Question

I would like to carry out a validation before saving by determining if a User has filled in a particular field, the Payment amount field below and chosen status = “Closed” before submitting the form. If he does one without the other then the form should not save

Edit page

<%= simple_form_for @invoice, :html => { :class => 'form-horizontal' } do |f| %>
<%= render "shared/error_messages", :target => @invoice %>

<%= f.association :customer, disabled: @invoice.persisted? %>
<%= f.input :due_date, as: :string, input_html: { class: "datepicker" }, disabled:  @invoice.persisted? %>
<%= f.input :invoice_date, as: :string, input_html: { class: "datepicker" }, disabled: @invoice.persisted? %>
<%= f.input :payment_method, as: :select, :collection => [['Cash','Cash'],['Cheque','Cheque'],['In-House transfer','In-House transfer'],['Account Ledger','Account ledger']], :selected => ['Cash','Cash'] %>
<%= f.input :reference_no, :label => 'Payment Reference No', as: :string %>
<%= f.input :amount, as: :string %>
<%= f.input :payment_date, as: :string, input_html: {class: "datepicker"} %>
<%= f.input :status, as: :select, collection: Invoice::VALID_STATUS %>

VALID_STATUS = [ ‘Draft’, ‘Open’, ‘Closed’, ‘Void’ ] in Invoice.rb

I would like that if the user changes the Status to Closed he should have entered an amount in the form. A user should not be able to change status to closed without entering an amount

Answer 1

In the model (app/models/invoice_model.rb) put

validate :close_must_have_amount

Then define it (same file)

def close_must_have_amount
  :status == 'closed' && :amount # May need to tweak this
end

To have the model level validations applied client side you can use
https://github.com/bcardarella/client_side_validations/