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Data Validation

Data validation is an important part of any application, as it helps to make sure that the data in a Model conforms to the business rules of the application. For example, you might want to make sure that passwords are at least eight characters long, or ensure that usernames are unique. Defining validation rules makes form handling much, much easier.

There are many different aspects to the validation process. What we’ll cover in this section is the model side of things. Essentially: what happens when you call the save() method of your model. For more information about how to handle the displaying of validation errors, check out FormHelper.

The first step to data validation is creating the validation rules in the Model. To do that, use the Model::validate array in the Model definition, for example:

class User extends AppModel {
    public $validate = array();
}

In the example above, the $validate array is added to the User Model, but the array contains no validation rules. Assuming that the users table has login, password, email and born fields, the example below shows some simple validation rules that apply to those fields:

class User extends AppModel {
    public $validate = array(
        'login' => 'alphaNumeric',
        'email' => 'email',
        'born'  => 'date'
    );
}

This last example shows how validation rules can be added to model fields. For the login field, only letters and numbers will be accepted, the email should be valid, and born should be a valid date. Defining validation rules enables CakePHP’s automagic showing of error messages in forms if the data submitted does not follow the defined rules.

CakePHP has many validation rules and using them can be quite easy. Some of the built-in rules allow you to verify the formatting of emails, URLs, and credit card numbers – but we’ll cover these in detail later on.

Here is a more complex validation example that takes advantage of some of these built-in validation rules:

class User extends AppModel {
    public $validate = array(
        'login' => array(
            'alphaNumeric' => array(
                'rule'     => 'alphaNumeric',
                'required' => true,
                'message'  => 'Letters and numbers only'
            ),
            'between' => array(
                'rule'    => array('between', 5, 15),
                'message' => 'Between 5 to 15 characters'
            )
        ),
        'password' => array(
            'rule'    => array('minLength', '8'),
            'message' => 'Minimum 8 characters long'
        ),
        'email' => 'email',
        'born' => array(
            'rule'       => 'date',
            'message'    => 'Enter a valid date',
            'allowEmpty' => true
        )
    );
}

Two validation rules are defined for login: it should contain letters and numbers only, and its length should be between 5 and 15. The password field should be a minimum of 8 characters long. The email should be a valid email address, and born should be a valid date. Also, notice how you can define specific error messages that CakePHP will use when these validation rules fail.

As the example above shows, a single field can have multiple validation rules. And if the built-in rules do not match your criteria, you can always add your own validation rules as required.

Now that you’ve seen the big picture on how validation works, let’s look at how these rules are defined in the model. There are three different ways that you can define validation rules: simple arrays, single rule per field, and multiple rules per field.

Simple Rules

As the name suggests, this is the simplest way to define a validation rule. The general syntax for defining rules this way is:

public $validate = array('fieldName' => 'ruleName');

Where, ‘fieldName’ is the name of the field the rule is defined for, and ‘ruleName’ is a pre-defined rule name, such as ‘alphaNumeric’, ‘email’ or ‘isUnique’.

For example, to ensure that the user is giving a well formatted email address, you could use this rule:

public $validate = array('user_email' => 'email');

One Rule Per Field

This definition technique allows for better control of how the validation rules work. But before we discuss that, let’s see the general usage pattern adding a rule for a single field:

public $validate = array(
    'fieldName1' => array(
        // or: array('ruleName', 'param1', 'param2' ...)
        'rule'       => 'ruleName',
        'required'   => true,
        'allowEmpty' => false,
        // or: 'update'
        'on'         => 'create',
        'message'    => 'Your Error Message'
    )
);

The ‘rule’ key is required. If you only set ‘required’ => true, the form validation will not function correctly. This is because ‘required’ is not actually a rule.

As you can see here, each field (only one field shown above) is associated with an array that contains five keys: ‘rule’, ‘required’, ‘allowEmpty’, ‘on’ and ‘message’. Let’s have a closer look at these keys.

rule

The ‘rule’ key defines the validation method and takes either a single value or an array. The specified ‘rule’ may be the name of a method in your model, a method of the core Validation class, or a regular expression. For more information on the rules available by default, see Core Validation Rules.

