of Element Object in ExtJS?

• Element wraps most of the DOM methods and properties that you'll need, providing a convenient, unified, cross-browser DOM interface (and you can still get direct access to the underlying DOM node when you need it via Element.dom)
• The Element.get() method provides internal caching, so multiple calls to retrieve the same object are incredibly fast
• The most common actions performed on DOM nodes are built into direct, cross-browser Element methods (add/remove CSS classes, add/remove event handlers, positioning, sizing, animation, drag/drop, etc.)

Pregunta 10. What is syntax for Extjs Button click event?

Ext.onReady(function() {
Ext.get('myButton').on('click', function(){
alert("You clicked the button");
});
});