From bb9a2ca87c280e1c6ff6740ee9d2764e1b5226a5 Mon Sep 17 00:00:00 2001 From: Matthew Hodgson Date: Thu, 31 Mar 2016 14:15:09 +0100 Subject: synthesise basig OG metadata from pages lacking it --- synapse/rest/media/v1/preview_url_resource.py | 47 +++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py index ca2529cc10..b1d5cabfaa 100644 --- a/synapse/rest/media/v1/preview_url_resource.py +++ b/synapse/rest/media/v1/preview_url_resource.py @@ -23,6 +23,7 @@ from synapse.http.client import SpiderHttpClient from synapse.http.server import request_handler, respond_with_json, respond_with_json_bytes import os +import re import ujson as json import logging @@ -70,6 +71,7 @@ class PreviewUrlResource(BaseMediaResource): # define our OG response for this media elif self._is_html(media_info['media_type']): + # TODO: somehow stop a big HTML tree from exploding synapse's RAM tree = html.parse(media_info['filename']) # suck it up into lxml and define our OG response. @@ -82,17 +84,58 @@ class PreviewUrlResource(BaseMediaResource): # "og:image" : "https://pbs.twimg.com/profile_images/500400952029888512/yI0qtFi7_400x400.png" # "og:description" : "Synapse 0.12 is out! Lots of polishing, performance &amp; bugfixes: /sync API, /r0 prefix, fulltext search, 3PID invites https://t.co/5alhXLLEGP" # "og:site_name" : "Twitter" + + # or: + + # "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" : " ", + # "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&autohide=1", og = {} for tag in tree.xpath("//*/meta[starts-with(@property, 'og:')]"): og[tag.attrib['property']] = tag.attrib['content'] + if not 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 if title else None + + images = tree.xpath("//img") + big_images = [ i for i in images if ( + 'width' in i and 'height' in i and + i.attrib['width'] > 64 and i.attrib['height'] > 64 + )] or images + og['og:image'] = images[0].attrib['src'] if images else None + + text_nodes = tree.xpath("//h1/text() | //h2/text() | //h3/text() | //p/text() | //div/text() | //span/text() | //a/text()") + text = '' + for text_node in text_nodes: + if len(text) < 1024: + text += text_node + ' ' + else: + break + text = re.sub(r'[\t ]+', ' ', text) + text = re.sub(r'[\t \r\n]*[\r\n]+', '\n', text) + text = text.strip()[:1024] + og['og:description'] = text if text else None + + # TODO: turn any OG media URLs into mxc URLs to capture and thumbnail them too # TODO: store our OG details in a cache (and expire them when stale) # TODO: delete the content to stop diskfilling, as we only ever cared about its OG else: logger.warn("Failed to find any OG data in %s", url) og = {} + logger.warn(og) + respond_with_json_bytes(request, 200, json.dumps(og), send_cors=True) except: # XXX: if we don't explicitly respond here, the request never returns. @@ -111,6 +154,10 @@ class PreviewUrlResource(BaseMediaResource): @defer.inlineCallbacks def _download_url(self, url, user): + # TODO: we should probably honour robots.txt... except in practice + # we're most likely being explicitly triggered by a human rather than a + # bot, so are we really a robot? + # XXX: horrible duplication with base_resource's _download_remote_file() file_id = random_string(24) -- cgit 1.4.1