Laravel Validation Rules

My need is just Laravel validation Rules. I want to use Laravel validation to check variables, and show custom errors by returning string in controller. (I don't use view, blade, session,... I just return string).

if(strlen($username) < 4) return '{"r": "US","msg": "username is short"}';
if(strlen($username) > 64) return '{"r": "UL","msg": "username is long"}';
if(strlen($address) > 200) return '{"r": "A","msg": "wrong address"}';

I want something like this:

if($validation->username->min has error)
     return 'string:username is short';

if($validation->address->max has error)
     return 'string:address is long';

if($validation->username->unique has error)
     return 'string:username already exists';

Solution

Have a look at the official documentation of validation in Laravel. You don't have to handle every case manually. Validator::make() will generate a validator object for you. The first parameter will take your data as an associative array. The second argument will define all rules as desired. As a third, optional parameter you may define alternative error messages if you don't like the default ones. The will be returned in the errors() method in case something isn't valid.

$validator = Validator::make($yourDataArray, [
    'username' => 'min:4|max:64|exists:table,username',
    'address' => 'max:64'
], [
    'min' => ':attribute is too short.',
    'exists' => ':attribute already exists.
]);

if ($validator->fails()) {
    return $validator->errors()->all();
}

If you don't want to get an array with all errors at once, you can get the state of each field like so:

if ($validator->errors()->has('username')) { // Username field is invalid
    return $validator->errors()->first('username'); // Get the first error
}

And if you want to know what rule exactly failed, you can use something like that:

if(isset($validator->failed()['username']['Max'])) {
    return 'Username is too long.';
}