Laravel Nova Filter using joined table - php

Question

I am trying to build a Laravel Nova Filter for my Model "Question", based on data from two different tables. I have figured out the exact SQL query I would need to use, but cannot figure out how to use it in the apply() method of the Nova filter.
Table "questions" columns:
id, ...
Table "themes" columns:
id, question_id, theme_id
The SQL Query I am trying to use:
SELECT questions.*
From questions
Inner JOIN themes on questions.id=themes.question_id
WHERE themes.theme_id = 3 (value taken from the Nova Filter options)
My Filter in Laravel Nova QuestionsThemeFilter.php:
class QuestionsThemeFilter extends BooleanFilter
{
public $name = 'filter by theme';
public function apply(Request $request, $query, $value) {
// This is what I'm missing...
}
public function options(Request $request) {
$themes = Themes::all();
$themesArray = array();
foreach($themes as $item) {
$themesArray[$item['title']] = strval($item['id']);
}
return $themesArray;
}
}
So, how exactly should I do this?
Other question: Since I am a beginner in Laravel, how exactly should I start debugging this? Using dd() doesn't work (the filter just breaks) and I don't know how I can debug this. Is there a way to dump some values from the apply method (for example the $value)?
Thanks in advance for any help, highly appreciated :-D

Answer 1

Check the comments in the code
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\Log;
class QuestionsThemeFilter extends BooleanFilter
{
public function apply(Request $request, $query, $value) {
// Since you are using BooleanFilter $value will be an associate array with true/false value
$selectedThemes = Arr::where($value, function ($v, $k) {
return $v === true;
});
$selectedThemeIds = array_keys($selectedThemes)
// For debugging print some logs and check
Log::info($value)
Log::info($selectedThemeIds);
return $query->join('themes', 'questions.id', '=', 'themes.question_id')
->whereIn('themes.theme_id', $selectedThemeIds);
// If you are using normal filter then below code will be enough
/*
return $query->join('themes', 'questions.id', '=', 'themes.question_id')
->where('themes.theme_id', $value);
*/
}
public function options(Request $request) {
// You can use Laravel collection method pluck
return Themes::pluck('id', 'title')->all();
}
}
References:
Pluck
Boolean Filter
Arr::where