Yii 2.0 view for models with foreign keys - yii

Question

I have 3 tables:
First table is main table TheSims4Pages. It has Primary Key named id.
Second table is relation table
CREATE TABLE IF NOT EXISTS `TheSims4PagesCategoriesRelations` (
`id` int(11) NOT NULL,
`postId` int(11) NOT NULL,
`catId` int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
ALTER TABLE `TheSims4PagesCategoriesRelations`
ADD CONSTRAINT `TheSims4PagesCategoriesRelations_ibfk_2` FOREIGN KEY (`catId`) REFERENCES `TheSims4PagesCategories` (`id`),
ADD CONSTRAINT `TheSims4PagesCategoriesRelations_ibfk_1` FOREIGN KEY (`postId`) REFERENCES `TheSims4Pages` (`id`);
And third table is TheSims4PagesCategories, with PK id.
Currently I have model TheSims4Pages:
<?php
namespace app\models\TheSims4;
use Yii;
/**
* This is the model class for table "TheSims4Pages".
*
* #property integer $id
* #property string $pageName
* #property string $pageEditDate
* #property integer $isDraft
* #property integer $authorId
* #property string $pageText
*
* #property SiteUsers $author
* #property TheSims4PagesCategoriesRelations[] $theSims4PagesCategoriesRelations
*/
class TheSims4Pages extends \yii\db\ActiveRecord {
/**
* #inheritdoc
*/
public static function tableName() {
return 'TheSims4Pages';
}
/**
* #inheritdoc
*/
public function rules() {
return [
[['pageName', 'authorId', 'pageText'], 'required'],
[['pageEditDate'], 'safe'],
[['isDraft', 'authorId'], 'integer'],
[['pageText'], 'string'],
[['pageName'], 'string', 'max' => 500],
[['authorId'], 'exist', 'skipOnError' => true, 'targetClass' => SiteUsers::className(), 'targetAttribute' => ['authorId' => 'id']],
];
}
/**
* #inheritdoc
*/
public function attributeLabels() {
return [
'id' => 'ID',
'pageName' => 'Page Name',
'pageEditDate' => 'Page Edit Date',
'isDraft' => 'Is Draft',
'authorId' => 'Author ID',
'pageText' => 'Page Text',
];
}
/**
* #return \yii\db\ActiveQuery
*/
public function getAuthor() {
return $this->hasOne(SiteUsers::className(), ['id' => 'authorId']);
}
/**
* #return \yii\db\ActiveQuery
*/
public function getTheSims4PagesCategoriesRelations() {
return $this->hasMany(TheSims4PagesCategoriesRelations::className(), ['postId' => 'id']);
}
}
How to make view for TheSims4Pages, with select element for getTheSims4PagesCategoriesRelations of the model, something like
echo $form->field($model, 'categoryId')->dropDownList($listData);
But for relation table?
Ie, I want to make select item with all categories from TheSims4PagesCategories table and save multiple selection of categories into the model
$model = new TheSims4Pages();
Thank you very much!

Answer 1

In view: (where 'categoryName' is column from category table that is used as label)
<?= $form->field($model, 'categories')
->dropDownList(ArrayHelper::map(TheSims4PagesCategories::find()->all(),
'id',
'categoryName'
), ['multiple'=>'multiple']) ?>
In model add virtual variable
// ...
class TheSims4Pages extends \yii\db\ActiveRecord {
public $categories;
public function rules()
{
return [
['categories', 'each', 'rule' => ['integer']],
// your other rules
];
}
// ...
public function afterFind()
{
parent::afterFind();
$this->categories = [];
if (!empty($this->theSims4PagesCategoriesRelations)) {
foreach ($this->theSims4PagesCategoriesRelations as $cat) {
$categories[$cat->catId] = $cat->catId;
}
$this->categories = $categories;
}
}
/* deleting might work better in afterSave
due to ending up with posts without categories on constraint fail
public function beforeSave($insert)
{
parent::beforeSave($insert);
if ($insert) {
} else {
TheSims4PagesCategoriesRelations::deleteAll(['postId' => $this->id]);
}
}
*/
public function afterSave($insert, $changedAttributes)
{
parent::afterSave($insert, $changedAttributes);
if ($insert) {
} else {
TheSims4PagesCategoriesRelations::deleteAll(['postId' => $this->id]);
}
if ($this->categories) {
foreach ($this->categories as $cat_id) {
$relation = new TheSims4PagesCategoriesRelations();
$relation->postId = $this->id;
$relation->catId = $cat_id;
$relation->save();
}
}
}
}