# NotEmpty

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 for Zend_Validate_NotEmpty

The following options are supported for `Zend_Validate_NotEmpty`:

- type: Sets the type of validation which will be processed. For details take a look into this section.

## Default behaviour for Zend_Validate_NotEmpty

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

    $valid = new Zend_Validate_NotEmpty();
    $value  = '';
    $result = $valid->isValid($value);
    // returns false

### Default behaviour differs from PHP

Without providing configuration, `Zend_Validate_NotEmpty`'s behaviour differs from PHP.

## Changing behaviour for Zend_Validate_NotEmpty

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 accomodate differing needs, `Zend_Validate_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. Per default this validation is not activated and returns `TRUE` on any integer values.

- float: Returns `FALSE` when an float 0.0 value is given. Per default this validation is not activated 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 an `NULL` value is given.

- php: Returns `FALSE` on the same reasons where PHP method `empty()` would return `TRUE`.

- space: Returns `FALSE` when an string is given which contains only whitespaces.

- 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 give an array, you can use constants, or you can give a textual string. See the following examples:

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

    // Returns false on 0 or '0'
    $validator = new Zend_Validate_NotEmpty(
        Zend_Validate_NotEmpty::INTEGER + Zend_NotEmpty::ZERO
    );

    // Returns false on 0 or '0'
    $validator = new Zend_Validate_NotEmpty(array(
        Zend_Validate_NotEmpty::INTEGER,
        Zend_Validate_NotEmpty::ZERO
    ));

    // Returns false on 0 or '0'
    $validator = new Zend_Validate_NotEmpty(array(
        'integer',
        'zero',
    ));

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