We previously had a system which would generate a 10x10px preview of images and add their URLs in a data-small-upload attribute. The client would then use that as the background-image of the `<img>` element. This works reasonably well on fast connections, but on slower connections it can take a few seconds for the placeholders to appear. The act of loading the placeholders can also break or delay the loading of the 'real' images.
This commit replaces the placeholder logic with a new approach. Instead of a 10x10px preview, we use imagemagick to calculate the average color of an image and store it in the database. The hex color value then added as a `data-dominant-color` attribute on the `<img>` element, and the client can use this as a `background-color` on the element while the real image is loading. That means no extra HTTP request is required, and so the placeholder color can appear instantly.
Dominant color will be calculated:
1. When a new upload is created
2. During a post rebake, if the dominant color is missing from an upload, it will be calculated and stored
3. Every 15 minutes, 25 old upload records are fetched and their dominant color calculated and stored. (part of the existing PeriodicalUpdates job)
Existing posts will continue to use the old 10x10px placeholder system until they are next rebaked
Dead and large images are replaced with a placeholder, either a broken
chain icon or a short text. This commit no longer applies this
transformation for images inside Oneboxes, but removes them instead.
This commit introduces a new site setting: `block_hotlinked_media`. When enabled, all attempts to hotlink media (images, videos, and audio) will fail, and be replaced with a linked placeholder. Exceptions to the rule can be added via `block_hotlinked_media_exceptions`.
`download_remote_image_to_local` can be used alongside this feature. In that case, hotlinked images will be blocked immediately when the post is created, but will then be replaced with the downloaded version a few seconds later.
This implementation is purely server-side, and does not impact the composer preview.
Technically, there are two stages to this feature:
1. `PrettyText.sanitize_hotlinked_media` is called during `PrettyText.cook`, and whenever new images are introduced by Onebox. It will iterate over all src/srcset attributes in the post HTML and check if they're allowed. If not, the attributes will be removed and replaced with a `data-blocked-hotlinked-src(set)` attribute
2. In the `CookedPostProcessor`, we iterate over all `data-blocked-hotlinked-src(set)` attributes and check whether we have a downloaded version of the media. If yes, we update the src to use the downloaded version. If not, the entire media element is replaced with a placeholder. The placeholder is labelled 'external media', and is a link to the offsite media.
Previously, with the default `editing_grace_period`, hotlinked images were pulled 5 minutes after a post is created. This delay was added to reduce the chance of automated edits clashing with user edits.
This commit refactors things so that we can pull hotlinked images immediately. URLs are immediately updated in the post's `cooked` HTML. The post's raw markdown is updated later, after the `editing_grace_period`.
This involves a number of behind-the-scenes changes including:
- Schedule Jobs::PullHotlinkedImages immediately after Jobs::ProcessPost. Move scheduling to after the `update_column` call to avoid race conditions
- Move raw changes into a separate job, which is delayed until after the ninja-edit window
- Move disable_if_low_on_disk_space logic into the `pull_hotlinked_images` job
- Move raw-parsing/replacing logic into `InlineUpload` so it can be easily be shared between `UpdateHotlinkedRaw` and `PullUserProfileHotlinkedImages`
Previously this mapping of **cooked** images was only being run for oneboxes. Now it runs for all images, so we can transform hotlinked images without needing to immediately update `raw`
This will make future changes to the 'pull hotlinked images' system easier. This commit should not introduce any functional change.
For now, the old post_custom_field data is kept in the database. This will be dropped in a future commit.
When a site has secure media enabled and a post is with secure
media, we were incorrectly cooking custom emoji URLs and using the
secure URL for those emojis, even though they should not be
considered secure (their corresponding upload records in the
database are _not_ secure). Now instead of the blanket
post.with_secure_media? boolean for the secure: param, we also
want to make sure the image whose URL is being cooked is also
_not_ a custom emoji.
