Button triggering automatically

[wrench100]

I've just added a new button to my plug-in interface. For some reason, when I open the plug-in, that button's function fires off automatically. Here's my code for defining the button:

self.unshelve_TSBL1_button = QPushButton(
            'Unshelve from TSBL 1', self)
        self.unshelve_TSBL1_button.clicked.connect(self.doUnshelve('status:TSBL1shelved'))
        self.l.addWidget(self.unshelve_TSBL1_button)

If I comment out the connect line, the interface appears as normal, with the new button showing properly. As soon as I uncomment the line, the doUnshelve routine gets called as soon as I open the plugin.

Any ideas?

[capink]

try this instead

from functools import partial

self.unshelve_TSBL1_button = QPushButton(
            'Unshelve from TSBL 1', self)
        self.unshelve_TSBL1_button.clicked.connect(partial(self.doUnshelve,'status:TSBL1shelved'))
        self.l.addWidget(self.unshelve_TSBL1_button)

[wrench100]

That worked! Thanks so much!

If it's not a hassle, could I trouble you for a quick explanation? Or an explanation to read somewhere else?

Thanks again!

[capink]

You are not supposed to call a function when connecting to a siganl, you just reference the function object and it will be called later when the signal is emitted. So when you do it as below (the wrong way), you are calling the function:

button.clicked.connect(myfunction())

You simply replace it with this:

button.clicked.connect(myfunction)

Here you are just referencing the function object to be called later when needed.

But what if the function expects additional arguments? how to pass them without calling the function?

Here is where the partial function comes into play, it takes the function and the args and makes new function like object that have the args built inside (sort of) it so that you do not need to supply them.

Simply searching for "python partial" in google will give enough material for further explanation.

[wrench100]

Great, thanks. I really appreciate the time and explanation. I'll keep reading.