How where method works in Laravel Models? - laravel

Question

We frequently use where method with our models but it's not defined in Base Model class so how laravel is doing this magic?
e.g MyModel::where('id, 2)->get();
The above where will definitely fetch the record having id equals 2 but where & how is this happening! I traced back to the Base Model in Laravel but didn't found where method!

Answer 1

Some of this magic resides behind a Facade Pattern https://www.tutorialspoint.com/design_pattern/facade_pattern.htm
But in Laravel case, they use Static methods in their Facades (\Illuminate\Support\Facades namespace), and create instance automatically to call those methods from instance, so you don't have to instantiate the Class yourself to start using the methods. For example when you use DB::, Cache::, Str:: to call static method.
However for Eloquent, Laravel uses this approach more internally without exposing the Model to \Illuminate\Support\Facades namespace, by configuring Eloquent Model to instantiate automatically the Model and creates\Illuminate\Database\Eloquent\Builder Eloquent Builder and forward those static methods call to the Eloquent Builder instance or to Query Builder one.
A model extends \Illuminate\Database\Eloquent\Model which has a special way to call any method statically at runtime.
/**
* Handle dynamic static method calls into the method.
*
* #param string $method
* #param array $parameters
* #return mixed
*/
public static function __callStatic($method, $parameters)
{
return (new static)->$method(...$parameters);
}
So at a certain point, the Builder classes an Eloquent use a Trait
use Illuminate\Support\Traits\ForwardsCalls;
to forward call to each others so that a Model can forward its static method to method from the created instance of Eloquent builder. So if model does not have where method, it will forward it to the where method of the newly created nstance of Eloquent Builder.
From a look of Facade Pattern, here is how Laravel calls a method from an instance but in a static way :
// \Illuminate\Support\Facades\Facade.php
/**
* Handle dynamic, static calls to the object.
*
* #param string $method
* #param array $args
* #return mixed
*
* #throws \RuntimeException
*/
public static function __callStatic($method, $args)
{
$instance = static::getFacadeRoot();
if (! $instance) {
throw new RuntimeException('A facade root has not been set.');
}
return $instance->$method(...$args);
}
So calling User::where() creates an instance of \Illuminate\Database\Eloquent\Builder and forward method call to that instance, here is the method :
// Illuminate\Database\Eloquent\Builder.php
/**
* Add a basic where clause to the query.
*
* #param string|array|\Closure $column
* #param mixed $operator
* #param mixed $value
* #param string $boolean
* #return $this
*/
public function where($column, $operator = null, $value = null, $boolean = 'and')
{
if ($column instanceof Closure) {
$column($query = $this->model->newModelQuery());
$this->query->addNestedWhereQuery($query->getQuery(), $boolean);
} else {
$this->query->where(...func_get_args());
}
return $this;
}

Answer 2

You can find the method here . framework/src/Illuminate/Database/Eloquent/Builder.php
public function where($column, $operator = null, $value = null, $boolean = 'and')
{
if ($column instanceof Closure) {
$column($query = $this->model->newModelQuery());
$this->query->addNestedWhereQuery($query->getQuery(), $boolean);
} else {
$this->query->where(...func_get_args());
}
return $this;
}
Some more info about it