If the rule does not require any parameters, ‘rule’ can be a single value e.g.:

public $validate = array(
    'login' => array(
        'rule' => 'alphaNumeric'
    )
);

If the rule requires some parameters (like the max, min or range), ‘rule’ should be an array:

public $validate = array(
    'password' => array(
        'rule' => array('minLength', 8)
    )
);

Remember, the ‘rule’ key is required for array-based rule definitions.

required

This key accepts either a boolean, or create or update. Setting this key to true will make the field always required. While setting it to create or update will make the field required only for update or create operations. If ‘required’ is evaluated to true, the field must be present in the data array. For example, if the validation rule has been defined as follows:

public $validate = array(
    'login' => array(
        'rule'     => 'alphaNumeric',
        'required' => true
    )
);

The data sent to the model’s save() method must contain data for the login field. If it doesn’t, validation will fail. The default value for this key is boolean false.

required => true does not mean the same as the validation rule notEmpty(). required => true indicates that the array key must be present - it does not mean it must have a value. Therefore validation will fail if the field is not present in the dataset, but may (depending on the rule) succeed if the value submitted is empty (‘’).

Changed in version 2.1: Support for create and update were added.

allowEmpty

If set to false, the field value must be nonempty, where “nonempty” is defined as !empty($value) || is_numeric($value). The numeric check is so that CakePHP does the right thing when $value is zero.

The difference between required and allowEmpty can be confusing. 'required' => true means that you cannot save the model without the key for this field being present in $this->data (the check is performed with isset); whereas, 'allowEmpty' => false makes sure that the current field value is nonempty, as described above.

on

The ‘on’ key can be set to either one of the following values: ‘update’ or ‘create’. This provides a mechanism that allows a certain rule to be applied either during the creation of a new record, or during update of a record.

If a rule has defined ‘on’ => ‘create’, the rule will only be enforced during the creation of a new record. Likewise, if it is defined as ‘on’ => ‘update’, it will only be enforced during the updating of a record.

The default value for ‘on’ is null. When ‘on’ is null, the rule will be enforced during both creation and update.

message

The message key allows you to define a custom validation error message for the rule:

public $validate = array(
    'password' => array(
        'rule'    => array('minLength', 8),
        'message' => 'Password must be at least 8 characters long'
    )
);

Note

Regardless of the rule, validation failure without a defined message defaults to “This field cannot be left blank.”

Multiple Rules per Field

The technique outlined above gives us much more flexibility than simple rules assignment, but there’s an extra step we can take in order to gain more fine-grained control of data validation. The next technique we’ll outline allows us to assign multiple validation rules per model field.

If you would like to assign multiple validation rules to a single field, this is basically how it should look:

public $validate = array(
    'fieldName' => array(
        'ruleName' => array(
            'rule' => 'ruleName',
            // extra keys like on, required, etc. go here...
        ),
        'ruleName2' => array(
            'rule' => 'ruleName2',
            // extra keys like on, required, etc. go here...
        )
    )
);

As you can see, this is quite similar to what we did in the previous section. There, for each field we had only one array of validation parameters. In this case, each ‘fieldName’ consists of an array of rule indexes. Each ‘ruleName’ contains a separate array of validation parameters.

This is better explained with a practical example:

public $validate = array(
    'login' => array(
        'loginRule-1' => array(
            'rule'    => 'alphaNumeric',
            'message' => 'Only alphabets and numbers allowed',
         ),
        'loginRule-2' => array(
            'rule'    => array('minLength', 8),
            'message' => 'Minimum length of 8 characters'
        )
    )
);

The above example defines two rules for the login field: loginRule-1 and loginRule-2. As you can see, each rule is identified with an arbitrary name.

When using multiple rules per field the ‘required’ and ‘allowEmpty’ keys need to be used only once in the first rule.

last

In case of multiple rules per field by default if a particular rule fails error message for that rule is returned and the following rules for that field are not processed. If you want validation to continue in spite of a rule failing set key last to false for that rule.

