How to load a webpage repeatedly using grease-monkey and check for an element?

Basically, I want to repeatedly load a URL say http://xyz.co.in and then check for the value of a particular element, just like a testing process and monitor server logs for that flow.

I'm trying to mi开发者_StackOverflow中文版mic a part of production traffic by hitting the same host repeatedly to do further processing. How best can I go about this ?

Flow

Load a webpage -> Monitor Server Logs -> Monitor certain element values on frontend -> Repeat again.

---

Greasemonkey is not the best tool for load testing web pages/servers/apps.

But here is a script that loads a page repeatedly and checks for an element:

// ==UserScript==
// @include         http://xyz.co.in/*
// @require         http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js
// ==/UserScript==

$(document).ready (Greasemonkey_main);

function Greasemonkey_main ()
{
    do
    {
        var TargetNode  = $("#TargetNode"); //-- Look for node with id, "TargetNode".

        if (TargetNode  &&  TargetNode.length)
        {
            //--- Maybe also check contents:
            if (/Node contents to search for/i.test (TargetNode.text () ) )
            {
                alert ("We found what we're looking for");
                break;
            }
        }

        //--- Failsafe check on number of reloads
        var NumReloads  = parseInt (document.location.search.replace (/.*num_gm_reloads=(\d+).*/, "$1") )
        if (NumReloads > 2)
        {
            alert ("After 2 reloads, we still didn't find what we were looking for.");
            break;
        }

        //--- We neither found the stop code nor exhausted our retries, so reload the page.
        if (NumReloads)
            NumReloads++;
        else
            NumReloads  = 1;

        var TargetURL   = window.location.href;
        //--- Strip old URL param, if any.  Note that it will always be at the end.
        TargetURL       = TargetURL.replace ( /(.*?)(?:\?|&)?num_gm_reloads=\d+(.*)/, "$1$2" );
        var ParamSep    = /\?/.test (TargetURL) ? "&" : "?";

        TargetURL       = TargetURL + ParamSep + 'num_gm_reloads=' + NumReloads;

        window.location.href    = TargetURL;    //-- Reload the page.

    } while (0)
}

---

I figured out that Selenium is the best testing tool for such scenarios.

Install Selenium IDE as FF addon and try below commands in series:-

Command   | Target | Value
1) open | _url_ | _blank_ |
2) waitForElementPresent | css=_selector_ or xpath=_selector_ |  _time in ms_ |
3) verifyElementPresent | css=_selector_ or xpath=_selector_ | _blank_ |

You can skip step 2 if the element to be verified is available on page load than on a deferred AJAX call.

If any of above steps fail, then its a failure else success. You can schedule this to run 'n' number of times.