REST API: Add support for threaded comments

[rmccue]

(I don't think we have a tracking ticket for this already.)

We should add support for threading comments, particularly in "flat" mode. Flat mode would allow threading in frontend code relatively easily.

The only issue with this is that it will overflow per_page. We intentionally treat this as an indicator and occasionally have less items already (if they're filtered inside the get_items() loop, e.g.), so I don't think this is a huge issue. In addition, threaded mode should be opt-in in any case.

Previously: ​https://github.com/WP-API/WP-API/issues/1612

[birgire]

#44555 was marked as a duplicate.

[brgweb]

I'd line to work on it. Should I fork github WP API repository or work with trac?

[brgweb]

Replying to brgweb:

I'd like to work on it. Should I fork github WP API repository or work with trac?

Nevermind... I'm using svn already.

[brgweb]

Enable threaded comments in rest api

[brgweb]

@birgire I've added a diff to this ticket that enables threaded comments in rest api.

It adds a boolean query parameter "hierarchical". Instead of passing "hierarchical" straight to WP_Comment_Query, it retrieves only top level comments (or just the first level if "parent" is set) and retrieve children inside prepare_items_for_response method.

I've tested with fake data and in a production environment and it worked as expected.

Replying to rmccue:

(I don't think we have a tracking ticket for this already.)

We should add support for threading comments, particularly in "flat" mode. Flat mode would allow threading in frontend code relatively easily.

The only issue with this is that it will overflow per_page. We intentionally treat this as an indicator and occasionally have less items already (if they're filtered inside the get_items() loop, e.g.), so I don't think this is a huge issue. In addition, threaded mode should be opt-in in any case.

Previously: ​https://github.com/WP-API/WP-API/issues/1612

[birgire]

Replying to brgweb:

@birgire I've added a diff to this ticket that enables threaded comments in rest api.

It adds a boolean query parameter "hierarchical". Instead of passing "hierarchical" straight to WP_Comment_Query, it retrieves only top level comments (or just the first level if "parent" is set) and retrieve children inside prepare_items_for_response method.

I've tested with fake data and in a production environment and it worked as expected.

great, thanks for the patch

Few notes on 41821.diff​:

• It seems to change the dynamic fields support in WP_REST_Comments_Controller::prepare_item_for_response(), so the _fields parameter is not working on the comment children. See [43087]. Are you working with the latest trunk?
• Is there any need for a check_read_permission() on the children, as seen ​here?
• It seems to implement the 'hierarchical' => 'threaded' according the children tree output response, not the 'hierarchical' => true for a flat array? I might be misunderstanding the patch and the ticket's description though :)
• We should consider unit tests for this support.
• Current unit tests fail and need to be updated.
• There are some issues regarding WordPress Code Standard, resulting in a larger diff file.

[brgweb]

Fix WPCS errors

[brgweb]

Thanks for the review! I've uplodaded another diff.

Replying to birgire:

great, thanks for the patch

Few notes on 41821.diff​:

• It seems to change the dynamic fields support in WP_REST_Comments_Controller::prepare_item_for_response(), so the _fields parameter is not working on the comment children. See [43087]. Are you working with the latest trunk?

I believe that I've changed the working copy during tests and was with a stable version of WordPress. It's fixed now.

• Is there any need for a check_read_permission() on the children, as seen ​here?

I've added this check in the new patch.

• It seems to implement the 'hierarchical' => 'threaded' according the children tree output response, not the 'hierarchical' => true for a flat array? I might be misunderstanding the patch and the ticket's description though :)

It implements the threaded array in WP_Comment_Query but it outputs a flat array. Working with threaded in the query made the code smaller and the implementation easier. For REST API json responses, I don't think there's a use for the threaded output (maybe I'm wrong :) )

• We should consider unit tests for this support.
• Current unit tests fail and need to be updated.

I'd like to help with unit tests too. I will work on it.

• There are some issues regarding WordPress Code Standard, resulting in a larger diff file.

Older version of the file and editor messing with spaces and tabs. Fixed in v2.