cascade_sample.php

<?php
namespace App\Http\Controllers\Admin;

use App\Http\Requests;
use App\Article;
use App\Tag;
use App\Category;
use Zofe\Rapyd\DataForm\Field\Checkboxgroup;

class AdminArticlesController extends AdminController
{
    
    public function anyArticle()
    {
        $edit = \DataEdit::source(new Article());
        $edit->add('title', 'Title', 'text')->rule('required');
        $edit->add('id_cat','Category','select')>rule('required')
            ->option("","")->options(Category::all()->lists('name','id'))
            ->onchange('$.get("/admin/articles/catcheckbox", {id_cat: $("#id_cat").val()} , function (data) { $("#div_tags").html(data) }');
        if ($edit->status!='create') 
        {
            $edit->add('tags','Tags','Checkboxgroup')
                ->options(
                Tag::whereHas('categories', function($query) use ($edit){
                    return  $query->where('id','=',$edit->model->id_cat);
                })->lists('title_tag','id_tag')
            )->separator('<br>');
        } else {
            $edit->add('tags','Tags','Checkboxgroup')->separator('<br>');
        }
        $form = $edit->getForm();
        return $edit->view('admin.articles.article', array('content' => $form));
    }
    
    public function anyCatcheckbox()
    {
        $id_cat = \Input::get('id_cat');
        $checks = new Checkboxgroup('tags', 'Tags');
        $checks->status = 'modify';
        $checks->options(
            Tag::whereHas('categories', function($query) use ($id_cat){
            return  $query->where('id_tag','=',$id_cat);
        })->lists('title_tag','id_tag'))->separator('<br>');;
        $checks->build();
        return $checks->output;
    }