In the following example even if “rule1” fails “rule2” will be processed and error messages for both failing rules will be returned if “rule2” also fails:

public $validate = array(
    'login' => array(
        'rule1' => array(
            'rule'    => 'alphaNumeric',
            'message' => 'Only alphabets and numbers allowed',
            'last'    => false
         ),
        'rule2' => array(
            'rule'    => array('minLength', 8),
            'message' => 'Minimum length of 8 characters'
        )
    )
);

When specifying validation rules in this array form it’s possible to avoid providing the message key. Consider this example:

public $validate = array(
    'login' => array(
        'Only alphabets and numbers allowed' => array(
            'rule'    => 'alphaNumeric',
         ),
    )
);

If the alphaNumeric rules fails the array key for this rule ‘Only alphabets and numbers allowed’ will be returned as error message since the message key is not set.

Custom Validation Rules

If you haven’t found what you need thus far, you can always create your own validation rules. There are two ways you can do this: by defining custom regular expressions, or by creating custom validation methods.

Custom Regular Expression Validation

If the validation technique you need to use can be completed by using regular expression matching, you can define a custom expression as a field validation rule:

public $validate = array(
    'login' => array(
        'rule'    => '/^[a-z0-9]{3,}$/i',
        'message' => 'Only letters and integers, min 3 characters'
    )
);

The example above checks if the login contains only letters and integers, with a minimum of three characters.

The regular expression in the rule must be delimited by slashes. The optional trailing ‘i’ after the last slash means the reg-exp is case insensitive.

Adding your own Validation Methods

Sometimes checking data with regular expression patterns is not enough. For example, if you want to ensure that a promotional code can only be used 25 times, you need to add your own validation function, as shown below:

class User extends AppModel {

    public $validate = array(
        'promotion_code' => array(
            'rule'    => array('limitDuplicates', 25),
            'message' => 'This code has been used too many times.'
        )
    );

    public function limitDuplicates($check, $limit) {
        // $check will have value: array('promotion_code' => 'some-value')
        // $limit will have value: 25
        $existingPromoCount = $this->find('count', array(
            'conditions' => $check,
            'recursive' => -1
        ));
        return $existingPromoCount < $limit;
    }
}

The current field to be validated is passed into the function as first parameter as an associated array with field name as key and posted data as value.

If you want to pass extra parameters to your validation function, add elements onto the ‘rule’ array, and handle them as extra params (after the main $check param) in your function.

Your validation function can be in the model (as in the example above), or in a behavior that the model implements. This includes mapped methods.

Model/behavior methods are checked first, before looking for a method on the Validation class. This means that you can override existing validation methods (such as alphaNumeric()) at an application level (by adding the method to AppModel), or at model level.

When writing a validation rule which can be used by multiple fields, take care to extract the field value from the $check array. The $check array is passed with the form field name as its key and the field value as its value. The full record being validated is stored in $this->data member variable:

class Post extends AppModel {

    public $validate = array(
        'slug' => array(
            'rule'    => 'alphaNumericDashUnderscore',
            'message' => 'Slug can only be letters,' .
                ' numbers, dash and underscore'
        )
    );

    public function alphaNumericDashUnderscore($check) {
        // $data array is passed using the form field name as the key
        // have to extract the value to make the function generic
        $value = array_values($check);
        $value = $value[0];

        return preg_match('|^[0-9a-zA-Z_-]*$|', $value);
    }
}

Note

Your own validation methods must have public visibility. Validation methods that are protected and private are not supported.

The method should return true if the value is valid. If the validation failed, return false. The other valid return value are strings which will be shown as the error message. Returning a string means the validation failed. The string will overwrite the message set in the $validate array and be shown in the view’s form as the reason why the field was not valid.

Dynamically change validation rules

Using the $validate property to declare validation rules is a good way of statically defining rules for each model. Nevertheless, there are cases when you want to dynamically add, change or remove validation rules from the predefined set.

All validation rules are stored in a ModelValidator object, which holds every rule set for each field in your model. Defining new validation rules is as easy as telling this object to store new validation methods for the fields you want to.

