Question

I have 4 different JQuery AJAX functions, each fetching different information from the last.fm API. This info has to be joined together in a tooltip.

These are my 4 functions:

1. Gets the album for a given track & artist. Returns track name.
2. Gets the artist image. Returns 1 URL.
3. Gets the top 3 albums of the artist. Returns array of 3 strings.
4. Gets the #1 top track of a given artist. Returns track name.

 

var getTrackAlbum = function(track, artist) {
    $.getJSON(
      settings.PHP_REQUEST_URL,
      {
        method: "track.getInfo",
        api_key : settings.LASTFM_APIKEY,
        track   : track,
        artist  : artist,
        format  : "json"
      },
      function(data) {
        return data.track.album.title;
      });
}

var getArtistImage = function(artist) {
    var options = {
      artSize: 'medium',
      noart: 'images/noartwork.gif',
    }

    if(options.artSize == 'small'){imgSize = 0}
    if(options.artSize == 'medium'){imgSize = 1}
    if(options.artSize == 'large'){imgSize = 2}

    $.getJSON(
      settings.PHP_REQUEST_URL,
      {
        method: "artist.getInfo",
        api_key : settings.LASTFM_APIKEY,
        artist  : artist,
        format  : "json"
      },
      function(data) {
        return stripslashes(data.artist.image[imgSize]['#text']);
      });
}

var getArtistTopAlbums = function(artist) {
    var albums = new Array();

    var onComplete = function() {
      return albums;
    }

    $.getJSON(
      settings.PHP_REQUEST_URL,
      {
        method: "artist.getTopAlbums",
        api_key : settings.LASTFM_APIKEY,
        artist  : artist,
        format  : "json"
      },
      function(data) {
        $.each(data.topalbums.album, function(i, item){
          albums[i] = item.name;

          if(i == 2) { 
            onComplete.call(this);
            return;
          }
        });
      });
}

var getArtistTopTrack = function(artist) {
    $.getJSON(
      settings.PHP_REQUEST_URL,
      {
        method: "artist.getTopTracks",
        api_key : settings.LASTFM_APIKEY,
        artist  : artist,
        format  : "json"
      },
      function(data) {
        return data.toptracks.track[0].name;
      });
}

I have decided against doing all the requests inside a unique method for reuse purposes. However, now I want to wait for ALL the AJAX requests to complete before I set the HTML of my tooltip.

Here’s the code of my tooltip:

$('.lfm_info').on('mouseover', function(){
          var toolTip = $(this).children('.tooltip');

          var trackhtml = $(this).parent().children('.lfm_song').html().split(".");
          var track = trackhtml[1].trim();
          var artist = $(this).parent().children('.lfm_artist').html();

        // needs to wait until the AJAX is done!    
        toolTip.html('html here');

        $('#tracks').mouseleave(function(){
         if(toolTip.is(':visible')){
           toolTip.fadeOut(500);  
         };    
       });

        toolTip.fadeIn(500);      
      });
}

How would I wait for all requests to complete before invoking toolTip.html(...)?

Answer 1

Store each request, then use $.when to create a single deferred object to listen for them all to be complete.

var req1 = $.ajax({...});
var req2 = $.ajax({...});
var req3 = $.ajax({...});

$.when( req1, req2, req3 ).done(function(){
    console.log("all done")
});