🖼️ Topic Gallery

Canapin · 2 februari 2026 om 14:27


	Summary	Add a gallery view for each topic
	Preview	Click to see a gallery example
	Repository Link	https://github.com/Canapin/discourse-topic-gallery
	Install Guide	How to install plugins in Discourse

Description

Topic Gallery displays all images from a discussion on a dedicated page.

Use cases

Ideal for image-focused communities and/or categories in which users post many pictures.
It allows for a full picture experience without the regular topic interface and other contents getting in the way.

Mobile view:

You can try it here. This is primarily a test instance, so the availability is not guaranteed.

Features

Main features

Infinite swiping! ^[1]
User and date filters
Starts gallery from a given post
Group-specific access
Category-based exclusions
Link to the source post below the currently open image, so you’re never lost:
Shows grouped pictures (belonging to the same post) on mouse over:

Navigation from a topic to a gallery

Several buttons are available to navigate from a Topic to a Gallery:

Below the timeline:

Topic Gallery timeline button290×174 2.26 KB
At the end of a topic:
On each post (can be disabled in the settings):

If you open the gallery from a post, the gallery is filtered and only shows images starting from this post. You can cancel this filter with a single click:

Gallery URLs

The gallery URL syntax is the same as a regular topic, but /t/ is replaced with /gallery/:

https://canapin.discourse.diy/t/share-your-pictures/10

https://canapin.discourse.diy/gallery/share-your-pictures/10

There’s also a public JSON endpoint:
https://canapin.discourse.diy/gallery/share-your-pictures/10.json

Security & queries

Feature access is restricted to allowed groups and in allowed categories.
Galleries are restricted to users with access to their source topic.

Uploads queries exclude:

Non-user-uploaded images
Non-post references (custom emojis, avatars, etc.)
Uploads from posts that the current user has no access to, meaning:
- Whispers (if the current user can’t see whispers)
- Hidden posts
- Deleted posts
- Ignored users’ posts

Gallery Behavior

Hotlinked images are not shown.
Small images are not shown (minimum resolution can be changed in settings).
Duplicate images are shown once.
Images inside quotes are shown.
Images in spoilers or any other block that alters their visibility, are shown.

Settings

Name	Type	Default	Description
`topic_gallery_enabled`	boolean	`true`	Enable the topic gallery plugin.
`topic_gallery_allowed_groups`	group_list	`admins`	Groups that are allowed to access the topic gallery.
`topic_gallery_minimum_image_size`	integer (0–1000)	`64`	Minimum width and height (in pixels) for images to appear in the gallery. Images smaller than this in either dimension are excluded.
`topic_gallery_excluded_categories`	category_list	`""`	Categories where the topic gallery is disabled. Topics in these categories will not show gallery buttons or the gallery page.
`topic_gallery_post_menu_button`	boolean	`true`	Show a gallery button inside each post.

By default, the plugin is enabled for admins only. Visit settings to enable other groups.

Reaching the end of the first batch of images automatically loads and appends the next batch. ↩︎

Canapin · 16 februari 2026 om 12:40

I finally released this plugin

You can see a preview here: Gallery - Share your pictures! - Canapin

MarkoK · 16 februari 2026 om 13:02

This is such a cool idea and implementation.
Will try this later but is there a way to add image description that would show on the image popup below image?

NateDhaliwal · 16 februari 2026 om 13:30

I think you can use alt text:

![Some alt text here](upload://...)

You can also click on the above image to see the alt text.

Canapin · 16 februari 2026 om 13:55

Ah, there’s an oversight from me. This plugin’s photoswipe configuration seems to show the original filename instead of the custom title. I’ll fix this

NateDhaliwal · 16 februari 2026 om 13:58

@Canapin Why not use the built-in Discourse lightbox()?

github.com/discourse/discourse

frontend/discourse/app/lib/lightbox.js

main

import { waitForPromise } from "@ember/test-waiters";
import { isRailsTesting, isTesting } from "discourse/lib/environment";
import { helperContext } from "discourse/lib/helpers";
import { SELECTORS } from "discourse/lib/lightbox/constants";
import quoteImage, {
  canBuildImageQuote,
} from "discourse/lib/lightbox/quote-image";
import { isDocumentRTL } from "discourse/lib/text-direction";
import { escapeExpression } from "discourse/lib/utilities";
import { i18n } from "discourse-i18n";

const INIT_PROMISES = new WeakMap();

export function sortLightboxItems(items) {
  const result = [];
  let i = 0;
  while (i < items.length) {
    const grid = items[i].closest(".d-image-grid");
    if (!grid) {
      result.push(items[i++]);

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Canapin · 16 februari 2026 om 14:08

Apparently, while I can use the built-in lightbox (that’s I was doing in the first versions of this plugin), I can’t configure and tweak it for my needs. Notably, I couldn’t have it interact with my methods for the infinite loading/swiping, so I had to ship my own.

