[utils] Add get_element_by_class

[youtube-dl] / youtube_dl / utils.py

diff --git a/youtube_dl/utils.py b/youtube_dl/utils.py
index 36d5b6c0f244c49526f9f6d2923ae9f40f1965ee..3498697b60d70c45d4041f80f59945aefeb9e035 100644 (file)
--- a/youtube_dl/utils.py
+++ b/youtube_dl/utils.py
@@ -310,9 +310,17 @@ def get_element_by_id(id, html):
     return get_element_by_attribute('id', id, html)
 
 
-def get_element_by_attribute(attribute, value, html):
+def get_element_by_class(class_name, html):
+    return get_element_by_attribute(
+        'class', r'[^\'"]*\b%s\b[^\'"]*' % re.escape(class_name),
+        html, escape_value=False)
+
+
+def get_element_by_attribute(attribute, value, html, escape_value=True):
     """Return the content of the tag with the specified attribute in the passed HTML document"""
 
+    value = re.escape(value) if escape_value else value
+
     m = re.search(r'''(?xs)
         <([a-zA-Z0-9:._-]+)
          (?:\s+[a-zA-Z0-9:._-]+(?:=[a-zA-Z0-9:._-]*|="[^"]*"|='[^']*'))*?
@@ -321,7 +329,7 @@ def get_element_by_attribute(attribute, value, html):
         \s*>
         (?P<content>.*?)
         </\1>
-    ''' % (re.escape(attribute), re.escape(value)), html)
+    ''' % (re.escape(attribute), value), html)
 
     if not m:
         return None