Paginated and dept-limited list of nodes

[mbajur]

Hello! First of all, thank you for this great piece of software.

I'm creating a website with threaded comments functionality - working kind of like reddit. There is a post, post can have many comments and each comment can have many sub-comments. closure_tree makes working with such setup a breeze but things gets complicated when i want to expose my comments through REST API in a consumer-friendly way.

My ultimate goal is to make it work like reddit comments works: initial story page load shows paginated list of root comments and their paginated children comments up to x depth (i'm not sure what's the exact depth but, say, 3). Example: https://www.reddit.com/r/ColorizedHistory/comments/8ojpss/queen_victoria_and_her_family_including_king/

I'm not able to reverse-engineer it as it seems that the initial comments list is rendered server-side but i'm gonna try to explain what such endpoint should return:

• Paginated list of root comments (say, 5 per page)
• for each root comment, a paginated list of sub-comments (say, 5 per page again)
• reapeat previous step recursively for each child comment until depth = 3

ORIGINAL POST
+-- Comment 1
|   +-- Sub comment 1
|       +-- [load children]
|   +-- Sub comment 2
|       +-- [load children]
|   +-- Sub comment 3
|       +-- [load children]
|   +-- [load more childs for Comment 1]
+-- Comment 2
|   +-- Sub comment 1
|   +-- Sub comment 2
|       +-- [load children]
|   +-- Sub comment 3
|   +-- [load more childs for Comment 2]
+-- Comment 3
|   +-- Sub comment 1
|       +-- [load children]
|   +-- Sub comment 2
|   +-- Sub comment 3
|   +-- [load more childs for Comment 3]
[load more root comments]

I'm not sure if my description is clear or if linked reddit story is a clear example of what i mean.

How i'm handling it so far is initially fetching just the paginated root comments (comments. find_all_by_generation(0)) and loading their children (recursively) only if user clicks "Load replies" button on the frontend side.

That endpoint might return the comments as a flat collection, they don't need to be nested (i'm using parent_id to show them in a proper thread on frontend side)

Thanks in advance for any tips, if something is unclear, i'm gonna try to explain it further.