Invoice Manager example - with repeatable field used to create and edit InvoiceItems

app\Http\Controllers\Admin\InvoiceCrudController.php

  <?php

namespace App\Http\Controllers\Admin;

use App\Http\Requests\InvoiceRequest;
use Backpack\CRUD\app\Http\Controllers\CrudController;
use Backpack\CRUD\app\Library\CrudPanel\CrudPanelFacade as CRUD;

/**
 * Class InvoiceCrudController
 * @package App\Http\Controllers\Admin
 * @property-read \Backpack\CRUD\app\Library\CrudPanel\CrudPanel $crud
 */
class InvoiceCrudController extends CrudController
{
    use \Backpack\CRUD\app\Http\Controllers\Operations\ListOperation;
    use \Backpack\CRUD\app\Http\Controllers\Operations\CreateOperation { store as traitStore; }
    use \Backpack\CRUD\app\Http\Controllers\Operations\UpdateOperation { update as traitUpdate; }
    use \Backpack\CRUD\app\Http\Controllers\Operations\DeleteOperation;
    use \Backpack\CRUD\app\Http\Controllers\Operations\ShowOperation;

    /**
     * Configure the CrudPanel object. Apply settings to all operations.
     * 
     * @return void
     */
    public function setup()
    {
        CRUD::setModel(\App\Models\Invoice::class);
        CRUD::setRoute(config('backpack.base.route_prefix') . '/invoice');
        CRUD::setEntityNameStrings('invoice', 'invoices');
    }

    /**
     * Define what happens when the List operation is loaded.
     * 
     * @see  https://backpackforlaravel.com/docs/crud-operation-list-entries
     * @return void
     */
    protected function setupListOperation()
    {
        CRUD::column('number');
        CRUD::column('series');
        CRUD::column('customer_id');
        CRUD::column('deleted_at');
        CRUD::column('created_at');
        CRUD::column('updated_at');

        /**
         * Columns can be defined using the fluent syntax or array syntax:
         * - CRUD::column('price')->type('number');
         * - CRUD::addColumn(['name' => 'price', 'type' => 'number']); 
         */
    }

    /**
     * Define what happens when the Create operation is loaded.
     * 
     * @see https://backpackforlaravel.com/docs/crud-operation-create
     * @return void
     */
    protected function setupCreateOperation()
    {
        CRUD::setValidation(InvoiceRequest::class);

        CRUD::field('series')->size(3);
        CRUD::field('number')->size(3);
        CRUD::field('customer_id')->size(6);
        CRUD::field('payment_method')->size(6);
        CRUD::field('payment_provider')->size(6);

        CRUD::field('items')
            ->type('repeatable')
            ->label('Items')
            ->fields([
                [
                    'name'    => 'id',
                    'type'    => 'hidden',
                ],
                [
                    'name'    => 'description',
                    'type'    => 'text',
                    'wrapper' => ['class' => 'form-group col-md-6'],
                ],
                [
                    'name'    => 'quantity',
                    'type'    => 'number',
                    'default' => 1,
                    'wrapper' => ['class' => 'form-group col-md-2'],
                ],
                [
                    'name'    => 'price',
                    'type'    => 'number',
                    'wrapper' => ['class' => 'form-group col-md-2'],
                ],
                [
                    'name'    => 'tax',
                    'type'    => 'number',
                    'default' => 0,
                    'wrapper' => ['class' => 'form-group col-md-2'],
                ],
            ]);
    }

    /**
     * Define what happens when the Update operation is loaded.
     * 
     * @see https://backpackforlaravel.com/docs/crud-operation-update
     * @return void
     */
    protected function setupUpdateOperation()
    {
        $this->setupCreateOperation();
    }

    protected function setupShowOperation()
    {
        CRUD::column('payment_method');
        CRUD::column('payment_provider');
        CRUD::column('items')->type('relationship');
    }

    public function store()
    {
        // create the main item as usual
        $response = $this->traitStore();

        // instead of returning, take a little time to create the InvoiceItems too
        $invoice_id = $this->crud->entry->id;
        $items = collect(json_decode(request('items'), true));

