       type: 'string'
       required: yes
       hexadecimal: yes
+      defaultsTo: ""
     email:
       type: 'string'
       required: yes
       email: yes
+      defaultsTo: ""
     mobile:
       type: 'string'
       required: yes
+      defaultsTo: ""
     application_id:
       type: 'string'
     email_template:

    # The list of fields.
    fields = ['user_id', 'email', 'mobile']

    # Check if at least one of the fields is found.
    found = false
    for field in fields
      if values[field]? and !_.isEmpty values[field]
        found = true
        break

    # Turn off presence validations when at least one fields is found,
    # turn on when all fields absent.
    this._validator.validations[field].required = !found for field in fields
    cb()

module.exports =
  # Allow only whitelisted attributes.
  schema: true

  # Turn off migrations.
  migrate: 'safe'

