Laravel Form Request Deep Dive: Understanding passedValidation() vs. $request->validated()

As senior developers working with Laravel, we often dive deep into the mechanics of how HTTP requests are processed. One area that frequently causes confusion is the subtle but critical difference between data accessible via $request->all() and $request->validated(), especially when custom logic like casting or transformation happens within a Form Request.

Today, we are dissecting a specific scenario involving the passedValidation() method in Laravel Form Requests to understand why transformed data might appear in one place but not another. We'll use your provided example to walk through the process and reveal the best practices for managing request data flow.

The Anatomy of Request Data in Laravel

To understand the issue, we must first clarify what these methods represent within the Laravel request lifecycle:

1. $request->all(): This method returns all input data received from the request, regardless of whether it passed validation or not. It represents the raw payload sent by the client.
2. $request->validated(): This method returns only the data that has successfully passed all defined validation rules. It is the clean, validated set of inputs intended for use in your application logic (e.g., saving to the database).
3. passedValidation(): This protected method is executed after the initial validation checks have passed but before the final data is committed or returned by the Form Request. It is designed for performing post-validation transformations on the request data.

The Mystery of the Missing Cast

Your observation is spot on: in your example, the custom phone number casting performed in passedValidation() does not appear in $request->validated(), but it does appear in $request->all() after validation.

This discrepancy arises because of the separation between data transformation and validation success.

When you use passedValidation(), you are modifying the internal state of the request object, which is why $request->all() reflects these changes immediately. However, $request->validated() is designed to return the data that successfully met the original rules defined in the rules() method. If your transformation logic happens outside the scope of what the validation system explicitly checks for (or if the transformation itself isn't part of the validated set), it might be excluded from the final validated array.

Analyzing Your Code Example

Let’s look at your specific implementation:

protected function passedValidation ()
{
   $this->merge( [
     'phone_field' => 
         (string) PhoneNumber::make ( $this->input('phone_field') , 
                                     $this->input('phone_country') )
   ]);
}

In this scenario, you are successfully transforming phone_field into a formatted string. The reason it's missing from $request->validated() is that the validation system primarily checks if the original data conforms to the rules. While passedValidation() modifies the request object for convenience (making it available in $request->all()), it doesn't automatically update the set of data considered "validated" unless you explicitly merge those results back into the validated set, or ensure the transformation is handled by a custom rule.

Best Practice: Merging Transformed Data Correctly

If you need transformed data to be available in $request->validated(), you must explicitly merge the changes into the validated array after passedValidation() has run. This ensures that whatever transformations you perform are included when the request is finally processed by your controller.

Here is how you can adjust your Form Request to ensure the casted data is present in the final validated set:

use Illuminate\Http\Request;
// ... other necessary imports

class CompanyFormRequest extends Request
{
    // ... rules() and authorize() methods remain the same

    protected function passedValidation ()
    {
       // Perform the transformation first
       $this->merge( [
         'phone_field' => 
             (string) PhoneNumber::make ( $this->input('phone_field') , 
                                         $this->input('phone_country') )
       ]);
       
       // Crucial step: Merge the transformed data into the validated set
       $this->merge($this->validated()); // Re-merging ensures transformations are included in the validated state
    }

    /**
     * Get the validated data.
     */
    public function validated()
    {
        // Return the merged data to ensure custom casts are included.
        return $this->validated();
    }
}

By explicitly calling $this->merge($this->validated()) within passedValidation(), you force the transformed values into the set that Laravel considers validated, making them accessible via $request->validated() in your controller. This technique is a powerful way to manage complex data preparation before hitting your business logic, which aligns perfectly with the robust architecture promoted by