Class: Irc::Bot::MessageMapper

Inherits:
Object
  • Object
show all
Defined in:
lib/rbot/messagemapper.rb

Overview

MessageMapper is a class designed to reduce the amount of regexps and string parsing plugins and bot modules need to do, in order to process and respond to messages.

You add templates to the MessageMapper which are examined by the handle method when handling a message. The templates tell the mapper which method in its parent class (your class) to invoke for that message. The string is split, optionally defaulted and validated before being passed to the matched method.

A template such as “foo :option :otheroption” will match the string “foo bar baz” and, by default, result in method foo being called, if present, in the parent class. It will receive two parameters, the message (derived from BasicUserMessage) and a Hash containing

{:option => "bar", :otheroption => "baz"}

See the #map method for more details.

Direct Known Subclasses

RemoteDispatcher

Defined Under Namespace

Classes: Failure, FriendlyFailure, NoActionFailure, NoMatchFailure, NotPrivateFailure, NotPublicFailure, PartialMatchFailure

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(parent) ⇒ MessageMapper

parent

parent class which will receive mapped messages

Create a new MessageMapper with parent class parent. This class will receive messages from the mapper via the handle() method.



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# File 'lib/rbot/messagemapper.rb', line 114

def initialize(parent)
  @parent = parent
  @templates = Array.new
  @fallback = :usage
end

Instance Attribute Details

#fallback=(value) ⇒ Object (writeonly)

used to set the method name used as a fallback for unmatched messages. The default fallback is a method called “usage”.



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# File 'lib/rbot/messagemapper.rb', line 108

def fallback=(value)
  @fallback = value
end

Instance Method Details

#each ⇒ Object

Iterate over each MessageTemplate handled.



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# File 'lib/rbot/messagemapper.rb', line 227

def each
  @templates.each {|tmpl| yield tmpl}
end

#handle(m) ⇒ Object

m

derived from BasicUserMessage

Examine the message m, comparing it with each map()‘d template to find and process a match. Templates are examined in the order they were map()’d - first match wins.

Returns true if a match is found including fallbacks, false otherwise.



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# File 'lib/rbot/messagemapper.rb', line 244

def handle(m)
  return false if @templates.empty?
  failures = []
  @templates.each do |tmpl|
    options = tmpl.recognize(m)
    if options.kind_of? Failure
      failures << options
    else
      action = tmpl.options[:action]
      unless @parent.respond_to?(action)
        failures << NoActionFailure.new(tmpl, m)
        next
      end
      auth = tmpl.options[:full_auth_path]
      debug "checking auth for #{auth}"
      if m.bot.auth.allow?(auth, m.source, m.replyto)
        debug "template match found and auth'd: #{action.inspect} #{options.inspect}"
        if !m.in_thread && (tmpl.options[:thread] || tmpl.options[:threaded])
          Thread.new do
            begin
              @parent.send(action, m, options)
            rescue Exception => e
              error "In threaded action: #{e.message}"
              debug e.backtrace.join("\n")
            end
          end
        else
          @parent.send(action, m, options)
        end

        return true
      end
      debug "auth failed for #{auth}"
      # if it's just an auth failure but otherwise the match is good,
      # don't try any more handlers
      return false
    end
  end
  failures.each {|r|
    debug "#{r.template.inspect} => #{r}"
  }
  debug "no handler found, trying fallback"
  if @fallback && @parent.respond_to?(@fallback)
    if m.bot.auth.allow?(@fallback, m.source, m.replyto)
      @parent.send(@fallback, m, {:failures => failures})
      return true
    end
  end
  return false
end

#last ⇒ Object

Return the last added MessageTemplate



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# File 'lib/rbot/messagemapper.rb', line 232

def last
  @templates.last
end

#map(botmodule, *args) ⇒ Object

call-seq: map(botmodule, template, options)

botmodule

the BotModule which will handle this map

template

a String describing the messages to be matched

options

a Hash holding variouns options

This method is used to register a new MessageTemplate that will map any BasicUserMessage matching the given template to a corresponding action. A simple example:

plugin.map 'myplugin :parameter'

(other examples follow).

By default, the action to which the messages are mapped is a method named like the first word of the template. The

:action => 'method_name'

option can be used to override this default behaviour. Example:

plugin.map 'myplugin :parameter', :action => 'mymethod'

By default whether a handler is fired depends on an auth check. In rbot versions up to 0.9.10, the first component of the string was used for the auth check, unless overridden via the :auth => ‘auth_name’ option. Since version 0.9.11, a new auth method has been implemented. TODO document.

Static parameters (not prefixed with ‘:’ or ‘*’) must match the respective component of the message exactly. Example:

plugin.map 'myplugin :foo is :bar'

will only match messages of the form “myplugin something is somethingelse”

Dynamic parameters can be specified by a colon ‘:’ to match a single component (whitespace separated), or a * to suck up all following parameters into an array. Example:

plugin.map 'myplugin :parameter1 *rest'

You can provide defaults for dynamic components using the :defaults parameter. If a component has a default, then it is optional. e.g:

plugin.map 'myplugin :foo :bar', :defaults => {:bar => 'qux'}

would match ‘myplugin param param2’ and also ‘myplugin param’. In the latter case, :bar would be provided from the default.

Static and dynamic parameters can also be made optional by wrapping them in square brackets []. For example

plugin.map 'myplugin :foo [is] :bar'

will match both ‘myplugin something is somethingelse’ and ‘myplugin something somethingelse’.

Components can be validated before being allowed to match, for example if you need a component to be a number:

plugin.map 'myplugin :param', :requirements => {:param => /^\d+$/}

will only match strings of the form ‘myplugin 1234’ or some other number.

Templates can be set not to match public or private messages using the :public or :private boolean options.

Summary of recognized options:

action

method to call when the template is matched

auth_path

TODO document

requirements

a Hash whose keys are names of dynamic parameters and whose values are regular expressions that the parameters must match

defaults

a Hash whose keys are names of dynamic parameters and whose values are the values to be assigned to those parameters when they are missing from the message. Any dynamic parameter appearing in the :defaults Hash is therefore optional

public

a boolean (defaults to true) that determines whether the template should match public (in channel) messages.

private

a boolean (defaults to true) that determines whether the template should match private (not in channel) messages.

threaded

a boolean (defaults to false) that determines whether the action should be called in a separate thread.

Further examples:

# match 'karmastats' and call my stats() method
plugin.map 'karmastats', :action => 'stats'
# match 'karma' with an optional 'key' and call my karma() method
plugin.map 'karma :key', :defaults => {:key => false}
# match 'karma for something' and call my karma() method
plugin.map 'karma for :key'

# two matches, one for public messages in a channel, one for
# private messages which therefore require a channel argument
plugin.map 'urls search :channel :limit :string',
          :action => 'search',
          :defaults => {:limit => 4},
          :requirements => {:limit => /^\d+$/},
          :public => false
plugin.map 'urls search :limit :string',
          :action => 'search',
          :defaults => {:limit => 4},
          :requirements => {:limit => /^\d+$/},
          :private => false



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# File 'lib/rbot/messagemapper.rb', line 222

def map(botmodule, *args)
  @templates << MessageTemplate.new(botmodule, *args)
end