AJAX - The Complete Reference

PART II

Chapter 5: Developing an Ajax Library 189

Data Format Handling

As discussed in Chapter 4, there are many ways to send data. Request data is almost always

sent in x-www-form-urlencoded format, whether it is in a query string or a message body.

However, it doesn’t have to be. Putting data into XML, JSON, comma-separated plain text,

or any other format you might conceive of, is certainly possible. It is possible to even further

encode data, for example, using a base64 encoding. There are two functions provided in the

data object to address the serialization of data. First, the serializeForm() function can be

called on a form object directly.

AjaxTCR.data.serializeForm(form [,encoding,trigger,evt])

By default, this function will encode the form data in the standard x-www-form-

urlencoded format and return it as a string. However, if you pass it an encoding string

with a value of “application/json”, “text/plain”, or “text/xml”, it will return the

data in the corresponding format. For example, given the form below:

<form action="#" method="GET" name="form1" id="form1">

<input type="text" name="field1" value="Testing" />

<input type="radio" name="field2" value="On" checked="checked" />

<input type="radio" name="field2" value="Off" />

<input type="submit" value="send" />

</form>

the standard serialization returned by serializeForm()would be:

field1=Testing&field2=On

If you serialized the form into JSON you would get:

{"field1" : "Testing" , "field2" : "On" }

As XML, it would look like:

<?xml version="1.0" encoding="UTF-8" ?>

<payload>

<field1>Testing</field1>

<field2>On</field2>

</payload>

Finally, as plain text it would put the data into a comma-separated value form, like so:

field1=Testing,field2=On

When building a payload manually, the, second function, serializeObject(), is quite

useful.

AjaxTCR.data.serializeObject(payload,obj,encoding)

This function is passed a payload string (or blank if nothing is there yet), an object

containing values to add to the payload, and finally, one of the encoding string values used

in the previous example. It will then return a string containing the payload encoded in the

correct format. The library also includes functions to handle encode/decode data as base64,