Validations

Validations

Client side

• We've inadvertently made it possible to save empty notes
• Let's make sure that notes have either title or body

• In our Note Backbone model we need to add a validate method

  • Add the logic required to ensure that in the event both title and content are blank something (and it can be anything) gets returned
  • Note that this only prevents saving if set and save are called separately

• In the ShowNote Backbone view add an initialize method

  • In the initialize method call the listenTo method to respond to the invalid event

    initialize: -> @listenTo(@model, 'invalid', @addError)

  • Add a new method called addError to handle this event

  • in the addError method add a class called error to the note div

    addError: => @$el.addClass('error')

  • Modify the beginEditing method to remove the error class from the note div if it's present

    beginEditing: -> @$el.addClass('editing') @$el.removeClass('error')

• Open the notes.css.scss file

  • define an error class under note

    &.error { border-color: red; }

Server side

• Remove the validation method from the Backbone model
• Now let's move the validations to Rails model
• If we attempt to save Rails returns a 422
• Note that the invalid event is not triggered
• If in our Note view we bind to the error event instead of invalid Backbone behaves the same as it did for client side validations

• Now we add the validation method back to the Backbone model

  initialize: ->
    @listenTo(@model, 'invalid', @addError)
    @listenTo(@model, 'error', @addError)
  

• Commit!