New backend functionnality : GetAlbumDetails

[SharkyFlou]

Start Date

No response

Implementation PR

No response

Reference Issues

No response

Summary

Get album mood (energetic, sad etc), top genre (and percentages), top subgenre (percentages), most repeated artist, average tempo and length.

Average popularity, hapiness, speechiness etc More info here : https://developer.spotify.com/documentation/web-api/reference/#/operations/get-several-audio-features

Basic Example

Would be called like that : GetPlaylistDetails(string:acces_token,string:paylist_id){...} Return a JSON with everything.

Drawbacks

Would allows to display mutliple interesting information about albums.

Unresolved questions

No response

[AlexLunaP]

Hi! Can I start contributing to this issue?

[SharkyFlou]

If you have any questions, don't hesitate to ask, I or someone else will answer them.

[AlexLunaP]

Hi, do I also need to give you my email, so I can use my spotify account to test the web? alexluna2001@hotmail.com

[HugoLAMOUREUX]

I've added you to the authorized users so you should be able to use it now ! I'm also gonna send you the content of the .env file

[AlexLunaP]

Hi, I think I managed to write a working code for this issue. I haven't tested it yet though, because the method getAlbumDetails needs to call getAlbumTracks method, and that issue is assigned to another contributor (#7) but it isn't done yet.

I also created other necessary files for this method to work:

• Added route to index.js
• albumRoute.js
• albumController.js

getAlbumDetails code:

const getAlbumDetails = async (req, res) => {
    if (!req.query.access_token || !req.query.album_id) {
      res.status(400);
    }
    const spotifyApi = new SpotifyWebApi({
      accessToken: req.query.access_token,
    });

    //set all default values to 0
    let return_value = {};
    return_value.mean_danceability = 0.0;
    return_value.mean_energy = 0.0;
    return_value.mean_loudness = 0;
    return_value.mean_speechiness = 0;
    return_value.mean_acousticness = 0;
    return_value.mean_instrumentalness = 0;
    return_value.mean_liveness = 0;
    return_value.mean_valence = 0;
    return_value.mean_tempo = 0;
    return_value.mean_time_signature = 0;
    return_value.mean_key = 0;
    return_value.mean_mode = 0;
    return_value.mean_duration_ms = 0;
    return_value.mean_popularity = 0;
    return_value.nbr_tracks_audio_ft = 0;
    return_value.nbr_tracks_get_norm = 0;
    return_value.nbr_tracks = 0;
    return_value.genres = {};
    return_value.artists = {};

    //is used to store the total number of tracks in the album
    let total;
    //is used to store temporarly the ids of the tracks that will be used to get the details of the tracks
    let tracks_ids = [];

    //get the first 50 track's ids of the album
    await getAlbumTracks(spotifyApi, req.query.album_id, 50, 0).then(
      function (data) {
        total = data.total;
        data.items.forEach((item) => {
          tracks_ids.push(item.track_id);
        });
      }
    );

    //get the details of the tracks
    return_value = await getTracksDetails(spotifyApi, tracks_ids, return_value);

    //if there are more tracks to get, get them
    if (total > 50) {
        for (let i = 0; i < (total - 50) / 50; i++) {
            tracks_ids = [];
            await getAlbumTracks(
                spotifyApi,
                req.query.album_id,
                50,
                (i + 1) * 50
            ).then(function (data) {
                data.items.forEach((item) => {
                tracks_ids.push(item.track_id);
                });
            });

            return_value = await getTracksDetails(
                spotifyApi,
                tracks_ids,
                return_value,
                res
            );
        }
    }

