* FEATURE: Add external_id to topics
This commit allows for topics to be created and fetched by an
external_id. These changes are API only for now as there aren't any
front changes.
* add annotations
* add external_id to this spec
* Several PR feedback changes
- Add guardian to find topic
- 403 is returned for not found as well now
- add `include_external_id?`
- external_id is now case insensitive
- added test for posts_controller
- added test for topic creator
- created constant for max length
- check that it redirects to the correct path
- restrain external id in routes file
* remove puts
* fix tests
* only check for external_id in webhook if exists
* Update index to exclude external_id if null
* annotate
* Update app/controllers/topics_controller.rb
We need to check whether the topic is present first before passing it to the guardian.
Co-authored-by: Alan Guo Xiang Tan <gxtan1990@gmail.com>
* Apply suggestions from code review
Co-authored-by: Alan Guo Xiang Tan <gxtan1990@gmail.com>
Co-authored-by: Alan Guo Xiang Tan <gxtan1990@gmail.com>
This allows plugins to override the permissions required to access
specific things like the Logster and Sidekiq web UI without the changes
leaking to the rest of Discourse routes.
An admin could search for all screened ip addresses in a block by
using wildcards. 192.168.* returned all IPs in range 192.168.0.0/16.
This feature allows admins to search for a single IP address in all
screened IP blocks. 192.168.0.1 returns all IP blocks that match it,
for example 192.168.0.0/16.
* FEATURE: Remove roll up button for screened IPs
* FIX: Match more specific screened IP address first
This commit introduces a new site setting "google_oauth2_hd_groups". If enabled, group information will be fetched from Google during authentication, and stored in the Discourse database. These 'associated groups' can be connected to a Discourse group via the "Membership" tab of the group preferences UI.
The majority of the implementation is generic, so we will be able to add support to more authentication methods in the near future.
https://meta.discourse.org/t/managing-group-membership-via-authentication/175950
Currently when a user creates posts that are moderated (for whatever
reason), a popup is displayed saying the post needs approval and the
total number of the user’s pending posts. But then this piece of
information is kind of lost and there is nowhere for the user to know
what are their pending posts or how many there are.
This patch solves this issue by adding a new “Pending” section to the
user’s activity page when there are some pending posts to display. When
there are none, then the “Pending” section isn’t displayed at all.
This commit refactors the direct external upload routes (get presigned
put, complete external, create/abort/complete multipart) into a
helper which is then included in both BackupController and the
UploadController. This is done so UploadController doesn't need
strange backup logic added to it, and so each controller implementing
this helper can do their own validation/error handling nicely.
This is a follow up to e4350bb966
* FIX: do not display add to calendar for past dates
There is no value in saving past dates into calendar
* FIX: remove postId and move ICS to frontend
PostId is not necessary and will make the solution more generic for dates which doesn't belong to a specific post.
Also, ICS file can be generated in JavaScript to avoid calling backend.
It allows saving local date to calendar.
Modal is giving option to pick between ics and google. User choice can be remembered as a default for the next actions.
The all inboxes was introduced in
016efeadf6 but we decided to roll it back
for performance reasons. The main performance challenge here is that PG
has to basically loop through all the PMs that a user is allowed to view
before being able to order by `Topic#bumped_at`. The all inboxes was not
planned as part of the new/unread filter so we've decided not to tackle
the performance issue for the upcoming release.
Follow-up to 016efeadf6
The previous excerpt was a simple truncated raw message. Starting with
this commit, the raw content of the draft is cooked and an excerpt is
extracted from it. The logic for extracting the excerpt mimics the the
`ExcerptParser` class, but does not implement all functionality, being
a much simpler implementation.
The two draft controllers have been merged into one and the /draft.json
route has been changed to /drafts.json to be consistent with the other
route names.
PresenceChannel aims to be a generic system for allow the server, and end-users, to track the number and identity of users performing a specific task on the site. For example, it might be used to track who is currently 'replying' to a specific topic, editing a specific wiki post, etc.
A few key pieces of information about the system:
- PresenceChannels are identified by a name of the format `/prefix/blah`, where `prefix` has been configured by some core/plugin implementation, and `blah` can be any string the implementation wants to use.
- Presence is a boolean thing - each user is either present, or not present. If a user has multiple clients 'present' in a channel, they will be deduplicated so that the user is only counted once
- Developers can configure the existence and configuration of channels 'just in time' using a callback. The result of this is cached for 2 minutes.
