XML DOM Parser
XML DOM Parser - Tree Based Parser
- Effective for apps that need random access to doc element. However, building a complete tree for every doc is expensive in terms of memory.
- Event-based parsers avoid this as they do not create data structure for entire document
Learn XML - XML tutorial - Tree based parser - XML examples - XML programs
- The Document Object Model (DOM) is an application programming interface (API) for HTML and XML documents.
- It defines the logical structure of documents and the way a document is accessed and manipulated .
- A DOM implementation will have a method to pass a XML file to a factory object that will return a Document object that represents root element of whole document
Learn XML - XML tutorial - XML DOM Parser - XML examples - XML programs
DOM Parser Tree
Learn XML - XML tutorial - DOM Parser Tree - XML examples - XML programs
Learn XML - XML tutorial - DOM Parse Tree - XML examples - XML programs
Example For DOM Parse Tree
Learn XML - XML tutorial - Tree based parser Example For DOM Parse Tree - XML examples - XML programs
Main features of DOM parser:
- A DOM parser creates an internal structure in memory which is a DOM document object.
- Client applications get the information of the original XML document by invoking methods on this Document object or on other objects it contains.
- DOM parser is tree-based (or DOM obj-based)
- Client application seems to be pulling the data actively, from the data flow point of view
Read AlsoAndroid XML DOM Parser
Example for XML DOM Parser
Learn XML - XML tutorial - XML DOM Parser Example - XML examples - XML programs
DOM Parser – XML Elements Explanation
1. The XML Declaration.
- The XML declaration (which, in fact, is optional):
<?xml version = "1.0"?>tells a parser that the document contains XML content.
- The declaration needs to appear right at the beginning of the documents.
2. Comments in XML Files.
- XML comments look just like HTML comments:
<!-- DOM Parser Example -->
3. Document Type Definition (DTD) :
- Usually, the document type definition is specified in a file that is separate from the XML document.
- However, in this simple example we lump the DTD and XML markup into a single file called “tutorial.xml.“
- The line of code:
- It defines "contacts" as a list containing one or more "contact" items. Each contact have "FirstName" and "LastName" elements.
- And the element have one argument: "gender" which can be set to "M" or "F."
- The "FirstName" and "LastName" arguments contain just plain text.(Parsed Character Data or PCDATA).
- Validating parsers read the DTD before they read your document so that they can identify where every element type ought to come and how each relates to the other, so that applications which need to know this in advance (most editors, search engines, navigators, databases) can set themselves up correctly.
Learn XML - XML tutorial - XML DOM Parser - Sample XML - XML examples - XML programs