Canapin · 16 februari 2026 om 14:59

I can’t fix this, unfortunately. Image titles are written in the posts’ content and aren’t stored in any table.

For performance reason, my queries don’t return the posts’ content, so I can’t parse it to retrieve the titles.

I guess I’ll leave the filenames then. Even tho this information is rarely valuable…
Non-modified filenames most of the time just reveal where the image comes from and nothing more.

For example in my test instance:

image.png → “image” filenames are images pasted directly in the composer
Gemini_Generated_Image_8h4wt58h4wt58h4w.jpg → Guess
ComfyUI-ExtraMD-Large_315126945425344_00000.jpg → Local AI image generator
the-tattooer-is-totally-right-v0-s2f8spm3l-D5908.jpg → Probably saved from a website
cropped-android-chrome-512x512-1-32x32.png → Smartphone screenshot

Etc.

Should I consider it as a sensitive information? Image names are used by default for titles when we upload them on Discourse. If we edit the titles, the original information is unavailable for users. Yet, this plugin discloses it.

Edit: Yeah, I should probably not display the original filename.

Re-edit: Fixed.

TheWalkingDead110 · 16 februari 2026 om 17:23

Gallery icon at the bottom of a topic on mobile is not designed well. (Does not follow other buttons shape/size). Looks fine on desktop. Thank you.

Canapin · 16 februari 2026 om 17:52

Before

After

Fixed, thanks for the report

TheWalkingDead110 · 16 februari 2026 om 17:57

Thank you! Would it also be possible to have a setting do disable the automatic “from post #123” when a user clicks on the gallery button mid-topic please? So basically the full gallery available no matter what specific gallery button you click.

Canapin · 16 februari 2026 om 18:00

You can disable the post buttons in the plugin’s setting. The remaining gallery buttons (timeline, and end of topic) open the gallery from the start.

Canapin · 27 april 2026 om 10:20

UX questions for connoisseurs.

More often than not, on desktop and mobile, I want to open the gallery from the last unread post:

For example, I open a topic, and it shows this:

My first instinct, especially on mobile, is to click the gallery icon next to the topic progression element. But this icon opens the gallery from the start.

If I want to open the gallery from the current post, I need to scroll down until I reach the bottom of the post, where the “open gallery from current post” button is:

I’m not sure how to solve this. Should I change which buttons open the gallery from the beginning or from the current post? Should I move the button somewhere else?

Any idea welcome

MiniForum · 14 september 2026 om 22:26

In the context of a forum for a school (one category per class), this plugin is quite interesting !

We can post pictures, add comments and have a nice overview.

Particularly useful would be this pull request: Add sitewide and category gallery scopes - Pull Request #23 - Canapin/discourse-topic-gallery - GitHub

Indeed the use case would be opening topics per events and posting pictures related to an event in a dedicated topic.

And with the sitewide and category gallery scopes people can have a nice overview of all pictures without having to go into each topic !

Canapin · 19 september 2026 om 15:17

I hear the request

I’m not against adding a setting for this.

But I’m not a programmer (I know the basics, though), and while I took the time and made the effort needed to fully review and understand the code AI provided for my plugin to ensure it was safe and reliable, I’m neither confident or motivated enough to review the current PR and ensure it’s as safe as reliable as the existing code, and that it doesn’t clutter the existing codebase.

I’d be very happy if an experienced programmer could review this change. I cannot allocate my own resources for this, but having a sponsored review (+ fixes of refactor if needed) would allow me to implement the feature.

If someone can have a broad estimate of how much time (or money, but that’s the same thing right?) such a non-AI work would take, perhaps it can be posted on Marketplace?

Canapin · 20 september 2026 om 13:36

A fix was pushed regarding groups permissions as per Granular group-based permissions for anonymous and logged in users.

So please update the plugin on your forum

If you previously had the group permission set as everyone, you need to change it for anonymous_users and logged_in_users for unregisterd users and registered members be able to see the galleries.

The demo link in the first post was broken because of this, and I repaired it.

satonotdead · 20 september 2026 om 16:35

Just want to thank for sharing this functionality and add my vote to the possibility of showing a general gallery.

It would be great if the same could be filtered by categories or tags

Topic		Antwoorden	Weergaven
What are good plugins or theme components for a forum emphasizing pictures? Community Building	12	2249	4 augustus 2025
Filter posts with images (gallery view) Feature	3	1528	3 september 2020
[Paid] Grid Gallery Plugin Marketplace	1	1667	15 februari 2018
Any working image gallery plugin? Feature	8	5100	6 april 2017
All latest images in posts from a category Feature	4	1479	12 juli 2020