Laravel - 背包 select 依赖于另一个 select

Question

I recently installed Laravel Backpack admin in my Laravel project. Currently right now I'm working on it. But I need help. So...

What I want:

I want to have two selects, first one is Category and the second one is Article . So Article select must depend on Category select. And Article belongsTo Category .

Category-Article

Category 1 = [ Article 1, Article 2, Article 3 ]
Category 2 = [ Article 4, Article 5 ]

This is just a showing of which article belongs to category. So for example, when I click Category 1 on category select, on article select it should show me only Article 1, Article 2 and Article 3 .

What I did

I followed instructions on Backpack docs, for Add a select2 field that depends on another field on this link . So what I did first:

I created two tables, Category table and Article table. Their models:

class Category extends Model
{
    use CrudTrait;

    /*
    |--------------------------------------------------------------------------
    | GLOBAL VARIABLES
    |--------------------------------------------------------------------------
    */

    protected $table = 'categories';
    protected $primaryKey = 'id';
    // public $timestamps = false;
    // protected $guarded = ['id'];
    protected $fillable = ['title'];
    // protected $hidden = [];
    // protected $dates = [];

    /*
    |--------------------------------------------------------------------------
    | FUNCTIONS
    |--------------------------------------------------------------------------
    */

    public function articles(){
        return $this->hasMany('App\Models\Article');
    }
}

This is a Category model, and this is Article model:

class Article extends Model
{
    use CrudTrait;

    /*
    |--------------------------------------------------------------------------
    | GLOBAL VARIABLES
    |--------------------------------------------------------------------------
    */

    protected $table = 'articles';
    protected $primaryKey = 'id';
    // public $timestamps = false;
    // protected $guarded = ['id'];
    protected $fillable = ['title', 'category_id'];
    // protected $hidden = [];
    // protected $dates = [];

    /*
    |--------------------------------------------------------------------------
    | FUNCTIONS
    |--------------------------------------------------------------------------
    */

    /*
    |--------------------------------------------------------------------------
    | RELATIONS
    |--------------------------------------------------------------------------
    */

    public function category(){
        return $this->belongsTo('App\Models\Category');
    }
}

I made relationships between these two models like this. So when I create Article it shows me title and I have to choose category_id from category select .

After all this I made Archive table and these are my migrations:

Schema::create('archives', function (Blueprint $table) {
   $table->increments('id');
   $table->string('title');

   $table->bigInteger('category_id')->unsigned();
   $table->foreign('category_id')->references('id')->on('categories');

   $table->bigInteger('article_id')->unsigned();
   $table->foreign('article_id')->references('id')->on('articles');

   $table->timestamps();
});

And my Archive.php model:

class Archive extends Model
{
    use CrudTrait;

    /*
    |--------------------------------------------------------------------------
    | GLOBAL VARIABLES
    |--------------------------------------------------------------------------
    */

    protected $table = 'archives';
    protected $primaryKey = 'id';
    // public $timestamps = false;
    // protected $guarded = ['id'];
    protected $fillable = ['title', 'category', 'article'];
    // protected $hidden = [];
    // protected $dates = [];

    /*
    |--------------------------------------------------------------------------
    | FUNCTIONS
    |--------------------------------------------------------------------------
    */

    /*
    |--------------------------------------------------------------------------
    | RELATIONS
    |--------------------------------------------------------------------------
    */

    public function category(){
        return $this->belongsTo('App\Models\Category');
    }

    public function article(){
        return $this->belongsTo('App\Models\Article');
    }
}

And then I followed instructions from the backpack docs . This is my ArchiveCrudController :

public function setup()
    {
        /*
        |--------------------------------------------------------------------------
        | CrudPanel Basic Information
        |--------------------------------------------------------------------------
        */
        $this->crud->setModel('App\Models\Archive');
        $this->crud->setRoute(config('backpack.base.route_prefix') . '/archive');
        $this->crud->setEntityNameStrings('archive', 'archives');

        $this->crud->setColumns(['title', 'category', 'article']);
        $this->crud->addField([
            'name' => 'title',
            'type' => 'text',
            'label' => "Archive title"
        ]);

