Laravel显示阵列json

Question

I want to show data from database: for every id_grup has many lapangan(court)

  $groups_resource = Groups::all();
  $groups = [];
  foreach($groups_resource as $group)
  {
    $g = new Groups();
    $g->id_group = "Group_".$group['id_group'];
    $g->name = $group['nama'];
    $g->expanded = true;
    $g->eventHeight = 25;
    $g->children = array();
    $groups[] = $g;

  $lapangan_resource = Lapangan::with('groups')->orderBy('nama')->get();
  foreach($lapangan_resource as $lapangan)
  {
    $l = new Lapangan();
    $l->id_lapangan = $lapangan['id_lapangan'];
    $l->name = $lapangan['nama_lapangan'];
    $g->children[] = $l;
  }
  }
    return json_encode($groups);

output for above code

[{"id_group":"Group_1","name":"Lapangan Badminton","expanded":true,"eventHeight":25,"children":[]},{"id_group":"Group_2","name":"Lapangan Tenis","expanded":true,"eventHeight":25,"children":[]}]

There is no value for children which might be like this.

[{"id":"group_1","name":"Indoor","expanded":true,"eventHeight":25,"children":[
{"id":"1","name":"Court 1"},
{"id":"2","name":"Court 2"},
{"id":"3","name":"Court 3"},
{"id":"4","name":"Court 4"}]},"id":"group_2","name":"Outdoor","expanded":true,"eventHeight":25,"children":[
{"id":"11","name":"Court 5"},
{"id":"12","name":"Court 6"},
{"id":"13","name":"Court 7"},
{"id":"14","name":"Court 8"}]}]

Answer 1

You are using wrong array braces. You shouldn't first initialize the children property of a group instead of that you can do it like this:

foreach($groups_resource as $group)
{
  $g = new Groups();
  $g->id_group = "Group_".$group['id_group'];
  $g->name = $group['nama'];
  $g->expanded = true;
  $g->eventHeight = 25;

  $l_arr = [];
  $lapangan_resource = Lapangan::with('groups')->orderBy('nama')->get();
  foreach($lapangan_resource as $lapangan)
  {
      $l = new Lapangan();
      $l->id_lapangan = $lapangan['id_lapangan'];
      $l->name = $lapangan['nama_lapangan'];
      $l_arr[] = $l;
  }

  $g->children = $l_arr;
  $groups[] = $g;
}

return json_encode($groups);

Hope this helps!