CakePHP 3 join table associations - php

Question

Alright, I have some issues understanding how the associations are working, particularly belongsTo here is my setup:
Articles can have multiple Categories
Categories can belong to multiple Articles
so in my database i have 3 tables:
articles, categories and a join table articles_categories
Table/ArticlesTable.php:
public function initialize(array $config)
{
$this->addBehavior('Timestamp');
$this->table('articles');
$this->belongsTo('Users');
$this->belongsToMany('Categories', [
'through' => 'ArticlesCategories',
'alias' => 'Categories',
'foreignKey' => 'article_id',
'joinTable' => 'articles_categories',
'targetForeignKey' => 'category_id'
]);
}
Table/CategoriesTable.php:
public function initialize(array $config)
{
$this->table('categories');
$this->displayField('name');
$this->primaryKey('id');
$this->addBehavior('Timestamp');
$this->belongsToMany('Articles', [
'through' => 'ArticlesCategories',
'alias' => 'Articles',
'foreignKey' => 'category_id',
'joinTable' => 'articles_categories',
'targetForeignKey' => 'article_id'
]);
}
Table/ArticlesCategoriesTable.php:
public function initialize(array $config)
{
$this->belongsTo('Articles');
$this->belongsTo('Categories');
}
Now inside in the view action CategoriesController.php i can overview a particular category and i need to retrieve some articles related to that category.
What is the right way to do such a thing? Here is what i have:
public function view($id = null)
{
$category = $this->Categories->find('all',['limit'=>1])->where(['Categories.id' => $id])->contain(['Articles']);
$this->set(['category'=> $category]);
}
It kinda does the job but I'd also need to be able to limit the number of related articles..

Answer 1

you can modify the query object used to load the associated models:
$category = $this->Categories->find('all',['limit'=>1])
->where(['Categories.id' => $id])
->contain(['Articles' => function($q) {
$q->limit(10);
return $q;
}
]);
edit: or you can do
$category = $this->Categories->get($id,
[
'contain' => [
'Articles' => function($q) {
$q->limit(10);
return $q;
}
]);
or maybe if you want the Articles without the Category data you can use matching
$articles = $this->Categories->Articles->find()
->matching('Categories', function ($q) use $id{
return $q->where(['id' => $id])
->limit(10);
I did not tested the last one but I think something like that should work
But as you can see the complexity is more o less the same