Paging: Improve sanity checks and add in 'DirCount' support

Some AVRs want to know the folder item count before entering it.

ycast/server.py

@@ -32,13 +32,21 @@ def check_my_stations_feature(config):
     my_stations_enabled = my_stations.set_config(config)
 
 
-def get_directories_page(subdir, directories, requestargs):
+def get_directories_page(subdir, directories, requestargs, item_count_function=None):
     page = vtuner.Page()
     if len(directories) == 0:
         page.add(vtuner.Display("No entries found."))
         return page
     for directory in get_paged_elements(directories, requestargs):
-        page.add(vtuner.Directory(directory, url_for(subdir, _external=True, directory=directory)))
+        vtuner_directory = vtuner.Directory(directory, url_for(subdir, _external=True, directory=directory))
+        if item_count_function:
+            try:
+                item_count = len(item_count_function(directory))
+                vtuner_directory.set_item_count(item_count)
+            except TypeError:
+                logging.error("Could not get item count of directory '%s'", directory)
+                pass
+        page.add(vtuner_directory)
     page.set_count(len(directories))
     return page
 
@@ -61,18 +69,20 @@ def get_paged_elements(items, requestargs):
         offset = int(requestargs.get('start')) - 1
     else:
         offset = 0
+    if offset > len(items):
+        logging.warning("Paging offset larger than item count")
+        return []
     if requestargs.get('enditems'):
         limit = int(requestargs.get('enditems'))
     elif requestargs.get('start') and requestargs.get('howmany'):
         limit = int(requestargs.get('start')) - 1 + int(requestargs.get('howmany'))
     else:
         limit = len(items)
-    if offset > len(items):
+    if limit < offset:
-        offset = len(items)
+        logging.warning("Paging limit smaller than offset")
+        return []
     if limit > len(items):
         limit = len(items)
-    if limit < offset:
-        limit = offset
     return items[offset:limit]
 
 
@@ -83,9 +93,10 @@ def landing(path):
     if request.args.get('token') == '0':
         return vtuner.get_init_token()
     page = vtuner.Page()
-    page.add(vtuner.Directory('Radiobrowser', url_for('radiobrowser_landing', _external=True)))
+    page.add(vtuner.Directory('Radiobrowser', url_for('radiobrowser_landing', _external=True), 4))
     if my_stations_enabled:
-        page.add(vtuner.Directory('My Stations', url_for('my_stations_landing', _external=True)))
+        page.add(vtuner.Directory('My Stations', url_for('my_stations_landing', _external=True),
+                                  len(my_stations.get_categories())))
     else:
         page.add(vtuner.Display("'My Stations' feature not configured."))
     return page.to_string()
@@ -96,7 +107,8 @@ def my_stations_landing():
     page = vtuner.Page()
     page.add(vtuner.Previous(url_for("landing", _external=True)))
     directories = my_stations.get_categories()
-    return get_directories_page('my_stations_category', directories, request.args).to_string()
+    return get_directories_page('my_stations_category', directories, request.args,
+                                my_stations.get_stations_by_category).to_string()
 
 
 @app.route('/' + PATH_ROOT + '/' + PATH_MY_STATIONS + '/<directory>')
@@ -109,9 +121,12 @@ def my_stations_category(directory):
 def radiobrowser_landing():
     page = vtuner.Page()
     page.add(vtuner.Previous(url_for('landing', _external=True)))
-    page.add(vtuner.Directory('Genres', url_for('radiobrowser_genres', _external=True)))
+    page.add(vtuner.Directory('Genres', url_for('radiobrowser_genres', _external=True),
-    page.add(vtuner.Directory('Countries', url_for('radiobrowser_countries', _external=True)))
+                              len(radiobrowser.get_genres())))
-    page.add(vtuner.Directory('Most Popular', url_for('radiobrowser_popular', _external=True)))
+    page.add(vtuner.Directory('Countries', url_for('radiobrowser_countries', _external=True),
+                              len(radiobrowser.get_countries())))
+    page.add(vtuner.Directory('Most Popular', url_for('radiobrowser_popular', _external=True),
+                              len(radiobrowser.get_stations_by_votes())))
     page.add(vtuner.Search('Search', url_for('radiobrowser_search', _external=True, path='')))
     return page.to_string()
 
@@ -119,7 +134,8 @@ def radiobrowser_landing():
 @app.route('/' + PATH_ROOT + '/' + PATH_RADIOBROWSER + '/' + PATH_RADIOBROWSER_COUNTRY + '/')
 def radiobrowser_countries():
     directories = radiobrowser.get_countries()
-    return get_directories_page('radiobrowser_country_stations', directories, request.args).to_string()
+    return get_directories_page('radiobrowser_country_stations', directories, request.args,
+                                radiobrowser.get_stations_by_country).to_string()
 
 
 @app.route('/' + PATH_ROOT + '/' + PATH_RADIOBROWSER + '/' + PATH_RADIOBROWSER_COUNTRY + '/<directory>')
@@ -131,7 +147,8 @@ def radiobrowser_country_stations(directory):
 @app.route('/' + PATH_ROOT + '/' + PATH_RADIOBROWSER + '/' + PATH_RADIOBROWSER_GENRE + '/')
 def radiobrowser_genres():
     directories = radiobrowser.get_genres()
-    return get_directories_page('radiobrowser_genre_stations', directories, request.args).to_string()
+    return get_directories_page('radiobrowser_genre_stations', directories, request.args,
+                                radiobrowser.get_stations_by_genre).to_string()
 
 
 @app.route('/' + PATH_ROOT + '/' + PATH_RADIOBROWSER + '/' + PATH_RADIOBROWSER_GENRE + '/<directory>')

ycast/vtuner.py

@@ -86,9 +86,10 @@ class Search:
 
 
 class Directory:
-    def __init__(self, title, destination):
+    def __init__(self, title, destination, item_count=-1):
         self.title = title
         self.destination = destination
+        self.item_count = item_count
 
     def append_to_xml(self, xml):
         item = etree.SubElement(xml, 'Item')
@@ -96,8 +97,12 @@ class Directory:
         etree.SubElement(item, 'Title').text = self.title
         etree.SubElement(item, 'UrlDir').text = add_bogus_parameter(self.destination)
         etree.SubElement(item, 'UrlDirBackUp').text = add_bogus_parameter(self.destination)
+        etree.SubElement(item, 'DirCount').text = str(self.item_count)
         return item
 
+    def set_item_count(self, item_count):
+        self.item_count = item_count
+
 
 class Station:
     def __init__(self, uid, name, description, url, logo, genre, location, mime, bitrate, bookmark):