Ajax in Firefox Plugin

Question

Is there a way to send an Ajax request to a server from a Firefox plugin? If so, how? If not, how do we communicate with the client server in the Firefox plugin?

I want to get some json data from the server and manipulate the dom object according to client input.

I'm new to plugin programming

Regards, Jishna

Answer 1

You can send ajax requests from the Firefox extension using xmlHTTPRequest , as in any other web application.

Answer 2

In a text document, you must add permissions to access cross-domain content, the URLs you want:

"permissions": {
    "cross-domain-content": ["http://example.org/", "http://example.com/"]
}

.

Answer 3

Here is a simple snippet that makes an XHR request without cookies (because of the flag Ci.nsIRequest.LOAD_ANONYMOUSit can be deleted for sending using cookies) ( MDN :: Info on flags ] Copy this first block of code, and then see examples of use below.

var {Cu: utils, Cc: classes, Ci: instances} = Components;
Cu.import('resource://gre/modules/Services.jsm');
function xhrGetPost(url, post_data, cb) {
    let xhr = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"].createInstance(Ci.nsIXMLHttpRequest);

    let handler = ev => {
        evf(m => xhr.removeEventListener(m, handler, !1));
        switch (ev.type) {
            case 'load':
                if (xhr.status == 200) {
                    cb(xhr.response);
                    break;
                }
            default:
                Services.prompt.alert(null, 'XHR Error', 'Error Fetching Package: ' + xhr.statusText + ' [' + ev.type + ':' + xhr.status + ']');
                break;
        }
    };

    let evf = f => ['load', 'error', 'abort'].forEach(f);
    evf(m => xhr.addEventListener(m, handler, false));

    xhr.mozBackgroundRequest = true;
    if (post_data == undefined) {
        post_data = null;
    }
    if (post_data) {
          xhr.open('POST', url, true);
    } else {
        xhr.open('GET', url, true);
    }
    xhr.channel.loadFlags |= Ci.nsIRequest.LOAD_ANONYMOUS | Ci.nsIRequest.LOAD_BYPASS_CACHE | Ci.nsIRequest.INHIBIT_PERSISTENT_CACHING;
    //xhr.responseType = "arraybuffer"; //dont set it, so it returns string, you dont want arraybuffer. you only want this if your url is to a zip file or some file you want to download and make a nsIArrayBufferInputStream out of it or something
    xhr.send(post_data);
}

Usage example for POST:

var href = 'http://www.bing.com/'
xhrGetPost(href, 'post_data1=blah&post_data2=blah_blah', data => {
    Services.prompt.alert(null, 'XHR Success', data);
});

Usage example for GET:

var href = 'http://www.bing.com/'
xhrGetPost(href, null, data => {
    Services.prompt.alert(null, 'XHR Success', data);
});