How to parse json files using ISuperObject in Delphi 10

Question

I'm trying to parse a JSON file using ISuperObject. My JSON file looks like this:

{
   "status":"ok",
   "follows":{
      "count":868,
      "page_info":{
         "has_previous_page":false,
         "start_cursor":null,
         "end_cursor":"SbXc6VJsoeTs",
         "has_next_page":true
      },
      "nodes":[
         {
            "username":"username1",
            "requested_by_viewer":false,
            "followed_by_viewer":true,
            "profile_pic_url":"URL link",
            "full_name":"name",
            "is_verified":false,
            "id":"ID"
         },
         {
            "username":"username2",
            "requested_by_viewer":false,
            "followed_by_viewer":true,
            "profile_pic_url":"URL link",
            "full_name":"username2",
            "is_verified":false,
            "id":"ID"
         },
         {
            "username":"_username3",
            "..."
         ]
      }

I want all of the username values to be listed in a Memo.

Here is what I have tried:

var
 json         : ISuperObject;
 row_item     : ISuperObject;
begin
  json := TSuperObject.ParseFile('C:\json.txt', TRUE); 
  for row_item in json['nodes'] do 
  begin
    Memo1.Lines.Add(elements_itemS['usernames']); 
  end;
end;

I get an Access Violation on the for loop. Any ideas?

Answer 1

The code should look more like this instead:

var
  json         : ISuperObject;
  node         : ISuperObject;
  item         : IMember;
begin
  json := TSuperObject.ParseFile('C:\json.txt', TRUE); 
  for item in json.O['follows'].A['nodes'] do 
  begin
    node := item.AsObject;
    Memo1.Lines.Add(node.S['username']); 
  end;
end;

Or this:

var
  json         : ISuperObject;
  node         : ISuperObject;
  item         : IMember;
begin
  json := TSuperObject.ParseFile('C:\json.txt', TRUE); 
  for item in json['follows.nodes'].AsArray do 
  begin
    node := item.AsObject;
    Memo1.Lines.Add(node.S['username']); 
  end;
end;