Fix up preview URL API. Add tests.
This includes: - Splitting out methods of a class into stand alone functions, to make them easier to test. - Adding unit tests to split out functions, testing HTML -> preview. - Handle the fact that elements in lxml may have tail text.
This commit is contained in:
Erik Johnston
parent
7c6f4f9427
commit
48b5829aea
|
|
@ -163,7 +163,7 @@ class PreviewUrlResource(Resource):
|
|||
|
||||
logger.debug("got media_info of '%s'" % media_info)
|
||||
|
||||
if self._is_media(media_info['media_type']):
|
||||
if _is_media(media_info['media_type']):
|
||||
dims = yield self.media_repo._generate_local_thumbnails(
|
||||
media_info['filesystem_id'], media_info
|
||||
)
|
||||
|
|
@ -184,11 +184,9 @@ class PreviewUrlResource(Resource):
|
|||
logger.warn("Couldn't get dims for %s" % url)
|
||||
|
||||
# define our OG response for this media
|
||||
elif self._is_html(media_info['media_type']):
|
||||
elif _is_html(media_info['media_type']):
|
||||
# TODO: somehow stop a big HTML tree from exploding synapse's RAM
|
||||
|
||||
from lxml import etree
|
||||
|
||||
file = open(media_info['filename'])
|
||||
body = file.read()
|
||||
file.close()
|
||||
|
|
@ -199,17 +197,35 @@ class PreviewUrlResource(Resource):
|
|||
match = re.match(r'.*; *charset=(.*?)(;|$)', media_info['media_type'], re.I)
|
||||
encoding = match.group(1) if match else "utf-8"
|
||||
|
||||
try:
|
||||
parser = etree.HTMLParser(recover=True, encoding=encoding)
|
||||
tree = etree.fromstring(body, parser)
|
||||
og = yield self._calc_og(tree, media_info, requester)
|
||||
except UnicodeDecodeError:
|
||||
# blindly try decoding the body as utf-8, which seems to fix
|
||||
# the charset mismatches on https://google.com
|
||||
parser = etree.HTMLParser(recover=True, encoding=encoding)
|
||||
tree = etree.fromstring(body.decode('utf-8', 'ignore'), parser)
|
||||
og = yield self._calc_og(tree, media_info, requester)
|
||||
og = decode_and_calc_og(body, media_info['uri'], encoding)
|
||||
|
||||
# pre-cache the image for posterity
|
||||
# FIXME: it might be cleaner to use the same flow as the main /preview_url
|
||||
# request itself and benefit from the same caching etc. But for now we
|
||||
# just rely on the caching on the master request to speed things up.
|
||||
if 'og:image' in og and og['og:image']:
|
||||
image_info = yield self._download_url(
|
||||
_rebase_url(og['og:image'], media_info['uri']), requester.user
|
||||
)
|
||||
|
||||
if _is_media(image_info['media_type']):
|
||||
# TODO: make sure we don't choke on white-on-transparent images
|
||||
dims = yield self.media_repo._generate_local_thumbnails(
|
||||
image_info['filesystem_id'], image_info
|
||||
)
|
||||
if dims:
|
||||
og["og:image:width"] = dims['width']
|
||||
og["og:image:height"] = dims['height']
|
||||
else:
|
||||
logger.warn("Couldn't get dims for %s" % og["og:image"])
|
||||
|
||||
og["og:image"] = "mxc://%s/%s" % (
|
||||
self.server_name, image_info['filesystem_id']
|
||||
)
|
||||
og["og:image:type"] = image_info['media_type']
|
||||
og["matrix:image:size"] = image_info['media_length']
|
||||
else:
|
||||
del og["og:image"]
|
||||
else:
|
||||
logger.warn("Failed to find any OG data in %s", url)
|
||||
og = {}
|
||||
|
|
@ -232,139 +248,6 @@ class PreviewUrlResource(Resource):
|
|||
|
||||
respond_with_json_bytes(request, 200, json.dumps(og), send_cors=True)
|
||||
|
||||
@defer.inlineCallbacks
|
||||
def _calc_og(self, tree, media_info, requester):
