Self.parent of a RepeatingPanel's item template returns None

Anvil Q&A
1

What I’m trying to do:

I’m trying to access a repeating panel from it’s item template as described in the documentation.

What I’ve tried and what’s not working:

I’ve tried accessing self.parent from the item template but it returns None

Code Sample:

class Form1(Form1Template):
  def __init__(self, **properties):
    # Set Form properties and Data Bindings.
    self.init_components(**properties)
    
    self.repeating_panel_1.var1 = 'test'
    self.repeating_panel_1.items = ['foo', 'bar', 'buzz'] 

class ItemTemplate1(ItemTemplate1Template):
  def __init__(self, **properties):
    # Set Form properties and Data Bindings.
    self.init_components(**properties)

    print(self.parent) # returns None
    print(self.parent.var1) # causes an error

Clone link:

2

Try to do that in the show event rather than in the __init__, because at this time the components are not fully setup.

3

Is the show event just called show without any underscores? This doesn’t print anything:

class ItemTemplate1(ItemTemplate1Template):
  def __init__(self, **properties):
    # Set Form properties and Data Bindings.
    self.init_components(**properties)
    self.label_1.text = self.item

  def show(self):
    print(self.parent)
    print(self.parent.var1)

Alternatively, calling self.show() at the end of the init produces the same error as having the code in the init itself.

Edit: Ah, I had to set the show event from the design panel too. My bad.

Referencing self.parent from the show event does indeed work and returns the expected object.

However, I would also expect it to work in the __init__ if it’s after self.init_components(**properties)

4

No, it cannot work in the __init__, because the component is still being built and something is still missing.

You use __init__ to initialize values that don’t need any (well, some) interactions, you use show when you need interactions.

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5

Picture the code that creates the instances of the repeating panel row template to add to the repeating panel. It would be something like this:

# this is the point where __init__ is called
new_row = RowTemplate()  

# this is the point where form_show is called and
# the row's self.parent is set up
self.add_component(new_row)

So self.parent is None in __init__ because the row hasn’t been added to the repeating panel yet.

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