NotEmpty Validator

This validator allows you to validate if a given value is not empty. This is often useful when working with form elements or other user input, where you can use it to ensure required elements have values associated with them.

Supported options

The following options are supported for Zend\Validator\NotEmpty:

Default behaviour

By default, this validator works differently than you would expect when you've worked with PHP's empty() operator. In particular, this validator will evaluate both the integer 0 and string '0' as empty.

$valid = new Zend\Validator\NotEmpty();
$value  = '';
$result = $valid->isValid($value);
// returns false

Specifying empty behavior

Some projects have differing opinions of what is considered an "empty" value: a string with only whitespace might be considered empty, or 0 may be considered non-empty (particularly for boolean sequences). To accommodate differing needs, Zend\Validator\NotEmpty allows you to configure which types should be validated as empty and which not.

The following types can be handled:

  • boolean: Returns false when the boolean value is false.
  • integer: Returns false when an integer 0 value is given. By default, this validation is not activate and returns true for any integer values.
  • float: Returns false when a float 0.0 value is given. By default, this validation is not activate and returns true on any float values.
  • string: Returns false when an empty string '' is given.
  • zero: Returns false when the single character zero ('0') is given.
  • empty_array: Returns false when an empty array is given.
  • null: Returns false when a null value is given.
  • php: Returns false on wherever PHP's empty() would return true.
  • space: Returns false when an string is given which contains only whitespace.
  • object: Returns true. false will be returned when object is not allowed but an object is given.
  • object_string: Returns false when an object is given and its __toString() method returns an empty string.
  • object_count: Returns false when an object is given, it implements Countable, and its count is 0.
  • all: Returns false on all above types.

All other given values will return true per default.

There are several ways to select which of the above types are validated. You can give one or multiple types and add them, you can provide an array, you can use constants, or you can provide a textual string. See the following examples:

use Zend\Validator\NotEmpty;

// Returns false on 0
$validator = new NotEmpty(NotEmpty::INTEGER);

// Returns false on 0 or '0'
$validator = new NotEmpty( NotEmpty::INTEGER | NotEmpty::ZERO);

// Returns false on 0 or '0'
$validator = new NotEmpty([ NotEmpty::INTEGER, NotEmpty::ZERO ]);

// Returns false on 0 or '0'
$validator = new NotEmpty(['integer', 'zero']);

You can also provide an instance of Traversable to set the desired types. To set types after instantiation, use the setType() method.

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