        $items->each(function($item, $key) use ($invoice_id) {
            $item['invoice_id'] = $invoice_id;

            \App\Models\InvoiceItem::create($item);
        });

        return $response;
    }

    public function update()
    {
        $response = $this->traitUpdate();

        // instead of returning, take a little time to update the InvoiceItems too
        $invoice_id = $this->crud->entry->id;
        $items = collect(json_decode(request('items'), true));

        $items->each(function($item, $key) use ($invoice_id) {
            $item['invoice_id'] = $invoice_id;

            if ($item['id']) {
                $invoice_item = \App\Models\InvoiceItem::find($item['id']);
                $invoice_item->update($item);
            } else {
                \App\Models\InvoiceItem::create($item);
            }

        });
      
        // delete removed InvoiceItems
        $related_items_in_request = $items->pluck('id');
        $related_items_in_db = $this->crud->entry->items;
        
        $related_items_in_db->each(function($item, $key) use ($related_items_in_request) {
            if (!$related_items_in_request->contains($item['id'])) {
                $item->delete();
            }
        });

        return $response;
    }
}

app\Http\Requests\InvoiceRequest.php

<?php

namespace App\Http\Requests;

use App\Http\Requests\Request;
use Illuminate\Foundation\Http\FormRequest;

class InvoiceRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        // only allow updates if the user is logged in
        return backpack_auth()->check();
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            'series' => 'required',
            'number' => 'required',
            'items'  => 'required',
        ];
    }

    /**
     * Get the validation attributes that apply to the request.
     *
     * @return array
     */
    public function attributes()
    {
        return [
            //
        ];
    }

    /**
     * Get the validation messages that apply to the request.
     *
     * @return array
     */
    public function messages()
    {
        return [
            //
        ];
    }
}

app\Models\Invoice.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\SoftDeletes;

class Invoice extends Model
{
    use \Backpack\CRUD\app\Models\Traits\CrudTrait;
    use SoftDeletes;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'number',
        'series',
        'payment_method',
        'payment_provider',
        'customer_id',
    ];

    /**
     * The attributes that should be cast to native types.
     *
     * @var array
     */
    protected $casts = [
        'id' => 'integer',
        'customer_id' => 'integer',
    ];

    public function items()
    {
        return $this->hasMany(\App\Models\InvoiceItem::class);
    }
}

app\Models\InvoiceItem.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class InvoiceItem extends Model
{
    use \Backpack\CRUD\app\Models\Traits\CrudTrait;
    
    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'invoice_id',
        'order',
        'description',
        'quantity',
        'price',
        'tax',
        'extras',
    ];

    /**
     * The attributes that should be cast to native types.
     *
     * @var array
     */
    protected $casts = [
        'id' => 'integer',
        'invoice_id' => 'integer',
        'extras' => 'array',
    ];


    public function invoice()
    {
        return $this->belongsTo(\App\Models\Invoice::class);
    }
}

database\migrations\2020_09_16_214657_create_invoices_table.php

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class CreateInvoicesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('invoices', function (Blueprint $table) {
            $table->id();
            $table->integer('number');
            $table->string('series');
            $table->string('payment_method')->nullable();
            $table->string('payment_provider')->nullable();
            $table->bigInteger('customer_id')->nullable();
            $table->softDeletes();
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('invoices');
    }
}

database\migrations\2020_09_16_215229_create_invoice_items_table.php

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class CreateInvoiceItemsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('invoice_items', function (Blueprint $table) {
            $table->id();
            $table->bigInteger('invoice_id');
            $table->unsignedInteger('order');
            $table->string('description');
            $table->unsignedInteger('quantity');
            $table->unsignedInteger('price');
            $table->unsignedInteger('tax');
            $table->json('extras');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('invoice_items');
    }
}

Hello, inquiring on how to populate the repeatable values to have the values of the related model for editing, the repeatable field doesn't seem to be filled on update by default and seem not to see the code doing that as per the screenshot you shared in the thread