QRegExpValidator(3) Used to check a string against a

SYNOPSIS

#include <qvalidator.h>

Inherits QValidator.

Public Members


QRegExpValidator ( QObject * parent, const char * name = 0 )

QRegExpValidator ( const QRegExp & rx, QObject * parent, const char * name = 0 )

~QRegExpValidator ()

virtual QValidator::State validate ( QString & input, int & pos ) const

void setRegExp ( const QRegExp & rx )

const QRegExp & regExp () const

DESCRIPTION

The QRegExpValidator class is used to check a string against a regular expression.

QRegExpValidator contains a regular expression, "regexp", used to determine whether an input string is Acceptable, Intermediate or Invalid.

The regexp is treated as if it begins with the start of string assertion, ^, and ends with the end of string assertion $ so the match is against the entire input string, or from the given position if a start position greater than zero is given.

For a brief introduction to Qt's regexp engine see QRegExp.

Example of use:


// regexp: optional '-' followed by between 1 and 3 digits
QRegExp rx( "-?\\d{1,3}" );
QValidator* validator = new QRegExpValidator( rx, this );

QLineEdit* edit = new QLineEdit( this );
edit->setValidator( validator );

Below we present some examples of validators. In practice they would normally be associated with a widget as in the example above.


// integers 1 to 9999
QRegExp rx( "[1-9]\\d{0,3}" );
// the validator treats the regexp as "^[1-9]\\d{0,3}$"
QRegExpValidator v( rx, 0 );
QString s;
int pos = 0;

s = "0"; v.validate( s, pos ); // returns Invalid
s = "12345"; v.validate( s, pos ); // returns Invalid
s = "1"; v.validate( s, pos ); // returns Acceptable

rx.setPattern( "\\S+" ); // one or more non-whitespace characters
v.setRegExp( rx );
s = "myfile.txt"; v.validate( s, pos ); // Returns Acceptable
s = "my file.txt"; v.validate( s, pos ); // Returns Invalid

// A, B or C followed by exactly five digits followed by W, X, Y or Z
rx.setPattern( "[A-C]\\d{5}[W-Z]" );
v.setRegExp( rx );
s = "a12345Z"; v.validate( s, pos ); // Returns Invalid
s = "A12345Z"; v.validate( s, pos ); // Returns Acceptable
s = "B12"; v.validate( s, pos ); // Returns Intermediate

// match most 'readme' files
rx.setPattern( "read\\S?me(\.(txt|asc|1st))?" );
rx.setCaseSensitive( FALSE );
v.setRegExp( rx );
s = "readme"; v.validate( s, pos ); // Returns Acceptable
s = "README.1ST"; v.validate( s, pos ); // Returns Acceptable
s = "read me.txt"; v.validate( s, pos ); // Returns Invalid
s = "readm"; v.validate( s, pos ); // Returns Intermediate

See also QRegExp, QIntValidator, QDoubleValidator, and Miscellaneous Classes.

MEMBER FUNCTION DOCUMENTATION

QRegExpValidator::QRegExpValidator ( QObject * parent, const char * name = 0 )

Constructs a validator that accepts any string (including an empty one) as valid. The object's parent is parent and its name is name.

QRegExpValidator::QRegExpValidator ( const QRegExp & rx, QObject * parent, const char * name = 0 )

Constructs a validator which accepts all strings that match the regular expression rx. The object's parent is parent and its name is name.

The match is made against the entire string, e.g. if the regexp is [A-Fa-f0-9]+ it will be treated as ^[A-Fa-f0-9]+$.

QRegExpValidator::~QRegExpValidator ()

Destroys the validator, freeing any resources allocated.

const QRegExp & QRegExpValidator::regExp () const

Returns the regular expression used for validation.

See also setRegExp().

void QRegExpValidator::setRegExp ( const QRegExp & rx )

Sets the regular expression used for validation to rx.

See also regExp().

QValidator::State QRegExpValidator::validate ( QString & input, int & pos ) const [virtual]

Returns Acceptable if input is matched by the regular expression for this validator, Intermediate if it has matched partially (i.e. could be a valid match if additional valid characters are added), and Invalid if input is not matched.

The pos parameter is set to the length of the input parameter.

For example, if the regular expression is &#92;w&#92;d&#92;d (that is, word-character, digit, digit) then "A57" is Acceptable," E5" is Intermediate and "+9" is Invalid.

See also QRegExp::match() and QRegExp::search().

Reimplemented from QValidator.

COPYRIGHT

Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the license file included in the distribution for a complete license statement.

AUTHOR

Generated automatically from the source code.

BUGS

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If you find errors in this manual page, please report them to [email protected]. Please include the name of the manual page (qregexpvalidator.3qt) and the Qt version (3.3.8).