Greasemonkey/Tampermonkey script for easy ad re-posting on Kijiji.ca - NOTE: This script is broken as of Nov 2016, it no longer works with Kijiji

kijiji_repost_ad.user.js

// ==UserScript==
// @name         Kijiji Repost Ad
// @namespace    KijijiScripts
// @version      0.4
// @description  Allows for easy ad reposting on Kijiji when managing your ads. A new link named "Repost Ad" will appear in the ad manage widget. Clicking it will redirect the page to the new ad page with most form field pre-filled. You can also specifiy a different category ID in the text field beside the "Repost Ad" button if you wish to repost to a different category than before. Note that this script assumes that you have a Kijiji account and are already logged in and able to manage your existing ads. Also note that when reposting the ad, you will have to manually upload the ad images again, as these are not saved or carried forward automatically (sorry!). Reposting an ad in this way actually creates a whole new ad, so you should delete your old ad as well.
// @match        http://www.kijiji.ca/v-view-details.html?*
// @match        https://www.kijiji.ca/v-view-details.html?*
// @match        http://www.kijiji.ca/p-post-ad.html?*
// @match        https://www.kijiji.ca/p-post-ad.html?*
// @grant        GM_setValue
// @grant        GM_getValue
// @grant        GM_listValues
// @grant        GM_deleteValue
// ==/UserScript==

// Add a "Repost Ad" link to the page if the ad manage widget exists
// (ie. they are viewing their own ad under their control)
function addLink(callback) {
    if (document.querySelector("#ManageAdWidget")) {
        var li_div = document.createElement('li');
        li_div.className = "divider";
        li_div.innerHTML = "|";

        var a = document.createElement('a');
        a.href = "#";
        a.innerHTML = "Repost Ad";
        a.onclick = callback;

        var i = document.createElement('input');
        i.type = "text";
        i.size = 3;
        i.maxLength = 4;
        i.id = "newCat";
        i.placeholder = "NewCat";

        var li = document.createElement('li');
        li.appendChild(a);
        li.appendChild(i);

        document.querySelector("#ManageAdWidget ul.vertical-ul").appendChild(li_div);
        document.querySelector("#ManageAdWidget ul.vertical-ul").appendChild(li);
    }
}

// Extract ad data from page and then redirect to new page
function extractDataAndRedirect() {
    // Get current ad category ID
    var catUrls = document.querySelectorAll(".category-selected[itemprop=url]");
    var adCat = catUrls[catUrls.length - 1].getAttribute('data-id');

    // Check if user specified their own category ID to use
    if (document.querySelector("input#newCat")) {
        var newCat = document.querySelector("input#newCat").value;
        if (newCat && !isNaN(newCat)) {
            adCat = newCat;
        }
    }

    // Extract important ad data
    var adTitle = document.querySelector("[itemprop=name]").innerText;
    var adDesc = document.querySelector("#itemdetails [itemprop=description]").innerHTML.replace(/^\s*/, '').replace(/<br(\s*\/|)>/g, '');
    var adPrice = document.querySelector("#itemdetails [itemprop=price]").innerText.replace(/\$/, '');
    var adAddress = document.querySelector("#itemdetails .ad-attributes tr:nth-child(3) > td").innerHTML.split("<br>")[0];
    var adPostal = /[A-Z][0-9][A-Z]\s*[0-9][A-Z][0-9]/g.exec(adAddress);
    adPostal = (null === adPostal) ? "" : adPostal[0];

    // Store data before loading new page
    GM_setValue("adTitle", adTitle);
    GM_setValue("adDesc", adDesc);
    GM_setValue("adPrice", adPrice);
    GM_setValue("adAddress", adAddress);
    GM_setValue("adPostal", adPostal);

    // Set flag for after page is reloaded
    GM_setValue("repostAd", "true");

    // Reload page to new location to post a new ad
    window.location.href = window.location.protocol + "//" + window.location.host + "/p-post-ad.html?categoryId=" + adCat;

    // A new page has now been requested, all previous javascript is lost, except for data stored using GM_setValue()
}

(function() {
    addLink(extractDataAndRedirect);

    if (window.location.href.indexOf("/p-post-ad.html?") != -1 && GM_getValue("repostAd") == "true") {
        // User has clicked on the repost ad link and we are coming from a previous repost ad page
        // We should now be on a "/p-post-ad.html?" page

        var h = document.createElement('h3');
        h.appendChild(document.createTextNode("Don't forget to re-upload ad pictures!"));
        var d = document.createElement('div');
        d.appendChild(h);
        var mainForm = document.querySelector("#PostAdMainForm");
        mainForm.insertBefore(d, mainForm.childNodes[0]);

        // Retrieve data
        var adTitle = GM_getValue("adTitle");
        var adDesc = GM_getValue("adDesc");
        var adPrice = GM_getValue("adPrice");
        var adAddress = GM_getValue("adAddress");
        var adPostal = GM_getValue("adPostal");

        // Fill in copied ad data
        document.querySelector("#priceAmount").value = adPrice;
        document.querySelector("#forsaleby_s[value=ownr]").checked = true;
        document.querySelector("#postad-title").value = adTitle;
        document.querySelector("#pstad-descrptn").value = adDesc;
        document.querySelector("#pstad-map-address").value = adAddress;
        document.querySelector("#PostalCode").value = adPostal;

        // Remove all previous saved data
        var keys = GM_listValues();
        for (var i = 0, key = null; key = keys[i]; i++) {
            GM_deleteValue(key);
        }
    }
})();

@sallyyollande Try using this much simpler script instead. It's what I use now and it should work for you too.

kijiji changed their url when you post an ad, so instead of www.kijiji.ca/p-post-ad.html? its now www.kijiji.ca/p-admarkt-post-ad.html?
Itried to fix the code by my own by replacing it but it didnt work.

@CalebDanechi This script broke a year ago when Kijiji updated their site and I am no longer maintaining this particular script.

If you are comfortable with running a Python script (Python is available on both Linux and windows), then I would suggest using the Kijiji-Repost-Headless project.

This is what I use now to repost my Kijiji ads, and it is being actively developed. Unfortunately it is not quite as simple to use as clicking a button in your browser, but it does work. Perhaps someday it could be developed into a real browser extension to make it easier to use.