Making an asynchronous request for data
You use the instance of the XMLHttpRequest
class you created to request data. You can request data using any HTTP method; typically you'll use GET or POST. GET is good if you don't need to pass any arguments, or if the arguments are encoded in the service URL; POST is necessary if you're going to post JSON to the server as arguments for your server-side script.
How to do it...
Continuing to enhance our client page script's doAjax
function, here's how to issue an asynchronous request, modifying the previous example:
function doAjax() { var xmlhttp; if (window.XMLHttpRequest) { // code for IE7+, Firefox, Chrome, Opera, Safari xmlhttp=newXMLHttpRequest(); xmlhttp.open("POST","/", true); xmlhttp.send(""); } }
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