QRegularExpressionValidator

The QRegularExpressionValidator class is used to check a string against a regular expression. More…

Synopsis

Functions

• def regularExpression ()

Slots

• def setRegularExpression (re)

Signals

• def regularExpressionChanged (re)

Detailed Description

QRegularExpressionValidator uses a regular expression (regexp) to determine whether an input string is Acceptable , Intermediate , or Invalid . The regexp can either be supplied when the QRegularExpressionValidator is constructed, or at a later time.

If the regexp partially matches against the string, the result is considered Intermediate . For example, “” and “A” are Intermediate for the regexp [A-Z][0-9] (whereas “_” would be Invalid ).

QRegularExpressionValidator automatically wraps the regular expression in the \\A and \\z anchors; in other words, it always attempts to do an exact match.

Example of use:

// regexp: optional '-' followed by between 1 and 3 digits
QRegularExpression rx("-?\\d{1,3}");
QValidator *validator = new QRegularExpressionValidator(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
QRegularExpression re("[1-9]\\d{0,3}");
// the validator treats the regexp as "^[1-9]\\d{0,3}$"
QRegularExpressionValidator v(re, 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

re.setPattern("\\S+");            // one or more non-whitespace characters
v.setRegularExpression(re);
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
re.setPattern("[A-C]\\d{5}[W-Z]");
v.setRegularExpression(re);
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
re.setPattern("read\\S?me(\.(txt|asc|1st))?");
re.setPatternOptions(QRegularExpression::CaseInsensitiveOption);
v.setRegularExpression(re);
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

QRegularExpression QIntValidator QDoubleValidator QRegExpValidator

class PySide2.QtGui.QRegularExpressionValidator([parent=None])

PySide2.QtGui.QRegularExpressionValidator(re[, parent=None])

param parent:

PySide2.QtCore.QObject

param re:

PySide2.QtCore.QRegularExpression

Constructs a validator with a parent object that accepts any string (including an empty one) as valid.

Constructs a validator with a parent object that accepts all strings that match the regular expression re .

PySide2.QtGui.QRegularExpressionValidator.regularExpression()

Return type:

PySide2.QtCore.QRegularExpression

This property holds the regular expression used for validation.

By default, this property contains a regular expression with an empty pattern (which therefore matches any string).

PySide2.QtGui.QRegularExpressionValidator.regularExpressionChanged(re)

Parameters:

re – PySide2.QtCore.QRegularExpression

PySide2.QtGui.QRegularExpressionValidator.setRegularExpression(re)

Parameters:

re – PySide2.QtCore.QRegularExpression

This property holds the regular expression used for validation.

By default, this property contains a regular expression with an empty pattern (which therefore matches any string).