Set Ability Command

Next up - we need a way to set character abilities. The processing is slightly different for each type of ability. We’re only going to look at the attribute set command in detail. There are two verisons of this command:

attribute/set <ability name>=<die step>  (for players)
attribute/set <char name>=<ability name>/<die step> (for admins)

This command is more complex than the previous ones we’ve looked at, so we’ll take it apart piece by piece.

Parsing Args

We can tell the difference between the two versions of the command based on whether the command args contains a ‘/’. That affects how we parse the arguments.

  attr_accessor :target_name, :ability_name, :die_step
  def parse_args
     # Admin version
     if (cmd.args =~ /\//)
       args = cmd.parse_args(ArgParser.arg1_equals_arg2_slash_arg3)
       self.target_name = titlecase_arg(args.arg1)
       self.ability_name = titlecase_arg(args.arg2)
       self.die_step = downcase_arg(args.arg3)
       args = cmd.parse_args(ArgParser.arg1_equals_arg2)
       self.target_name = enactor_name
       self.ability_name = titlecase_arg(args.arg1)
       self.die_step = downcase_arg(args.arg2)

Error Checking

There are a number of error checks needed here. First we want to make sure that all the pieces of the command were specified.

  def required_args
    [self.target_name, self.ability_name, self.die_step]

Then we check that the die step is valid. We can use one of the helper methods for that.

  def check_valid_die_step
    return t('cortex.invalid_die_step') if !Cortex.is_valid_die_step?(self.die_step)
    return nil

There’s a similar check to make sure the attribute name is valid, since Cortex has a fixed list.

  def check_valid_ability
    return t('cortex.invalid_ability_name') if !Cortex.is_valid_attribute_name?(self.ability_name)
    return nil

Next we make sure the character is allowed to edit abilities. If the target is yourself, you can. Otherwise we use a helper to ensure they have the ‘manage_apps’ permission.

  def check_can_set
    return nil if enactor_name == self.target_name
    return nil if Cortex.can_manage_abilities?(enactor)
    return t('dispatcher.not_allowed')

Finally we make sure that their character is unlocked. The character gets locked by the chargen system once they’ve submitted their app (to prevent changes while the staff is reviewing) and when they’re approved. Admins are allowed to override this.

  def check_chargen_locked
    return nil if Cortex.can_manage_abilities?(enactor)


Finally we can actually set the attribute! We use the target name to look up the character. The with_a_character helper does all the error checking for us to make sure the character exists.

def handle
  ClassTargetFinder.with_a_character(self.target_name, client, enactor) do |model|
     # See if we already have this attribute
     attr = Cortex.find_attribute(model, self.ability_name)
     # If so, update it.  Otherwise create a new one.
     if (attr)
       attr.update(die_step: self.die_step)
       CortexAttribute.create(name: self.ability_name, die_step: self.die_step, character: model)
     client.emit_success t('cortex.ability_set')

This article is part of the Creating a Plugin tutorial.