https://meta.discourse.org/t/markdown-preview-and-result-differ/263878
The result of this markdown had different results in the composer preview and the post. This is solved by updating Loofah to the latest version and using html5 fragments like our user had reported. While the change was only needed in cooked_post_processor.rb for this fix, other areas also had to be updated due to various side effects.
When doing local oneboxes we sometimes want to allow
SVGs in the final preview HTML. The main case currently
is for the new cooked hashtags, which include an SVG
icon.
SVGs will be included in local oneboxes via `ExcerptParser` _only_
if they have the d-icon class, and if the caller for `post.excerpt`
specifies the `keep_svg: true` option.
This is a much better description of its function. It performs idempotent normalization of a URL. If consumers truly need to `encode` a URL (including double-encoding of existing encoded entities), they can use the existing `.encode` method.
In 7328a2bfb0 we changed the
InlineOneboxer#onebox_for method to run the title of the
onebox through WatchedWord#censor_text. However, it is
allowable for the title to be nil, which was causing this
error in production:
> NoMethodError : undefined method gsub for nil:NilClass
We just need to check whether the title is nil before trying
to censor it.
Meta topic: https://meta.discourse.org/t/prevent-to-linkify-when-there-is-a-redirect/226964/2?u=osama.
This commit adds a new site setting `block_onebox_on_redirect` (default off) for blocking oneboxes (full and inline) of URLs that redirect. Note that an initial http → https redirect is still allowed if the redirect location is identical to the source (minus the scheme of course). For example, if a user includes a link to `http://example.com/page` and the link resolves to `https://example.com/page`, then the link will onebox (assuming it can be oneboxed) even if the setting is enabled. The reason for this is a user may type out a URL (i.e. the URL is short and memorizable) with http and since a lot of sites support TLS with http traffic automatically redirected to https, so we should still allow the URL to onebox.
Currently we’re reopening the `Sanitize::Config` class (which is part of
the `sanitize` gem) to put our custom config for Onebox in it. This is
unnecessary as we can simply create a dedicated module to hold our
custom configuration.
The `blocked onebox domains` setting lets site owners change what sites
are allowed to be oneboxed. When a link is entered into a post,
Discourse checks the domain of the link against that setting and blocks
the onebox if the domain is blocked. But if there's a chain of
redirects, then only the final destination website is checked against
the site setting.
This commit amends that behavior so that every website in the redirect
chain is checked against the site setting, and if anything is blocked
the original link doesn't onebox at all in the post. The
`Discourse-No-Onebox` header is also checked in every response and the
onebox is blocked if the header is set to "1".
Additionally, Discourse will now include the `Discourse-No-Onebox`
header with every response if the site requires login to access content.
This is done to signal to a Discourse instance that it shouldn't attempt
to onebox other Discourse instances if they're login-only. Non-Discourse
websites can also use include that header if they don't wish to have
Discourse onebox their content.
Internal ticket: t59305.
In an earlier PR, we decided that we only want to block a domain if
the blocked domain in the SiteSetting is the final destination (/t/59305). That
PR used `FinalDestination#get`. `resolve` however is used several places
but blocks domains along the redirect chain when certain options are provided.
This commit changes the default options for `resolve` to not do that. Existing
users of `FinalDestination#resolve` are
- `Oneboxer#external_onebox`
- our onebox helper `fetch_html_doc`, which is used in amazon, standard embed
and youtube
- these folks already go through `Oneboxer#external_onebox` which already
blocks correctly
* FEATURE: Onebox can match engines based on the content_type
`FinalDestination` now returns the `content_type` of a resolved URL.
`Oneboxer` passes this value to `Onebox` itself. Onebox engines can now specify a `matches_content_type` regex of content_types that the engine can handle, regardless of the URL.
`ImageOnebox` will match URLs with a content type of `image/png`, `jpg`, `gif`, `bmp`, `tif`, etc.