The file size error messages for max_image_size_kb and
max_attachment_size_kb are shown to the user in the KB
format, regardless of how large the limit is. Since we
are going to support uploading much larger files soon,
this KB-based limit soon becomes unfriendly to the end
user.
For example, if the max attachment size is set to 512000
KB, this is what the user sees:
> Sorry, the file you are trying to upload is too big (maximum
size is 512000KB)
This makes the user do math. In almost all file explorers that
a regular user would be familiar width, the file size is shown
in a format based on the maximum increment (e.g. KB, MB, GB).
This commit changes the behaviour to output a humanized file size
instead of the raw KB. For the above example, it would now say:
> Sorry, the file you are trying to upload is too big (maximum
size is 512 MB)
This humanization also handles decimals, e.g. 1536KB = 1.5 MB
Still excludes GitHub avatars. Those were the original reason for adding
this broad exclusion. Context at https://meta.discourse.org/t/165713/4
If we find more oneboxes which are unsuitable for thumbnails, we can add
them to this selector.
Previously we would always take the first image in a post to use as the
thumbnail. On media-heavy sites, users may want to manually select a
specific image as the topic thumbnail. This commit allows this to be
done via a `|thumbnail` attribute in markdown.
For example, in this case, bbb would be chosen as the thumbnail:
```
```
CookedPostProcessor replaces all large images with their optimized
versions, but for GIF images the optimized version is limited to first
frame only. This caused animations it cooked posts to require a click
to show up the lightbox and start playing.
We must guarantee that "rel=noopener" was set if "target=_blank" is present, which is not always the case for trusted users. Also, if the link contains the "nofollow" attribute, it has to have the "ugc" attribute as well.
This commit should cause no functional change
- Split into functions to avoid deep nesting
- Register custom field type, and remove manual json parse/serialize
- Recover from deleted upload records
Also adds a test to ensure pull_hotlinked_images redownloads secure images only once
Previously the pull hotlinked images job was skipped after system edits. This ensured that we never had an infinite loop of system-edit/pull-hotlinked/system-edit/pull-hotlinked etc.
A side effect was that edits made by system for any other reason (e.g. API, removing full quotes) would prevent pulling hotlinked images. This commit removes the system edit check, and replaces it with another method to avoid an infinite job scheduling loop.
There were two constants here, `INLINE_ONEBOX_LOADING_CSS_CLASS` and
`INLINE_ONEBOX_CSS_CLASS` that were both longer than the strings they
were DRYing up: `inline-onebox-loading` and `inline-onebox`
I normally appreciate constants, but in this case it meant that we had
a lot of JS imports resulting in many more lines of code (and CPU cycles
spent figuring them out.)
It also meant we had an `.erb` file and had to invoke Ruby to create the
JS file, which meant the app was harder to port to Ember CLI.
I removed the constants. It's less DRY but faster and simpler, and
arguably the loss of DRYness is not significant as you can still search
for the `inline-onebox-loading` and `inline-onebox` strings easily if
you are refactoring.
This introduces new APIs for obtaining optimized thumbnails for topics. There are a few building blocks required for this:
- Introduces new `image_upload_id` columns on the `posts` and `topics` table. This replaces the old `image_url` column, which means that thumbnails are now restricted to uploads. Hotlinked thumbnails are no longer possible. In normal use (with pull_hotlinked_images enabled), this has no noticeable impact
- A migration attempts to match existing urls to upload records. If a match cannot be found then the posts will be queued for rebake
- Optimized thumbnails are generated during post_process_cooked. If thumbnails are missing when serializing a topic list, then a sidekiq job is queued
- Topic lists and topics now include a `thumbnails` key, which includes all the available images:
```
"thumbnails": [
{
"max_width": null,
"max_height": null,
"url": "//example.com/original-image.png",
"width": 1380,
"height": 1840
},
{
"max_width": 1024,
"max_height": 1024,
"url": "//example.com/optimized-image.png",
"width": 768,
"height": 1024
}
]
```
- Themes can request additional thumbnail sizes by using a modifier in their `about.json` file:
```
"modifiers": {
"topic_thumbnail_sizes": [
[200, 200],
[800, 800]
],
...
