diff options
| -rw-r--r-- | synapse/rest/media/v1/preview_url_resource.py | 106 | ||||
| -rw-r--r-- | tests/test_preview.py | 139 |
2 files changed, 193 insertions, 52 deletions
diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py index ebd07d696b..b2e2e7e624 100644 --- a/synapse/rest/media/v1/preview_url_resource.py +++ b/synapse/rest/media/v1/preview_url_resource.py @@ -347,58 +347,7 @@ class PreviewUrlResource(Resource): re.sub(r'\s+', '\n', el.text).strip() for el in cloned_tree.iter() if el.text ) - - # Try to get a summary of between 200 and 500 words, respecting - # first paragraph and then word boundaries. - # TODO: Respect sentences? - MIN_SIZE = 200 - MAX_SIZE = 500 - - description = '' - - # Keep adding paragraphs until we get to the MIN_SIZE. - for text_node in text_nodes: - if len(description) < MIN_SIZE: - description += text_node + '\n' - else: - break - - description = description.strip() - description = re.sub(r'[\t ]+', ' ', description) - description = re.sub(r'[\t \r\n]*[\r\n]+', '\n', description) - - # If the concatenation of paragraphs to get above MIN_SIZE - # took us over MAX_SIZE, then we need to truncate mid paragraph - if len(description) > MAX_SIZE: - new_desc = "" - - # This splits the paragraph into words, but keeping the - # (preceeding) whitespace intact so we can easily concat - # words back together. - for match in re.finditer("\s*\S+", description): - word = match.group() - - # Keep adding words while the total length is less than - # MAX_SIZE. - if len(word) + len(new_desc) < MAX_SIZE: - new_desc += word - else: - # At this point the next word *will* take us over - # MAX_SIZE, but we also want to ensure that its not - # a huge word. If it is add it anyway and we'll - # truncate later. - if len(new_desc) < MIN_SIZE: - new_desc += word - break - - # Double check that we're not over the limit - if len(new_desc) > MAX_SIZE: - new_desc = new_desc[:MAX_SIZE] - - # We always add an ellipsis because at the very least - # we chopped mid paragraph. - description = new_desc.strip() + "…" - og['og:description'] = description if description else None + og['og:description'] = _summarize_paragraphs(text_nodes) # TODO: delete the url downloads to stop diskfilling, # as we only ever cared about its OG @@ -506,3 +455,56 @@ class PreviewUrlResource(Resource): content_type.startswith("application/xhtml") ): return True + + +def summarize_paragraphs(text_nodes, min_size=200, max_size=500): + # Try to get a summary of between 200 and 500 words, respecting + # first paragraph and then word boundaries. + # TODO: Respect sentences? + + description = '' + + # Keep adding paragraphs until we get to the MIN_SIZE. + for text_node in text_nodes: + if len(description) < min_size: + text_node = re.sub(r'[\t \r\n]+', ' ', text_node) + description += text_node + '\n\n' + else: + break + + description = description.strip() + description = re.sub(r'[\t ]+', ' ', description) + description = re.sub(r'[\t \r\n]*[\r\n]+', '\n\n', description) + + # If the concatenation of paragraphs to get above MIN_SIZE + # took us over MAX_SIZE, then we need to truncate mid paragraph + if len(description) > max_size: + new_desc = "" + + # This splits the paragraph into words, but keeping the + # (preceeding) whitespace intact so we can easily concat + # words back together. + for match in re.finditer("\s*\S+", description): + word = match.group() + + # Keep adding words while the total length is less than + # MAX_SIZE. + if len(word) + len(new_desc) < max_size: + new_desc += word + else: + # At this point the next word *will* take us over + # MAX_SIZE, but we also want to ensure that its not + # a huge word. If it is add it anyway and we'll + # truncate later. + if len(new_desc) < min_size: + new_desc += word + break + + # Double check that we're not over the limit + if len(new_desc) > max_size: + new_desc = new_desc[:max_size] + + # We always add an ellipsis because at the very least + # we chopped mid paragraph. + description = new_desc.strip() + "…" + return description if description else None diff --git a/tests/test_preview.py b/tests/test_preview.py new file mode 100644 index 0000000000..2a801173a0 --- /dev/null +++ b/tests/test_preview.py @@ -0,0 +1,139 @@ +# -*- coding: utf-8 -*- +# Copyright 2014-2016 OpenMarket Ltd +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from . import unittest + +from synapse.rest.media.v1.preview_url_resource import summarize_paragraphs + + +class PreviewTestCase(unittest.TestCase): + + def test_long_summarize(self): + example_paras = [ + """Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami: + Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in + Troms county, Norway. The administrative centre of the municipality is + the city of Tromsø. Outside of Norway, Tromso and Tromsö are + alternative spellings of the city.Tromsø is considered the northernmost + city in the world with a population above 50,000. The most populous town + north of it is Alta, Norway, with a population of 14,272 (2013).""", + + """Tromsø lies in Northern Norway. The municipality has