AddEventListener not fired when used in chrome extension
I am trying to make a chrome extension that will search various cache databases for a given page. However, it doesn't work as I expect.
<!DOCTYPE HTML>
<html>
<head>
<script type="text/javascript">
var x;
var img = document.getElementsByTagName("img");
for(x in img) {
img[x].addEventListener('click',openPage, false);
}
function openPage(event) {
alert("clicked");
var e = event.target;
switch(e.alt) {
case "WayBack Machine":
chrome.tabs.update(tab.id, { url: "http://wayback.archive.org/web/*/" + tab.url });
break;
case "Google Cache":
if(tab.url.substring(0, 5) == "http:")
chrome.tabs.update(tab.id, { url: 'http://webcache.googleusercontent.com/search?q=cache:' + tab.url.substr(7) });
else if(tab.url.substring(0,6) == "https:")
chrome.tabs.update(tab.id, { url: 'http://webcache.googleusercontent.com/search?q=cache:' + tab.url.substr(8) });
break;
case "Yahoo Cache":
// Need the yahoo cache url
break;
case "Bing Cache":
chrome.tabs.update(tab.id, { url: "http://cc.bingj.com/cache.aspx?q=" + tab.url + "&d=4572216504747453&mkt=en-US&setlang=en-US&w=802790a9,218b61b8" });
break;
case "Gigablast":
chrome.tabs.update(tab.id, { url: "http://www.gigablast.com/get?q=" + tab.url + "&c=main&d=70166151696&cnsp=0" });
break;
case "CoralCDN":
chrome.tabs.update(tab.id, { url: tab.url + ".nyud.net" });
break;
default: // Webcite
// Need to send a request, this won't do
chrome.tabs.update(tab.id, { url: "http://webcitation.org/query" });
break;
}
}
</script>
</head>
<body>
<img src="Google Cache.png", alt="WayBack Machine" class="button" id="WayBack Machine" height ="40px" />
<img src="Google Cache.png", alt="Google Cache" class="button" id="Google Cache" height ="40px" />
<img src="Google Cache.png", alt="Yahoo Cache" class="button" id="Yahoo Cache" height ="40px" />
<img src="Google Cache.png", alt="Bing Cache" class="button" id="Bing Cache" height ="40px" />
<img src="Google Cache.png", alt="Gigablast" class="button" id="Gigablast" height ="40px" />
<img src="Google Cache.png", alt="CoralCDN" class="button" id="CoralCDN" height ="40px" />
<img src="Google Cache.png", alt="Webcite" class="button" id="Webcite" height ="40px" />
</body>
</html>
However, it doesn't even warn (); When I try to execute the code in jsfiddle.net it works: http://jsfiddle.net/RZ2wC/
Here is my manifest.json:
{
"name": "gCache",
"version": "1.1.5",
"description": "View the Google Cache of a page",
"browser_action": {
"default_icon": "icon.png",
"default_text": "Google Cache version of this page",
"default_popup": "cacheList.html"
},
"permissions": [
"tabs"
]
}
Any help would be greatly appreciated. For this question and any errors you see in my code that I haven't received yet. Many thanks!
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Debugging your sample by right clicking on the browserAction button and selecting "view popup" (this will lead to "further errors") showed that you were trying to add an event to "0"
Uncaught TypeError: Object 0 has no method 'addEventListener'
The reason for this is IMHO the page hasn't loaded yet, but you are trying to access the DOM of the images.
Try swapping your addEvents in a function like
function magic() {
var x;
var img = document.getElementsByTagName("img");
for(x=0; x < img['length']; ++x) {
img[x].addEventListener('click',openPage, false);
}
}
and call it from body-onload event (or $ (document) .ready () if using jQuery)
<body onload="magic()">
<img src="Google Cache.png", alt="WayBack Machine" class="button" id="WayBack Machine" height ="40px" />
<img src="Google Cache.png", alt="Google Cache" class="button" id="Google Cache" height ="40px" />
...
</body>
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Try to include your javascript as external files, referencing the bottom of your page (right before closing the body).
Also, to make sure the DOM is indeed loaded, wrap it in DOMContentLoaded-listenener:
document.addEventListener('DOMContentLoaded', function() {
/* Add your event listeners here */
});
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