invalid parent_id when using add_node

[Otterpatsch]

Hello there,

First of all im still learning lua and just started with my current project (a bitbucket reviewer).
And im facing an issue which i cannt solve for some hours now.
So what do i try to archieve?
I want a NuiTree which contains all the comments of a pr with their corresponding subcomments.
So i thought alright just set the node id to the comment id and if in the decoded json the key "parent" exists then lets use the value of the subkey "id" in add_node as second value but there i get invalid parent_id when im trying to use

tree:add_node(node, value["parent"]["id"])

So i thought this might be because its not a uuid so i just google and fully copied from here https://gist.github.com/jrus/3197011

But still im getting this issue. I tried for both "methods" to cast to a string with tostring(value) but this still didnt solve the issue.
So im pretty much clueless how to solve this. But im pretty sure im facing a totally lua beginner issue.

So the full function which is causin the issue is down below following

function M.get_comments(id)
  id = id or pull_request_id
  local request_url = base_request_url .. "/pullrequests/" .. id .. "/comments"
  local response = curl.get(request_url, {
        accept = "application/json",
        auth = username .. ":" .. app_password
      })
  local values = vim.fn.json_decode(response.body)["values"]
  local buffer_number = utils.create_vertial_slit()
  local tree = NuiTree({bufnr = buffer_number})
  local node_ids = {}
  for index ,value in pairs(values) do
    local comment_text = value["content"]["html"]
    local author = value["user"]["display_name"]
    comment_text = author 
    local comment_id = value["id"]
    local node_uuid = utils.uuid()
    local node = NuiTree.Node({text=comment_text,id=node_uuid, comment_id= comment_id})
    node_ids[comment_id] = node_uuid
    if value["parent"] then
      tree:add_node(node, node_ids[value["parent"]["id"]])
    else
      tree:add_node(node)
    end
  end
  tree:render()
end

[MunifTanjim]

The second parameter of tree:add_node is parent_id, which is supposed to be the id of a node that already exists in that tree.

So when you're calling tree:add_node(node, node_ids[value["parent"]["id"]]), no node with the id node_ids[value["parent"]["id"]] is yet added to that tree. That's why you're getting the error.

---

Instead of adding one node at a time, you can create a map first:

local nodes_by_parent_id = { _root = {} }

for _, value in ipairs(values) do
  local html = value["content"]["html"]
  local author = value["user"]["display_name"]
  local id = value["id"]
  local parent_id = value["parent"] and value["parent"]["id"] or "_root"
  if not nodes_by_parent_id[parent_id] then
    nodes_by_parent_id[parent_id] = {}
  end
  table.insert(nodes_by_parent_id[parent_id], {
    html = html,
    author = author,
    id = id,
  })
end

and then add those to the tree:

tree:set_nodes(nodes_by_parent_id._root)

for parent_id, nodes in pairs(nodes_by_parent_id) do
  if parent_id ~= "_root" then
    tree:set_nodes(nodes, parent_id)
  end
end

and render:

tree:render()

[MunifTanjim]

This can happen if values has reference to a parent comment that does not exist in the values.

Can you share the value of values here?

Maybe the response is paginated? In that case, you can fetch all the comments first (instead of just fetching the first page)... and then try to add those in tree.

---

Imagine you have these values:

• Comment(A) - Parent(NONE)
• Comment(B) - Parent(A)
• Comment(C) - Parent(NONE)
• Comment(D) - Parent(F)

Then nodes_by_parent_id will have shape like this:

{
  _root = { A, C },
  A = { B },
  F = { D },
}

When you'll try to call set_nodes with parent_id of F:

tree:set_nodes({ D }, F)

You'll face that error. Because Comment(F) does not exist in the tree yet.

[MunifTanjim]

In short... in order to set/render a nested node, you'll need to have the parent node in the tree first. I hope that makes sense.

[Otterpatsch]

Alright yeah it kinda makes sense. So as far as i understand now set_nodes will in the end of the call add all the nodes at once. So if in that moment a node doesnt exist yet it obviously cannt be a parent (make sense). So it does not add the table i give each node one by one to the tree? Is is possible to just add a single node and then just add the next one which could be a child of the previous added one? I thought add_node does this but this also didnt worked out.

Anyhow so is the thing im trying to archive in theory possible? Do you got any idea how i could solve this? I just would like to show the comments and their replys in a tree like structure. But maybe there is also something else i could use? I just like the idea to useyour nuitree

So im now thinking a function which add the comments level wise would work? Like first call set_nodes for all the nodes which got no parent, then set_nodes for those which got the previous ones as parent and so on?

So here is an example return of the api (i removed entries which are not really used at the moment and/or contain names and stuff
https://github.com/Otterpatsch/bitbucket.nvim/blob/main/test.json

[MunifTanjim]

Here's a rough draft for you to get started:

local Popup = require("nui.popup")
local Line = require("nui.line")
local Text = require("nui.text")
local Tree = require("nui.tree")

local popup = Popup({
  position = "50%",
  size = {
    width = 40,
    height = 20,
  },
  relative = "editor",
})

local tree = Tree({
  bufnr = popup.bufnr,
  get_node_id = function(node)
    -- this is telling NuiTree where we're storing the id
    return node.id
  end,
  prepare_node = function(node)
    -- You can format the text however you want here
    -- Maybe add some colors and styles etc.
    local lines = {}
    for _, raw_line in ipairs(vim.split(node.text, "\n")) do
      table.insert(lines, Line({ Text(raw_line) }))
    end
    table.insert(lines, Line({ Text("--------------------") }))
    return lines
  end,
})

local node_by_id = {}

local values = vim.fn.json_decode(blob)["values"]
for _, value in ipairs(values) do
  local text = value["content"]["raw"]
  local author = value["user"]["display_name"]
  local id = tostring(value["id"]) -- id needs to be string
  local parent_id = value["parent"] and tostring(value["parent"]["id"]) -- id needs to be string
  local node = Tree.Node({
    text = text,
    author = author,
    id = id,
    parent_id = parent_id,
  }, {})
  node:expand()
  node_by_id[id] = node
end

local function add_node_to_tree(id)
  local node = tree:get_node(id)
  if node then
    return
  end

  node = node_by_id[id]
  if not node then
    return
  end

  local parent_id = node.parent_id
  if parent_id and not tree:get_node(parent_id) then
    -- ensure parent is added before the child
    add_node_to_tree(parent_id)
  end
  tree:add_node(node, parent_id)
end

for id in pairs(node_by_id) do
  add_node_to_tree(id)
end

tree:render()
popup:mount()

[MunifTanjim]

So im now thinking a function which add the comments level wise would work? Like first call set_nodes for all the nodes which got no parent, then set_nodes for those which got the previous ones as parent and so on?

Yes, that's the idea in the draft above.

[Otterpatsch]

Thank you now its working :)