validate data entry

lincoln

Hi guys, I'm doing tests for the validation of the data entry, I'm using Pyside2, I'm trying to validate the full name of a person, I've tried to do it with regular expressions but the truth is that I have not achieved anything good, here is my code to see if you can give me any suggestions on how I can solve my problem.

code:

iimport re

from PySide2.QtCore import *
from PySide2.QtGui import *
from PySide2.QtWidgets import *

class Ui_Dialog(QDialog):
  def setupUi(self, Dialog):
    if not Dialog.objectName():
      Dialog.setObjectName(u"Dialog")
    Dialog.resize(312, 71)
    Dialog.setWindowFlags(Qt.Dialog|Qt.MSWindowsFixedSizeDialogHint)
    self.verticalLayout = QVBoxLayout(Dialog)
    self.verticalLayout.setObjectName(u"verticalLayout")
    self.horizontalLayout = QHBoxLayout()
    self.horizontalLayout.setObjectName(u"horizontalLayout")
    
    self.label = QLabel(Dialog)
    self.label.setObjectName(u"label")
    self.horizontalLayout.addWidget(self.label)

    self.txtNombres = QLineEdit(Dialog)
    self.txtNombres.setObjectName(u"txtNombres")
    self.horizontalLayout.addWidget(self.txtNombres)

    self.verticalLayout.addLayout(self.horizontalLayout)

    self.horizontalLayout_2 = QHBoxLayout()
    self.horizontalLayout_2.setObjectName(u"horizontalLayout_2")
    
    #self.horizontalSpacer = QSpacerItem(40, 20, QSizePolicy.Expanding, QSizePolicy.Minimum)
    #self.horizontalLayout_2.addItem(self.horizontalSpacer)
    self.horizontalLayout_2.addStretch()
    self.btnSalir = QPushButton(Dialog)
    self.btnSalir.setObjectName(u"btnSalir")
    self.btnSalir.setIcon(QIcon("img/cancel.png"))
    self.horizontalLayout_2.addWidget(self.btnSalir)
    self.btnSalir.clicked.connect(self.cancelar)

    self.btnEnviar = QPushButton(Dialog)
    self.btnEnviar.setObjectName(u"btnEnviar")
    self.btnEnviar.setIcon(QIcon("img/accept.png"))
    self.horizontalLayout_2.addWidget(self.btnEnviar)
    self.btnEnviar.clicked.connect(self.enviar)
    
    
    self.verticalLayout.addLayout(self.horizontalLayout_2)

    

    self.retranslateUi(Dialog)

    QMetaObject.connectSlotsByName(Dialog)
  # setupUi

  def retranslateUi(self, Dialog):
    Dialog.setWindowTitle(QCoreApplication.translate("Dialog", u"Dialog", None))
    self.label.setText(QCoreApplication.translate("Dialog", u"Nombres:", None))
    self.btnSalir.setText(QCoreApplication.translate("Dialog", u"Cancelar", None))
    self.btnEnviar.setText(QCoreApplication.translate("Dialog", u"Enviar", None))
  # retranslateUi

  def enviar(self):
    #self.nombre=" ".join(self.txtNombres.text().split())
    if not self.nomIsValid(self.txtNombres.text()):
      QMessageBox.warning(self,qApp.applicationName(),"Datos incorrectos.")
      self.txtNombres.selectAll()
      self.txtNombres.setFocus()
      return
    QMessageBox.information(self,"Mensaje",
      "Información enviada.\nSus datos: {}".format(self.txtNombres.text()))
    self.txtNombres.clear()
    self.txtNombres.setFocus()

  def nomIsValid(self,nom):
    ptrn=re.compile(r'^[a-zA-ZñÑ]+')    
    if ptrn.fullmatch(nom) is None:
      return False
    return True

  def cancelar(self):
    quit()

the main script:

from PySide2.QtWidgets import QApplication, QDialog
from Ventana import Ui_Dialog

if __name__ == "__main__":
    import sys
    app=QApplication(sys.argv)
    app.setStyle("Fusion")
    app.setApplicationName("App_test")
    mWindow=QDialog()
    ui=Ui_Dialog()
    ui.setupUi(mWindow)
    mWindow.show()
    sys.exit(app.exec_())

I always get the message that the data is incorrect.

