When users create complex websites with lots of dynamic content, such as Twitter widgets or other components that fetch external data, refreshing the entire page every time a user interacts with the website can quickly become a gruelling experience for visitors.
In such situations, using Asynchronous JavaScript and XML (AJAX) can greatly accelerate user navigation by only displaying subsets of data on visitor-facing pages and dynamically retrieving updates to isolated sections. More specifically, AJAX allows the browser to send requests to a web server, including data parameters, and to insert the data that it receives back in the web page, replacing or augmenting the original content.
This recipe shows how to add AJAX support to the bug tracking system created in Chapter 8, Creating Custom MySQL Database Tables.
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