Class: Caty

Inherits:
Object
  • Object
show all
Extended by:
HelpSystem
Defined in:
lib/caty.rb

Overview

Handles command line parsing.

Subclass this and add public methods. These methods will become tasks, which will be callable via

app method_name

Use the #global_options() and #task_options() methods to add global or task-specific options.

Use the ::map() method to create aliases for tasks.

Use the ::start!() method to start parsing.

Use ::default() to set a default task.

Use ::before() and ::after() to define Rails-style before and after filters.

Defined Under Namespace

Modules: HasDescription, HelpSystem, Helpers Classes: BooleanConverter, Converter, GlobalOption, IntegerConverter, NoSuchTaskError, Option, OptionArgumentError, OptionArray, OptionConstructor, StringConverter, Task, TaskHash

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Attribute Details

#global_options ⇒ Object

Returns the global options for this invocation as an OpenHash.



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# File 'lib/caty.rb', line 47

def global_options
  @global_options
end

#task_options ⇒ Object

Returns the options for the called task as an OpenHash.



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# File 'lib/caty.rb', line 41

def task_options
  @task_options
end

Class Method Details

.append(&block) ⇒ Object

Simply class_evals the given block on your Caty subtype, thus allowing you to add new tasks in different source files.

class X < Caty
end

X.append do
    def bar
        puts 'bar task'
    end
end

X.start!(%w{bar})



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# File 'lib/caty.rb', line 116

def append( &block )
    self.class_eval(&block)
end

.start!(args = ARGV) ⇒ Object

Starts command line parsing.

Subclass.start!( arguments_array )
Subclass.start!

Returns true on success, false when an ArgumentError was detected.



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# File 'lib/caty.rb', line 60

def start!( args = ARGV )
    initialize_instance

    begin
        caty = self.new
        caty.global_options = @global_options.grep!(args)

        task_name = args.delete_at(0) || @default
        raise Caty::NoSuchTaskError, "You need to provide a task" if task_name.nil?

        task = @tasks.resolve(task_name.to_sym)

        if task.nil?
            raise Caty::NoSuchTaskError, "There is no task named `#{task_name}'"
        else
            caty.task_options = task.parse!(args)

            caty.instance_exec(task_name.to_sym, &@before) unless @before.nil?
            task.execute(caty)
            caty.instance_exec(task_name.to_sym, &@after)  unless @after.nil?
        end

        return true

    rescue Caty::NoSuchTaskError, Caty::OptionArgumentError => e
        $stdout.puts e.message
        return false

    rescue ArgumentError => e
        # verify that this is actually the task throwing the error
        if is_task_argument_error(e.backtrace, task_name)
            $stdout.puts "Bad arguments for task #{task.name}."
            $stdout.puts "Usage: #{task.to_s}"
            return false
        else
            raise
        end
    end
end