GM.xmlHttpRequest: Received no URL Error

Question

This script is run on a Amazon deals page:

// ==UserScript==
// @name     Unnamed Script 138015
// @version  1
//@include     http://www.amazon.in/*
// @grant       GM_setValue   
// @grant       GM_getValue  
// @grant       GM.xmlHttpRequest
// @grant       GM_xmlhttpRequest
// @grant       GM.addStyle
// @grant       GM.getResourceText
// @grant       GM.getValue
// @grant       GM.setValue
// @grant       GM.info
// @require     http://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js
// ==/UserScript==
var x=document.getElementById("dealTitle"); //fetches the URL
alert(x);
GM.xmlHttpRequest ( {
    method: "GET",
    url: x,
    onload: function (response) {
        var parser  = new DOMParser ();
        var doc         = parser.parseFromString (response.responseText, "text/html");
        var price  = document.getElementsByClassName("a-size-medium a-color-price")[0];
        $("body").prepend ('<h1>' + price + '</h1>');
    },
    onerror: function (e) {
        console.error ('**** error ', e);
    },
    onabort: function (e) {
        console.error ('**** abort ', e);
    },
    ontimeout: function (e) {
        console.error ('**** timeout ', e);
    }
} );

It shows the following error in the console log.

Error: GM.xmlHttpRequest: Received no URL.
Stack trace:
GM_xmlHttpRequest@user-script:null/Unnamed%20Script%20138015:572:21
userScript@user-script:null/Unnamed%20Script%20138015:504:1
scopeWrapper@user-script:null/Unnamed%20Script%20138015:632:9
@user-script:null/Unnamed%20Script%20138015:487:17

Is there any way to use the link fetched from the page to be sent in the HttpRequest?

Brock Adams · Accepted Answer · 2018-04-28T18:19:18.937

1

getElementById does not return a URL; it returns a node.
The dealTitle element is added via AJAX; it does not exist when your script first runs. So, you need to use AJAX-aware techniques in your script.

Something like this should work:

// ==UserScript==
// @name        Unnamed Script 138015
// @version     2
// @match       *://www.amazon.in/*
// @grant       GM.xmlHttpRequest
// @grant       GM_xmlhttpRequest
// @require     http://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js
// @require     https://gist.github.com/raw/2625891/waitForKeyElements.js
// ==/UserScript==

waitForKeyElements ("#dealTitle", fetchDealPage);

function fetchDealPage (jNode) {
    var dURL = jNode.attr ("href");
    console.log ("dURL: ", dURL);

    GM.xmlHttpRequest ( {
        method: "GET",
        url: dURL,
    //etc...
}

Although you may have to install Tampermonkey, and change the line to GM_xmlhttpRequest ( {.
Not sure GM4 supports using GM.xmlHttpRequest that way.

edited Apr 28 '18 at 18:19

answered Apr 28 '18 at 18:12

Brock Adams

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Hello Brock, Thanks for the help,it worked. I have another question, as you may have noticed each deal has the ID dealTitle so can you tell a way to fetch the URL of the next deal after I am done with the first one. Thanks again. :) – Chirag Jagga Apr 29 '18 at 19:26
That's a fair bit more complicated as you need to tweak the selector and also chain or queue the XML calls. Both of those topics are covered in other questions here. But, if you can't figure out how to get it to work open an new question. – Brock Adams Apr 29 '18 at 20:03
Ohk, will give it a few tries or post a new question. – Chirag Jagga Apr 29 '18 at 20:08

GM.xmlHttpRequest: Received no URL Error

1 Answers1