Adding new validation rules

New in version 2.2.

The ModelValidator objects allows several ways for adding new fields to the set. The first one is using the add method:

// Inside a model class
$this->validator()->add('password', 'required', array(
    'rule' => 'notEmpty',
    'required' => 'create'
));

This will add a single rule to the password field in the model. You can chain multiple calls to add to create as many rules as you like:

// Inside a model class
$this->validator()
    ->add('password', 'required', array(
        'rule' => 'notEmpty',
        'required' => 'create'
    ))
    ->add('password', 'size', array(
        'rule' => array('between', 8, 20),
        'message' => 'Password should be at least 8 chars long'
    ));

It is also possible to add multiple rules at once for a single field:

$this->validator()->add('password', array(
    'required' => array(
        'rule' => 'notEmpty',
        'required' => 'create'
    ),
    'size' => array(
        'rule' => array('between', 8, 20),
        'message' => 'Password should be at least 8 chars long'
    )
));

Alternatively, you can use the validator object to set rules directly to fields using the array interface:

$validator = $this->validator();
$validator['username'] = array(
    'unique' => array(
        'rule' => 'isUnique',
        'required' => 'create'
    ),
    'alphanumeric' => array(
        'rule' => 'alphanumeric'
    )
);

Modifying current validation rules

New in version 2.2.

Modifying current validation rules is also possible using the validator object, there are several ways in which you can alter current rules, append methods to a field or completely remove a rule from a field rule set:

// In a model class
$this->validator()->getField('password')->setRule('required', array(
    'rule' => 'required',
    'required' => true
));

You can also completely replace all the rules for a field using a similar method:

// In a model class
$this->validator()->getField('password')->setRules(array(
    'required' => array(...),
    'otherRule' => array(...)
));

If you wish to just modify a single property in a rule you can set properties directly into the CakeValidationRule object:

// In a model class
$this->validator()->getField('password')
    ->getRule('required')->message = 'This field cannot be left blank';

Properties in any CakeValidationRule get their name from the array keys one is allowed to use when defining a validation rule’s properties, such as the array keys ‘message’ and ‘allowEmpty’ for example.

As with adding new rule to the set, it is also possible to modify existing rules using the array interface:

$validator = $this->validator();
$validator['username']['unique'] = array(
    'rule' => 'isUnique',
    'required' => 'create'
);

$validator['username']['unique']->last = true;
$validator['username']['unique']->message = 'Name already taken';

Removing rules from the set

New in version 2.2.

It is possible to both completely remove all rules for a field and to delete a single rule in a field’s rule set:

// Completely remove all rules for a field
$this->validator()->remove('username');

// Remove 'required' rule from password
$this->validator()->remove('password', 'required');

Optionally, you can use the array interface to delete rules from the set:

$validator = $this->validator();
// Completely remove all rules for a field
unset($validator['username']);

// Remove 'required' rule from password
unset($validator['password']['required']);

Core Validation Rules

class Validation

The Validation class in CakePHP contains many validation rules that can make model data validation much easier. This class contains many oft-used validation techniques you won’t need to write on your own. Below, you’ll find a complete list of all the rules, along with usage examples.

static Validation::alphaNumeric(mixed $check)

The data for the field must only contain letters and numbers.:

public $validate = array(
    'login' => array(
        'rule'    => 'alphaNumeric',
        'message' => 'Usernames must only contain letters and numbers.'
    )
);
static Validation::between(string $check, integer $min, integer $max)

The length of the data for the field must fall within the specified numeric range. Both minimum and maximum values must be supplied. Uses = not.:

public $validate = array(
    'password' => array(
        'rule'    => array('between', 5, 15),
        'message' => 'Passwords must be between 5 and 15 characters long.'
    )
);

The length of data is “the number of bytes in the string representation of the data”. Be careful that it may be larger than the number of characters when handling non-ASCII characters.

static Validation::blank(mixed $check)

