When you create your data using an XML editor (that you can write), you can not only input the content of your data, but also define the structural relationships that exist inside your data. By allowing you to define your own tags and create the proper structural relationships in your information (with a DTD), you can use any XML parser to check the validity and integrity of the data stored in your XML documents. This makes it very easy to validate the structure and content of your information when you use XML. Without XML, you could also provide this validation feature at the expense of developing the code to this yourself. XML is a great time saver because most of the features that are available in XML are used by most programmers when working on most projects.
By using XML and Java, you can quickly create and use information that is properly structured and valid. By using (or creating) DTDs and storing your information in XML documents, you have a cross-platform and language independent data validation mechanism (for free) in all your projects!
You might use XML to define file formats to store information that is generated and used by your applications. This is another use of the structured nature of XML. The only limitation is that binary information can't be embedded in the body of XML documents. For example, if you wrote a word processor in Java, you might choose to save your word processor documents to an XML (actually your ApplicationML) file. If you use a DTD then your word processor would also get input file format validation as a feature for free. There are many other advantages to using XML and a file storage format for your applications which will be illustrated later in the chapter.
Sunday 04th of December 2016 04:51:23 AM
by Eric A. Meyer
First edition, published May 2000.
(See the catalog page for this book.)
Search the text of Cascading Style Sheets: The Definitive Guide.
Copyright © 2002 O'Reilly & Associates. All rights reserved.
Styles such as these comprise the bulk of any embedded stylesheet -- style rules both simple and complex, short and long. Itwill be only rarely that you have a document where theSTYLE element does not contain any rules.
For those of youconcerned about making your documents accessible to older browsers,there is an important warning to be made. You're probably aware By making the W3C the keeper of the XML standard, it ensures that no one vendor should be able to cause interoperability problems to occur between systems that use the open standard. This should be reassuring to most companies making an investment in this technology, by being vendor neutral, this solution proposes to keep even small companies out of reach of big companies choosing to change the standards on them. For example, if a big company chooses to change the platform at its whim, then most other companies relying on that platform suffer. By keeping all data in XML and using XML in communications protocols, companies can maximize the lifetime of their investment in their products and solutions.
By being language independent, XML bypasses the requirement to have a standard binary encoding or storage format. Language independence also fosters immense interoperability amongst heterogeneous systems. It is also good for future compatilbilty. For example, if in the future a product needs to be changed in order to deal with a new computing paradigm or network protocol, by keeping XML flowing through the system, addition of a new layer to deal with this change is feasible.