fix: gracefully handle missing playlist data in EmissionManager

The playlist data is only available for the currently selected show. Any
playlists used in other shows will not be available and we should
gracefully handle that.

This is a quick fix to address #132. A more permanent and helpful
resolution is outlined in #135 and #136.

src/Pages/EmissionManager.vue

@@ -158,7 +158,7 @@
                     <span class="tw-block">
                       <strong>{{ $t('emissionTable.playlist') }}:</strong>
                       {{
-                        getPlaylistById(timeslot.show.default_playlist_id).description ||
+                        getPlaylistById(timeslot.show.default_playlist_id)?.description ||
                         timeslot.show.default_playlist_id
                       }}
                     </span>
@@ -168,7 +168,7 @@
                     {{ $t('calendar.empty') }}
                   </span>
                 </div>
-                <div v-else class="tw-leading-none">
+                <div v-else-if="timeslot.playlist" class="tw-leading-none">
                   <span class="tw-block">
                     <strong>{{ $t('emissionTable.playlist') }}:</strong>
                     {{ timeslot.playlist.description || timeslot.playlist_id }}
@@ -184,6 +184,9 @@
                     </span>
                   </span>
                 </div>
+                <div v-else>
+                  <p>{{ $t('emissionTable.missingPlaylistData') }}</p>
+                </div>
               </div>
             </div>
           </div>
@@ -291,10 +294,13 @@ export default {
         .map((timeslot) => {
           const id = timeslot.show
           const show = this.getShow({ id })
+          const playlist = timeslot.playlist_id
+            ? this.getPlaylistById(timeslot.playlist_id) ?? null
+            : null
 
           return {
             ...timeslot,
-            playlist: timeslot.playlist_id ? this.getPlaylistById(timeslot.playlist_id) : null,
+            playlist,
             show: {
               ...show,
             },

src/i18n/de.js

@@ -87,6 +87,8 @@ export default {
     duration: 'Dauer',
     playlist: 'Playlist',
     actions: 'Aktionen',
+    missingPlaylistData:
+      'Informationen zur Playlist stehen gerade nicht zur Verfügung. Wechsle zur Sendereihe dieser Ausstrahlung.',
   },
 
   fileManager: {

src/i18n/en.js

@@ -90,6 +90,8 @@ export default {
     duration: 'Duration',
     playlist: 'Playlist',
     actions: 'Actions',
+    missingPlaylistData:
+      'Information for this playlist is currently not available. Switch to the show of this emission.',
   },
 
   fileManager: {