manipulate request parameters

I have an input text in which a user can enter a single username or comma separated usernames.

I have a rule that validates whether the usernames exist. In that rule if the string consists of comma separated usernames i create an array of usernames and then validate the array.

class CommaSeparatedUsernames implements Rule
{
 	public function passes($attribute, $value)
    	{
        	if (str_contains($value, ',')) {
            	$this->validateMultipleUsernames($attribute, $value);
       	 }
        return $this->validateUsername($attribute, $value);
    }
}

However, the value in the request parameter remains the same ( a string which consists of comma separated usernames ) and then i have to split again the string into an array in order to use the usernames.

Right now i have this function within the rule

class CommaSeparatedUsernames implements Rule
{
 	public function passes($attribute, $value)
    	{
        	if (str_contains($value, ',')) {
		    $this->validateMultipleUsernames($attribute, $value);
		    $this->replaceParticipantsParameter($value);
            
                 }
                 return $this->validateUsername($attribute, $value);
    	}

	 public function replaceParticipantsParameter($commaSeparatedNames)
    	{
        	request()->merge(
            		['participants' => $this->getNames($commaSeparatedNames)]
        	);
    	}
	
	public function getNames($commaSeparatedNames)
    	{
        	return array_map(
            	    fn($name) => trim($name, ' '),
            	    explode(',', $commaSeparatedNames)
        	    );
         }

}

My question is where should i put the code for manipulation the request parameter

Does it make sense to create a middleware that manipulates the request parameter ?
Should i put that code in the Controller or in the Model that uses the request parameter ?

GeordieJackson

5 years ago

Level 18

I would use a FormRequest class. See: https://laravel.com/docs/8.x/validation#form-request-validation

and in the form request class, use the prepareForValidation() method to manipulate the request fields (e.g. exploding the names field) and then let the validation run as normal - with the validation in the rules() method.

e.g.

    protected function prepareForValidation()
    {
        // Manipulate request fields here
    }

    public function rules()
    {
        return [
            // Set validation rules here
        ];
    }

    public function validated()
    {
        // Post validation manipulation can be done here if required
    }

2 likes

orest

5 years ago

Level 13

thanks for the suggestion.

if i wanted to apply this particular manipulation to different routes though, how should i approach it ?

Because the user can enter comma separated names in different forms where each form consists of different request parameters.

Therefore if i manipulate the request parameter in the prepareForValidation method, i would end up repeating the code for manipulating se same request parameter.

GeordieJackson

5 years ago

Level 18

So you want to be able to do the names check independently of any other validation you're doing and on more than one form?

This sounds like a good use case for an Action class. See: https://stitcher.io/blog/laravel-beyond-crud-03-actions

i.e. create an Action class with your code in it that can be called whenever needed.

1 like

orest

5 years ago

Level 13

exactly.

i want to change the value of a request parameter and validate it independently.

thanks again, i will check this out

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