A New Breed of MUSH Server

Sheet Command

Now that we have some abilities, we can create a character sheet command to show them.

sheet <name>

Command Class

The command class for this one is pretty simple, allowing an optional target name that defaults to the enactor name. This version makes all character sheets public, but you could easily add an error check to restrict viewing if you wanted.

module AresMUSH    
  module Cortex
    class SheetCmd
      include CommandHandler
      attr_accessor :target_name
      def parse_args
         self.target_name = cmd.args ? titlecase_arg(cmd.args) : enactor_name
      def handle
        ClassTargetFinder.with_a_character(self.target_name, client, enactor) do |model|
           template =
           client.emit template.render

Sheet Template

The real work lies in generating the Template. Without a template, we’d have to build up the sheet output line by line, which would be a real chore. Templates provide a way to cleanly render multi-line output.

The real template has a bunch of pieces to show attributes, skills and traits. We’re just going to examine the attribute section. The others are very similar.

Template ERB File

The first part of the template is the ERB (Embedded Ruby) file. This mixes plain text and Ruby code.

This snippet shows the header line, character sheet title, attributes title, the attributes display, and then the footer line:

<%= t('cortex.sheet_title', :name => %>
<%= line_with_text t('cortex.attributes_title') -%>
<% attrs.each do |a| -%>
<%= a -%>
<% end %>

Here are a few quick notes about template code. For more information, see Template.

  • We can use our template helper methods, like line_with_text and left() to help format things.
  • <%= ruby code %> displays the result of the Ruby code. For example: <%= t(‘key’) %> will display the translated string.
  • <% ruby code %> (without the equals sign) is a non-display version, typically used in ‘each’ loops.
  • We can use formatting codes like %xh for bold and %lh for the header line.
  • There’s no need to use %R for linebreaks; whenever there’s a new line in the file - there will be a new line in the output. A line that ends in -%> won’t have a linebreak after it though.

Template Renderer

In the above example, we used two things - char and attrs - that don’t appear anywhere in the ERB file. Where did they come from? Every template has a helper class called a Renderer. This defines methods and variables that can be accessed by the template’s ERB file. It also provides the base render method called by the command class.

module AresMUSH    
  module Cortex
    class SheetTemplate < ErbTemplateRenderer
      attr_accessor :char
      def initialize(char)
        @char = char
        super File.dirname(__FILE__) + "/sheet.erb"
      def attrs
        @char.cortex_attributes.to_a.sort_by { |a| }
            .map do |a, i| 
              linebreak = i % 2 == 0 ? "\n" : ""
              title = left("#{ }:", 15)
              step = left(a.die_step, 20)
              "#{linebreak}%xh#{title}%xn #{step}"

The char variable is passed in from the command class when it does template =

The attrs method loops through each of the attributes and formats them for display. Technically we could do this in the ERB file. But since we want to show two attributes on each line in columns, the ERB template code would look pretty messy. It’s cleaner to do it this way. In general, you want to minimize the amount of code that appears in your ERB file and leave it to simple data access like <%= %> or <% attrs.each >.

This article is part of the Creating a Plugin tutorial.