Self.item is being set to a list?

Anvil Q&A
1

What I’m trying to do:
I am trying to set the items of a Repeating Panel (RP) to a row in my data table. In my data table it is perfectly normal to have many cells to be None! I have a high suspicion that this could be a bug, but on the other hand, I have done this exact way of setting an RP’s items in the past with no errors. I am pretty clueless.

What I’ve tried and what’s not working:
I have tried the code below but it gives me an error and tells me that self.item is in fact a list (no clue how this has come to be). I have tried printing out self.item within the RP and this is what shows me it is a list (see Console Output) and this is strange because when I am setting the items of my RP I printed it out and it is just a normal row. However, it looks like most of the data has been lost in transit.

Form Code:

print(f"Form: {dict(anvil.server.call('getPupWeightTitles', self.litterID))}")
self.rpPupWeightTitles.items = anvil.server.call('getPupWeightTitles', self.litterID)

Server Code:

'''Get PupWeights from datatable that matches ID'''
@anvil.server.callable
def getPupWeightTitles(matchID):
  rows = app_tables.firstfortnightfile___pupweights.search(ID=matchID)
  if len(rows) > 0: # Check if the list of rows is not empty
    # print(f"PupWeights {matchID}: Existing row found")
    # Return the first row matching the ID
    return rows[0]
  else: # If row doesn't exist, create a new row and return it
    # print(f"PupWeights {matchID}: Creating new row")
    raise Exception("Row does not exist")

RepeatingPanel Code:

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

    # Any code you write here will run before the form opens.
    self.fillLables()


  def fillLables(self):
    # f"{self.item['Name']}\n{self.item['CollarColour']}"
    print(f"RP: {self.item}")
    self.dateObj = self.item['StartingDate']

Console Output: Line 23 is: self.dateObj = self.item['StartingDate']

Form: {'Day6': None, 'Day8': None, 'CollarColour': 'Dark green', 'Day12': None, 'Day9': None, 'Name': 'Ben', 'StartingDate': datetime.date(2023, 6, 25), 'Day0': 1234, 'Day5': None, 'Day1': None, 'Day7': None, 'Day3': None, 'Day11': None, 'Day2': None, 'ID': 1, 'Day10': None, 'Day4': None, 'Day13': None}
RP: ['Day6', None]
TypeError: list indices must be integers or slices, not str
at FirstWhelpingFortnight.PupWeightsTitles, line 23

SOLVED
To fix this issue I followed what stefano.menci’s comment says and just put the single row that I was returning into a list:

return [rows[0]]
2

Your server function returns a dict and you assign it to the repeating panel’s items, which expects a list.

The repeating panel then iterates what it thinks is a list, but it’s a dict, and assigns one item of the dictionary per template panel, and ends up creating one row per key/value pair.

You should assign a list of dicts (or row objects) to the items, so the repeating panel will create one instance of the template and assign one dict to each template’s item.

1 Like
3

Sorry for the confusion @stefano.menci, but the server does in fact return a row object. The row object can be turned into a dictionary if put into the dict() function, and that is what I am doing with the print statement!

4

As Stefano says, your server function is returning a single row (which is a dict like object). A repeating panel expects a list of rows (or dicts). Change your server function to return the entire set of rows, instead of indexing and returning just the first one.

1 Like
5

So @jshaffstall, I understand what you are saying, but in the past I have done this exact thing with only returning a single row (except I used get() and not search()) and it has worked. Maybe I just got lucky? Although I understand your point, I still don’t understand why self.item only contains the ‘Day6’ and None. Where did the rest of the row data go?

6

Stefano covered that nicely. Each “row” in the repeating panel is one of the entries in the actual row. You must pass a list of rows or dicts into the repeating panel’s items property, not a single row or dict.

Without seeing the code that worked we can’t say why, but what you’re trying now won’t work.

1 Like
7

Ah thank you very much,. I must have missed that part. Thank you for both of your help and assistance.