AJAX Thoughts, Suggestions and Examples Part III
Special Characters: Since XML is the format which our data is transmitted, some key
characters will need to be escaped. The ones that I am aware of are "<", ">" and "&".
There may be more, however, from my testing all other characters on a United States standard
keyboard seem to be fine. If I am incorrect, please let me know.
our xml values, but then on the server side, we need to ensure we are unescaping all of the values
which are passed. I personally don't like this way as well, and we would still need to unescape
these characters when we receive XML from the server.
are shown below integrated with the other functions described next, getText() and getNodeText().
The getText() function has two parameters, the XML to be parsed and the node of which to retrieve
data. The getNodeText() function has a single parameter, the XML node which data should be retrieved.
To use them, simply call the appropriate function from the callback procedure. These functions
xmlDecode() function never need be called from anywhere except the getText() and getNodeText()
functions as shown below. The xmlEncode() function will need to be called whenever the XML data
to be sent to the server is constructed.
Browser Compatibility: If you have read any basic articles on AJAX coding, you will
notice that the most pointed out browser incompatibility is with the HTTP Request Object and many
examples are given on making this cross browser compatible, but I want to talk about the more in depth
issues I have seen. Once again I've seen so-called "professional" programmers use
AJAX, but their code only works for a single browser (yes, the evil, but most widely used one).
Good old Microsoft uses some proprietary XML object attributes for parsing xml such as the xml and text
attributes. These work quite well
if using IE of course, but do not work with any other browsers. The above code has been tested
and does work on IE6+, Firefox 0.8+, Netscape 7.0+ and Safari for Mac. It has not been tested
thoroughly, but should also work on Opera 6.0+. Other browser testing has not been attempted,
it may or may not work.
This completes my ramblings on AJAX for now. If I come up with anything else in the
future, I may post it. Once again, I will disclaim, improvements can probably be applied to
my code examples, but they have been tested and used in real world environments with great