This will allow images that exist at a URL without a file type extension to be correctly rendered, assuming a valid `content_type` is returned.
* FIX: return an empty result if response from Amazon is missing attributes
Check we have the basic attributes requires to construct a Onebox for Amazon.
This is an attempt to handle scenarios where we receive a valid 200-status response from an Amazon request that does not include the data we’re expecting.
* Update lib/onebox/engine/amazon_onebox.rb
Co-authored-by: Régis Hanol <regis@hanol.fr>
Co-authored-by: Régis Hanol <regis@hanol.fr>
* DEV: Allow wildcards in Oneboxer optional domain Site Settings
Allows a wildcard to be used as a subdomain on Oneboxer-related SiteSettings, e.g.:
- `force_get_hosts`
- `cache_onebox_response_body_domains`
- `force_custom_user_agent_hosts`
* DEV: fix typos
* FIX: Try doing a GET after receiving a 500 error from a HEAD
By default we try to do a `HEAD` requests. If this results in a 500 error response, we should try to do a `GET`
* DEV: `force_get_hosts` should be a hidden setting
* DEV: Oneboxer Strategies
Have an alternative oneboxing ‘strategy’ (i.e., set of options) to use when an attempt to generate a Onebox fails. Keep track of any non-default strategies that were used on a particular host, and use that strategy for that host in the future.
Initially, the alternate strategy (`force_get_and_ua`) forces the FinalDestination step of Oneboxing to do a `GET` rather than `HEAD`, and forces a custom user agent.
* DEV: change stubbed return code
The stubbed status code needs to be a value not recognized by FinalDestination
CookedPostProcessor used Loofah to parse the cooked content of a post
and Nokogiri to parse cooked Oneboxes. Even though Loofah is built on
top of Nokogiri, replacing an element from the cooked post (a Nokogiri
node) with a parsed onebox (a Loofah node) produced a strange result
which included XML namespaces. Removing the mix and using Loofah
to parse Oneboxes fixed the problem.
* FEATURE: Cache successful HTTP GET requests during Oneboxing
Some oneboxes may fail if when making excessive and/or odd requests against the target domains. This change provides a simple mechanism to cache the results of succesful GET requests as part of the oneboxing process, with the goal of reducing repeated requests and ultimately improving the rate of successful oneboxing.
To enable:
Set `SiteSetting.cache_onebox_response_body` to `true`
Add the domains you’re interesting in caching to `SiteSetting. cache_onebox_response_body_domains` e.g. `example.com|example.org|example.net`
Optionally set `SiteSetting.cache_onebox_user_agent` to a user agent string of your choice to use when making requests against domains in the above list.
* FIX: Swap order of duration and value in redis call
The correct order for `setex` arguments is `key`, `duration`, and `value`.
Duration and value had been flipped, however the code would not have thrown an error because we were caching the value of `1.day.to_i` for a period of 1 seconds… The intention appears to be to set a value of 1 (purely as a flag) for a period of 1 day.
It has been observed that doing a HEAD against an Amazon store URL may result in a 405 error being returned.
Skipping the HEAD request may result in an improved oneboxing experience when requesting these URLs.
`Onebox.preview` can return 0-to-n errors, where the errors are missing OpenGraph attributes (e.g. title, description, image, etc.). If any of these attributes are missing, we construct an error message and attach it to the Oneboxer preview HTML. The error message is something like:
“Sorry, we were unable to generate a preview for this web page, because the following oEmbed / OpenGraph tags could not be found: description, image”
However, if the only missing tag is `image` we don’t need to display the error, as we have enough other data (title, description, etc.) to construct a useful/complete Onebox.
Uses discourse/onebox@ff9ec90
Adds a hidden site setting called disable_onebox_media_download_controls which will add controlslist="nodownload" to video and audio oneboxes, and also to the local video and audio oneboxes within Discourse.
It used to insert block Oneboxes inside paragraphs which resulted in
invalid HTML. This needed an additional parsing for removal of empty
paragraphs and the resulting HTML could still be invalid.
