Quizz: Working with the DOM
May 20, 2009 | English | By Hazel | No Comments | Leer en EspańolThe time has come to evaluate the knowledge we acquired about the DOM and how we can manipulate it in a very simple way by using the Ext JS Framework. Good luck!
Author: Hazel
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What is the correctly way to check if the DOM is ready to be used?
- Ext.addEvent(document,’ready’,functionToExcute);
- Ext.on(‘ready’,functionToExecute, scope );
- Ext.onReady(functionToExecute, scope );
- Ext.ready(functionToExecute, scope );
How can we get elements from the DOM?
- Ext.getElement(‘id’);
- Ext.get(‘id’);
- Ext.getElementById(‘id’);
- Ext.getCpm(‘id’);
What is the method Ext.fly?
- Is the same as the method Ext.get, that’s why it shouldn’t even exists.
- Allows you to select a DOM element using CSS and XPath selectors.
- With this method we’re only going to have the DOM node and not an object Ext.Element.
- Saves memory and makes our application more efficient since it reuses memory by not creating new instances of the object Ext.Element.
The purpose of the Ext.DomHelper component is:
- Helps the DOM to be generated faster.
- Displays the HTML in a graphical form.
- Helps us to remove the nodes we don’t use anymore.
- Makes it easy to handle the DOM to insert and create elements with JavaScript.
When executing the following code, what’s the value of the variable “items”?
var items = Ext.DomQuery.select('div[id=menu] > ul li a');
- All the anchors that are inside of a div and have the id of “menu” and contains a node type “ul” that has a “li” element.
- A list of nodes “li”.
- The selector is incorrect.
When executing the following code, what’s the value of the variable “old”?
var old = Ext.DomQuery.selectNode('#menu ul li a[class*=item-selected]');
- An anchor of where the mouse is.
- An array of links that are found in the menu, encapsulated in a “li” list.
- The link that contains a class called “item-selected” and it’s inside of the element “menu” encapsulated in a “li” list.
- The variable doesn’t have a value because the expression is wrong.
