backpack laravel - preselect select filter with $_GET param

Question

I have a Document and Post (for that document) Backpack CRUD resources. I want to create a button inside the post datatable so that when I click that button, it will link to the documents of that post.

this is my model post

class Post extends Model{
    ...
    function allDocuments(){
        return '<a href="/admin/document/?post_id='.$this->id.'" class="btn btn-xs btn-default"><i class="fa fa-list"></i> Documents</a>';
    }
}

this is my PostCrudController

class PostCrudController extends CrudController{
    ...
    $this->crud->addButtonFromModelFunction('line', 'all_documents', 'allDocuments', 'beginning');

}

and that's my DocumentCrudController

class DocumentCrudController extends CrudController{
    ...
            $this->crud->addFilter([ 
              'name' => 'post_id',
              'type' => 'select2',
              'label'=> 'Post To Filter',
              'value' => $_GET['post_id'] // <------- Hoped this works, but doesn't
            ], function() {
                $condos = [];
                foreach(Post::get() as $c){
                    $condos[$c->id] = $c->title." >> ".$c->category->name." >> ".$c->category->condomimium->name;
                }
                return $condos;
            }, function($value) { // if the filter is active
                $this->crud->addClause('where', 'post_id', $value);
            });
}

I've seen that backpack datatables uses a POST request with the parameters (in my case post_id ) to filter the datatable, but I need to call a GET request to preselect my filter with the datatable result accordingly.

thanks in advance

Answer 1

Why not using Request in laravel ? something like this $request->input(post_id); and instantiate the request in the method like this

use Illuminate\Http\Request;

public function store(Request $request) { // logic here }

Answer 2

Actually it works even without 'value' => $_GET['post_id'] . Backpack recognizes automatically filter. The name of the filter must match to the name of the GET param