Target binding: support BelongsToMany relationships (#34)

CHANGELOG.md

@@ -2,6 +2,14 @@
 
 All notable changes to `laravel-form-components` will be documented in this file
 
+## 2.5.0 - 2020-12-22
+
+- Support for `BelongsToMany`, `MorphMany`, and `MorphToMany` relationships (select element)
+
+## 2.4.0 - 2020-12-11
+
+- Support for Livewire modifiers
+
 ## 2.3.0 - 2020-12-01
 
 - Support for PHP 8.0

README.md

@@ -280,6 +280,20 @@ If you want a select element where multiple options can be selected, add the `mu
 <x-form-select name="country_code" :options="$countries" multiple :default="['be', 'nl']" />
 ```
 
+#### Using Eloquent relationships
+
+This package has built-in support for `BelongsToMany`, `MorphMany`, and `MorphToMany` relationships. To utilize this feature, you must add both the `multiple` and `many-relation` attribute to the select element.
+
+In the example below, you can attach one or more tags to the bound video. By using the `many-relation` attribute, it will correctly retrieve the selected options (attached tags) from the database.
+
+```blade
+<x-form>
+    @bind($video)
+        <x-form-select name="tags" :options="$tags" multiple many-relation />
+    @endbind
+</x-form>
+```
+
 ### Checkbox elements
 
 Checkboxes have a default value of `1`, but you can customize it as well.

src/Components/FormSelect.php

@@ -2,6 +2,7 @@
 
 namespace ProtoneMedia\LaravelFormComponents\Components;
 
+use Illuminate\Contracts\Support\Arrayable;
 use Illuminate\Support\Arr;
 use Illuminate\Support\Str;
 
@@ -28,18 +29,24 @@ public function __construct(
         $bind = null,
         $default = null,
         bool $multiple = false,
-        bool $showErrors = true
+        bool $showErrors = true,
+        bool $manyRelation = false
     ) {
-        $this->name    = $name;
-        $this->label   = $label;
-        $this->options = $options;
+        $this->name         = $name;
+        $this->label        = $label;
+        $this->options      = $options;
+        $this->manyRelation = $manyRelation;
 
         if ($this->isNotWired()) {
             $inputName = Str::before($name, '[]');
 
             $default = $this->getBoundValue($bind, $inputName) ?: $default;
 
             $this->selectedKey = old($inputName, $default);
+
+            if ($this->selectedKey instanceof Arrayable) {
+                $this->selectedKey = $this->selectedKey->toArray();
+            }
         }
 
         $this->multiple   = $multiple;

src/Components/HandlesBoundValues.php

@@ -2,10 +2,21 @@
 
 namespace ProtoneMedia\LaravelFormComponents\Components;
 
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
+use Illuminate\Database\Eloquent\Relations\MorphMany;
 use ProtoneMedia\LaravelFormComponents\FormDataBinder;
 
 trait HandlesBoundValues
 {
+    /**
+     * Wether to retrieve the default value as a single
+     * attribute or as a collection from the database.
+     *
+     * @var boolean
+     */
+    protected $manyRelation = false;
+
     /**
      * Get an instance of FormDataBinder.
      *
@@ -41,6 +52,44 @@ private function getBoundValue($bind, string $name)
 
         $bind = $bind ?: $this->getBoundTarget();
 
+        return $this->manyRelation
+            ? $this->getAttachedKeysFromRelation($bind, $name)
+            : data_get($bind, $name);
+    }
+
+    /**
+     * Returns an array with the attached keys.
+     *
+     * @param mixed $bind
+     * @param string $name
+     * @return void
+     */
+    private function getAttachedKeysFromRelation($bind, string $name): ?array
+    {
+        if (!$bind instanceof Model) {
+            return data_get($bind, $name);
+        }
+
+        $relation = $bind->{$name}();
+
+        if ($relation instanceof BelongsToMany) {
+            $relatedKeyName = $relation->getRelatedKeyName();
+
+            return $relation->getBaseQuery()
+                ->get($relation->getRelated()->qualifyColumn($relatedKeyName))
+                ->pluck($relatedKeyName)
+                ->all();
+        }
+
+        if ($relation instanceof MorphMany) {
+            $parentKeyName = $relation->getLocalKeyName();
+
+            return $relation->getBaseQuery()
+                ->get($relation->getQuery()->qualifyColumn($parentKeyName))
+                ->pluck($parentKeyName)
+                ->all();
+        }
+
         return data_get($bind, $name);
     }
 }

tests/Feature/InteractsWithDatabase.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace ProtoneMedia\LaravelFormComponents\Tests\Feature;
+
+use Illuminate\Database\Eloquent\Model;
+
+trait InteractsWithDatabase
+{
+    protected function setupDatabase()
+    {
+        Model::unguard();
+
+        $this->app['config']->set('database.default', 'sqlite');
+        $this->app['config']->set('database.connections.sqlite', [
+            'driver'   => 'sqlite',
+            'database' => ':memory:',
+            'prefix'   => '',
+        ]);
+
+        include_once __DIR__ . '/database/create_posts_table.php';
+        include_once __DIR__ . '/database/create_comments_table.php';
+        include_once __DIR__ . '/database/create_comment_post_table.php';
+        include_once __DIR__ . '/database/create_commentables_table.php';
+
+        (new \CreatePostsTable)->up();
+        (new \CreateCommentsTable)->up();
+        (new \CreateCommentPostTable)->up();
+        (new \CreateCommentablesTable)->up();
+    }
+}

tests/Feature/SelectRelationTest.php

@@ -0,0 +1,139 @@
