Modifying PMIComboxBox DataSetComboBoxModel clears selected item

Ignition
1

I’m using my code in this post to make changes to the drop down menu component’s DataSetComboBoxModel and NewPMIComboBoxRenderer classes, however it’s always had the issue where the component will show <Select One> when the DataSetComboBoxModel is replaced. I can work around this by getting the selected item prior to replacing the model, then after replacing it, writing it back to it, but I wonder how I can do this within the class itself?

The section of interest is this:

class NewPMIComboBoxModel(DataSetComboBoxModel):
	def __init__(self, target):
		DataSetComboBoxModel.__init__(self, target, target.data)
		self.target = target

As soon as I run the below, the drop down selection will be lost and <Select One> will display:

RC = system.gui.getParentWindow(event).rootContainer
PMIComboBox = RC.getComponent("Dropdown")
PMIComboBox.setModel(NewPMIComboBoxModel(PMIComboBox))

How can I maintain the selection?
Cheers

2

In your subclass of DataSetComboBoxModel, call self.setSelectedItem() within your __init__() method, so that it is already “selected” when the model object replacement takes effect.

3

Hmm, I thought I’d tried this already but I have it working now. Actually I was calling self.target.setSelectedItem() instead.
Thanks! :slight_smile:

Strangely though, when I run print self.getSelectedItem(), it still returns <Select One>, but the component itself shows the actual selected item… print target.getSelectedItem() alternatively shows the actual selected item.

Running either self.setSelectedItem(self.getSelectedItem()) or self.setSelectedItem(target.getSelectedItem()) both ensure the item is selected.

4

Good timing. Time for me to crash. (:

5

FWIW, I would use:

        try:
            self.selectedItem = target.model.selectedItem
        except:
            pass

I always use netbeans syntax for readability, and I tend to be paranoid about unexpected failures.

6

Noted and good point RE try/except. Thanks again!