|
||||
# suck our tree into lxml and define our OG response.
|
||||
|
||||
# if we see any image URLs in the OG response, then spider them
|
||||
# (although the client could choose to do this by asking for previews of those
|
||||
# URLs to avoid DoSing the server)
|
||||
|
||||
# "og:type" : "video",
|
||||
# "og:url" : "https://www.youtube.com/watch?v=LXDBoHyjmtw",
|
||||
# "og:site_name" : "YouTube",
|
||||
# "og:video:type" : "application/x-shockwave-flash",
|
||||
# "og:description" : "Fun stuff happening here",
|
||||
# "og:title" : "RemoteJam - Matrix team hack for Disrupt Europe Hackathon",
|
||||
# "og:image" : "https://i.ytimg.com/vi/LXDBoHyjmtw/maxresdefault.jpg",
|
||||
# "og:video:url" : "http://www.youtube.com/v/LXDBoHyjmtw?version=3&autohide=1",
|
||||
# "og:video:width" : "1280"
|
||||
# "og:video:height" : "720",
|
||||
# "og:video:secure_url": "https://www.youtube.com/v/LXDBoHyjmtw?version=3",
|
||||
|
||||
og = {}
|
||||
for tag in tree.xpath("//*/meta[starts-with(@property, 'og:')]"):
|
||||
if 'content' in tag.attrib:
|
||||
og[tag.attrib['property']] = tag.attrib['content']
|
||||
|
||||
# TODO: grab article: meta tags too, e.g.:
|
||||
|
||||
# "article:publisher" : "https://www.facebook.com/thethudonline" />
|
||||
# "article:author" content="https://www.facebook.com/thethudonline" />
|
||||
# "article:tag" content="baby" />
|
||||
# "article:section" content="Breaking News" />
|
||||
# "article:published_time" content="2016-03-31T19:58:24+00:00" />
|
||||
# "article:modified_time" content="2016-04-01T18:31:53+00:00" />
|
||||
|
||||
if 'og:title' not in og:
|
||||
# do some basic spidering of the HTML
|
||||
title = tree.xpath("(//title)[1] | (//h1)[1] | (//h2)[1] | (//h3)[1]")
|
||||
og['og:title'] = title[0].text.strip() if title else None
|
||||
|
||||
if 'og:image' not in og:
|
||||
# TODO: extract a favicon failing all else
|
||||
meta_image = tree.xpath(
|
||||
"//*/meta[translate(@itemprop, 'IMAGE', 'image')='image']/@content"
|
||||
)
|
||||
if meta_image:
|
||||
og['og:image'] = self._rebase_url(meta_image[0], media_info['uri'])
|
||||
else:
|
||||
# TODO: consider inlined CSS styles as well as width & height attribs
|
||||
images = tree.xpath("//img[@src][number(@width)>10][number(@height)>10]")
|
||||
images = sorted(images, key=lambda i: (
|
||||
-1 * float(i.attrib['width']) * float(i.attrib['height'])
|
||||
))
|
||||
if not images:
|
||||
images = tree.xpath("//img[@src]")
|
||||
if images:
|
||||
og['og:image'] = images[0].attrib['src']
|
||||
|
||||
# pre-cache the image for posterity
|
||||
# FIXME: it might be cleaner to use the same flow as the main /preview_url
|
||||
# request itself and benefit from the same caching etc. But for now we
|
||||
# just rely on the caching on the master request to speed things up.
|
||||
if 'og:image' in og and og['og:image']:
|
||||
image_info = yield self._download_url(
|
||||
self._rebase_url(og['og:image'], media_info['uri']), requester.user
|
||||
)
|
||||
|
||||
if self._is_media(image_info['media_type']):
|
||||
# TODO: make sure we don't choke on white-on-transparent images
|
||||
dims = yield self.media_repo._generate_local_thumbnails(
|
||||
image_info['filesystem_id'], image_info
|
||||
)
|
||||
if dims:
|
||||
og["og:image:width"] = dims['width']
|
||||
og["og:image:height"] = dims['height']
|
||||
else:
|
||||
logger.warn("Couldn't get dims for %s" % og["og:image"])
|
||||
|
||||
og["og:image"] = "mxc://%s/%s" % (
|
||||
self.server_name, image_info['filesystem_id']
|
||||
)
|
||||
og["og:image:type"] = image_info['media_type']
|
||||
og["matrix:image:size"] = image_info['media_length']
|
||||
else:
|
||||
del og["og:image"]
|
||||
|
||||
if 'og:description' not in og:
|
||||
meta_description = tree.xpath(
|
||||
"//*/meta"
|
||||
"[translate(@name, 'DESCRIPTION', 'description')='description']"
|
||||
"/@content")
|
||||
if meta_description:
|
||||
og['og:description'] = meta_description[0]
|
||||
else:
