Wt::WValidator Class Reference

A validator is used to validate user input according to pre-defined rules. More...

#include <Wt/WValidator.h>

Inheritance diagram for Wt::WValidator:

Classes
class	Result
	A class that holds a validation result. More...

Public Types
typedef ValidationState	State
	Typedef for enum Wt::ValidationState.

Public Member Functions
	WValidator (bool mandatory=false)
	Creates a new validator. More...
virtual	~WValidator ()
	Destructor. More...
void	setMandatory (bool how)
	Sets if input is mandatory. More...
bool	isMandatory () const
	Returns if input is mandatory.
void	setInvalidBlankText (const WString &text)
	Sets the message to display when a mandatory field is left blank. More...
WString	invalidBlankText () const
	Returns the message displayed when a mandatory field is left blank. More...
virtual Result	validate (const WString &input) const
	Validates the given input. More...
virtual WString	format () const
	Returns the validator format. More...
virtual std::string	javaScriptValidate () const
	Creates a Javascript object that validates the input. More...
virtual std::string	inputFilter () const
	Returns a regular expression that filters input. More...

Detailed Description

A validator is used to validate user input according to pre-defined rules.

A validator may be associated with a form widget using WFormWidget::setValidator().

The validator validates the user input. A validator may have a split implementation to provide both validation at the client-side (which gives instant feed-back to the user while editing), and server-side validation (to be sure that the client was not tampered with). The feed-back given by (client-side and server-side) validation is reflected in the style class of the form field: a style class of Wt-invalid is set for a field that is invalid.

This WValidator only checks that mandatory fields are not empty. This class is reimplemented in WDateValidator, WIntValidator, WDoubleValidator, WLengthValidator and WRegExpValidator. All these validators provide both client-side and server-side validation.

If these validators are not suitable, you can inherit from this class, and provide a suitable implementation to validate() which does the server-side validation. If you want to provide client-side validation for your own validator, you may also reimplement javaScriptValidate().

i18n

The strings used in this class can be translated by overriding the default values for the following localization keys:

• Wt.WValidator.Invalid: This field cannot be empty

See also

WFormWidget

Constructor & Destructor Documentation

WValidator()

Wt::WValidator::WValidator

(

bool

mandatory = false

)

Creates a new validator.

Indicate whether input is mandatory.

See also

setMandatory(bool)

~WValidator()

Wt::WValidator::~WValidator ( )

virtual

Destructor.

The validator automatically removes itself from all formfields to which it was associated.

Member Function Documentation

format()

WString Wt::WValidator::format ( ) const

virtual

Returns the validator format.

The default implementation returns an empty string.

Reimplemented in Wt::WTimeValidator, and Wt::WDateValidator.

inputFilter()

std::string Wt::WValidator::inputFilter ( ) const

virtual

Returns a regular expression that filters input.

The returned regular expression is used to filter keys presses. The regular expression should accept valid single characters.

For details on valid regular expressions, see WRegExpValidator. As an example, "[0-9]" would only accept numbers as valid input.

The default implementation returns an empty string, which does not filter any input.

See also

javaScriptValidate()

Reimplemented in Wt::WIntValidator.

invalidBlankText()

WString Wt::WValidator::invalidBlankText

(

)

const

Returns the message displayed when a mandatory field is left blank.

See also

setInvalidBlankText(const WString&)

javaScriptValidate()

std::string Wt::WValidator::javaScriptValidate ( ) const

virtual

Creates a Javascript object that validates the input.

The JavaScript expression should evaluate to an object which contains a validate(text) function, which returns an object that contains the following two fields:

• fields: a boolean valid,
• a message that indicates the problem if not valid.

Returns an empty string if the validator does not provide a client-side validation implementationq.

See also

inputFilter()

Reimplemented in Wt::WTimeValidator, Wt::WRegExpValidator, Wt::WLengthValidator, Wt::WIntValidator, Wt::WEmailValidator, Wt::WDoubleValidator, and Wt::WDateValidator.

setInvalidBlankText()

void Wt::WValidator::setInvalidBlankText

(

const WString &

text

)

Sets the message to display when a mandatory field is left blank.

The default value is "This field cannot be empty".

setMandatory()

void Wt::WValidator::setMandatory

(

bool

how

)

Sets if input is mandatory.

When an input is not mandatory, then an empty field is always valid.

validate()

WValidator::Result Wt::WValidator::validate ( const WString &  input ) const

virtual

Validates the given input.

Note

The signature for this method changed in Wt 3.2.0.

Reimplemented in Wt::Auth::AbstractPasswordService::AbstractStrengthValidator, Wt::WTimeValidator, Wt::WRegExpValidator, Wt::WLengthValidator, Wt::WIntValidator, Wt::WEmailValidator, Wt::WDoubleValidator, and Wt::WDateValidator.