node-tomahawkjs

Implementation of the JS plugins API from Tomahawk as a library for NodeJS and io.js. It also features an executable tomahawkjs which can be used to execute resolver functionality from the commandline without the need to write any code.

(This implementation is not fully feature complete compared to the desktop client but hubot-tomahk is an exmple usage of parts of it)

tomahawkjs Usage

This utility supports calling the typical functionalities of a single resolver. While its main purpose is to support developing resolvers, you can use it also standalone. For example given the soundcloud resolver, you can build your own commandline (headless) soundcloud player with just this single commandline:

tomahawkjs resolve soundcloud.axe <artist> <title> | jq -r .url | xargs cvlc

This requires jq and vlc to be installed on your machine.

Generate a new resolver scaffold

TODO

Resolve a song using a resolver

Resolving a song using a given resolver can either be done with a bundled .axe or a directory containing all the files as in a developemnt setting.

tomahawkjs resolve <path-to-resolver> <artist> <title> [<album>]

Search with a resolver

Search works similarily to resolving but you can specify an arbitrary number of commandline arfuments which will be joined together to form a single search query.

tomahawkjs search <path-to-resolver> <query-part1> [<query-part2> [..]]

Library Usage

Create a resolver instance

To load a single resolver, we simply use the following code if we know the path to the .axe file:

var TomahawkJS = require('tomahawkjs');

TomahawkJS.loadAxe(pathtoaxe, function(err, axe) {
  // TODO: Check for error in err
  // After load the axe, we most likely want to have an instance of the resolver
  axe.getInstance(function(err, instance_context) {
    // TODO: Check for error in err
    var instance = instance_context.instance;
    // Each Resolver instance runs in its own global JavaScript context
    var context = instance_context.context;
    // Start the instance
    // Due to the architecture of the resolveres, this may do some background work and will not block.
    instance.init();
    // We can now use the instance
  });
});

Checking for a capability

As the time of writing, Tomahawk resolvers were all implicitly able to resolve from a combination of Artist and Title (and Albumname) to a stream URL if their feeding service provided this tune. Furthermore there are some other capabilities that can be implemented:

• browsable: Resolver exposes a music collection that can be browsed.
• playlistsync: Can sync playlists
• urllookup: Can resolve from an URL to a combination of Artist+Title/Album/Playlist

Checking for one of these can be done via:

context.hasCapability('urllookup')

Resolving

The main functionality of a Tomahawk resolver is to find a stremable URL for a combination of artist and song title and optionally an album. The requests for resolving should be indentified with a unqiue id for each query. Alternatively we can search a given string without specifying explicitly artist or title.

context.on('track-result', function (qid, result) {
  console.log('Found a new streamable URL for request ' + qid + ':' + result.url);
});

// Search for a streambale URL for song title by artist on album.
instance.resolve(someId1, artist, album, title);

// Search for a streamable URL for a song similar to searchquery
instance.search(someId2, searchquery);

URL Lookup

As an inverse for the lookup of (Artist, Title) -> stream-URL, many resolvers have the urllookup capability to resolve from a URL pointing to a music service to artist/album/playlist/.. that is encoded in the URL.

// Define a handler for found URL mappings
context.on('url-result', function (url, result) {
  if (result.type == 'track') {
    console.log('Found URL for track ' + result.artist + ' - ' + result.title);
  } else if (result.type == 'album') {
    console.log('Found URL for album ' + result.artist + ' - ' + result.name);
  } else if (result.type == 'playlist') {
    console.log('Found URL for playlist ' + result.title);
  } else if (result.type == 'artist') {
    console.log('Found URL for artist ' + result.name);
  }
});

// Check if resolver has URLLookup capability
if (context.hasCapability('urllookup')) {
  // Can we handle this URL?
  if (instance.canParseUrl(url)) {
    instance.lookupUrl(url);
  }
}

Collection Browsing

Resolver that have the browsable capability export the whole collection of music material that can be streamed from them. The browsing of the collection is done by pulling the relevant information on demand.

// Handler for the list of artists (string[])
context.on('artist-results', function (qid, artists) {
  console.log('Got a list of ' + artists.length + ' artists');
  
  // Query the albums for the first artist
  instance.albums(qid + artists[0], artists[0]);
});

// Handler for a list of albums (string[])
context.on('album-results', function(qid, artist, albums) {
  console.log('Got a list of ' + albums.length + ' albums for artist ' + artist);
  
  // Query the first album for all its tracks
  instance.tracks(qid + album, artist, album);
});

// Handler for a list of tracks for an album
content.on('albumtrack-results', function (qid, artist, album, tracks) {
  console.log('Got a list of ' + tracks.length + ' songs on ' + album + ' by ' + artist);
  console.log('The first song is called ' + tracks[0].track);
});


if (context.hasCapability('browsable')) {
  // Get basic information about the collection
  var info = instance.collection();
  // Not all collections support the retrieval of the total number of tracks
  if (info.trackcount == null) {
    console.log('We are browsing the collection ' + info.prettyname + ': ' + info.description);
  } else {
    console.log('We are browsing the collection (' + info.trackcount + ' tracks) ' + info.prettyname + ': ' + info.description);
  }
  
  // Query for the list of all artists
  instance.artists(someQid);
}