WEBDEV Concepts

Part 1: Internet: basic concepts 25 Automatic AJAX The diagram below presents how AJAX can be used automatically in a WEBDEV site: Browser Action 1 Web server 2 Send the request 3 Run the request 4 Send the modified elements only AUTOMATIC update of modified elements 5 For example, a Web page contains the different characteristics of a country (capital, currency, flag, location, etc.). The corresponding information is displayed according to the country selected by the user. Internet user’s action. In our example, the Web user selects the country in the "Select a country" combo box. The request is sent to the server. The request is executed: the characteristics of the selected country are searched for. The result of the request is sent: • without AJAX: the entire page is returned. • with AJAX: the characteristics of the selected country are returned. The characteristics of the country are displayed: • without AJAX: the entire page is redisplayed. • with AJAX: the controls containing the country characteristics are refreshed.