+<?php
+
+namespace ProtoneMedia\LaravelFormComponents\Tests\Feature;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Route;
+use ProtoneMedia\LaravelFormComponents\Tests\TestCase;
+
+class PostBelongsToMany extends Model
+{
+    protected $table = 'posts';
+
+    public function comments()
+    {
+        return $this->belongsToMany(Comment::class, 'comment_post', 'post_id', 'comment_id');
+    }
+}
+
+class PostMorphMany extends Model
+{
+    protected $table = 'posts';
+
+    public function comments()
+    {
+        return $this->morphMany(Comment::class, 'commentable');
+    }
+}
+
+class PostMorphToMany extends Model
+{
+    protected $table = 'posts';
+
+    public function comments()
+    {
+        return $this->morphToMany(Comment::class, 'commentable');
+    }
+}
+
+class Comment extends Model
+{
+}
+
+class SelectRelationTest extends TestCase
+{
+    use InteractsWithDatabase;
+
+    /** @test */
+    public function it_handles_belongs_to_many_relationships()
+    {
+        $this->setupDatabase();
+
+        $post = PostBelongsToMany::create(['content' => 'Content']);
+
+        $commentA = Comment::create(['content' => 'Content A']);
+        $commentB = Comment::create(['content' => 'Content B']);
+        $commentC = Comment::create(['content' => 'Content C']);
+
+        $post->comments()->sync([$commentA->getKey(), $commentC->getKey()]);
+
+        $options = Comment::get()->pluck('content', 'id');
+
+        Route::get('select-relation', function () use ($post, $options) {
+            return view('select-relation')
+                ->with('post', $post)
+                ->with('options', $options);
+        })->middleware('web');
+
+        DB::enableQueryLog();
+
+        $this->visit('/select-relation')
+            ->seeElement('option[value="' . $commentA->getKey() . '"]:selected')
+            ->seeElement('option[value="' . $commentB->getKey() . '"]:not(:selected)')
+            ->seeElement('option[value="' . $commentC->getKey() . '"]:selected');
+
+        // make sure we cache the result for each option element
+        $this->assertCount(1, DB::getQueryLog());
+    }
+
+    /** @test */
+    public function it_handles_morph_many_relationships()
+    {
+        $this->setupDatabase();
+
+        $post = PostMorphMany::create(['content' => 'Content']);
+
+        $commentA = $post->comments()->create(['content' => 'Content A']);
+        $commentB = Comment::create(['content' => 'Content B']);
+        $commentC = $post->comments()->create(['content' => 'Content C']);
+
+        $options = Comment::get()->pluck('content', 'id');
+
+        Route::get('select-relation', function () use ($post, $options) {
+            return view('select-relation')
+                ->with('post', $post)
+                ->with('options', $options);
+        })->middleware('web');
+
+        DB::enableQueryLog();
+
+        $this->visit('/select-relation')
+            ->seeElement('option[value="' . $commentA->getKey() . '"]:selected')
+            ->seeElement('option[value="' . $commentB->getKey() . '"]:not(:selected)')
+            ->seeElement('option[value="' . $commentC->getKey() . '"]:selected');
+
+        // make sure we cache the result for each option element
+        $this->assertCount(1, DB::getQueryLog());
+    }
+
+    /** @test */
+    public function it_handles_morph_to_many_relationships()
+    {
+        $this->setupDatabase();
+
+        $post = PostMorphToMany::create(['content' => 'Content']);
+
+        $commentA = $post->comments()->create(['content' => 'Content A']);
+        $commentB = Comment::create(['content' => 'Content B']);
+        $commentC = $post->comments()->create(['content' => 'Content C']);
+
+        $options = Comment::get()->pluck('content', 'id');
+
+        Route::get('select-relation', function () use ($post, $options) {
+            return view('select-relation')
+                ->with('post', $post)
+                ->with('options', $options);
+        })->middleware('web');
+
+        DB::enableQueryLog();
+
+        $this->visit('/select-relation')
+            ->seeElement('option[value="' . $commentA->getKey() . '"]:selected')
+            ->seeElement('option[value="' . $commentB->getKey() . '"]:not(:selected)')
+            ->seeElement('option[value="' . $commentC->getKey() . '"]:selected');
+
+        // make sure we cache the result for each option element
+        $this->assertCount(1, DB::getQueryLog());
+    }
+}

tests/Feature/database/create_comment_post_table.php

@@ -0,0 +1,30 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class CreateCommentPostTable extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::create('comment_post', function (Blueprint $table) {
+            $table->unsignedBigInteger('post_id');
+            $table->unsignedBigInteger('comment_id');
+        });
+    }
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::dropIfExists('comment_post');
+    }
+}

tests/Feature/database/create_commentables_table.php

@@ -0,0 +1,31 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class CreateCommentablesTable extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::create('commentables', function (Blueprint $table) {
+            $table->bigIncrements('id');
+            $table->unsignedBigInteger('comment_id');
+            $table->morphs('commentable');
+        });
+    }
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::dropIfExists('comments');
+    }
+}