This commit ensure that block Oneboxes are inserted correctly, by
splitting the paragraph containing the link and putting the block
between the two. Paragraphs left with nothing but whitespaces will
be removed.
Follow up to 7f3a30d79f.
* DEV: More robust processing of URLs
The previous `UrlHelper.encode_component(CGI.unescapeHTML(UrlHelper.unencode(uri))` method would naively process URLs, which could result in a badly formed response.
`Addressable::URI.normalized_encode(uri)` appears to deal with these edge-cases in a more robust way.
* DEV: onebox should use UrlHelper
* DEV: fix spec
* DEV: Escape output when rendering local links
* FEATURE: onebox for local categories
This commit adjusts the category onebox to look more like the category boxes do on the category page.
Co-authored-by: Jordan Vidrine <jordan@jordanvidrine.com>
* FEATURE: display error if Oneboxing fails due to HTTP error
- display warning if onebox URL is unresolvable
- display warning if attributes are missing
* FEATURE: Use new Instagram oEmbed endpoint if access token is configured
Instagram requires an Access Token to access their oEmbed endpoint. The requirements (from https://developers.facebook.com/docs/instagram/oembed/) are as follows:
- a Facebook Developer account, which you can create at developers.facebook.com
- a registered Facebook app
- the oEmbed Product added to the app
- an Access Token
- The Facebook app must be in Live Mode
The generated Access Token, once added to SiteSetting.facebook_app_access_token, will be passed to onebox. Onebox can then use this token to access the oEmbed endpoint to generate a onebox for Instagram.
* DEV: update user agent string
* DEV: don’t do HEAD requests against news.yahoo.com
* DEV: Bump onebox version from 2.1.5 to 2.1.6
* DEV: Avoid re-reading templates
* DEV: Tweaks to onebox mustache templates
* DEV: simplified error message for missing onebox data
* Apply suggestions from code review
Co-authored-by: Gerhard Schlager <mail@gerhard-schlager.at>
This commit adds a new site setting "allowed_onebox_iframes". By default, all onebox iframes are allowed. When the list of domains is restricted, Onebox will automatically skip engines which require those domains, and use a fallback engine.
When linking to a topic in the same Discourse, we try to onebox the link to show the title
and other various information depending on whether it's a "standard" or "inline" onebox.
However, we were not properly detecting links to topics that had no slugs (eg. https://meta.discourse.org/t/1234).
Previously if somehow a user created a blank markdown document using tag
tricks (eg `<p></p><p></p><p></p><p></p><p></p><p></p>`) and so on, we would
completely strip the document down to blank on post process due to onebox
hack.
Needs a followup cause I am still unclear about the reason for empty p stripping
and it can cause some unclear cases when we re-cook posts.
For consistency this PR introduces using custom markdown and short upload:// URLs for video and audio uploads, rather than just treating them as links and relying on the oneboxer. The markdown syntax for videos is  and for audio it is .
This is achieved in discourse-markdown-it by modifying the rules for images in mardown-it via md.renderer.rules.image. We return HTML instead of the token when we encounter audio or video after | and the preview renders that HTML. Also when uploading an audio or video file we insert the relevant markdown into the composer.
We already cache failed onebox URL requests client-side, we now want to cache this on the server-side for extra protection. failed onebox previews will be cached for 1 hour, and any more requests for that URL will fail with a 404 status. Forcing a rebake via the Rebake HTML action will delete the failed URL cache (like how the oneboxer preview cache is deleted).
Sam
Penar Musaraj
Gerhard Schlager
Bianca Nenciu
Daniel Waterworth
David Taylor
Martin Brennan
Jarek Radosz
Osama Sayegh
Loïc Guitaut
Natalie Tay
jbrw
Arpit Jalan
Joffrey JAFFEUX
Martin Brennan
Dan Ungureanu
Krzysztof Kotlarek
Guo Xiang Tan
Régis Hanol