Update attribute of dependent record in association

Discussion in 'Ruby' started by ddoherty03, May 25, 2012.

  1. ddoherty03

    ddoherty03 Guest


    I have a rails app with a Transaction class that has_many :entries. It
    starts like this. Each Transaction has many edits, and those with the
    debit attribute true are debits, false are credits.

    class Transaction < ActiveRecord::Base
    has_many :entries
    has_many :debits, :class_name => 'Entry', :conditions => {:debit => true}
    has_many :credits, :class_name => 'Entry', :conditions => {:debit => false}

    I want to be able to complete an Transaction if there is exactly one
    Entry that has its amount set to nil. I want to set that amount to a
    debit or credit of the proper amount to make the Transaction balance.

    Sounded easy to me, but I am having trouble with my balance! method.
    The relevant part of it is:

    def balance!
    if num_nils == 1
    # Set the sole nil entry to amount needed to balance Transaction
    plug = debit_total - credit_total
    entries.where:)amount => nil).each do |e|
    e.amount = plug.abs
    e.debit = (plug < 0)

    The problem is that when I finish this, the entries associated with my
    Transaction are not affected. I appears to make a copy, change it, and
    leave the Entry associated with my Transaction with a nil amount.

    What am I missing?


    Dan Doherty
    ddoherty03, May 25, 2012
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