Arrays returning undefined for API calls (spotify app)
Hey guys I'm working on a Javascript web app which uses Spotify API. I'm trying to return the top 5 albums of a given artist in a table. So far I got the API calls working and they return a table which displays ALL the albums of an artist in no particular order. I'm trying to shrink the table to the top 5 albums based on "popularity" which is the fifth column of the table.
var popsort = new Array(new Array());
var count = 0;
$(document).ready(function () {
$("#searchbutton").click(function () {
search();
});
,
function search() {
var query1 = document.getElementById('querybox').value;
$.get("https://api.spotify.com/v1/search?q=" + query1 + "&type=artist", function (data) {
//alert(data.artists.items[0].id);
getSeveralAlbums(data.artists.items[0].id);
});
}
function getSeveralAlbums(artistid) {
//alert(artistid);
$.getJSON("https://api.spotify.com/v1/artists/" + artistid + "/albums?album_type=album",
function (json) {
//bob = json;
//console.log(json);
console.log(json.items.length);
for (var i = 0; i < json.items.length; i++) {
createArray(json.items[i].href);
}
//console.log(count);
popsort.sort(sortPopularity);
//getAlbumInfo(json.items[i].href);
getAlbumInfo(popsort);
});
}
function getAlbumInfo(popsort) {
var tr;
console.log(popsort);
// i<json.length
// Sort the array first by popularity. And then create a for loop and print the first five.
tr = $('<tr/>');
for (var i = 0; i < 5; i++) {
tr.append("<td>" + popsort[i][0] + "</td>"); // Album Name
tr.append("<td>" + popsort[i][1] + "</td>"); // Artist Name
tr.append("<td>" + popsort[i][2] + "</td>"); // Release Date
tr.append("<td>" + popsort[i][3] + "</td>"); // Number of Tracks
tr.append("<td>" + popsort[i][4] + "</td>"); // Popularity
}
$('table').append(tr);
}
function createArray(albumhref) {
//console.log(albumhref);
$.getJSON(albumhref,
function (json) {
// i<json.length
// Sort the array first by popularity. And then create a for loop and print the first five.
console.log(count);
popsort[count][0].push(json.name);
popsort[count][1].push(json.artists[0].name);
popsort[count][2].push(json.release_date);
popsort[count][3].push(json.tracks.total);
popsort[count][4].push(json.popularity);
++count;
//alert("table compiled");
//alert("Table done");
});
}
function sortPopularity(a, b) {
if (a[4] === b[4]) {
return 0;
}
else {
return (a[4] < b[4]) ? -1 : 1;
}
}
});
I use the click function at the top to get the artist name from a textbox , pass that into the " search " function which returns an artistid . I pass this artistid into the " getSeveralAlbums " functions. The json call in this function returns the hrefs to all the albums of a specific artist which I want to store in an 2D array along with the popularity. My " sortPopularity " function near the bottom will ideally sort this array by the fifth element which is "popularity" and then I plan to pass this sorted array ( popsort ) into the getAlbumInfo function which has a for loop printing 5 times, which will ideally print the first five elements of the popsort array. After sorting this will ideally be the top 5 most popular albums of an artist.
When I try to run this program, it returns an error undefined for both popsort[count][0].push(json.name); in the createArray function, and it returns an error undefined for tr.append("<td>" + popsort[i][0] + "</td>"); in the getAlbumInfo function. What am I doing wrong?
Update: (new code)
var popsort = new Array(new Array());
var count = 0;
var looopCount = 0;
$(document).ready(function () {
$("#searchbutton").click(function () {
search();
});
function search() {
var query1 = document.getElementById('querybox').value;
$.get("https://api.spotify.com/v1/search?q=" + query1 + "&type=artist", function (data) {
getSeveralAlbums(data.artists.items[0].id);
});
}
function getSeveralAlbums(artistid) {
$.getJSON("https://api.spotify.com/v1/artists/" + artistid + "/albums?album_type=album",
function (json) {
console.log(json.items.length);
looopCount = json.items.length;
for (var i = 0; i < json.items.length; i++) {
createArray(json.items[i].href);
}
});
}
function getAlbumInfo(popsort) {
var tr;
// Sort the array first by popularity. And then create a for loop and print the first five.
tr = $('<tr/>');
for (var i = 0; i < 5; i++) {
tr.append("<td>" + popsort[i][0] + "</td>"); // Album Name
tr.append("<td>" + popsort[i][1] + "</td>"); // Artist Name
tr.append("<td>" + popsort[i][2] + "</td>"); // Release Date
tr.append("<td>" + popsort[i][3] + "</td>"); // Number of Tracks
tr.append("<td>" + popsort[i][4] + "</td>"); // Popularity
}
$('table').append(tr);
}
function createArray(albumhref) {
$.getJSON(albumhref,
function (json) {
if (popsort.length <= count) {
popsort.push(new Array());
}
// Sort the array first by popularity. And then create a for loop and print the first five.
popsort[count].push(json.name);
popsort[count].push(json.artists[0].name);
popsort[count].push(json.release_date);
popsort[count].push(json.tracks.total);
popsort[count].push(json.popularity);
++count;
batchSort(--looopCount);
});
}
function sortPopularity(a, b) {
if (a[4] === b[4]) {
return 0;
}
else {
return (a[4] > b[4]) ? -1 : 1;
}
}
function batchSort(i) {
if (i <= 0) {
popsort.sort(sortPopularity);
getAlbumInfo(popsort);
}
}
});
First is that you are accessing undefined key of popsort in createArray() , use .push() instead. Second, the getAlbumInfo(sortPopularity); function is already called while the first $.getJSON(albumhref, fn...); reponse has not yet returned thus leaving you with an empty array to access. Tht is why you get an undefined return when accessing the popsort
What I would do is I will create a descending counter and add it to the createArray 's $.getJSON() callback, like this:
var popsort = new Array(new Array());
var count = 0;
var looopCount = 0;
function getSeveralAlbums(artistid) {
$.getJSON("https://api.spotify.com/v1/artists/" + artistid + "/albums?album_type=album",
function (json) {
console.log(json.items.length);
looopCount = json.items.length
for (var i = 0; i < json.items.length; i++) {
createArray(json.items[i].href);
}
// call both popsort.sort(sortPopularity); and getAlbumInfo(popsort); after all the data is loaded to popsort, not here.
});
}
function createArray(albumhref) {
$.getJSON(albumhref,
function (json) {
if (popsort.length <= count) {
// if the length of popsort is less than count, it means that that index(count) is not yet present in popsort
// push to add an item with index=count to popsort
popsort.push(new Array());
}
popsort[count].push(json.name);
popsort[count].push(json.artists[0].name);
popsort[count].push(json.release_date);
popsort[count].push(json.tracks.total);
popsort[count].push(json.popularity);
++count;
batchSort(--looopCount);
});
}
function batchSort(i) {
if (i <= 0) {
popsort.sort(sortPopularity);
getAlbumInfo(popsort);
}
}
});
function getAlbumInfo(popsort) {
for (var i = 0; i < 5; i++) {
tr.append("<tr><td>" + popsort[i][0] + "</td>"); // Album Name
tr.append("<td>" + popsort[i][1] + "</td>"); // Artist Name
tr.append("<td>" + popsort[i][2] + "</td>"); // Release Date
tr.append("<td>" + popsort[i][3] + "</td>"); // Number of Tracks
tr.append("<td>" + popsort[i][4] + "</td></tr>"); // Popularity
}
}
Haven't tested it though, but that's the thought.. Hope it helped.
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