Trouble passing an argument

[benlyboy]

Hi I have been working on this all day and it has me beat.
I want to pass the contents of a Qtextedit as a argument in a connect statement.

I tryed this.

self.connect(self.pb1a,SIGNAL("clicked()"),(lambda s=[str(self.cboxa.toPlainText())] : self._edit_(s)))
 
def _edit_(self,inptname):
      print inptname

self.connect(self.pb1a,SIGNAL("clicked()"),(lambda s=[str(self.cboxa.toPlainText())] : self._edit_(s)))

def _edit_(self,inptname):
      print inptname

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But all I seem to get with this is a empty string, but if i do this it works.

self.connect(self.pb1a,SIGNAL("clicked()"),self._edit_()))
 
def _edit_(self,inptname):
      print str(self.cboxa.toPlainText())

self.connect(self.pb1a,SIGNAL("clicked()"),self._edit_()))

def _edit_(self,inptname):
      print str(self.cboxa.toPlainText())

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Just to make it even more confusing this works

self.connect(self.pb1a,SIGNAL("clicked()"),(lambda s="this is a string"] : self._edit_(s)))
 
def _edit_(self,inptname):
      print inptname

self.connect(self.pb1a,SIGNAL("clicked()"),(lambda s="this is a string"] : self._edit_(s)))

def _edit_(self,inptname):
      print inptname

To copy to clipboard, switch view to plain text mode 

So way can't i pass the text from the Qtextedit.

What am I missing..???

[Lykurg]

you can't pass values inside a connect statement. The way to go is: connect the clicked() signal with a custom slot. In there emit a costumiced signal (which has QString as an argument), this you can connect to any function you want.

For a better answer, you might want to describe a litte more how your application looks like (where is your text edit and where is the function you want call...). It seems you can use a simple pointer to the text edit in your edit slot. So you don't have to pass the text at all. just use self.cboxa.toPlainText() inside your slot.

[benlyboy]

Thanks for the reply

The function the textedit are part of the same class, at this point at least. But I wanted to write the program in such a way that later I could move it out side the class as this function will be used by other classes

I should point out that i am writing in pyqt

[Lykurg]

But I wanted to write the program in such a way that later I could move it out side the class as this function will be used by other classes

Then create and emit your own signal.

class YourClass {
  Q_OBJECT
 signals:
   mySignal(QString);
  private slots:
    emitMySignal() {
      emit mySignal(pointerToTextEdit->toText());
    }
};

class YourClass {
  Q_OBJECT
 signals:
   mySignal(QString);
  private slots:
    emitMySignal() {
      emit mySignal(pointerToTextEdit->toText());
    }
};

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Just translate that to python and connect the button click to the private slot.

[benlyboy]

Thanks I will try that.

I am still interested in why this wouldn't work...after all shouldn't "str(self.cboxa.toPlainText())" just return a string?

self.connect(self.pb1a,SIGNAL("clicked()"),(lambda s=[str(self.cboxa.toPlainText())] : self._edit_(s)))
 
def _edit_(self,inptname):
print inptname

self.connect(self.pb1a,SIGNAL("clicked()"),(lambda s=[str(self.cboxa.toPlainText())] : self._edit_(s)))

def _edit_(self,inptname):
print inptname

To copy to clipboard, switch view to plain text mode 

and thats all this is a string isn't it? and yet this works

self.connect(self.pb1a,SIGNAL("clicked()"),(lambda s="this is a string"] : self._edit_(s)))
 
def _edit_(self,inptname):
print inptname

self.connect(self.pb1a,SIGNAL("clicked()"),(lambda s="this is a string"] : self._edit_(s)))
  
def _edit_(self,inptname):
print inptname

To copy to clipboard, switch view to plain text mode 

[squidge]

The signal parameters must match the slot being called upon reception of that signal. So if you use the signal "clicked()" then your slot can not have a parameter, as there will be none passed to it. You can't pass a parameter in the connect statement. Therefore the best solution would be to call a method that doesn't expect a parameters, and then emit another signal that does emit a signal with appropriate parameter.

That said, I'm no PyQt expert, so I'm not sure about the qwerks and workings of that language, but what I say above is normal for Qt.