def render_html(self, highlight_locations=None, start_offset=None, end_offset=None):
# Start by chopping the block down to the proper window.
text = self.text_block[start_offset:end_offset]
# Invert highlight_locations to a location -> term list
term_list = []
for term, locations in highlight_locations.items():
term_list += [(loc - start_offset, term) for loc in locations]
loc_to_term = sorted(term_list)
# Prepare the highlight template
if self.css_class:
hl_start = '<%s class="%s">' % (self.html_tag, self.css_class)
else:
hl_start = '<%s>' % (self.html_tag)
hl_end = '</%s>' % self.html_tag
highlight_length = len(hl_start + hl_end)
# Copy the part from the start of the string to the first match,
# and there replace the match with a highlighted version.
highlighted_chunk = ""
matched_so_far = 0
prev = 0
prev_str = ""
for cur, cur_str in loc_to_term:
# This can be in a different case than cur_str
actual_term = text[cur:cur + len(cur_str)]
# Handle incorrect highlight_locations by first checking for the term
if actual_term.lower() == cur_str:
highlighted_chunk += text[prev + len(prev_str):cur] + hl_start + actual_term + hl_end
prev = cur
prev_str = cur_str
# Keep track of how far we've copied so far, for the last step
matched_so_far = cur + len(actual_term)
# Don't forget the chunk after the last term
highlighted_chunk += text[matched_so_far:]
# Unicode characters at the end of highlighted_chunk might get split,
# leaving behind partial encodings at the end that break Javascript.
# So our highlighted_chunk could be "My heart is in the \u4".
#
# Remove the orphaned encodings by calling trim().
from haystack import trim
highlighted_chunk = trim.trim(highlighted_chunk)
if start_offset > 0:
highlighted_chunk = '...%s' % highlighted_chunk
if end_offset < len(self.text_block):
highlighted_chunk = '%s...' % highlighted_chunk
return highlighted_chunk
def test_trim(self):
"""Checks the output of trim() against selected test cases."""
str0 = "34\u2345\u3456"
str1 = "\u1234\u2345\u3456"
str2 = "\u2345\u3456\\"
str3 = "34\u2345\u3456 \u"
str4 = "34\u2345\u3456\u3"
str5 = "34\u2345\u3456\u34"
str6 = "34\u2345\u3456\u345"
str7 = ""
self.assertTrue(trim.is_trimmed(trim.trim(str0)))
self.assertTrue(trim.is_trimmed(trim.trim(str1)))
self.assertTrue(trim.is_trimmed(trim.trim(str2)))
self.assertTrue(trim.is_trimmed(trim.trim(str3)))
self.assertTrue(trim.is_trimmed(trim.trim(str4)))
self.assertTrue(trim.is_trimmed(trim.trim(str5)))
self.assertTrue(trim.is_trimmed(trim.trim(str6)))
self.assertTrue(trim.is_trimmed(trim.trim(str7)))