This rule is used to make sure that the field is left blank or only white space characters are present in its value. White space characters include space, tab, carriage return, and newline.:

public $validate = array(
    'id' => array(
        'rule' => 'blank',
        'on'   => 'create'
    )
);
static Validation::boolean(string $check)

The data for the field must be a boolean value. Valid values are true or false, integers 0 or 1 or strings ‘0’ or ‘1’.:

public $validate = array(
    'myCheckbox' => array(
        'rule'    => array('boolean'),
        'message' => 'Incorrect value for myCheckbox'
    )
);
static Validation::cc(mixed $check, mixed $type = 'fast', boolean $deep = false, string $regex = null)

This rule is used to check whether the data is a valid credit card number. It takes three parameters: ‘type’, ‘deep’ and ‘regex’.

The ‘type’ key can be assigned to the values of ‘fast’, ‘all’ or any of the following:

  • amex
  • bankcard
  • diners
  • disc
  • electron
  • enroute
  • jcb
  • maestro
  • mc
  • solo
  • switch
  • visa
  • voyager

If ‘type’ is set to ‘fast’, it validates the data against the major credit cards’ numbering formats. Setting ‘type’ to ‘all’ will check with all the credit card types. You can also set ‘type’ to an array of the types you wish to match.

The ‘deep’ key should be set to a boolean value. If it is set to true, the validation will check the Luhn algorithm of the credit card (http://en.wikipedia.org/wiki/Luhn_algorithm). It defaults to false.

The ‘regex’ key allows you to supply your own regular expression that will be used to validate the credit card number:

public $validate = array(
    'ccnumber' => array(
        'rule'    => array('cc', array('visa', 'maestro'), false, null),
        'message' => 'The credit card number you supplied was invalid.'
    )
);
static Validation::comparison(mixed $check1, string $operator = null, integer $check2 = null)

Comparison is used to compare numeric values. It supports “is greater”, “is less”, “greater or equal”, “less or equal”, “equal to”, and “not equal”. Some examples are shown below:

public $validate = array(
    'age' => array(
        'rule'    => array('comparison', '>=', 18),
        'message' => 'Must be at least 18 years old to qualify.'
    )
);

public $validate = array(
    'age' => array(
        'rule'    => array('comparison', 'greater or equal', 18),
        'message' => 'Must be at least 18 years old to qualify.'
    )
);
static Validation::custom(mixed $check, string $regex = null)

Used when a custom regular expression is needed:

public $validate = array(
    'infinite' => array(
        'rule'    => array('custom', '\u221E'),
        'message' => 'Please enter an infinite number.'
    )
);
static Validation::date(string $check, mixed $format = 'ymd', string $regex = null)

This rule ensures that data is submitted in valid date formats. A single parameter (which can be an array) can be passed that will be used to check the format of the supplied date. The value of the parameter can be one of the following:

  • ‘dmy’ e.g. 27-12-2006 or 27-12-06 (separators can be a space, period, dash, forward slash)
  • ‘mdy’ e.g. 12-27-2006 or 12-27-06 (separators can be a space, period, dash, forward slash)
  • ‘ymd’ e.g. 2006-12-27 or 06-12-27 (separators can be a space, period, dash, forward slash)
  • ‘dMy’ e.g. 27 December 2006 or 27 Dec 2006
  • ‘Mdy’ e.g. December 27, 2006 or Dec 27, 2006 (comma is optional)
  • ‘My’ e.g. (December 2006 or Dec 2006)
  • ‘my’ e.g. 12/2006 or 12/06 (separators can be a space, period, dash, forward slash)
  • ‘ym’ e.g. 2006/12 or 06/12 (separators can be a space, period, dash, forward slash)
  • ‘y’ e.g. 2006 (separators can be a space, period, dash, forward slash)

If no keys are supplied, the default key that will be used is ‘ymd’:

public $validate = array(
    'born' => array(
        'rule'       => array('date', 'ymd'),
        'message'    => 'Enter a valid date in YY-MM-DD format.',
        'allowEmpty' => true
    )
);

While many data stores require a certain date format, you might consider doing the heavy lifting by accepting a wide-array of date formats and trying to convert them, rather than forcing users to supply a given format. The more work you can do for your users, the better.