- Configuration of a channel can specify permissions in a similar way to MessageBus (public boolean, a list of allowed_user_ids, and a list of allowed_group_ids). A channel can also be placed in 'count_only' mode, where the identity of present users is not revealed to end-users.
- The backend implementation uses redis lua scripts, and is designed to scale well. In the future, hard limits may be introduced on the maximum number of users that can be present in a channel.
- Clients can enter/leave at will. If a client has not marked itself 'present' in the last 60 seconds, they will automatically 'leave' the channel. The JS implementation takes care of this regular check-in.
- On the client-side, PresenceChannel instances can be fetched from the `presence` ember service. Each PresenceChannel can be used entered/left/subscribed/unsubscribed, and the service will automatically deduplicate information before interacting with the server.
- When a client joins a PresenceChannel, the JS implementation will automatically make a GET request for the current channel state. To avoid this, the channel state can be serialized into one of your existing endpoints, and then passed to the `subscribe` method on the channel.
- The PresenceChannel JS object is an ember object. The `users` and `count` property can be used directly in ember templates, and in computed properties.
- It is important to make sure that you `unsubscribe()` and `leave()` any PresenceChannel objects after use
An example implementation may look something like this. On the server:
```ruby
register_presence_channel_prefix("site") do |channel|
next nil unless channel == "/site/online"
PresenceChannel::Config.new(public: true)
end
```
And on the client, a component could be implemented like this:
```javascript
import Component from "@ember/component";
import { inject as service } from "@ember/service";
export default Component.extend({
presence: service(),
init() {
this._super(...arguments);
this.set("presenceChannel", this.presence.getChannel("/site/online"));
},
didInsertElement() {
this.presenceChannel.enter();
this.presenceChannel.subscribe();
},
willDestroyElement() {
this.presenceChannel.leave();
this.presenceChannel.unsubscribe();
},
});
```
With this template:
```handlebars
Online: {{presenceChannel.count}}
<ul>
{{#each presenceChannel.users as |user|}}
<li>{{avatar user imageSize="tiny"}} {{user.username}}</li>
{{/each}}
</ul>
```
There are certain design decisions that were made in this commit.
Private messages implements its own version of topic tracking state because there are significant differences between regular and private_message topics. Regular topics have to track categories and tags while private messages do not. It is much easier to design the new topic tracking state if we maintain two different classes, instead of trying to mash this two worlds together.
One MessageBus channel per user and one MessageBus channel per group. This allows each user and each group to have their own channel backlog instead of having one global channel which requires the client to filter away unrelated messages.
This pull request introduces the endpoints required, and the JavaScript functionality in the `ComposerUppyUpload` mixin, for direct S3 multipart uploads. There are four new endpoints in the uploads controller:
* `create-multipart.json` - Creates the multipart upload in S3 along with an `ExternalUploadStub` record, storing information about the file in the same way as `generate-presigned-put.json` does for regular direct S3 uploads
* `batch-presign-multipart-parts.json` - Takes a list of part numbers and the unique identifier for an `ExternalUploadStub` record, and generates the presigned URLs for those parts if the multipart upload still exists and if the user has permission to access that upload
* `complete-multipart.json` - Completes the multipart upload in S3. Needs the full list of part numbers and their associated ETags which are returned when the part is uploaded to the presigned URL above. Only works if the user has permission to access the associated `ExternalUploadStub` record and the multipart upload still exists.
After we confirm the upload is complete in S3, we go through the regular `UploadCreator` flow, the same as `complete-external-upload.json`, and promote the temporary upload S3 into a full `Upload` record, moving it to its final destination.
* `abort-multipart.json` - Aborts the multipart upload on S3 and destroys the `ExternalUploadStub` record if the user has permission to access that upload.
Also added are a few new columns to `ExternalUploadStub`:
* multipart - Whether or not this is a multipart upload
* external_upload_identifier - The "upload ID" for an S3 multipart upload
* filesize - The size of the file when the `create-multipart.json` or `generate-presigned-put.json` is called. This is used for validation.
