Add Custom Conditional Validation rules to the same attribute

Question

I'm trying to add custom validation logic for file uploads for my admin panel. Right now my file fields can return either Illuminate\Http\UploadedFile or string|null if the file is not uploaded or changed or whatever. What I'm doing is, I created a custom rule that looks like this:

'image' => [
    'required',
    'admin_file:mimes:jpeg;png,dimensions:min_width=800;min_height=600'
]

I then parse all the arguments I pass, and the thing is, I naturally want all of them applied only if my value is an instance of UploadedFile. I use the following code for my custom validation:

<?php

class AdminFileValidator
{
    public function validate($attribute, $value, $parameters, Validator $validator)
    {
        $rules = implode(
            "|",
            array_map(function($item) {
                return str_replace(";", ",", $item);
            }, $parameters)
        );

        $validator->sometimes($attribute, $rules, function() use ($value) {
            return $value instanceof UploadedFile;
        });

        return true;
    }
}

The problem is with adding additional rules to an attribute via sometimes doesn't work that way. The added rules are not being processed by a validator.

Is there any way to validate these rules without revalidating the whole thing manually?

It honestly makes no sense why you would want to create a custom validator for this. Laravel comes with file rule to check if the file was successfully uploaded. There are also rules to make it optional. — Sandeesh
There are many different types of files that i need to validate. Like documents, images, images+pdf, and others. And mime rule only accepts UploadedFile instances, and fails if i the string is being passed (which i cannot reasonably avoid, because everything is wrapped into FormRequest) — Eternal1
So you want a string value to be successfully processed instead of throwing an error? As far as i see, the rules file, mimetypes, mimes along with sometimes does exactly what you need except for string allowance. I'm not sure how'd you get a string in a form file input. — Sandeesh
@Sandeesh, I assume that there are two different forms that could be used. 1. Where the user can select an image form PC 2. Where user can select a url or image path.. Both of them pointing to same request — manix
@manix then wouldn't it be easier to have a url input and add a required_unless rule. — Sandeesh

manix manix · Accepted Answer · 2017-05-23T18:38:39

What I see is that your are using sometimes inside of a rule. From my perspective you need to take it out, even better without use a custom class.

Using Validator object:

$validator = Validator::make($data, [
    'image' => 'required',
]);

$validator->sometimes('image', 'mimes:jpeg;png,dimensions:min_width=800', function($value) {
    return $value instanceof UploadedFile;
});

If you are using a Request class you could override the function getValidatorInstance in order apply the conditional rules:

protected function getValidatorInstance(){
    $validator = parent::getValidatorInstance();

    $validator->sometimes('image', 'mimes:jpeg;png,dimensions:min_width=800', function($value) {
        return $value instanceof UploadedFile;
    });

    return $validator;
}

Add Custom Conditional Validation rules to the same attribute

1 Answers