Changed in version 2.4: The ym and y formats were added.

static Validation::datetime(array $check, mixed $dateFormat = 'ymd', string $regex = null)

This rule ensures that the data is a valid datetime format. A parameter (which can be an array) can be passed to specify the format of the date. The value of the parameter can be one or more of the following:

  • ‘dmy’ e.g. 27-12-2006 or 27-12-06 (separators can be a space, period, dash, forward slash)
  • ‘mdy’ e.g. 12-27-2006 or 12-27-06 (separators can be a space, period, dash, forward slash)
  • ‘ymd’ e.g. 2006-12-27 or 06-12-27 (separators can be a space, period, dash, forward slash)
  • ‘dMy’ e.g. 27 December 2006 or 27 Dec 2006
  • ‘Mdy’ e.g. December 27, 2006 or Dec 27, 2006 (comma is optional)
  • ‘My’ e.g. (December 2006 or Dec 2006)
  • ‘my’ e.g. 12/2006 or 12/06 (separators can be a space, period, dash, forward slash)

If no keys are supplied, the default key that will be used is ‘ymd’:

public $validate = array(
    'birthday' => array(
        'rule'    => array('datetime', 'dmy'),
        'message' => 'Please enter a valid date and time.'
    )
);

Also a second parameter can be passed to specify a custom regular expression. If this parameter is used, this will be the only validation that will occur.

Note that unlike date(), datetime() will validate a date and a time.

static Validation::decimal(string $check, integer $places = null, string $regex = null)

This rule ensures that the data is a valid decimal number. A parameter can be passed to specify the number of digits required after the decimal point. If no parameter is passed, the data will be validated as a scientific float, which will cause validation to fail if no digits are found after the decimal point:

public $validate = array(
    'price' => array(
        'rule' => array('decimal', 2)
    )
);
static Validation::email(string $check, boolean $deep = false, string $regex = null)

This checks whether the data is a valid email address. Passing a boolean true as the second parameter for this rule will also attempt to verify that the host for the address is valid:

public $validate = array('email' => array('rule' => 'email'));

public $validate = array(
    'email' => array(
        'rule'    => array('email', true),
        'message' => 'Please supply a valid email address.'
    )
);
static Validation::equalTo(mixed $check, mixed $compareTo)

This rule will ensure that the value is equal to, and of the same type as the given value.

public $validate = array(
    'food' => array(
        'rule'    => array('equalTo', 'cake'),
        'message' => 'This value must be the string cake'
    )
);
static Validation::extension(mixed $check, array $extensions = array('gif', 'jpeg', 'png', 'jpg'))

This rule checks for valid file extensions like .jpg or .png. Allow multiple extensions by passing them in array form.

public $validate = array(
    'image' => array(
        'rule'    => array(
            'extension',
            array('gif', 'jpeg', 'png', 'jpg')
        ),
        'message' => 'Please supply a valid image.'
    )
);
static Validation::fileSize($check, $operator = null, $size = null)

This rule allows you to check filesizes. You can use $operator to decide the type of comparison you want to use. All the operators supported by comparison() are supported here as well. This method will automatically handle array values from $_FILES by reading from the tmp_name key if $check is an array an contains that key:

public $validate = array(
    'image' => array(
        'rule' => array('fileSize', '<=', '1MB'),
        'message' => 'Image must be less than 1MB'
    )
);

New in version 2.3: This method was added in 2.3

static Validation::inList(string $check, array $list, boolean $caseInsensitive = false)

This rule will ensure that the value is in a given set. It needs an array of values. The field is valid if the field’s value matches one of the values in the given array.

