nicer fragments: no anchors in text, prettier short_text

[wolnelektury.git] / apps / catalogue / utils.py

diff --git a/apps/catalogue/utils.py b/apps/catalogue/utils.py
index 0fdeaf8..185f5fa 100644 (file)
--- a/apps/catalogue/utils.py
+++ b/apps/catalogue/utils.py
@@ -5,6 +5,7 @@
 from __future__ import with_statement
 
 import random
+import re
 import time
 from base64 import urlsafe_b64encode
 
@@ -12,6 +13,7 @@ from django.http import HttpResponse, HttpResponseRedirect, Http404, HttpRespons
 from django.core.files.uploadedfile import UploadedFile
 from django.core.files.base import File
 from django.core.files.storage import DefaultStorage
+from django.utils.encoding import force_unicode
 from django.utils.hashcompat import sha_constructor
 from django.conf import settings
 from celery.task import task
@@ -51,7 +53,7 @@ class ExistingFile(UploadedFile):
 
     def __init__(self, path, *args, **kwargs):
         self.path = path
-        return super(ExistingFile, self).__init__(*args, **kwargs)
+        super(ExistingFile, self).__init__(*args, **kwargs)
 
     def temporary_file_path(self):
         return self.path
@@ -189,3 +191,72 @@ class MultiQuerySet(object):
                     offset = 0
                     stop = total_len - len(items)
                     continue
+
+
+def truncate_html_words(s, num, end_text='...'):
+    """Truncates HTML to a certain number of words (not counting tags and
+    comments). Closes opened tags if they were correctly closed in the given
+    html. Takes an optional argument of what should be used to notify that the
+    string has been truncated, defaulting to ellipsis (...).
+
+    Newlines in the HTML are preserved.
+
+    This is just a version of django.utils.text.truncate_html_words with no space before the end_text.
+    """
+    s = force_unicode(s)
+    length = int(num)
+    if length <= 0:
+        return u''
+    html4_singlets = ('br', 'col', 'link', 'base', 'img', 'param', 'area', 'hr', 'input')
+    # Set up regular expressions
+    re_words = re.compile(r'&.*?;|<.*?>|(\w[\w-]*)', re.U)
+    re_tag = re.compile(r'<(/)?([^ ]+?)(?: (/)| .*?)?>')
+    # Count non-HTML words and keep note of open tags
+    pos = 0
+    end_text_pos = 0
+    words = 0
+    open_tags = []
+    while words <= length:
+        m = re_words.search(s, pos)
+        if not m:
+            # Checked through whole string
+            break
+        pos = m.end(0)
+        if m.group(1):
+            # It's an actual non-HTML word
+            words += 1
+            if words == length:
+                end_text_pos = pos
+            continue
+        # Check for tag
+        tag = re_tag.match(m.group(0))
+        if not tag or end_text_pos:
+            # Don't worry about non tags or tags after our truncate point
+            continue
+        closing_tag, tagname, self_closing = tag.groups()
+        tagname = tagname.lower()  # Element names are always case-insensitive
+        if self_closing or tagname in html4_singlets:
+            pass
+        elif closing_tag:
+            # Check for match in open tags list
+            try:
+                i = open_tags.index(tagname)
+            except ValueError:
+                pass
+            else:
+                # SGML: An end tag closes, back to the matching start tag, all unclosed intervening start tags with omitted end tags
+                open_tags = open_tags[i+1:]
+        else:
+            # Add it to the start of the open tags list
+            open_tags.insert(0, tagname)
+    if words <= length:
+        # Don't try to close tags if we don't need to truncate
+        return s
+    out = s[:end_text_pos]
+    if end_text:
+        out += end_text
+    # Close any tags still open
+    for tag in open_tags:
+        out += '</%s>' % tag
+    # Return string
+    return out