    //calculate the mean of each feature
    return_value.mean_danceability = (
        return_value.mean_danceability / return_value.nbr_tracks_audio_ft
    ).toFixed(2);

    return_value.mean_energy = (
        return_value.mean_energy / return_value.nbr_tracks_audio_ft
    ).toFixed(2);

    return_value.mean_loudness = (
        return_value.mean_loudness / return_value.nbr_tracks_audio_ft
    ).toFixed(2);

    return_value.mean_speechiness = (
        return_value.mean_speechiness / return_value.nbr_tracks_audio_ft
    ).toFixed(2);

    return_value.mean_acousticness = (
        return_value.mean_acousticness / return_value.nbr_tracks_audio_ft
    ).toFixed(2);

    return_value.mean_instrumentalness = (
        return_value.mean_instrumentalness / return_value.nbr_tracks_audio_ft
    ).toFixed(2);

    return_value.mean_liveness = (
        return_value.mean_liveness / return_value.nbr_tracks_audio_ft
    ).toFixed(2);

    return_value.mean_valence = (
        return_value.mean_valence / return_value.nbr_tracks_audio_ft
    ).toFixed(2);

    return_value.mean_tempo = (
        return_value.mean_tempo / return_value.nbr_tracks_audio_ft
    ).toFixed(2);

    return_value.mean_time_signature = (
        return_value.mean_time_signature / return_value.nbr_tracks_audio_ft
    ).toFixed(2);

    return_value.mean_key = (
        return_value.mean_key / return_value.nbr_tracks_audio_ft
    ).toFixed(2);

    return_value.mean_mode = (
        return_value.mean_mode / return_value.nbr_tracks_audio_ft
    ).toFixed(2);

    return_value.mean_duration_s = (
        return_value.mean_duration_ms /
        return_value.nbr_tracks_audio_ft /
        1000
    ).toFixed(2);

    return_value.mean_popularity = (
        return_value.mean_popularity / return_value.nbr_tracks_get_norm
    ).toFixed(2);

    //delete for more clarity
    delete return_value.nbr_tracks_audio_ft;
    delete return_value.nbr_tracks_get_norm;

    return_value.nbr_tracks = total;

    //sort artists by number of tracks they appear in
    let sorted_artists = Object.keys(return_value.artists).sort(function (a, b) {
        return return_value.artists[b].nbr - return_value.artists[a].nbr;
    });

    //get the 10 most common artists
    return_value.common_artists = [];
    for (let i = 0; i < 10; i++) {
        if (sorted_artists[i] != undefined) {
        return_value.artists[sorted_artists[i]].id = i + 1;
        return_value.common_artists.push(return_value.artists[sorted_artists[i]]);
        }
    }
    delete return_value.artists;

    res.status(200).json(return_value);
};

Check the rest of the code files: https://github.com/AlexLunaP/Spotidata

[AlexLunaP]

Hi, as the method getAlbumTracks is already implemented, now I can test my code for getAlbumDetails, any help on this? Not sure how to test it.

[SharkyFlou]

Ok, to test your function, you need to use Postman, which allows you to easily make requests to the back-end and see what the function returns.

To do this, :

• Install Postman.
• Run the front-end in VS-Code, then connect with Spotify on Spotidata.
• Still on Spotidata, click on "Make a request" to get your access token (it will be active for one hour).
• To access your token, go to the developer mode of your browser and in the console your access token will be printed, copy it.
• Now go back to VS-Code and launch the back-end. (you can launch it before, it doesn't change anything).
• On Postman there are several ways to send requests, select "GET" if not already selected.
• In the url type this http://127.0.0.1:5000/api/spotify/NameOfWhatYouWantToTest, eg : http://127.0.0.1:5000/api/spotify/GetAlbumDetails
• Now you need to add your access token to the request; to do this, under the URL, in the Params tab, click on the first case and add the key as "access_token" and as value your access token. (And check the line)
• If you have other parameters to enter, such as the album id, proceed in the same way: enter the key "album_id" and the value of the album id (parameter req.query.xxx). Now send the query and see the result.

Good luck !

And if I was not clear, don't hesitate to leave a message here, I'll be happy to help.

[AlexLunaP]

Hi. Thanks, it is well explained.

I am having some trouble testing some methods. Some of them give the correct response in Postman, but others are not working for me (maybe I'm using the wrong parameters?) Would you mind if I show you on Discord or similar? I think it can be faster to explain. My email is alexluna2001@hotmail.com

Thanks in advance

[SharkyFlou]

Yes, sorry for the delay, I'll send you my discord by mail.