|
||||
# grab any text nodes which are inside the <body/> tag...
|
||||
# unless they are within an HTML5 semantic markup tag...
|
||||
# <header/>, <nav/>, <aside/>, <footer/>
|
||||
# ...or if they are within a <script/> or <style/> tag.
|
||||
# This is a very very very coarse approximation to a plain text
|
||||
# render of the page.
|
||||
|
||||
# We don't just use XPATH here as that is slow on some machines.
|
||||
|
||||
# We clone `tree` as we modify it.
|
||||
cloned_tree = deepcopy(tree.find("body"))
|
||||
|
||||
TAGS_TO_REMOVE = ("header", "nav", "aside", "footer", "script", "style",)
|
||||
for el in cloned_tree.iter(TAGS_TO_REMOVE):
|
||||
el.getparent().remove(el)
|
||||
|
||||
# Split all the text nodes into paragraphs (by splitting on new
|
||||
# lines)
|
||||
text_nodes = (
|
||||
re.sub(r'\s+', '\n', el.text).strip()
|
||||
for el in cloned_tree.iter()
|
||||
if el.text and isinstance(el.tag, basestring) # Removes comments
|
||||
)
|
||||
og['og:description'] = summarize_paragraphs(text_nodes)
|
||||
|
||||
# TODO: delete the url downloads to stop diskfilling,
|
||||
# as we only ever cared about its OG
|
||||
defer.returnValue(og)
|
||||
|
||||
def _rebase_url(self, url, base):
|
||||
base = list(urlparse.urlparse(base))
|
||||
url = list(urlparse.urlparse(url))
|
||||
if not url[0]: # fix up schema
|
||||
url[0] = base[0] or "http"
|
||||
if not url[1]: # fix up hostname
|
||||
url[1] = base[1]
|
||||
if not url[2].startswith('/'):
|
||||
url[2] = re.sub(r'/[^/]+$', '/', base[2]) + url[2]
|
||||
return urlparse.urlunparse(url)
|
||||
|
||||
@defer.inlineCallbacks
|
||||
def _download_url(self, url, user):
|
||||
# TODO: we should probably honour robots.txt... except in practice
|
||||
|
|
@ -445,11 +328,167 @@ class PreviewUrlResource(Resource):
|
|||
"etag": headers["ETag"][0] if "ETag" in headers else None,
|
||||
})
|
||||
|
||||
def _is_media(self, content_type):
|
||||
|
||||
def decode_and_calc_og(body, media_uri, request_encoding=None):
|
||||
from lxml import etree
|
||||
|
||||
try:
|
||||
parser = etree.HTMLParser(recover=True, encoding=request_encoding)
|
||||
tree = etree.fromstring(body, parser)
|
||||
og = _calc_og(tree, media_uri)
|
||||
except UnicodeDecodeError:
|
||||
# blindly try decoding the body as utf-8, which seems to fix
|
||||
# the charset mismatches on https://google.com
|
||||
parser = etree.HTMLParser(recover=True, encoding=request_encoding)
|
||||
tree = etree.fromstring(body.decode('utf-8', 'ignore'), parser)
|
||||
og = _calc_og(tree, media_uri)
|
||||
|
||||
return og
|
||||
|
||||
|
||||
def _calc_og(tree, media_uri):