When the user completes a direct S3 upload, either regular or multipart, we take the `filesize` that was captured when the `ExternalUploadStub` was first created and compare it with the final `Content-Length` size of the file where it is stored in S3. Then, if the two do not match, we throw an error, delete the file on S3, and ban the user from uploading files for N (default 5) minutes. This would only happen if the user uploads a different file than what they first specified, or in the case of multipart uploads uploaded larger chunks than needed. This is done to prevent abuse of S3 storage by bad actors.
Also included in this PR is an update to vendor/uppy.js. This has been built locally from the latest uppy source at d613b849a6. This must be done so that I can get my multipart upload changes into Discourse. When the Uppy team cuts a proper release, we can bump the package.json versions instead.
This adds a few different things to allow for direct S3 uploads using uppy. **These changes are still not the default.** There are hidden `enable_experimental_image_uploader` and `enable_direct_s3_uploads` settings that must be turned on for any of this code to be used, and even if they are turned on only the User Card Background for the user profile actually uses uppy-image-uploader.
A new `ExternalUploadStub` model and database table is introduced in this pull request. This is used to keep track of uploads that are uploaded to a temporary location in S3 with the direct to S3 code, and they are eventually deleted a) when the direct upload is completed and b) after a certain time period of not being used.
### Starting a direct S3 upload
When an S3 direct upload is initiated with uppy, we first request a presigned PUT URL from the new `generate-presigned-put` endpoint in `UploadsController`. This generates an S3 key in the `temp` folder inside the correct bucket path, along with any metadata from the clientside (e.g. the SHA1 checksum described below). This will also create an `ExternalUploadStub` and store the details of the temp object key and the file being uploaded.
Once the clientside has this URL, uppy will upload the file direct to S3 using the presigned URL. Once the upload is complete we go to the next stage.
### Completing a direct S3 upload
Once the upload to S3 is done we call the new `complete-external-upload` route with the unique identifier of the `ExternalUploadStub` created earlier. Only the user who made the stub can complete the external upload. One of two paths is followed via the `ExternalUploadManager`.
1. If the object in S3 is too large (currently 100mb defined by `ExternalUploadManager::DOWNLOAD_LIMIT`) we do not download and generate the SHA1 for that file. Instead we create the `Upload` record via `UploadCreator` and simply copy it to its final destination on S3 then delete the initial temp file. Several modifications to `UploadCreator` have been made to accommodate this.
2. If the object in S3 is small enough, we download it. When the temporary S3 file is downloaded, we compare the SHA1 checksum generated by the browser with the actual SHA1 checksum of the file generated by ruby. The browser SHA1 checksum is stored on the object in S3 with metadata, and is generated via the `UppyChecksum` plugin. Keep in mind that some browsers will not generate this due to compatibility or other issues.
We then follow the normal `UploadCreator` path with one exception. To cut down on having to re-upload the file again, if there are no changes (such as resizing etc) to the file in `UploadCreator` we follow the same copy + delete temp path that we do for files that are too large.
3. Finally we return the serialized upload record back to the client
There are several errors that could happen that are handled by `UploadsController` as well.
Also in this PR is some refactoring of `displayErrorForUpload` to handle both uppy and jquery file uploader errors.
* Copy remove_member to new `leave` method
* Remove unneeded code from the leave method
* Rearrange the leave method
* Remove unneeded code from the remove_member method
* Add tests
* Implement on the client side
* Copy the add_members method to the new join method
* Remove unneeded code from the join method
* Rearrange the join method
* Remove unneeded stuff from the add_members method
* Extract add_user_to_group method
* Implement of the client side
* Tests
* Doesn't inline users.uniq
* Return promise from join.then()
* Remove unnecessary begin and end
* Revert "Return promise from join.then()"
This reverts commit bda84d8d
* Remove variable already_in_group
And also move all the "top topics by period" routes to query string param.
/top/monthly => /top?period=monthly
/c/:slug/:id/l/top/monthly => /c/:slug/:id/l/top?period=monthly
/tag/:slug/l/top/daily => /tag/:slug/l/top?period=daily (new)
Before this change, calling `StyleSheet::Manager.stylesheet_details`
for the first time resulted in multiple queries to the database. This is
because the code was modelled in a way where each `Theme` was loaded
from the database one at a time.
This PR restructures the code such that it allows us to load all the
theme records in a single query. It also allows us to eager load the
required associations upfront. In order to achieve this, I removed the
support of loading multiple themes per request. It was initially added
to support user selectable theme components but the feature was never
completed and abandoned because it wasn't a feature that we thought was
worth building.