Example:

public $validate = array(
    'function' => array(
         'allowedChoice' => array(
             'rule'    => array('inList', array('Foo', 'Bar')),
             'message' => 'Enter either Foo or Bar.'
         )
     )
 );

Comparison is case sensitive by default. You can set $caseInsensitive to true if you need case insensitive comparison.

static Validation::ip(string $check, string $type = 'both')

This rule will ensure that a valid IPv4 or IPv6 address has been submitted. Accepts as option ‘both’ (default), ‘IPv4’ or ‘IPv6’.

public $validate = array(
    'clientip' => array(
        'rule'    => array('ip', 'IPv4'), // or 'IPv6' or 'both' (default)
        'message' => 'Please supply a valid IP address.'
    )
);
Model::isUnique()

The data for the field must be unique, it cannot be used by any other rows:

public $validate = array(
    'login' => array(
        'rule'    => 'isUnique',
        'message' => 'This username has already been taken.'
    )
);

You can validate that a set of fields are unique by providing multiple fields:

public $validate = array(
    'email' => array(
        'rule'    => array('isUnique', 'email', 'username'),
        'message' => 'This username & email combination has already been used.'
    )
);

Make sure to include the original field in the list of fields when making a unique rule across multiple fields.

static Validation::luhn(string|array $check, boolean $deep = false)

The Luhn algorithm: A checksum formula to validate a variety of identification numbers. See http://en.wikipedia.org/wiki/Luhn_algorithm for more information.

static Validation::maxLength(string $check, integer $max)

This rule ensures that the data stays within a maximum length requirement.

public $validate = array(
    'login' => array(
        'rule'    => array('maxLength', 15),
        'message' => 'Usernames must be no larger than 15 characters long.'
    )
);

The length here is “the number of bytes in the string representation of the data”. Be careful that it may be larger than the number of characters when handling non-ASCII characters.

static Validation::mimeType(mixed $check, array|string $mimeTypes)

New in version 2.2.

This rule checks for valid mime types. Comparison is case sensitive.

Changed in version 2.5.

Since 2.5 $mimeTypes can be a regex string.

public $validate = array(
    'image' => array(
        'rule'    => array('mimeType', array('image/gif')),
        'message' => 'Invalid mime type.'
    ),
    'logo' => array(
        'rule'    => array('mimeType', '#image/.+#'),
        'message' => 'Invalid mime type.'
    ),
);
static Validation::minLength(string $check, integer $min)

This rule ensures that the data meets a minimum length requirement.

public $validate = array(
    'login' => array(
        'rule'    => array('minLength', 8),
        'message' => 'Usernames must be at least 8 characters long.'
    )
);

The length here is “the number of bytes in the string representation of the data”. Be careful that it may be larger than the number of characters when handling non-ASCII characters.

static Validation::money(string $check, string $symbolPosition = 'left')

This rule will ensure that the value is in a valid monetary amount.

Second parameter defines where symbol is located (left/right).

public $validate = array(
    'salary' => array(
        'rule'    => array('money', 'left'),
        'message' => 'Please supply a valid monetary amount.'
    )
);
static Validation::multiple(mixed $check, mixed $options = array(), boolean $caseInsensitive = false)

Use this for validating a multiple select input. It supports parameters “in”, “max” and “min”.

public $validate = array(
    'multiple' => array(
        'rule' => array('multiple', array(
            'in'  => array('do', 're', 'mi', 'fa', 'sol', 'la', 'ti'),
            'min' => 1,
            'max' => 3
        )),
        'message' => 'Please select one, two or three options'
    )
);

Comparison is case sensitive by default. You can set $caseInsensitive to true if you need case insensitive comparison.

static Validation::notEmpty(mixed $check)

The basic rule to ensure that a field is not empty.:

public $validate = array(
    'title' => array(
        'rule'    => 'notEmpty',
        'message' => 'This field cannot be left blank'
    )
);

Do not use this for a multiple select input as it will cause an error. Instead, use “multiple”.

static Validation::numeric(string $check)

Checks if the data passed is a valid number.:

public $validate = array(
    'cars' => array(
        'rule'    => 'numeric',
        'message' => 'Please supply the number of cars.'
    )
);
static Validation::naturalNumber(mixed $check, boolean $allowZero = false)

New in version 2.2.