|
||||
# suck our tree into lxml and define our OG response.
|
||||
|
||||
# if we see any image URLs in the OG response, then spider them
|
||||
# (although the client could choose to do this by asking for previews of those
|
||||
# URLs to avoid DoSing the server)
|
||||
|
||||
# "og:type" : "video",
|
||||
# "og:url" : "https://www.youtube.com/watch?v=LXDBoHyjmtw",
|
||||
# "og:site_name" : "YouTube",
|
||||
# "og:video:type" : "application/x-shockwave-flash",
|
||||
# "og:description" : "Fun stuff happening here",
|
||||
# "og:title" : "RemoteJam - Matrix team hack for Disrupt Europe Hackathon",
|
||||
# "og:image" : "https://i.ytimg.com/vi/LXDBoHyjmtw/maxresdefault.jpg",
|
||||
# "og:video:url" : "http://www.youtube.com/v/LXDBoHyjmtw?version=3&autohide=1",
|
||||
# "og:video:width" : "1280"
|
||||
# "og:video:height" : "720",
|
||||
# "og:video:secure_url": "https://www.youtube.com/v/LXDBoHyjmtw?version=3",
|
||||
|
||||
og = {}
|
||||
for tag in tree.xpath("//*/meta[starts-with(@property, 'og:')]"):
|
||||
if 'content' in tag.attrib:
|
||||
og[tag.attrib['property']] = tag.attrib['content']
|
||||
|
||||
# TODO: grab article: meta tags too, e.g.:
|
||||
|
||||
# "article:publisher" : "https://www.facebook.com/thethudonline" />
|
||||
# "article:author" content="https://www.facebook.com/thethudonline" />
|
||||
# "article:tag" content="baby" />
|
||||
# "article:section" content="Breaking News" />
|
||||
# "article:published_time" content="2016-03-31T19:58:24+00:00" />
|
||||
# "article:modified_time" content="2016-04-01T18:31:53+00:00" />
|
||||
|
||||
if 'og:title' not in og:
|
||||
# do some basic spidering of the HTML
|
||||
title = tree.xpath("(//title)[1] | (//h1)[1] | (//h2)[1] | (//h3)[1]")
|
||||
og['og:title'] = title[0].text.strip() if title else None
|
||||
|
||||
if 'og:image' not in og:
|
||||
# TODO: extract a favicon failing all else
|
||||
meta_image = tree.xpath(
|
||||
"//*/meta[translate(@itemprop, 'IMAGE', 'image')='image']/@content"
|
||||
)
|
||||
if meta_image:
|
||||
og['og:image'] = _rebase_url(meta_image[0], media_uri)
|
||||
else:
|
||||
# TODO: consider inlined CSS styles as well as width & height attribs
|
||||
images = tree.xpath("//img[@src][number(@width)>10][number(@height)>10]")
|
||||
images = sorted(images, key=lambda i: (
|
||||
-1 * float(i.attrib['width']) * float(i.attrib['height'])
|
||||
))
|
||||
if not images:
|
||||
images = tree.xpath("//img[@src]")
|
||||
if images:
|
||||
og['og:image'] = images[0].attrib['src']
|
||||
|
||||
if 'og:description' not in og:
|
||||
meta_description = tree.xpath(
|
||||
"//*/meta"
|
||||
"[translate(@name, 'DESCRIPTION', 'description')='description']"
|
||||
"/@content")
|
||||
if meta_description:
|
||||
og['og:description'] = meta_description[0]
|
||||
else:
|
||||
# grab any text nodes which are inside the <body/> tag...
|
||||
# unless they are within an HTML5 semantic markup tag...
|
||||
# <header/>, <nav/>, <aside/>, <footer/>
|
||||
# ...or if they are within a <script/> or <style/> tag.
|
||||
# This is a very very very coarse approximation to a plain text
|
||||
# render of the page.
|
||||
|
||||
# We don't just use XPATH here as that is slow on some machines.
|
||||
|
||||
from lxml import etree
|
||||
|
||||
TAGS_TO_REMOVE = (
|
||||
"header", "nav", "aside", "footer", "script", "style", etree.Comment
|
||||
)
|
||||
|
||||
# Split all the text nodes into paragraphs (by splitting on new
|
||||
# lines)
|
||||
text_nodes = (
|
||||
re.sub(r'\s+', '\n', el).strip()
|
||||
for el in _iterate_over_text(tree.find("body"), *TAGS_TO_REMOVE)
|
||||
)
|
||||
og['og:description'] = summarize_paragraphs(text_nodes)
|
||||
|
||||
# TODO: delete the url downloads to stop diskfilling,
|
||||
# as we only ever cared about its OG
|
||||
return og
|
||||
|
||||
|
||||
def _iterate_over_text(tree, *tags_to_ignore):
|
||||
"""Iterate over the tree returning text nodes in a depth first fashion,
|
||||
skipping text nodes inside certain tags.
|
||||
"""
|
||||
import itertools
|
||||
|
||||
# This is basically a stack that we extend using itertools.chain.
|
||||
# This will either consist of an element to iterate over *or* a string
|
||||
# to be returned.
|
||||
elements = iter([tree])
|
||||
while True:
|
||||
el = elements.next()
|
||||
if isinstance(el, basestring):
|
||||
yield el
|
||||
elif el.tag not in tags_to_ignore:
|
||||
# el.text is the text before the first child, so we can immediately
|
||||
# return it if the text exists.
|
||||
if el.text:
