[FIXED] CakePHP 3 validator - Unable to call method “” in “default” provider for upload field

Issue

Here is my validator for the field article where pdf files should be uploaded:

 $validator
->add('article', [
    'rule' => [
        'extension' => [
            ['article', 'pdf'],
            'message' => 'Only  pdf!'
        ]
    ]
])
->notEmpty('article');

This gives an error:

"Unable to call method "" in "default" provider for field "article""

How can I fix this to enable uploading only pdf files to the field article?

Solution

The order of the elements in your code is wrong.

Also worth a look: API Class Validation - Extension

$validator
  ->add('article', [
    'extension' => [
      'rule' => [ 'extension', ['pdf'] ],
      'message' => 'Only PDF!'
    ]
  ])
  ->notEmpty('article', 'This field is required')
  ;

You should also check the mimeType to enhance security. Works similar, see also the example in the book in the chapter conditional validation

Answered By - Oops D'oh