This rule checks if the data passed is a valid natural number. If $allowZero is set to true, zero is also accepted as a value.

public $validate = array(
    'wheels' => array(
        'rule'    => 'naturalNumber',
        'message' => 'Please supply the number of wheels.'
    ),
    'airbags' => array(
        'rule'    => array('naturalNumber', true),
        'message' => 'Please supply the number of airbags.'
    ),
);
static Validation::phone(mixed $check, string $regex = null, string $country = 'all')

Phone validates US phone numbers. If you want to validate non-US phone numbers, you can provide a regular expression as the second parameter to cover additional number formats.

public $validate = array(
    'phone' => array(
        'rule' => array('phone', null, 'us')
    )
);
static Validation::postal(mixed $check, string $regex = null, string $country = 'us')

Postal is used to validate ZIP codes from the U.S. (us), Canada (ca), U.K (uk), Italy (it), Germany (de) and Belgium (be). For other ZIP code formats, you may provide a regular expression as the second parameter.

public $validate = array(
    'zipcode' => array(
        'rule' => array('postal', null, 'us')
    )
);
static Validation::range(string $check, integer $lower = null, integer $upper = null)

This rule ensures that the value is in a given range. If no range is supplied, the rule will check to ensure the value is a legal finite on the current platform.

public $validate = array(
    'number' => array(
        'rule'    => array('range', -1, 11),
        'message' => 'Please enter a number between 0 and 10'
    )
);

The above example will accept any value which is larger than 0 (e.g., 0.01) and less than 10 (e.g., 9.99).

Note

The range lower/upper are not inclusive

static Validation::ssn(mixed $check, string $regex = null, string $country = null)

Ssn validates social security numbers from the U.S. (us), Denmark (dk), and the Netherlands (nl). For other social security number formats, you may provide a regular expression.

public $validate = array(
    'ssn' => array(
        'rule' => array('ssn', null, 'us')
    )
);
static Validation::time(string $check)

Time validation, determines if the string passed is a valid time. Validates time as 24hr (HH:MM) or am/pm ([H]H:MM[a|p]m) Does not allow/validate seconds.

static Validation::uploadError(mixed $check)

New in version 2.2.

This rule checks if a file upload has an error.

public $validate = array(
    'image' => array(
        'rule'    => 'uploadError',
        'message' => 'Something went wrong with the upload.'
    ),
);
static Validation::url(string $check, boolean $strict = false)

This rule checks for valid URL formats. Supports http(s), ftp(s), file, news, and gopher protocols:

public $validate = array(
    'website' => array(
        'rule' => 'url'
    )
);

To ensure that a protocol is in the url, strict mode can be enabled like so:

public $validate = array(
    'website' => array(
        'rule' => array('url', true)
    )
);

This validation method uses a complex regular expression that can sometimes cause issues with Apache2 on Windows using mod_php.

static Validation::userDefined(mixed $check, object $object, string $method, array $args = null)

Runs an user-defined validation.

static Validation::uuid(string $check)

Checks that a value is a valid UUID: http://tools.ietf.org/html/rfc4122

Localized Validation

The validation rules phone() and postal() will pass off any country prefix they do not know how to handle to another class with the appropriate name. For example if you lived in the Netherlands you would create a class like:

class NlValidation {
    public static function phone($check) {
        // ...
    }
    public static function postal($check) {
        // ...
    }
}

This file could be placed in APP/Validation/ or App/PluginName/Validation/, but must be imported via App::uses() before attempting to use it. In your model validation you could use your NlValidation class by doing the following:

public $validate = array(
    'phone_no' => array('rule' => array('phone', null, 'nl')),
    'postal_code' => array('rule' => array('postal', null, 'nl')),
);

When your model data is validated, Validation will see that it cannot handle the nl locale and will attempt to delegate out to NlValidation::postal() and the return of that method will be used as the pass/fail for the validation. This approach allows you to create classes that handle a subset or group of locales, something that a large switch would not have. The usage of the individual validation methods has not changed, the ability to pass off to another validator has been added.

Tip

The Localized Plugin already contains a lot of rules ready to use: https://github.com/cakephp/localized Also feel free to contribute with your localized validation rules.