a population of + (2015) 72,066, but with an annual influx of students it has over 75,000 + most of the year. It is the largest urban area in Northern Norway and the + third largest north of the Arctic Circle (following Murmansk and Norilsk). + Most of Tromsø, including the city centre, is located on the island of + Tromsøya, 350 kilometres (217 mi) north of the Arctic Circle. In 2012, + Tromsøya had a population of 36,088. Substantial parts of the urban area + are also situated on the mainland to the east, and on parts of Kvaløya—a + large island to the west. Tromsøya is connected to the mainland by the Tromsø + Bridge and the Tromsøysund Tunnel, and to the island of Kvaløya by the + Sandnessund Bridge. Tromsø Airport connects the city to many destinations + in Europe. The city is warmer than most other places located on the same + latitude, due to the warming effect of the Gulf Stream.""", + + """The city centre of Tromsø contains the highest number of old wooden + houses in Northern Norway, the oldest house dating from 1789. The Arctic + Cathedral, a modern church from 1965, is probably the most famous landmark + in Tromsø. The city is a cultural centre for its region, with several + festivals taking place in the summer. Some of Norway's best-known + musicians, Torbjørn Brundtland and Svein Berge of the electronica duo + Röyksopp and Lene Marlin grew up and started their careers in Tromsø. + Noted electronic musician Geir Jenssen also hails from Tromsø.""", + ] + + desc = summarize_paragraphs(example_paras, min_size=200, max_size=500) + + self.assertEquals( + desc, + "Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:" + " Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in" + " Troms county, Norway. The administrative centre of the municipality is" + " the city of Tromsø. Outside of Norway, Tromso and Tromsö are" + " alternative spellings of the city.Tromsø is considered the northernmost" + " city in the world with a population above 50,000. The most populous town" + " north of it is Alta, Norway, with a population of 14,272 (2013)." + ) + + desc = summarize_paragraphs(example_paras[1:], min_size=200, max_size=500) + + self.assertEquals( + desc, + "Tromsø lies in Northern Norway. The municipality has a population of" + " (2015) 72,066, but with an annual influx of students it has over 75,000" + " most of the year. It is the largest urban area in Northern Norway and the" + " third largest north of the Arctic Circle (following Murmansk and Norilsk)." + " Most of Tromsø, including the city centre, is located on the island of" + " Tromsøya, 350 kilometres (217 mi) north of the Arctic Circle. In 2012," + " Tromsøya had a population of 36,088. Substantial parts of the…" + ) + + def test_short_summarize(self): + example_paras = [ + "Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:" + " Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in" + " Troms county, Norway.", + + "Tromsø lies in Northern Norway. The municipality has a population of" + " (2015) 72,066, but with an annual influx of students it has over 75,000" + " most of the year.", + + "The city centre of Tromsø contains the highest number of old wooden" + " houses in Northern Norway, the oldest house dating from 1789. The Arctic" + " Cathedral, a modern church from 1965, is probably the most famous landmark" + " in Tromsø.", + ] + + desc = summarize_paragraphs(example_paras, min_size=200, max_size=500) + + self.assertEquals( + desc, + "Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:" + " Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in" + " Troms county, Norway.\n" + "\n" + "Tromsø lies in Northern Norway. The municipality has a population of" + " (2015) 72,066, but with an annual influx of students it has over 75,000" + " most of the year." + ) + + def test_small_then_large_summarize(self): + example_paras = [ + "Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:" + " Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in" + " Troms county, Norway.", + + "Tromsø lies in Northern Norway. The municipality has a population of" + " (2015) 72,066, but with an annual influx of students it has over 75,000" + " most of the year." + " The city centre of Tromsø contains the highest number of old wooden" + " houses in Northern Norway, the oldest house dating from 1789. The Arctic" + " Cathedral, a modern church from 1965, is probably the most famous landmark" + " in Tromsø.", + ] + + desc = summarize_paragraphs(example_paras, min_size=200, max_size=500) + self.assertEquals( + desc, + "Tromsø (Norwegian pronunciation: [ˈtrʊmsœ] ( listen); Northern Sami:" + " Romsa; Finnish: Tromssa[2] Kven: Tromssa) is a city and municipality in" + " Troms county, Norway.\n" + "\n" + "Tromsø lies in Northern Norway. The municipality has a population of" + " (2015) 72,066, but with an annual influx of students it has over 75,000" + " most of the year. The city centre of Tromsø contains the highest number" + " of old wooden houses in Northern Norway, the oldest house dating from" + " 1789. The Arctic Cathedral, a modern church…" + ) |