This overhauls the user interface for the group email settings management, aiming to make it a lot easier to test the settings entered and confirm they are correct before proceeding. We do this by forcing the user to test the settings before they can be saved to the database. It also includes some quality of life improvements around setting up IMAP and SMTP for our first supported provider, GMail. This PR does not remove the old group email config, that will come in a subsequent PR. This is related to https://meta.discourse.org/t/imap-support-for-group-inboxes/160588 so read that if you would like more backstory.
### UI
Both site settings of `enable_imap` and `enable_smtp` must be true to test this. You must enable SMTP first to enable IMAP.
You can prefill the SMTP settings with GMail configuration. To proceed with saving these settings you must test them, which is handled by the EmailSettingsValidator.
If there is an issue with the configuration or credentials a meaningful error message should be shown.
IMAP settings must also be validated when IMAP is enabled, before saving.
When saving IMAP, we fetch the mailboxes for that account and populate them. This mailbox must be selected and saved for IMAP to work (the feature acts as though it is disabled until the mailbox is selected and saved):
### Database & Backend
This adds several columns to the Groups table. The purpose of this change is to make it much more explicit that SMTP/IMAP is enabled for a group, rather than relying on settings not being null. Also included is an UPDATE query to backfill these columns. These columns are automatically filled when updating the group.
For GMail, we now filter the mailboxes returned. This is so users cannot use a mailbox like Sent or Trash for syncing, which would generally be disastrous.
There is a new group endpoint for testing email settings. This may be useful in the future for other places in our UI, at which point it can be extracted to a more generic endpoint or module to be included.
Re-lands the change initially proposed on #8359 but without a new nginx
location block, so it has less change surface.
Co-authored-by: Jeff Wong <awole20@gmail.com>
Co-authored-by: Jeff Wong <awole20@gmail.com>
This commit allows site admins to run theme tests in production via a new `/theme-qunit` route. When you visit `/theme-qunit`, you'll see a list of the themes/components installed on your site that have tests, and from there you can select a theme or component that you run its tests.
We also have a new rake task `themes:install_and_test` that can be used to install a list of themes/components on a temporary database and run the tests of the themes/components that are installed. This rake task can be useful when upgrading/deploying a Discourse instance to make sure that the installed themes/components are compatible with the new Discourse version being deployed, and if the tests fail you can abort the build/deploy process so you don't end up with a broken site.
This commit allows site admins to run theme tests in production via a new `/theme-qunit` route. When you visit `/theme-qunit`, you'll see a list of the themes/components installed on your site that have tests, and from there you can select a theme or component that you run its tests.
We also have a new rake task `themes:install_and_test` that can be used to install a list of themes/components on a temporary database and run the tests of the themes/components that are installed. This rake task can be useful when upgrading/deploying a Discourse instance to make sure that the installed themes/components are compatible with the new Discourse version being deployed, and if the tests fail you can abort the build/deploy process so you don't end up with a broken site.
The old share modal used to host both share and invite functionality,
under two tabs. The new "Share Topic" modal can be used only for
sharing, but has a link to the invite modal.
Among the sharing methods, there is also "Notify" which points out
that existing users will simply be notified (this was not clear
before). Staff members can notify as many users as they want, but
regular users are restricted to one at a time, no more than
max_topic_invitations_per_day. The user will not receive another
notification if they have been notified of the same topic in past hour.
The "Create Invite" modal also suffered some changes: the two radio
boxes for selecting the type (invite or email) have been replaced by a
single checkbox (is email?) and then the two labels about emails have
been replaced by a single one, some fields were reordered and the
advanced options toggle was moved to the bottom right of the modal.
This commit allows themes and theme components to have QUnit tests. To add tests to your theme/component, create a top-level directory in your theme and name it `test`, and Discourse will save all the files in that directory (and its sub-directories) as "tests files" in the database. While tests files/directories are not required to be organized in a specific way, we recommend that you follow Discourse core's tests [structure](https://github.com/discourse/discourse/tree/master/app/assets/javascripts/discourse/tests).
Writing theme tests should be identical to writing plugins or core tests; all the `import` statements and APIs that you see in core (or plugins) to define/setup tests should just work in themes.