        $this->crud->addField([    // SELECT2
            'label'         => 'Category',
            'type'          => 'select',
            'name'          => 'category_id',
            'entity'        => 'category',
            'attribute'     => 'title',
        ]);
        $this->crud->addField([ // select2_from_ajax: 1-n relationship
            'label'                => "Article", // Table column heading
            'type'                 => 'select2_from_ajax',
            'name'                 => 'article_id', // the column that contains the ID of that connected entity;
            'entity'               => 'article', // the method that defines the relationship in your Model
            'attribute'            => 'title', // foreign key attribute that is shown to user
            'data_source'          => url('api/article'), // url to controller search function (with /{id} should return model)
            'placeholder'          => 'Select an article', // placeholder for the select
            'minimum_input_length' => 0, // minimum characters to type before querying results
            'dependencies'         => ['category'], // when a dependency changes, this select2 is reset to null
            //'method'                    => ‘GET’, // optional - HTTP method to use for the AJAX call (GET, POST)
        ]);


        /*
        |--------------------------------------------------------------------------
        | CrudPanel Configuration
        |--------------------------------------------------------------------------
        */

        // TODO: remove setFromDb() and manually define Fields and Columns
        //$this->crud->setFromDb();

        // add asterisk for fields that are required in ArchiveRequest
        $this->crud->setRequiredFields(StoreRequest::class, 'create');
        $this->crud->setRequiredFields(UpdateRequest::class, 'edit');
    }

Like from backpack docs . Then I made Api folder in App\Http\Controller and then I made ArticleController in it, like this:

<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Models\Article;
use Illuminate\Http\Request;

class ArticleController extends Controller
{
    public function index(Request $request)
    {
        $search_term = $request->input('q');
        $form = collect($request->input('form'))->pluck('value', 'name');

        $options = Article::query();

        // if no category has been selected, show no options
        if (! $form['category']) {
            return [];
        }

        // if a category has been selected, only show articles in that category
        if ($form['category']) {
            $options = $options->where('category_id', $form['category']);
        }

        if ($search_term) {
            $results = $options->where('title', 'LIKE', '%'.$search_term.'%')->paginate(10);
        } else {
            $results = $options->paginate(10);
        }

        return $options->paginate(10);
    }

    public function show($id)
    {
        return Article::find($id);
    }
}

I just copy-paste code from docs but of course I changed model for my need. And finally my routes :

Route::get('api/article', 'App\Http\Controllers\Api\ArticleController@index');
Route::get('api/article/{id}', 'App\Http\Controllers\Api\ArticleController@show');

I copy-paste these routes in my web.php in routes folder and in custom.php in routes/backpack folder.

But when I choose category in my Archive create no articles showing. Can someone please help me with this?

Answer 1

From backpack 4.1 you should include 'include_all_form_fields' => true attribute on the dependent field.

Answer 2

you have some issue in your code i hope this would solve them:

1- in ArchiveCrudController: be sure that the dependencies with category_id not category...

'dependencies'         => ['category_id'], 

 $this->crud->addField([ // select2_from_ajax: 1-n relationship
            'label'                => "Article", 
            'type'                 => 'select2_from_ajax',
            'name'                 => 'article_id',
            'entity'               => 'article',
            'attribute'            => 'title', 
            'data_source'          => url('api/article'), 
            'placeholder'          => 'Select an article',
            'minimum_input_length' => 0, querying results
            'dependencies'         => ['category_id'], 
            //'method'                    => ‘GET’,
        ]);

2- in Archive Model $fillable should take db column names not relations...

 protected $fillable = ['title', 'category_id', 'article_id'];

3- also when you get $form request parameter, it comes with name category_id like you name it in Crud not (category)

public function index(Request $request)
    {
        $search_term = $request->input('q');
        $form = collect($request->input('form'))->pluck('value', 'name');

        $options = Article::query();

        // if no category has been selected, show no options
        if (! $form['category_id']) {
            return [];
        }

        // if a category has been selected, only show articles in that category
        if ($form['category_id']) {
            $options = $options->where('category_id', $form['category_id']);
        }

        if ($search_term) {
            $results = $options->where('title', 'LIKE', '%'.$search_term.'%')->paginate(10);
        } else {
            $results = $options->paginate(10);
        }

        return $options->paginate(10);
    }