Create format_list once per SubredditPage

tests/test_subreddit.py

@@ -781,6 +781,7 @@ def test_subreddit_page__draw_item_format(terminal, subreddit_page):
         # Loop through each individual format specifier and check for the desired behavior.
         for fmt in filter(None, '%i %t %s %v %c %r %e %a %S %u %U %A %h %T %g %n %f %F'.split()):
                 subreddit_page.config['subreddit_format'] = fmt
+                subreddit_page.FORMAT_LIST = subreddit_page._create_format_list()
                 subreddit_page._draw_item_format(win, data, 0, 0)
 
                 try:
@@ -829,6 +830,7 @@ def test_subreddit_page__draw_item_format(terminal, subreddit_page):
         # Ensure spaces aren't printed consecutively if data is absent
         data['gold'] = 0
         subreddit_page.config['subreddit_format'] = ' %g '
+        subreddit_page.FORMAT_LIST = subreddit_page._create_format_list()
         subreddit_page._draw_item_format(win, data, 0, 0)
 
         assert terminal.add_line.call_count == 1
@@ -837,6 +839,7 @@ def test_subreddit_page__draw_item_format(terminal, subreddit_page):
 
         # Test for correct handling of separators
         subreddit_page.config['subreddit_format'] = ' | '
+        subreddit_page.FORMAT_LIST = subreddit_page._create_format_list()
         subreddit_page._draw_item_format(win, data, 0, 0)
 
         # Should be called thrice - ' ', '|', ' '

tuir/subreddit_page.py

@@ -26,8 +26,9 @@ class SubredditPage(Page):
 
     # Format separators, used by _create_format and _draw_item_format for
     # attribute handling logic
-    FORMAT_SEP = r"<>/{}[]()|_-~"
+    FORMAT_SEP = r'<>/{}[]()|_-~'
 
+    FORMAT_LIST = ''
     name = 'subreddit'
 
     def __init__(self, reddit, term, config, oauth, name):
@@ -42,6 +43,23 @@ class SubredditPage(Page):
         self.nav = Navigator(self.content.get)
         self.toggled_subreddit = None
 
+        self.FORMAT_LIST = self._create_format_list()
+
+    # Split this out to a function mostly to simplify testing
+    def _create_format_list(self):
+        if self.config['subreddit_format']:
+            # Split the list between %., newlines, and separator characters to
+            # treat them separately
+            format_list = re.split(r'(%.|[\n' + re.escape(self.FORMAT_SEP) + '])',
+                    self.config['subreddit_format'], re.DOTALL)
+
+            # Clean the list of null items. We don't need to join this list
+            # together again, so this is safe.
+            # https://stackoverflow.com/q/2197451
+            return [item for item in format_list if item != '']
+        else:
+            return None
+
     def handle_selected_page(self):
         """
         Open all selected pages in subwindows except other subreddit pages.
@@ -278,20 +296,11 @@ class SubredditPage(Page):
     def _draw_item_format(self, win, data, valid_rows, offset):
         first = True
 
-        # Split the list between %., newlines, and separator characters to
-        # treat them separately
-        format_list = re.split(r'(%.|[\n' + re.escape(self.FORMAT_SEP) + '])', self.config['subreddit_format'], re.DOTALL)
-
-        # Clean the list of null items. We don't need to join this list
-        # together again, so this is safe.
-        # https://stackoverflow.com/q/2197451
-        format_list = [item for item in format_list if item != '']
-
         # Remember whether or not the last character printed was a space. If it
         # was, printing more spaces should be avoided.
         last_was_space = False
 
-        for item in format_list:
+        for item in self.FORMAT_LIST:
             col = 1 if first else None
 
             # We don't want to print consecutive spaces, so check if a space
@@ -598,7 +607,7 @@ class SubredditPage(Page):
         valid_rows = range(0, n_rows)
         offset = 0 if not inverted else - (data['n_rows'] - n_rows)
 
-        # FIXME - this assumes default doesn't have a subreddit_format. In the
+        # TODO - this assumes default doesn't have a subreddit_format. In the
         # future it should, and when it does it will break this if
         if self.config['subreddit_format']:
             self._draw_item_format(win, data, valid_rows, offset)