DOCUMENT OBJECT MODEL PDF
|Language:||English, Spanish, Dutch|
|Genre:||Health & Fitness|
|ePub File Size:||26.84 MB|
|PDF File Size:||10.42 MB|
|Distribution:||Free* [*Regsitration Required]|
It provides a structural representation of an XML document, enabling users to access and modify its contents.
It provides a set of enhancements that make several common operations much simpler to perform, and make possible certain things you simply could not do before. The first part of this article covers operations on nodes; the second part focuses on operations on documents and type information, and explains how to use DOM in Xerces. We show you how DOM Level 3 Core can make your life easier when working with nodes, whether it is renaming a node, moving nodes from one document to another, or comparing them.
We also show you how DOM Level 3 Core lets you access and modify the text content of your document in a more natural way than having to deal with Text nodes that tend to get in the way. DOM Level 3 can do a lot of work for you. First, it allows you to store a reference to your application object on a Node.
The object is associated with a key that you can use to retrieve that object later.
The Window object
You can have as many objects on a Node as you want; all you need to do is use different keys. Second, you can register a handler that is called when anything that could affect your own structure occurs. These are events such as a node being cloned, imported to another document, deleted, or renamed. With this, you can now much more easily manage the data you associate with your DOM.
You no longer have to worry about maintaining the two in parallel. You simply need to implement the appropriate handler and let it be called whenever you modify your DOM tree.
And you can do this with the flexibility of using a global handler or a different one on each node as you see fit.
In any case, when something happens to a node on which you have attached some data, the handler you registered is called and provides you with all the information you need to update your own structure accordingly July 15, This article uses examples to show you how to save XML data in this way -- how to serialize XML data into different types of output streams with different encodings.
Users can stream the output data into a string, an internal buffer, the standard output, or a file In practical terms, the DOM makes it easier to create Web pages with features that are more animated and functional.
With scripts, authors can make Web pages process forms, launch pop-up menus and windows, and execute style changes on the fly. Without the DOM, authors would have to code separately for each scripting language to interact with each different browser.
The DOM is meant to create a 'write once, run everywhere' standard for Web page scripting. However, W3C staff urged developers to use scripts sparingly, criticizing the development technique as less efficient and accessible than alternative W3C-recommended methods of creating dynamic Web pages. The group, in concert with the United States National Institute of Standards and Technology NIST , also updated its free test suite that developers can use to check their adherence to the standard.
Analysis of many projects yields advice and suggested code. December The DOM offers a flexible and powerful means for creating, processing, and manipulating XML documents, but it can be awkward to use and can lead to brittle and buggy code. It defines a standard set of interfaces for representing documents, as well as a standard set of methods for accessing and manipulating them. Unfortunately, several aspects of the specification, such as its language-neutral interface and its use of the "everything-is-a-node" abstraction, make it difficult to use and prone to generating brittle code.
This was particularly evident in a recent review of several large DOM projects that were created by a variety of developers over the past year. The common problems, and their remedies, are discussed below The language-neutral design of the DOM has given it very wide applicability and brought about implementations on a large number of systems and platforms.
This has come at the expense of making DOM more difficult and less intuitive than APIs designed specifically for each language. DOM forms a very effective base on which easy-to-use systems can be built by following a few simple principles.
Future versions of DOM are being designed with the combined wisdom and experience of a large group of users, and will likely present solutions to some of the problems discussed here. Projects such as JDOM are adapting the API for a more natural Java feel, and techniques such as those described in this article can help make XML manipulation easier, less verbose, and less prone to bugs.
Leveraging these projects and following these usage patterns allows DOM to be an excellent platform for XML-based projects. From IBM developerWorks. August This article examines the DOM Traversal module in depth, showing how to find out if this module is supported in your parser and how to use it to walk either sets of selected nodes or the entire DOM tree.
Eight sample code listings demonstrate the techniques. This object model represents an XML document in your application, and it provides a simple way to read XML data and to write and change data within an existing document see Resources for more background if you're new to the DOM.
If you're on your way to being an XML guru, you've probably learned the DOM backward and forward, and you know how to use almost every method that it offers. However, there is a lot more to the DOM than most developers realize.
Most developers actually have experience with the core of the DOM. That means the specification that outlines what represents the DOM, how it should operate, what methods it makes available, and so forth.
Even experienced developers do not have much knowledge or understanding of the variety of extra DOM modules that are available.
These modules allow developers to work more efficiently with trees, deal with ranges of nodes at the same time, operate upon HTML or CSS pages, and more all with an ease not possible using just the core DOM specification. Over the next few months, I plan articles to detail several of the modules, including the HTML module -- the Range module -- and in this article, the Traversal module.
Moving through DOM trees in a filtered way makes it easy to look for elements, attributes, text, and other DOM structures. You should also be able to write more efficient, better organized code using the DOM Traversal module.
Learning to use DOM Traversal, you'll see how quickly it can move throughout a DOM tree, build custom object filters to easily find the data you want, and walk a DOM tree more easily than ever. I'll also introduce you to a utility that lets you check your parser of choice for specific DOM module support, and along the way I'll manage to throw a lot of other sample code in as well A preview of DOM Level 3.
What’s the Document Object Model, and why you should know how to use it.
Careful memory leaks in brwoser might get you however. January In the code below I use the same html structure used in the previous code example except this time I use replaceChild to update the nodes instead of removing them.
Client-Side vs. However, this time it is only allowed to inspect the layout and cannot modify the DOM. I will discus this in more detail in the Element node chapter. Second, you can register a handler that is called when anything that could affect your own structure occurs.
- MODELS FOR WRITERS 10TH EDITION PDF
- OBJECT THINKING DAVID WEST PDF
- MECHANICAL OBJECTIVE EBOOK
- AGENT-BASED AND INDIVIDUAL-BASED MODELING A PRACTICAL INTRODUCTION PDF
- REGRESSION MODELING STRATEGIES PDF
- THE DECISION BOOK FIFTY MODELS FOR STRATEGIC THINKING
- LEKHPAL MODEL TEST PAPER PDF
- RD SHARMA OBJECTIVE MATHEMATICS PDF
- COMO FAZER DE UM DOCUMENTO EM PDF
- O DUQUE E EU JULIA QUINN PDF
- SQL TUTORIAL W3SCHOOLS PDF
- CLINICAL NEUROLOGY AMINOFF PDF