You do need a working Discourse install to run theme tests, and you have 2 ways to run theme tests:
* In the browser at the `/qunit` route. `/qunit` will run tests of all active themes/components as well as core and plugins. The `/qunit` now accepts a `theme_name` or `theme_url` params that you can use to run tests of a specific theme/component like so: `/qunit?theme_name=<your_theme_name>`.
* In the command line using the `themes:qunit` rake task. This take is meant to run tests of a single theme/component so you need to provide it with a theme name or URL like so: `bundle exec rake themes:qunit[name=<theme_name>]` or `bundle exec rake themes:qunit[url=<theme_url>]`.
There are some refactors to how Discourse processes JavaScript that comes with themes/components, and these refactors may break your JS customizations; see https://meta.discourse.org/t/upcoming-core-changes-that-may-break-some-themes-components-april-12/186252?u=osama for details on how you can check if your themes/components are affected and what you need to do to fix them.
This commit also improves theme error handling in Discourse. We will now be able to catch errors that occur when theme initializers are run and prevent them from breaking the site and other themes/components.
This commit allows themes and theme components to have QUnit tests. To add tests to your theme/component, create a top-level directory in your theme and name it `test`, and Discourse will save all the files in that directory (and its sub-directories) as "tests files" in the database. While tests files/directories are not required to be organized in a specific way, we recommend that you follow Discourse core's tests [structure](https://github.com/discourse/discourse/tree/master/app/assets/javascripts/discourse/tests).
Writing theme tests should be identical to writing plugins or core tests; all the `import` statements and APIs that you see in core (or plugins) to define/setup tests should just work in themes.
You do need a working Discourse install to run theme tests, and you have 2 ways to run theme tests:
* In the browser at the `/qunit` route. `/qunit` will run tests of all active themes/components as well as core and plugins. The `/qunit` now accepts a `theme_name` or `theme_url` params that you can use to run tests of a specific theme/component like so: `/qunit?theme_name=<your_theme_name>`.
* In the command line using the `themes:qunit` rake task. This take is meant to run tests of a single theme/component so you need to provide it with a theme name or URL like so: `bundle exec rake themes:qunit[name=<theme_name>]` or `bundle exec rake themes:qunit[url=<theme_url>]`.
There are some refactors to internal code that's responsible for processing themes/components in Discourse, most notably:
* `<script type="text/discourse-plugin">` tags are automatically converted to modules.
* The `theme-settings` service is removed in favor of a simple `lib` file responsible for managing theme settings. This was done to allow us to register/lookup theme settings very early in our Ember app lifecycle and because there was no reason for it to be an Ember service.
These refactors should 100% backward compatible and invisible to theme developers.
In Improve invite system, a newly created link only invite cannot
be retrieved via API with the invitee's email once created. A new
route, /invites/retrieve, is introduced to fetch an already
created invite by email address.
Users can now pin bookmarks from their bookmark list. This will anchor the bookmark to the top of the list, and show a pin icon next to it. This also applies in the nav bookmarks panel. If there are multiple pinned bookmarks they sort by last updated order.
* FIX: Be able to handle long file extensions
Some applications have really long file extensions, but if we truncate
them weird behavior ensues.
This commit changes the file extension size from 10 characters to 255
characters instead.
See:
https://meta.discourse.org/t/182824
* Keep truncation at 10, but allow uppercase and dashes
The user interface has been reorganized to show email and link invites
in the same screen. Staff has more control over creating and updating
invites. Bulk invite has also been improved with better explanations.
On the server side, many code paths for email and link invites have
been merged to avoid duplicated logic. The API returns better responses
with more appropriate HTTP status codes.
This pull requests contains a series of improvements to groups
settings and member management such as:
- Showing which users have set a group as primary
- Moving similar settings together under Effects
- Adding bulk select and actions to members page
Previously, `/u/by-external/{id}` would only work for 'Discourse SSO' systems. This commit adds a new 'provider' parameter to the URL: `/u/by-external/{provider}/{id}`
This is compatible with all auth methods which have migrated to the 'ManagedAuthenticator' pattern. That includes all core providers, and also popular plugins such as discourse-oauth2-basic and discourse-openid-connect.
The new route is admin-only, since some authenticators use sensitive information like email addresses as the external id.