JonB

@lincoln
Firstly do not use the old QRegExp class, use the newer QRegularExpression class for everything, https://doc.qt.io/qt-5/qregularexpression.html.

Secondly, I don't know why you are having trouble with an expression for full name. Depends what you want to support, but we could just take your previous expression and allow spaces: [a-zA-ZñÑ ]+. Now this is a bit simplistic, because you could just type one or more spaces only and it would match. So we might improve to: [a-zA-ZñÑ][a-zA-ZñÑ ]+. That is a mandatory letter first, then follow by one or more letters or spaces. And we could continue improving, according to your requirements/definition of a "full name". We could also change the a-zA-ZñÑ to be a broader category of possible letters, regular expressions have special "character classes".

If you want to "play" with regular expressions I suggest you go to somewhere online like https://regex101.com/ where you can develop and test proposed expressions against whatever inputs you expect to accept/reject, till you have something you like. Then bring it back to a Qt QRegularExpression. Sometimes these are not 100% identical to what is accepted by QRegularExpression --- if you use "advanced" constructs --- but mostly it works straight off, or with a minor adjustment.

JonB

@lincoln

ptrn=re.compile(r'^[a-zA-ZñÑ]+')
if ptrn.fullmatch(nom) is None:

Two possibilities:

Does your "the full name of a person" mean you are entering forename followed by space and then surname? (Or even leading/trailing spaces in the text edit?) If so you are not matching the space. You should at least show an example of the input your match is failing on!
I haven't tested, but because you are using fullmatch(), that will already put in the ^ anchor for you at the start. Is it treating the ^ you have as a literal ^ to match at the start? Test it out in Python.

As a completely separate point, are you aware that Qt has https://doc.qt.io/qt-5/qvalidator.html, validators which can be placed on, say, QLineEdit to validate as user types? For example, it could disallow the user from even typing a digit into a name. You may or may not wish to use that approach, but you might want to look at it.

lincoln

ok, thanks I am using QRegExp to validate and the exactMatch function, and it was better for me, and yes, good regarding your comment, well yes, it is the full name, but I have not been able to make the regular expression to validate that field yet, no I have found an expression that meets the pattern for the full name, first and last names, any suggestion of how I could do that validation would be very appreciated, greetings.

JonB

@lincoln
Firstly do not use the old QRegExp class, use the newer QRegularExpression class for everything, https://doc.qt.io/qt-5/qregularexpression.html.

Secondly, I don't know why you are having trouble with an expression for full name. Depends what you want to support, but we could just take your previous expression and allow spaces: [a-zA-ZñÑ ]+. Now this is a bit simplistic, because you could just type one or more spaces only and it would match. So we might improve to: [a-zA-ZñÑ][a-zA-ZñÑ ]+. That is a mandatory letter first, then follow by one or more letters or spaces. And we could continue improving, according to your requirements/definition of a "full name". We could also change the a-zA-ZñÑ to be a broader category of possible letters, regular expressions have special "character classes".

If you want to "play" with regular expressions I suggest you go to somewhere online like https://regex101.com/ where you can develop and test proposed expressions against whatever inputs you expect to accept/reject, till you have something you like. Then bring it back to a Qt QRegularExpression. Sometimes these are not 100% identical to what is accepted by QRegularExpression --- if you use "advanced" constructs --- but mostly it works straight off, or with a minor adjustment.

SGaist

@JonB There's no need for duplicating the character class as the + implies at least one element of the expression before it.

@lincoln As for the chars, there might be simpler expression encompassing all what you need. Check this page about unicode. I did not test yet what is available using the PCRE version used by Qt but it's worth checking.

JonB

@SGaist said in validate data entry:

@JonB There's no need for duplicating the character class as the + implies at least one element of the expression before it.

I don't know what you are referring to. If you mean the [a-zA-ZñÑ][a-zA-ZñÑ ]+, that is deliberate! The second [...] includes a space character. The whole point was:

That is a mandatory letter first, then follow by one or more letters or spaces.

Else what are you speaking about?

SGaist

@JonB my bad, I misread the second part, your proposition is correct.