Network request initiators

When you type a url such as myprogrammingnotes.com in Firefox’s address bar and type the enter key, the browser will send many http requests to the network. These requests are not only for getting/posting the url myprogrammingnotes.com you input in the address bar but also for other network resources the page myprogrammingnotes.com needs such as css files/javascript files/image files, etc.

In firefox F12 console, click the Network tab, you can see all the http requests some of which are GET requests, others are POST requests.

The columns Status,Method,Domain,File,Type are clear, but what is the Initiator column? The possible values of Initiator are: document, script, img, etc, which look like element names, but they are not tag names in the html file actually.

The first http request after you input the url and type the enter key has a tabbrower.js:xxx (document) initiator.

The http request caused by refreshing the current page, clicking a link on the page, or clicking a submitting button on a form has a document initiator.

The http request for a js script, i.e., caused by the <script src=”xxx.js”></script> tag has a script initiator.

The http request for a css file, i.e., caused by the <link href=”xxx.cs” rel=”stylesheet”> tag has a stylesheet initiator.

The http request for an image file, i.e. caused by <img src=”xxx.png” /> or <button type=”image” src=”xxx.png”></button> has an img initiator.

The http request for a xhr request will list the js file that sends the XMLHttpRequest as the initiator. And the location after the file name is the line number of the statement that calls the XMLHttpRequest.send function. Note that if you are using jQuery, the initiator is not the file that calls $.ajax or $.post function, but the file that calls XMLHttpRequest.send, and usually this file is the jQuery script(jquery-x.x.x.js).

Did you like this?
Tip admin with Cryptocurrency