Thoughts about JSON

JSON is a really interesting new trend in webservices it stands for JavaScript Object Notation. For those of you who use AJAX you should know that the key call XMLHttpRequest will only work within the same domain and so you have to have an interface hosted on your server to call the XML output (if it is on a 3rd party server) and re-render it for your AJAX (or DHTML if you are old fashioned like me) interface.

JSON is different since JSON returns a series of javascript arrays and elements in the same way as you would from a javascript include. This means a programmer doesn't need to know the complicated XML Dom model processing in Javascript to do dynamic work but instead the programmer only needs to know how to handle variables.

JSON also gives bandwidth savings in the majority of cases since the JSON code sent contains fewer characters (in general) than XML in specifying elements and variables.

So with this double upside a lot of companies are starting to offer JSON for example the excellent yahoo geocoding is now offering JSON as described in this O'Reilly XML.com post.

I feel however the strongest JSON offering (if you understand XSL) is the eBay REST XSLT service. This service allows you to upload a stylesheet of your design to the eBay servers and have the response to any REST GetSearchResults call converted instantly into your favourite flavour (which could be JSON) using a stylesheet you design. This doesn't tend to notably slow down the REST call and saves time and coding on the developer side of the equation. I am really excited to see how JSON expands and am throwing together a few tests myself but wanted to shout about what a great opportunity it is and how everyone should be using it :)