watch_page: refactor music list into flask template

youtube/templates/watch.html

@@ -192,7 +192,24 @@
 
                     <span class="description">{{ description }}</span>
                     <div class="music-list">
-{{ music_list|safe }}
+                        {% if music_list.__len__() != 0 %}
+                            <hr>
+                            <table>
+                                <caption>Music</caption>
+                                <tr>
+                                    {% for attribute in music_attributes %}
+                                        <th>{{ attribute }}</th>
+                                    {% endfor %}
+                                </tr>
+                                {% for track in music_list %}
+                                    <tr>
+                                        {% for attribute in music_attributes %}
+                                            <td>{{ track.get(attribute.lower(), '') }}</td>
+                                        {% endfor %}
+                                    </tr>
+                                {% endfor %}
+                            </table>
+                        {% endif %}
                     </div>
 {{ comments|safe }}
                 </article>

youtube/watch.py

@@ -110,10 +110,7 @@ def get_subtitle_sources(info):
     return sources
 
 
-def get_music_list_html(music_list):
+def get_ordered_music_list_attributes(music_list):
-    if len(music_list) == 0:
-        music_list_html = ''
-    else:
     # get the set of attributes which are used by atleast 1 track
     # so there isn't an empty, extraneous album column which no tracks use, for example
     used_attributes = set()
@@ -126,30 +123,7 @@ def get_music_list_html(music_list):
         if attribute.lower() in used_attributes:
             ordered_attributes.append(attribute)
 
-        music_list_html = '''<hr>
+    return ordered_attributes
-<table>
-<caption>Music</caption>
-<tr>
-'''
-        # table headings
-        for attribute in ordered_attributes:
-            music_list_html += "<th>" + attribute + "</th>\n"
-        music_list_html += '''</tr>\n'''
-
-        for track in music_list:
-            music_list_html += '''<tr>\n'''
-            for attribute in ordered_attributes:
-                try:
-                    value = track[attribute.lower()]
-                except KeyError:
-                    music_list_html += '''<td></td>'''
-                else:
-                    music_list_html += '''<td>''' + html.escape(value) + '''</td>'''
-            music_list_html += '''</tr>\n'''
-        music_list_html += '''</table>\n'''
-    return music_list_html
-
-
 
 
 def extract_info(downloader, *args, **kwargs):
@@ -231,10 +205,11 @@ def get_watch_page():
         video_sources           = get_video_sources(info),
         subtitle_sources        = get_subtitle_sources(info),
         related                 = related_videos,
+        music_list              = info['music_list'],
+        music_attributes        = get_ordered_music_list_attributes(info['music_list']),
 
         # TODO: refactor these
         comments                = comments_html,
-        music_list              = get_music_list_html(info['music_list']),
 
         title       = info['title'],
         uploader    = info['uploader'],