How to edit a serialized Array with unknown keys

问题

I have the following Model with serialized variables:

create_expenses.rb

class CreateExpenses < ActiveRecord::Migration
  def change
    create_table :expenses do |t|

    t.belongs_to    :user, index: true
    t.string :ref
    t.integer :year
    t.integer :month
    t.text :traject_names, Array
    t.text :vehicles_used, Array
    t.text :nb_kms, Array
    t.text :parkings, Array
    t.text :trains, Array
    t.text :taxis, Array
    t.text :metros, Array
    t.text :meals, Array
    t.text :hotels, Array
    t.text :natures, Array
    t.text :amounts, Array
    t.text :o_ns, Array
    t.text :clients, Array
    t.timestamps
    end
  end
end

expense.rb

class Expense < ActiveRecord::Base
  belongs_to :user

  serialize :traject_names
  serialize :nb_kms
  serialize :parkings
  serialize :trains
  serialize :taxis
  serialize :metros
  serialize :meals
  serialize :hotels
  serialize :natures
  serialize :amounts
  serialize :o_ns
  serialize :clients
end

They all look like the same. Example: nb_kms = ["34", "4", "6"]. I want to be able to edit all the values. I've tried severals ways but didn't find anything working.

Last thing I've tried is the following:

<%= f.fields_for :nb_kms, @expense.nb_kms[i] do |answer_fields| %>
    <%= answer_fields.text_field "", :value => @expense.nb_kms[i] %>
<% end %>

but it doesn't work. Any tips?

回答1:

Found a workaround, not sure if this is optimized though...

For each array, use input instead of f.text_field:

<input type="number" name="nb_kms[]" value="<%= @nb_kms[i] %>">

Then, in your update action:

params['nb_kms'].each_with_index do |nb_km, i|
      @expense.nb_kms[i] = nb_km
end
if @expense.update(expense_params)
      ...

I'm currently doing a loop for each array. There's probably a cleaner way to update my arrays but I don't know how (which array should be updated at a given index?)

Finally, since I allow the user to edit the data from the show View page, I had to add this line in my routes.rb file:

patch '/expenses/:year/:month/'  => 'expenses#update'

I'm open to other solutions.

来源：https://stackoverflow.com/questions/28415176/how-to-edit-a-serialized-array-with-unknown-keys

标签

ruby-on-rails

arrays

serialization