XML Khái niệm cơ bản Mặc dù tên Extensible Markup Language (XML) âm thanh một chút khó hiểu, đừng lo lắng: các định dạng chính nó là thực sự khá dễ hiểu. Tóm lại, XML cung cấp một cách định dạng và cấu trúc thông tin để tiếp nhận các ứng dụng có thể dễ dàng hiểu và sử dụng dữ liệu đó khi nó di chuyển từ nơi này đến nơi khác. Mặc dù bạn có thể không nhận thức được nó, bạn đã có rất nhiều kinh nghiệm cơ cấu và tổ chức thông tin. Hãy xem xét. | XML Basics Although the name Extensible Markup Language XML sounds a bit cryptic don t worry the format itself is actually quite easy to understand. In a nutshell XML provides a way of formatting and structuring information so that receiving applications can easily interpret and use that data when it s moved from place to place. Although you may not realize it you already have plenty of experience structuring and organizing information. Consider the following example. Suppose you want to write a letter to a friend. You structure your thoughts information in a format you know your friend will recognize. You begin by writing words on a piece of paper starting in the upper-left corner and breaking your thoughts into paragraphs sentences and words. You could use images to convey your thoughts or write your words in a circle but that probably would confuse your friend. By writing your letter in a format familiar to your friend you can be confident that your message will be conveyed that is you will have transferred your thoughts data information to the letter s recipient. You can use XML in much the same way as a format for conveying information. For example if you want to send data out of Flash for processing by a Web server you format that data as XML. The server then interprets the XML-formatted data and uses it in the manner intended. Without XML you could send chunks of data to a server but the server probably wouldn t know what to do with the first chunk or the second or even how the first chunk related to the second. XML gives meaning to these disparate bits of data so the server can work with them in an organized and intelligent manner. XML s simple syntax resembles HTML in that it employs tags attributes and values but the similarity ends there. Where HTML uses predefined tags for example body head and html in XML you create your own tags that is you don t pull them from an existing library of tag names. Look at the following simple XML document MyFriends Name