|
||||
yield el.text
|
||||
|
||||
# We add to the stack all the elements children, interspersed with
|
||||
# each child's tail text (if it exists). The tail text of a node
|
||||
# is text that comes *after* the node, so we always include it even
|
||||
# if we ignore the child node.
|
||||
elements = itertools.chain(
|
||||
itertools.chain.from_iterable( # Basically a flatmap
|
||||
[child, child.tail] if child.tail else [child]
|
||||
for child in el.iterchildren()
|
||||
),
|
||||
elements
|
||||
)
|
||||
|
||||
|
||||
def _rebase_url(url, base):
|
||||
base = list(urlparse.urlparse(base))
|
||||
url = list(urlparse.urlparse(url))
|
||||
if not url[0]: # fix up schema
|
||||
url[0] = base[0] or "http"
|
||||
if not url[1]: # fix up hostname
|
||||
url[1] = base[1]
|
||||
if not url[2].startswith('/'):
|
||||
url[2] = re.sub(r'/[^/]+$', '/', base[2]) + url[2]
|
||||
return urlparse.urlunparse(url)
|
||||
|
||||
|
||||
def _is_media(content_type):
|
||||
if content_type.lower().startswith("image/"):
|
||||
return True
|
||||
|
||||
def _is_html(self, content_type):
|
||||
|
||||
def _is_html(content_type):
|
||||
content_type = content_type.lower()
|
||||
if (
|
||||
content_type.startswith("text/html") or
|
||||
|
|
|
|||
|
|
@ -15,7 +15,9 @@
|
|||
|
||||
from . import unittest
|
||||
|
||||
from synapse.rest.media.v1.preview_url_resource import summarize_paragraphs
|
||||
from synapse.rest.media.v1.preview_url_resource import (
|
||||
summarize_paragraphs, decode_and_calc_og
|
||||
)
|
||||
|
||||
|
||||
class PreviewTestCase(unittest.TestCase):
|
||||
|
|
@ -137,3 +139,79 @@ class PreviewTestCase(unittest.TestCase):
|
|||
" of old wooden houses in Northern Norway, the oldest house dating from"
|
||||
" 1789. The Arctic Cathedral, a modern church…"
|
||||
)
|
||||
|
||||
|
||||
class PreviewUrlTestCase(unittest.TestCase):
|
||||
def test_simple(self):
|
||||
html = """
|
||||
<html>
|
||||
<head><title>Foo</title></head>
|
||||
<body>
|
||||
Some text.
|
||||
</body>
|
||||
</html>
|
||||
"""
|
||||
|
||||
og = decode_and_calc_og(html, "http://example.com/test.html")
|
||||
|
||||
self.assertEquals(og, {
|
||||
"og:title": "Foo",
|
||||
"og:description": "Some text."
|
||||
})
|
||||
|
||||
def test_comment(self):
|
||||
html = """
|
||||
<html>
|
||||
<head><title>Foo</title></head>
|
||||
<body>
|
||||
<!-- HTML comment -->
|
||||
Some text.
|
||||
</body>
|
||||
</html>
|
||||
"""
|
||||
|
||||
og = decode_and_calc_og(html, "http://example.com/test.html")
|
||||
|
||||
self.assertEquals(og, {
|
||||
"og:title": "Foo",
|
||||
"og:description": "Some text."
|
||||
})
|
||||
|
||||
def test_comment2(self):
|
||||
html = """
|
||||
<html>
|
||||
<head><title>Foo</title></head>
|
||||
<body>
|
||||
Some text.
|
||||
<!-- HTML comment -->
|
||||
Some more text.
|
||||
<p>Text</p>
|
||||
More text
|
||||
</body>
|
||||
</html>
|
||||
"""
|
||||
|
||||
og = decode_and_calc_og(html, "http://example.com/test.html")
|
||||
|
||||
self.assertEquals(og, {
|
||||
"og:title": "Foo",
|
||||
"og:description": "Some text.\n\nSome more text.\n\nText\n\nMore text"
|
||||
})
|
||||
|
||||
def test_script(self):
|
||||
html = """
|
||||
<html>
|
||||
<head><title>Foo</title></head>
|
||||
<body>
|
||||
<script> (function() {})() </script>
|
||||
Some text.
|
||||
</body>
|
||||
</html>
|
||||
"""
|
||||
|
||||
og = decode_and_calc_og(html, "http://example.com/test.html")
|
||||
|
||||
self.assertEquals(og, {
|
||||
"og:title": "Foo",
|
||||
"og:description": "Some text."
|
||||
})
|
||||
|
|
|
|||
Loading…
Reference in New Issue