* Move new/edit category modals to its own page
* Fix JS tests
* Minor fixes to new-category UI
* Add mobile toggle
* Use global pretender endpoint so plugins can benefit too
* Alignment fix
* Minor review fixes
* Styling refactor
* Move some SCSS out of the modal
Adds a new slow mode for topics that are heating up. Users will have to wait for a period of time before being able to post again.
We store this interval inside the topics table and track the last time a user posted using the last_posted_at datetime in the TopicUser relation.
Enabling the moderators_manage_categories_and_groups site setting will allow moderator users to create/manage groups.
* show New Group form to moderators
* Allow moderators to update groups and read logs, where appropriate
* Rename site setting from create -> manage
* improved tests
* Migration should rename old log entries
* Log group changes, even if those changes mean you can no longer see the group
* Slight reshuffle
* RouteTo /g if they no longer have permissions to view group
When a tab is open but left unattended for a while, the red, green, and blue
pills tend to go out of sync.
So whevener we open the notifications menu, we sync up the notification count
(eg. blue and green pills) with the server.
However, the reviewable count (eg. the red pill) is not a notification and
is located in the hamburger menu. This commit adds a new route on the server
side to retrieve the reviewable count for the current user and a ping
(refreshReviewableCount) from the client side to sync the reviewable count
whenever they open the hamburger menu.
REFACTOR: I also refactored the hamburger-menu widget code to prevent repetitive uses
of "this.".
PERF: I improved the performance of the 'notify_reviewable' job by doing only 1 query
to the database to retrieve all the pending reviewables and then tallying based on the
various rights.
* FEATURE: set notification levels when added to a group
This feature allows admins and group owners to define default
category and tag tracking levels that will be applied to user
preferences automatically at the time when users are added to the
group. Users are free to change those preferences afterwards.
When removed from a group, the user's notification preferences aren't
changed.
* Added scopes UI
* Create scopes when creating a new API key
* Show scopes on the API key show route
* Apply scopes on API requests
* Extend scopes from plugins
* Add missing scopes. A mapping can be associated with multiple controller actions
* Only send scopes if the use global key option is disabled. Use the discourse plugin registry to add new scopes
* Add not null validations and index for api_key_id
* Annotate model
* DEV: Move default mappings to ApiKeyScope
* Remove unused attribute and improve UI for existing keys
* Support multiple parameters separated by a comma
Category and tag hashtags used to be handled differently even though
most of the code was very similar. This design was the root cause of
multiple issues related to hashtags.
This commit reduces the number of requests (just one and debounced
better), removes the use of CSS classes which marked resolved hashtags,
simplifies a lot of the code as there is a single source of truth and
previous race condition fixes are now useless.
It also includes a very minor security fix which let unauthorized users
to guess hidden tags.
Discourse needs a bunch of data preloaded before it can start up.
Normally we throw blobs of this into the HTML document that is requested
but in some cases that's awkward to retrieve.
For example with Ember CLI you have a separate javascript application
that needs to make its own HTML.
This API endpoint returns a JSON object with all the data Discourse needs to
bootstrap and start up.
This reverts commit 20780a1eee.
* SECURITY: re-adds accidentally reverted commit:
03d26cd6: ensure embed_url contains valid http(s) uri
* when the merge commit e62a85cf was reverted, git chose the 2660c2e2 parent to land on
instead of the 03d26cd6 parent (which contains security fixes)
The main thrust of this PR is to take all the conditional checks based on the `enable_bookmarks_with_reminders` away and only keep the code from the `true` path, making bookmarks with reminders the core bookmarks feature. There is also a migration to create `Bookmark` records out of `PostAction` bookmarks for a site.
### Summary
* Remove logic based on whether enable_bookmarks_with_reminders is true. This site setting is now obsolete, the old bookmark functionality is being removed. Retain the setting and set the value to `true` in a migration.
* Use the code from the rake task to create a database migration that creates bookmarks from post actions.
* Change the bookmark report to read from the new table.
* Get rid of old endpoints for bookmarks
* Link to the new bookmarks list from the user summary page
Users can now edit the bookmark name and reminder time from their list of bookmarks.
We use "Custom" for the date and time in the modal because if the user set a reminder for "tomorrow" then edit the reminder "tomorrow", the definition of what "tomorrow" is has changed.
If the feature is enabled, staff members can construct a URL and publish a
topic for others to browse without the regular Discourse chrome.
This is useful if you want to use Discourse like a CMS and publish
topics as articles, which can then be embedded into other systems.