Document Object Model Training and Certification

In order to represent the objects in the documents such as HTML, XHTML and XML, a conventional language-independent cross platform was discovered, which is said to DOM. A tree structure will be organized in such a way that the nodes of every document are represented in it. It is called as DOM tree.

DOM facilitates the modification, deletion, addition and navigation of the structure of the contents of any HTML and XML documents.

1. DOM acts as a robust API (Application programming interface) for the DOM tree
2. The modification of the data structure and the extraction of data is made relatively simple
3. The sections of the documents can be rearranged without altering the contents of it
4. Traversal of the document tree as well as the sub trees of any element on the tree is possible with the search index
5. The complete isolation of document’s structure from its contents can also be made

Basic knowledge about HTML, XML and XHTML

The piece of software that considers the parsed XML or HTML document and therefore makes it available for processing through the DOM interfaces is said to be DOM implementation. It is also called as host implementation.

The implemented document is allowed to perform certain task with the help of the software called DOM application software. The browser that allows to a script is an example of such an application. The application is also called as a client application.

Based on the support of the browser, the DOM can be used in the HTML page in two ways,

• By writing a JavaScript or VBScript
• By the usage of an external application such as plug-in, ActiveX control or Java applet

If consistent results have to be obtained, the pages should not be broken in general. In that case, if you mix JavaScript or VBScript, there is a possibility of getting some odd results.