Problems with parsing JSON objects

Question

My website calls the Spotify Web API and gets all the public playlists for a given user. The response is originally in JSON but my code decodes it.

The next thing I want the code to do, is to display only the objects [external_urls], [name] and [tracks] for each item in the response. For that I've tried this:

foreach($response_2['items'] as $item) {
echo 'Link: ' . $item['external_urls'] . '<br />'; 
echo 'Name: ' . $item['name'] . '<br />';
echo 'Tracks: ' . $item['tracks'] . '<br />'; }

...but it doesn't work as properly. All the [name]-objects (which is a string) are echoed correctly but for all [external_urls] and [tracks] (which are objects) it only says "Array" in the browser.

I guess I should be using print_r() for those objects but I can't get it to work.

Any suggestions?

My code:

<?php

$url = 'https://accounts.spotify.com/api/token';
$method = 'POST';

$credentials = "hidden:hidden";

$headers = array(
        "Accept: */*",
        "Content-Type: application/x-www-form-urlencoded",
        "Authorization: Basic " . base64_encode($credentials));
$data = 'grant_type=client_credentials';

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response_1 = curl_exec($ch);

curl_close($ch);

$response_1 = json_decode($response_1, true);

$token = $response_1['access_token'];

$headers_2 = array(
        "Accept: */*",
        "Content-Type: application/x-www-form-urlencoded",
        ('Authorization: Bearer ' . $token));

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,'https://api.spotify.com/v1/users/wizzler/playlists');
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers_2);
curl_setopt($ch, CURLOPT_POST, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response_2 = curl_exec($ch);

curl_close($ch);

$response_2 = json_decode($response_2, true);

?>

The API-response:

{
    "href": "https://api.spotify.com/v1/users/wizzler/playlists",
    "items": [
        {
            "collaborative": false,
            "external_urls": {
                "spotify": "http://open.spotify.com/user/wizzler/playlists/53Y8wT46QIMz5H4WQ8O22c"
            },
            "href": "https://api.spotify.com/v1/users/wizzler/playlists/53Y8wT46QIMz5H4WQ8O22c",
            "id": "53Y8wT46QIMz5H4WQ8O22c",
            "name": "Wizzlers Big Playlist",
            "owner": {
                "external_urls": {
                    "spotify": "http://open.spotify.com/user/wizzler"
                },
                "href": "https://api.spotify.com/v1/users/wizzler",
                "id": "wizzler",
                "type": "user",
                "uri": "spotify:user:wizzler"
            },
            "public": true,
            "tracks": {
                "href": "https://api.spotify.com/v1/users/wizzler/playlists/53Y8wT46QIMz5H4WQ8O22c/tracks",
                "total": 30
            },
            "type": "playlist",
            "uri": "spotify:user:wizzler:playlist:53Y8wT46QIMz5H4WQ8O22c"
        },
        {
            "collaborative": false,
            "external_urls": {
                "spotify": "http://open.spotify.com/user/wizzlersmate/playlists/1AVZz0mBuGbCEoNRQdYQju"
            },
            "href": "https://api.spotify.com/v1/users/wizzlersmate/playlists/1AVZz0mBuGbCEoNRQdYQju",
            "id": "1AVZz0mBuGbCEoNRQdYQju",
            "name": "Another Playlist",
            "owner": {
                "external_urls": {
                    "spotify": "http://open.spotify.com/user/wizzlersmate"
                },
                "href": "https://api.spotify.com/v1/users/wizzlersmate",
                "id": "wizzlersmate",
                "type": "user",
                "uri": "spotify:user:wizzlersmate"
            },
            "public": true,
            "tracks": {
                "href": "https://api.spotify.com/v1/users/wizzlersmate/playlists/1AVZz0mBuGbCEoNRQdYQju/tracks",
                "total": 58
            },
            "type": "playlist",
            "uri": "spotify:user:wizzlersmate:playlist:1AVZz0mBuGbCEoNRQdYQju"...
        }
    ],
    "limit": 9,
    "next": null,
    "offset": 0,
    "previous": null,
    "total": 9
}

You're previous question applies here as well. Objects and arrays cannot be output using echo. Use var_dump() or print_r() for objects as well as arrays... — War10ck
– War10ck, Commented Jul 2, 2014 at 19:49
As I mention in my question I've tried that: "I guess I should be using print_r() for those objects but I can't get it to work.". Can I mix print_r() and echo the same "foreach"? When I do, it still get "Array" when I use this: print_r ('Link: ' . $item['external_urls'] . '<br />'); — Rawland Hustle
– Rawland Hustle, Commented Jul 2, 2014 at 20:00
echo forces the array to be transformed to a string. So does concatenating it with another string and calling print_r after. — Sergiu Paraschiv
– Sergiu Paraschiv, Commented Jul 2, 2014 at 20:18

War10ck · Accepted Answer · 2014-07-02 20:30:49Z

1

Both external_urls and tracks are objects. In order to get the data, you either need to know the exact properties or cast them to an array (array) and traverse the newly created array to ensure you output all values. Since the names are pluralized I'm assuming you could have more than one external url and more than one track. For this reason, I've casted the properties to arrays and traversed through them:

foreach($response_2['items'] as $item) {
    echo "LINKS <br />";
    $item['external_urls'] = (array)$item['external_urls'];
    foreach($item['external_urls'] as $key => $value) {
        echo ucfirst($key) . ": " . $value . "<br />";
    }
    echo "Name: " . $item['name'] . "<br />";
    echo "TRACKS <br />";
    $item['tracks'] = (array)$item['tracks'];
    foreach($item['tracks'] as $key => $value) {
        echo ucfirst($key) . ": " . $value . "<br />";
    } 
}

Alternatively, if you know that you will only have one url and one track and you know the property names, you can access the properties using object syntax object->key; The same example from above is rewritten below using object syntax:

foreach($response_2['items'] as $item) {
    echo "LINKS <br />";
    echo "Spotify: " . $item['external_urls']->spotify . "<br />";
    echo "Name: " . $item['name'] . "<br />";
    echo "TRACKS <br />";
    echo "Href: " . $item['tracks']->href . "<br />";
    echo "Total: " . $item['tracks']->total . "<br />";
}

Sample Output for Item 1:

LINKS
Spotify: http://open.spotify.com/user/wizzler/playlists/53Y8wT46QIMz5H4WQ8O22c
Name: Wizzlers Big Playlist
TRACKS
Href: https://api.spotify.com/v1/users/wizzler/playlists/53Y8wT46QIMz5H4WQ8O22c/tracks
Total: 30

edited Jul 2, 2014 at 20:30

answered Jul 2, 2014 at 20:17

War10ck

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3 Comments

Rawland Hustle Over a year ago

Thanks! It didn't work at first but then I noticed that "echo ucfirs" was missing a "t". How do I show the items like this: Wizzlers Big Playlist

Sergiu Paraschiv Over a year ago

In his case they are arrays, not objects. Notice how he calls json_decode.

Rawland Hustle Over a year ago

Thanks guys! This was the code I went with

foreach($response_2['items'] as $item) {     $item['external_urls'] = (array)$item['external_urls'];     foreach($item['external_urls'] as $key => $value) {         echo "<a href='" . $value .  "'>" . $item['name'] . "</a>" . "<br />";     }

It shows each playlist (item) like this: Movie Soundtrack Masterpieces

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