[PHP] XML
Web Development
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http://w3schools.com/xml/default.asp
http://www.php.net/manual/en/ref.xml.php
XML is not a replacement for HTML. It's a language specification to describe the information in HTML documents, whereas HTMLonly presents information. It's used in conjunction with Java to create small applications in mobile phones, and also to organize and transmit information (AJAX). The XML DOM is very similar to the HTML DOM in Javascript, but its structure is not based on how a web page should be formed, only information. Here is an example of a document:
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<?xml version="1.0" encoding="ISO-5589-1"?> <document> <tag /> </document>
Select what you want to copy and in doing so you will keep the formatting when pasting it.
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It looks like a HTML document, but it has an odd DOC-TYPE and unrecognizable tags. Because of this, browsers cannot read it on its own. You have to design your own back-end in order to parse the XML. There are a couple of rules to designing a XML document, which you may be familiar with if you ever worked with XHTML.
All elements must be within a root element.
The root element would be the instance of the document, because it will be the first node you access. It can also be referred to as an entry-point, etc., but it can be anything you want.
All tags must be enclosed.
Just like XHTML, XML isn't very forgiving when it comes to tags. If you don't close nested tags or a single, empty tag, it will throw an error. That means if you've worked with just HTML thus far, you better get used to it.
Now that you know how to structure an XML document, you may be wondering about how it is read by the browser. There are several language specifications for XML that directly support it, but you can also use server-side languages like PHP, ASP, and Javascript's HTML DOM (client-side). To style the document, you can use CSS or XLST. Using CSS, you can just import the file.
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<?xml-stylesheet type="text/css" href="style.css"?>
Select what you want to copy and in doing so you will keep the formatting when pasting it.
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Remind you of anything? XLST, however, works with XPath. XPath uses regular expressions to search and match nodes and then styled using XLST functions. Since I have no actual experience with them, I won't explain them here. As for parsing the documents, you can read a short article I wrote about using the built-in DOM module here: http://www.coderprofile.com/coding-article/92/php-xml-html-dom-basics.
PHP.net also explains the built-in XML parser module and SimpleXML library. This all being in PHP. However, you may be wondering how you can use Javascript. You may not realize it, but you use the HTML DOM all the time when you are writing scripts (ie, document.write, document.getElementById(element)). I won't explain the OOP mechanics of the language here, you can look up C++ or Java if you want to know more about it. But these objects refer to the elements of the document in the DOM.
Using AJAX, you can load an XML document and then parse it.
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Comments
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Sure, this is alright. But you are missing the whole point of XML really, as a
in-between for transfers. XML is used as the middle-man.
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I'm sorry, but you comment on how my article was rehashing, when clearly this is
the same.
Again, W3Shools has a far more understandable documentation on the basics of what
an XML document is, how to structure it, what the rules are and even the use of both
the Javascript and PHP DOMs.
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