Javascript: Remove duplicate values from an array

I did a Google search for different methods of removing duplicate values from an array, and I found a bunch of crappy algorithms that all returned a new array, rather than paring down the original array. So I wrote this, which wouldn't work on identical complex objects, but works great for primitive data types and objects stored by reference.

function removeDuplicates(arr) {
  arr.sort();
  var i = arr.length - 1;
  while (i > 0) {
    if (arr[i] === arr[i - 1]) arr.splice(i, 1);
    i--;
  }
}

Javascript: Get the original size of an image

Sometimes you need to know the original dimensions of an image that you've loaded via javascript, or that's already loaded in the DOM. Here's a little class that will take the location of an image, and a callback function that receives the original width and height:

var getImageSizeWithCallback = function( src, callback ) {
  var image = new Image();
  image.onload = function () {
    if( callback ) callback( image.width, image.height );
    image.onload = image.onerror = null;
  };
  image.onerror = function () {
    if( callback ) callback( -1, -1 );
    image.onload = image.onerror = null;
  };
  // load it
  image.src = src;
};

Usage:

getImageSizeWithCallback( 'images/path/to/img.jpg', function( w, h ) {
  console.log( 'image size:', w, h );
});

Bookmarklet: Scrape a web page for YouTube videos and generate a playlist

I wrote this little script to capture about 50 YouTube videos from a music blog I was browsing. I figured it would be useful for others, so I turned it into a bookmarklet:

// get html source
var src = document.getElementsByTagName('html')[0].innerHTML;
// handle old youtube vids, and https
var vids = src.replace(/\"/g).replace(/http:\/\/www.youtube.com\/v\//gi,'http://www.youtube.com/embed/').replace(/https/gi,'http');
// parse the source for youtube embeds
var vidArr = vids.split('http://www.youtube.com/embed/')
var links = ''; 
// build string for playlist
var playlist = 'http://www.ytplaylist.com/?pl='; 
// build links
if(vidArr.length > 1) {
  // keep track of IDs so we don't get duplicates
  var videos = [];
  for(var i=1; i < vidArr.length; i++) { 
    // grab 11-character YouTube ID
    var ytID = vidArr[i].substr(0,11);
    if(videos.indexOf(ytID) == -1) {
      // add link to video, and to playlist link
      var link = 'http://www.youtube.com/watch?v='+ytID;
      links += '<a target="_blank" href="'+link+'">'+link+'</a><br/>';
      playlist += ytID+';';
      videos.push(ytID);
    }
  }
  playlist = playlist.substr(0,playlist.length-1);
  // draw it to the page
  var container = document.createElement('div');
  container.innerHTML = 'Videos Found:<br/><br/>'+links+'<br/><br/>'+'<a target="_blank" href="'+playlist+'">View as Playlist</a><br/>';
  container.style.position='fixed';
  container.style.background='#fff';
  container.style.border='5px solid black';
  container.style.padding='10px';
  container.style.top='0';
  container.style.right='0';
  container.style.zIndex='999';
  document.body.appendChild(container);
} else {
  alert('No YouTube videos found');
}

And here's the bookmarklet link text:

javascript:(function(){var%20src%20%3D%20document.getElementsByTagName('html')%5B0%5D.innerHTML%3B%0Avar%20vids%20%3D%20src.replace(%2F%5C%22%2Fg).replace(%2Fhttp%3A%5C%2F%5C%2Fwww.youtube.com%5C%2Fv%5C%2F%2Fgi%2C'http%3A%2F%2Fwww.youtube.com%2Fembed%2F').replace(%2Fhttps%2Fgi%2C'http')%3B%0Avar%20vidArr%20%3D%20vids.split('http%3A%2F%2Fwww.youtube.com%2Fembed%2F')%0Avar%20links%20%3D%20''%3B%20%0Avar%20playlist%20%3D%20'http%3A%2F%2Fwww.ytplaylist.com%2F%3Fpl%3D'%3B%20%0A%2F%2F%20build%20links%0Aif(vidArr.length%20%3E%201)%20%7B%0A%20%20var%20videos%20%3D%20%5B%5D%3B%0A%20%20for(var%20i%3D1%3B%20i%20%3C%20vidArr.length%3B%20i%2B%2B)%20%7B%20%0A%20%20%20%20var%20ytID%20%3D%20vidArr%5Bi%5D.substr(0%2C11)%3B%0A%20%20%20%20if(videos.indexOf(ytID)%20%3D%3D%20-1)%20%7B%0A%20%20%20%20%20%20var%20link%20%3D%20'http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D'%2BytID%3B%0A%20%20%20%20%20%20links%20%2B%3D%20'%3Ca%20target%3D%22_blank%22%20href%3D%22'%2Blink%2B'%22%3E'%2Blink%2B'%3C%2Fa%3E%3Cbr%2F%3E'%3B%0A%20%20%20%20%20%20playlist%20%2B%3D%20ytID%2B'%3B'%3B%0A%20%20%20%20%20%20videos.push(ytID)%3B%0A%20%20%20%20%7D%0A%20%20%7D%0A%20%20playlist%20%3D%20playlist.substr(0%2Cplaylist.length-1)%3B%0A%20%20var%20container%20%3D%20document.createElement('div')%3B%0A%20%20container.innerHTML%20%3D%20'Videos%20Found%3A%3Cbr%2F%3E%3Cbr%2F%3E'%2Blinks%2B'%3Cbr%2F%3E%3Cbr%2F%3E'%2B'%3Ca%20target%3D%22_blank%22%20href%3D%22'%2Bplaylist%2B'%22%3EView%20as%20Playlist%3C%2Fa%3E%3Cbr%2F%3E'%3B%0A%20%20container.style.position%3D'fixed'%3B%0A%20%20container.style.background%3D'%23fff'%3B%0A%20%20container.style.border%3D'5px%20solid%20black'%3B%0A%20%20container.style.padding%3D'10px'%3B%0A%20%20container.style.top%3D'0'%3B%0A%20%20container.style.right%3D'0'%3B%0A%20%20container.style.zIndex%3D'999'%3B%0A%20%20document.body.appendChild(container)%3B%0A%7D%20else%20%7B%0A%20%20alert('No%20YouTube%20videos%20found')%3B%0A%7D}());