Question

Alright, so I’m trying to make a Chrome extension. I’m quite a bit of a noob at this, which is why I’ve started off by taking an example extension from a tutorial site and adding stuff to it. I got it off some site which I can’t remember, if you really want attribution, I can have a search for it. Code:

var req = new XMLHttpRequest();
req.open(
"GET",
"http://api.flickr.com/services/rest/?" +
    "method=flickr.photos.search&" +
    "api_key=90485e931f687a9b9c2a66bf58a3861a&" +
    "text=hello_world&" +
    "safe_search=1&" +  
    "content_type=1&" +  
    "sort=relevance&" +  
    "per_page=24",
true);
req.onload = showPhotos;
req.send(null);

function showPhotos() {
  var photos = req.responseXML.getElementsByTagName("photo");

  for (var i = 0, photo; photo = photos[i]; i++) {
    var img = document.createElement("image");
    img.src = constructImageURL(photo);
    document.getElementById("images").appendChild(img);
  }
}

function constructImageURL(photo) {
  return "http://farm" + photo.getAttribute("farm") +
  ".static.flickr.com/" + photo.getAttribute("server") +
  "/" + photo.getAttribute("id") +
  "_" + photo.getAttribute("secret") +
  "_s.jpg";
}

So anyway, what the extension does is it sends an XMLHttpRequest to Flickr’s API, getting some images (img tags in XML format). It then loops through those tags with a for loop, and for every tag it makes a new img element using createElement(), gives it a src attribute using the constructImageURL() function and appends it to the popup page. What I wanted to do is make it so you can actually click on those images, and be taken to the image’s page. I tried to make a snippet of code based on the one that creates the image elements, but to create anchor (a) elements, which I added to the for loop. It looks like this:

var a = document.createElement("link");
a.href = constructImageURL(photo);
a.target = "_blank";
document.getElementById("images").appendChild(a);

and I then added some code to append the img elements to the anchor elements, effectively making a <a><img /></a> structure:

document.a.appendChild(img);

But, it doesn’t work. Can someone please help?

Answer 1

Well, you should check the developer tools console by right-clicking the browser action and clicking “Inspect popup” and see what’s wrong.

I think you might want to use setAttribute, just to make sure. And the element for a link is <a> not <link>, as well as the element for an image is <img> not <image>. Also, you don’t want document.a.appendChild, you want to append the image to the current variable. So it should be something like:

function showPhotos() {
    var photos = req.responseXML.getElementsByTagName("photo");
    var a = document.createElement("a");
    a.setAttribute("href",constructImageURL(photo));
    a.setAttribute("target","_blank");

    var img = document.createElement("img");
    img.setAttribute("src",constructImageURL(photo));

    a.appendChild(img);
    document.getElementById("images").appendChild(a);
}