Saving data including lookup tables

Anvil Q&A
2

There are several approaches you could take here depending on preference.

  • self.item['Concept'] is a string from a dropdown
  • you want to use the selected value to create a new row in the expenses table
  • where actually table_row['Concept'] should be a linked row not a string

server code - just an idea

@anvil.server.callable
def new_expense(dict_new_expense):
  concept_row = app_tables.concepts.get(description=dict_new_expense['Concept'])
  dict_new_expense['Concept'] = concept_row
  app_tables.expenses.add_row(**dict_new_expenses)

For me - I get this type of situation often - and I would typically not use strings in my dropdown but use tuples

In my very first server call I would store concepts as a variable in a Globals module

concepts = anvil.server.call('get_concepts')

@anvil.server.callable
def get_concepts():
  return [(c['description'], c) for c in app_tables.concepts.search()]
  # this is a list of tuples for dropdowns

For the dropdown I would then bind the items property to self.concepts
and bind the selected value to self.item['concept']

from Globals import concepts

class Form1(Form1Template):
  def __init__(self, **properties):
    self.concepts = concepts  # set concepts before the databindings
    self.init_components(**properties)

This way I can change my server code for adding an expense to be:

@anvil.server.callable
def new_expense(dict_new_expense):
  app_tables.expenses.add_row(**dict_new_expenses)

Other notes - you can’t make links between rows of tables if you have a ‘view’ of a table. This is a limitation of anvil tables, which is the error you’re seeing.


a couple of forum points:

  • try using backticks ``` to display code snippets rather than >
  • clone links for questions like this are super helpful since descriptions of code can only go so far
  • for us to really get a picture of your approach seeing the source code would be beneficial - see:
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