Class: Excavator::Runner

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

Overview

Public: Runner is the entry point into an Excavator script library. When running an Excavator script from the command line, a Runner object is created.

Runner duties:

  • Load all Excavator commands.
  • Provides the object that Excavator::DSL manipulates.
  • Finds the command from the command line arguments and executes.
  • Creates a useful help message to list all commands defined in the library.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Runner

Returns a new instance of Runner.



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# File 'lib/excavator/runner.rb', line 26

def initialize
  @namespace = Namespace.new(:default)
  @current_namespace = @namespace
end

Instance Attribute Details

#command_paths ⇒ Object

Public: An Array of filesystem paths where Excavator commands are found. Defaults to the current directory's "command/" directory.



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# File 'lib/excavator/runner.rb', line 43

def command_paths
  @command_paths = Excavator.command_paths || [cwd.join("commands")]
end

#current_namespace ⇒ Object (readonly)

Public: A pointer to the current namespace being worked on.



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# File 'lib/excavator/runner.rb', line 24

def current_namespace
  @current_namespace
end

Instance Method Details

#clear_last_command! ⇒ Object

Public: Clear the last command being worked on. This is designed for use with Excavator::DSL methods.



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# File 'lib/excavator/runner.rb', line 122

def clear_last_command!
  @last_command = nil
end

#cwd ⇒ Object

Public: Return the current working directory for the script.



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# File 'lib/excavator/runner.rb', line 32

def cwd
  Excavator.cwd
end

#display_help ⇒ Object

Internal: Display the list of all command names and their descriptions.



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# File 'lib/excavator/runner.rb', line 127

def display_help
  table_view = Excavator::TableView.new do |t|
    t.title "#{File.basename($0)} commands:\n"
    t.header "Command"
    t.header "Description"
    t.divider "\t"

    namespace.commands_and_descriptions.sort.each do |command|
      t.record *command
    end
  end

  puts table_view
end

#find_command(cmd) ⇒ Object

Public: Find a command given it's full name.

cmd - A String/Symbol full name of the Command to look up. (e.g., "server:test:integration")

Returns a Command.



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# File 'lib/excavator/runner.rb', line 102

def find_command(cmd)
  *namespaces, command_name = cmd.to_s.split(':').collect {|c| c.to_sym }
  cur_namespace = current_namespace
  namespaces.each do |n|
    cur_namespace = cur_namespace.namespace(n)
  end

  cur_namespace.command(command_name)
end

#in_namespace(name) ⇒ Object

Public: A helper to move the current_namespace pointer to new namespace, yield, and then return the pointer back to the previous namespace. If the namespace argument already exists (e.g., created by another file), then this points to the previously created namespace.

name - A String/Symbol of the namespace to move the current_namespace pointer to.

Examples

runner = Runner.new
runner.in_namespace("test") do
runner.current_namespace
# => <Namespace "test">
end

Returns nothing.



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# File 'lib/excavator/runner.rb', line 64

def in_namespace(name)
  ns = @current_namespace.namespace(name) ||
       Excavator.namespace_class.new(name)
  @current_namespace << ns

  @current_namespace = ns
  yield
  @current_namespace = ns.parent
end

#last_command ⇒ Object

Public: The last command being worked on. This is designed for use with Excavator::DSL methods.



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# File 'lib/excavator/runner.rb', line 114

def last_command
  @last_command ||= Excavator.command_class.new(
    self, :namespace => current_namespace
  )
end

#namespace ⇒ Object

Internal: The root namespace for all other commands and namespaces.



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# File 'lib/excavator/runner.rb', line 143

def namespace
  @namespace
end

#run(args = ARGV) ⇒ Object

Public: The entry point into all commands. This will load all commands from any external Excavator files, find the command from the command line, and execute the command.

This method is never called directly. See Excavator.run.

Returns value returned from the Command.



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# File 'lib/excavator/runner.rb', line 81

def run(args = ARGV)
  args.flatten!

  name = args.delete_at(0)
  load_commands

  if (name.nil? && args.size == 0) || display_help?(name)
    display_help
    return
  end

  command = find_command name
  command.execute *args
end