create playlist plugin (#1018)

added playlist parser plugin

plugin/wavesurfer.playlistparser.js

@@ -0,0 +1,68 @@
+'use strict';
+
+/* Playlist Plugin */
+WaveSurfer.Playlist = {
+    init: function (params) {
+        this.params = params;
+
+        var wavesurfer = this.wavesurfer = params.wavesurfer;
+
+        if (!this.wavesurfer) {
+            throw new Error('No WaveSurfer instance provided');
+        }
+
+        // parse playlist and set params
+        this.playlistFileGET = this.params.playlistFile || null;
+        this.playlistType = this.params.playlistType || 'm3u';
+        this.playlistData = [];
+
+        if (this.playlistFileGET != null) {
+            var ajaxData = wavesurfer.util.ajax({
+                url: this.playlistFileGET,
+                responseType: 'text'
+            });
+
+            var _this = this;
+            ajaxData.on('success', function (data, e) {
+                _this.loadPlaylist(data);
+                _this.wavesurfer.fireEvent('playlist-ready');
+            });
+            ajaxData.on('error', function (e) {
+                throw new Error('Error reading the playlist file' + 'XHR error: ' + e.target.statusText);
+            });
+
+        } else {
+            throw new Error('No playlist file provided');
+        }
+    },
+
+    getPlaylist: function() {
+        return this.playlistData;
+    },
+
+    loadPlaylist: function(playlistFile) {
+        // check if playlist type is given
+        var playlist = [];
+
+        if (this.playlistType == 'm3u' || this.playlistType == 'audio/mpegurl') {
+            playlist = playlistFile.replace(/^.*#.*$|#EXTM3U|#EXTINF:/mg, '').split('\n');
+        } else {
+            throw new Error('No valid playlist file provided');
+        }
+
+        // playlist type is set return the playlist
+        var outputArray = [];
+        for (var i = 0; i < playlist.length; i++) {
+            if (playlist[i]) {
+                // check if file name has .mp3 or .wav before adding the playlist array
+                if(playlist[i].indexOf('.mp3') !== -1 || playlist[i].indexOf('.wav') !== -1) {
+                    outputArray.push(playlist[i].toString());
+                }
+            }
+        }
+        this.playlistData = outputArray;
+        return;
+    }
+};
+
+WaveSurfer.util.extend(WaveSurfer.Playlist, WaveSurfer.Observer);