The DomHelper class provides a layer of abstraction from DOM and transparently supports creating +elements via DOM or using HTML fragments. It also has the ability to create HTML fragment templates +from your DOM building code.
+ + + + +DomHelper element specification object
+ + +A specification object is used when creating elements. Attributes of this object +are assumed to be element attributes, except for 4 special attributes: +
Insertion methods
+ + +Commonly used insertion methods: +
Example
+ + +This is an example, where an unordered list with 3 children items is appended to an existing
+element with id 'my-div':
+
+
var dh = Ext.core.DomHelper; // create shorthand alias
+// specification object
+var spec = {
+ id: 'my-ul',
+ tag: 'ul',
+ cls: 'my-list',
+ // append children after creating
+ children: [ // may also specify 'cn' instead of 'children'
+ {tag: 'li', id: 'item0', html: 'List Item 0'},
+ {tag: 'li', id: 'item1', html: 'List Item 1'},
+ {tag: 'li', id: 'item2', html: 'List Item 2'}
+ ]
+};
+var list = dh.append(
+ 'my-div', // the context element 'my-div' can either be the id or the actual node
+ spec // the specification object
+);
+ Element creation specification parameters in this class may also be passed as an Array of +specification objects. This can be used to insert multiple sibling nodes into an existing +container very efficiently. For example, to add more list items to the example above: +
dh.append('my-ul', [
+ {tag: 'li', id: 'item3', html: 'List Item 3'},
+ {tag: 'li', id: 'item4', html: 'List Item 4'}
+]);
+Templating
+ + +The real power is in the built-in templating. Instead of creating or appending any elements, +createTemplate returns a Template object which can be used over and over to +insert new elements. Revisiting the example above, we could utilize templating this time: +
// create the node
+var list = dh.append('my-div', {tag: 'ul', cls: 'my-list'});
+// get template
+var tpl = dh.createTemplate({tag: 'li', id: 'item{0}', html: 'List Item {0}'});
+
+for(var i = 0; i < 5, i++){
+ tpl.append(list, [i]); // use template to append to the actual node
+}
+An example using a template: +
var html = '{2}';
+
+var tpl = new Ext.core.DomHelper.createTemplate(html);
+tpl.append('blog-roll', ['link1', 'http://www.edspencer.net/', "Ed's Site"]);
+tpl.append('blog-roll', ['link2', 'http://www.dustindiaz.com/', "Dustin's Site"]);
+The same example using named parameters: +
var html = '{text}';
+
+var tpl = new Ext.core.DomHelper.createTemplate(html);
+tpl.append('blog-roll', {
+ id: 'link1',
+ url: 'http://www.edspencer.net/',
+ text: "Ed's Site"
+});
+tpl.append('blog-roll', {
+ id: 'link2',
+ url: 'http://www.dustindiaz.com/',
+ text: "Dustin's Site"
+});
+Compiling Templates
+Templates are applied using regular expressions. The performance is great, but if +you are adding a bunch of DOM elements using the same template, you can increase +performance even further by "compiling" the template. +The way "compile()" works is the template is parsed and +broken up at the different variable points and a dynamic function is created and eval'ed. +The generated function performs string concatenation of these parts and the passed +variables instead of using regular expressions. +
var html = '{text}';
+
+var tpl = new Ext.core.DomHelper.createTemplate(html);
+tpl.compile();
+
+//... use template like normal
+Performance Boost
+DomHelper will transparently create HTML fragments when it can. Using HTML fragments instead +of DOM can significantly boost performance.
+Element creation specification parameters may also be strings. If useDom is false, +then the string is used as innerHTML. If useDom is true, a string specification +results in the creation of a text node. Usage:
+Ext.core.DomHelper.useDom = true; // force it to use DOM; reduces performance
+Creates new DOM element(s) without inserting them to the document.
+Creates new DOM element(s) without inserting them to the document.
+Creates new DOM element(s) and appends them to el.
+Creates new DOM element(s) and appends them to el.
+The context element
+The DOM object spec (and children) or raw HTML blob
+(optional) true to return a Ext.core.Element
+The new node
+Applies a style specification to an element.
+Applies a style specification to an element.
+The element to apply styles to
+A style specification string e.g. 'width:100px', or object in the form {width:'100px'}, or +a function which returns such a specification.
+Creates a new Ext.Template from the DOM object spec.
+Creates a new Ext.Template from the DOM object spec.
+The DOM object spec (and children)
+The new template
+Creates new DOM element(s) and inserts them after el.
+Creates new DOM element(s) and inserts them after el.
+The context element
+The DOM object spec (and children)
+(optional) true to return a Ext.core.Element
+The new node
+Creates new DOM element(s) and inserts them before el.
+Creates new DOM element(s) and inserts them before el.
+The context element
+The DOM object spec (and children) or raw HTML blob
+(optional) true to return a Ext.core.Element
+The new node
+Creates new DOM element(s) and inserts them as the first child of el.
+Creates new DOM element(s) and inserts them as the first child of el.
+The context element
+The DOM object spec (and children) or raw HTML blob
+(optional) true to return a Ext.core.Element
+The new node
+Inserts an HTML fragment into the DOM.
+Inserts an HTML fragment into the DOM.
+Where to insert the html in relation to el - beforeBegin, afterBegin, beforeEnd, afterEnd.
+The context element
+The HTML fragment
+The new node
+Returns the markup for the passed Element(s) config.
+Returns the markup for the passed Element(s) config.
+The DOM object spec (and children)
+Creates new DOM element(s) and overwrites the contents of el with them.
+Creates new DOM element(s) and overwrites the contents of el with them.
+The context element
+The DOM object spec (and children) or raw HTML blob
+(optional) true to return a Ext.core.Element
+The new node
+