Class: SCParse::Command

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

Overview

A command is a block of code that should have its options parsed before being executed. A command can also be a parent to subcommands.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, execute_prerequisites = true) ⇒ Command

Returns a new instance of Command.



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# File 'lib/scparse.rb', line 63

def initialize(name, execute_prerequisites = true)
  @name = name
  @execute_prerequisites = execute_prerequisites
end

Instance Attribute Details

#commands ⇒ Object (readonly)

Returns the value of attribute commands.



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# File 'lib/scparse.rb', line 59

def commands
  @commands
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/scparse.rb', line 58

def name
  @name
end

#options ⇒ Object

Returns the value of attribute options.



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

def options
  @options
end

#parent ⇒ Object

Returns the value of attribute parent.



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# File 'lib/scparse.rb', line 61

def parent
  @parent
end

Instance Method Details

#add_command(command) ⇒ Object 



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# File 'lib/scparse.rb', line 68

def add_command(command)
  @commands ||= CommandHash.new
  @commands[command.name] = command
  command.parent = self
end

#execute(args) ⇒ Object

Run the main block of code for this command, first running the prerequisite block of code if supposed to do so.



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# File 'lib/scparse.rb', line 128

def execute(args)
  parents.reverse_each {|parent| parent.prerequisites} if execute_prerequisites?
  @execution_block.call(self, args) if @execution_block
end

#execute_prerequisites? ⇒ Boolean

Is this command supposed to run its prerequisiste block of code before executing (as defined in the constructor)?

Returns:

  • (Boolean) 


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# File 'lib/scparse.rb', line 117

def execute_prerequisites?
  return @execute_prerequisites
end

#has_command?(command) ⇒ Boolean

Does this command have a given subcommand? Note: returns the command or nil, not true/false.

Returns:

  • (Boolean) 


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# File 'lib/scparse.rb', line 95

def has_command?(command)
  return @commands[command]
end

#has_commands? ⇒ Boolean

Does this command have any subcommands it’s a parent to?

Returns:

  • (Boolean) 


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# File 'lib/scparse.rb', line 100

def has_commands?
  return @commands.nil? ? false : true
end

#parents ⇒ Object

Return an array of parents for this command, up to but not including the uber-parent ScriptCommandParser object.



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# File 'lib/scparse.rb', line 83

def parents
  cmd = self
  parents = [cmd]
  begin
    cmd = cmd.parent
    parents << cmd
  end until cmd.parent.is_a?(ScriptCommandParser)
  return parents
end

#prerequisites ⇒ Object

Run the prerequisite block of code



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# File 'lib/scparse.rb', line 111

def prerequisites
  @prerequisites_block.call(self) if @prerequisites_block
end

#scparser ⇒ Object

Return the uber-parent, which is a ScriptCommandParser object.



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# File 'lib/scparse.rb', line 75

def scparser
  cmd = parent
  cmd = cmd.parent while !cmd.nil? && !cmd.is_a?(ScriptCommandParser)
  return cmd
end

#set_execution_block(&block) ⇒ Object

Set the main block of code for this command.



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# File 'lib/scparse.rb', line 122

def set_execution_block(&block)
  @execution_block = block
end

#set_prerequisites_block(&block) ⇒ Object

Set the block of code to run as a prerequisite to executing the command (such as bootstrapping code).



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# File 'lib/scparse.rb', line 106

def set_prerequisites_block(&block)
  @prerequisites_block = block
end

#show_help ⇒ Object

Along with showing the usage for the command, this also displays any and all the child subcommands that belong to this command.



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# File 'lib/scparse.rb', line 150

def show_help
  puts usage
  puts
  if has_commands?
    list_commands
    puts
  end
  unless options.nil? || options.summarize.empty?
    puts "Available options:"
    puts options.summarize
  end
end

#usage ⇒ Object

Define the usage of this command, using the name of the command and the uber-parent ScriptCommandParser.



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# File 'lib/scparse.rb', line 135

def usage
  usage = "Usage: #{scparser.name}"
  usage << " [options] "
  usage << parents.reverse.collect do |parent|
    unless parent.name == "main"
      use = parent.name
      use << " [options]"
    end
  end.join('')
  usage << (has_commands? ? " COMMAND [options] [ARGS]" : " [ARGS] ")
  return usage
end