```
Remember that these are generated asynchronously, so your theme should include logic to fallback to other available thumbnails if your requested size has not yet been generated
- Two new raw plugin outlets are introduced, to improve the customisability of the topic list. `topic-list-before-columns` and `topic-list-before-link`
* When copying the markdown for an image between posts, we were not adding the srcset and data-small-image attributes which are done by calling optimize_image! in cooked post processor
* Refactored the code which was confusing in its current state (the consider_for_reuse method was super confusing) and fixed the issue
* FIX: Perform crop using user-specified image sizes
It used to resize the images to max width and height first and then
perform the crop operation. This is wrong because it ignored the user
specified image sizes from the Markdown.
* DEV: Use real images in test
* Do not grant badges for posts with no user
* Ensure instructions are correct in Change Owner modal
* Hide user-dependent actions from posts with no user
* Make PostRevisor work with posts with no user
* Ensure posts with no user can be deleted
* discourse-narrative-bot should ignore posts with no user
* Skip TopicLink creation for posts with no user
This normalizes it so we only carry one place for grabbing disk space size
It also normalizes the command made so it uses Discourse.execute_command
which splits off params in a far cleaner way.
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.
Basically, say you had already downloaded a certain image from a certain URL
using pull_hotlinked_images and the onebox. The upload would be stored
by its sha as an upload record. Whenever you linked to the same URL again
in a post (e.g. in our case an og:image on review.discourse) we would
would reuse the original upload record because of the sha1.
However when you turned on secure media this could cause problems as
the first post that uses that upload after secure media is enabled
will set the access control post for the upload to the new post.
Then if the post is deleted every single onebox/link to that same image
URL will fail forever with 403 as the secure-media-uploads URL fails
if the access control post has been deleted.
To fix this when cooking posts and pulling hotlinked images, we only
allow using an original upload by URL if its access control post
matches the current post, and if the original_sha1 is filled in,
meaning it was uploaded AFTER secure media was enabled. otherwise
we just redownload the media again to be safe, as the URL will always
be new then.
When pull_hotlinked_images tried to run on posts with secure media (which had already been downloaded from external sources) we were getting a 404 when trying to download the image because the secure endpoint doesn't allow anon downloads.
Also, we were getting into an infinite loop of pull_hotlinked_images because the job didn't consider the secure media URLs as "downloaded" already so it kept trying to download them over and over.
In this PR I have also refactored secure-media-upload URL checks and mutations into single source of truth in Upload, adding a SECURE_MEDIA_ROUTE constant to check URLs against too.
When we were pulling hotlinked images for oneboxes in the CookedPostProcessor, we were using the direct S3 URL, which returned a 403 error and thus did not set widths and heights of the images. We now cook the URL first based on whether the upload is secure before handing off to FastImage.
It used to check how many quotes were inside a post, without taking
considering that some quotes can contain other quotes. This commit
selects only top level quotes.
I had to use XPath because I could not find an equivalent CSS
selector.
`available_disk_space` calls `df` which exits with an error if the `uploads` path doesn't exist. That's often the case when the `Discourse.store.external?` is true.
By doing the `external?` check first the `disable_if_low_on_disk_space` does less work and doesn't output any errors to the console.
This fixes the following issues:
* The link element on the lightbox which pops open the lightbox was linking to the S3 URL with a private ACL instead of the secure media URL for the image
* Change to use `@post.with_secure_media?` in `CookedPostProcessor` for URL cooking, as in some cases, like when a post is edited and an upload is added, `upload.secure?` can be false which resulted in `srcset` URLs not being cooked correctly to secure media upload urls.
