Class: HighLine::Menu

Attributes

flow [RW] This attribute is passed directly on as the mode to HighLine.list() by all the preset layouts. See that method for appropriate settings.

header [RW] Used by all the preset layouts to display title and/or introductory information, when set. Defaults to nil.

index [R] An index to append to each menu item in display. See Menu.index=() for details.

index_suffix [RW] The String placed between an index and a menu item. Defaults to ". ". Switches to " ", when index is set to a String (like "-").

layout [R] An ERb layout to use when displaying this Menu object. See Menu.layout=() for details.

list_option [RW] This setting is passed on as the third parameter to HighLine.list() by all the preset layouts. See that method for details of its effects. Defaults to nil.

nil_on_handled [RW] When true, any selected item handled by provided action code, will return nil, instead of the results to the action code. This may prove handy when dealing with mixed menus where only the names of items without any code (and nil, of course) will be returned. Defaults to false.

prompt [RW] Used by all the preset layouts to ask the actual question to fetch a menu selection from the user. Defaults to "? ".

select_by

[RW]

The select_by attribute controls how the user is allowed to pick a menu item. The available choices are:

`:index`:	The user is allowed to type the numerical or alphetical index for their selection.
`:index_or_name`:	Allows both methods from the `:index` option and the `:name` option.
`:name`:	Menu items are selected by typing a portion of the item name that will be auto-completed.

shell [RW] When set to true, responses are allowed to be an entire line of input, including details beyond the command itself. Only the first "word" of input will be matched against the menu choices, but both the command selected and the rest of the line will be passed to provided action blocks. Defaults to false.

Public Class methods

new( ) {|self if block_given?| ...}

Create an instance of HighLine::Menu. All customization is done through the passed block, which should call accessors and choice() and choices() as needed to define the Menu. Note that Menus are also Questions, so all that functionality is available to the block as well.

[Source]

# File lib/highline/menu.rb, line 26
    def initialize(  )
      #
      # Initialize Question objects with ignored values, we'll
      # adjust ours as needed.
      # 
      super("Ignored", [ ], &nil)    # avoiding passing the block along
      
      @items           = [ ]
      @hidden_items    = [ ]
      @help            = Hash.new("There's no help for that topic.")

      @index           = :number
      @index_suffix    = ". "
      @select_by       = :index_or_name
      @flow            = :rows
      @list_option     = nil
      @header          = nil
      @prompt          = "?  "
      @layout          = :list
      @shell           = false
      @nil_on_handled  = false
      
      # Override Questions responses, we'll set our own.
      @responses       = { }
      # Context for action code.
      @highline        = nil
      
      yield self if block_given?

      init_help if @shell and not @help.empty?
    end

Public Instance methods

choice( name, help = nil, &action )

Adds name to the list of available menu items. Menu items will be displayed in the order they are added.

An optional action can be associated with this name and if provided, it will be called if the item is selected. The result of the method will be returned, unless nil_on_handled is set (when you would get nil instead). In shell mode, a provided block will be passed the command chosen and any details that followed the command. Otherwise, just the command is passed. The @highline variable is set to the current HighLine context before the action code is called and can thus be used for adding output and the like.

[Source]

# File lib/highline/menu.rb, line 138
    def choice( name, help = nil, &action )
      @items << [name, action]
      
      @help[name.to_s.downcase] = help unless help.nil?
      update_responses  # rebuild responses based on our settings
    end

choices( *names, &action )

A shortcut for multiple calls to the sister method choice(). Be warned: An action set here will apply to all provided names. This is considered to be a feature, so you can easily hand-off interface processing to a different chunk of code.

[Source]

# File lib/highline/menu.rb, line 151
    def choices( *names, &action )
      names.each { |n| choice(n, &action) }
    end

help( topic, help )

Used to set help for arbitrary topics. Use the topic "help" to override the default message.

[Source]

# File lib/highline/menu.rb, line 216
    def help( topic, help )
      @help[topic] = help
    end

hidden( name, help = nil, &action )

Identical to choice(), but the item will not be listed for the user.

[Source]

# File lib/highline/menu.rb, line 156
    def hidden( name, help = nil, &action )
      @hidden_items << [name, action]
      
      @help[name.to_s.downcase] = help unless help.nil?
    end

index=( style )

Sets the indexing style for this Menu object. Indexes are appended to menu items, when displayed in list form. The available settings are:

`:number`:	Menu items will be indexed numerically, starting with 1. This is the default method of indexing.
`:letter`:	Items will be indexed alphabetically, starting with a.
`:none`:	No index will be appended to menu items.
any String:	Will be used as the literal index.

Setting the index to :none a literal String, also adjusts index_suffix to a single space and select_by to :none. Because of this, you should make a habit of setting the index first.

[Source]

# File lib/highline/menu.rb, line 177
    def index=( style )
      @index = style
      
      # Default settings.
      if @index == :none or @index.is_a?(String)
        @index_suffix = " "
        @select_by    = :name
      end
    end

init_help( )

Initializes the help system by adding a :help choice, some action code, and the default help listing.

[Source]

# File lib/highline/menu.rb, line 191
    def init_help(  )
      return if @items.include?(:help)
      
      topics    = @help.keys.sort
      help_help = @help.include?("help") ? @help["help"] :
                  "This command will display helpful messages about " +
                  "functionality, like this one.  To see the help for " +
                  "a specific topic enter:\n\thelp [TOPIC]\nTry asking " +
                  "for help on any of the following:\n\n" +
                  "<%= list(#{topics.inspect}, :columns_across) %>"
      choice(:help, help_help) do |command, topic|
        topic.strip!
        topic.downcase!
        if topic.empty?
          @highline.say(@help["help"])
        else
          @highline.say("= #{topic}\n\n#{@help[topic]}")
        end
      end
    end

layout=( new_layout )

Setting a layout with this method also adjusts some other attributes of the Menu object, to ideal defaults for the chosen layout. To account for that, you probably want to set a layout first in your configuration block, if needed.

Accepted settings for layout are:

`:list`:	The default layout. The header if set will appear at the top on its own line with a trailing colon. Then the list of menu items will follow. Finally, the prompt will be used as the ask()-like question.
`:one_line`:	A shorter layout that fits on one line. The header comes first followed by a colon and spaces, then the prompt with menu items between trailing parenthesis.
`:menu_only`:	Just the menu items, followed up by a likely short prompt.
any ERb String:	Will be taken as the literal layout. This String can access `@header`, `@menu` and `@prompt`, but is otherwise evaluated in the typical HighLine context, to provide access to utilities like HighLine.list() primarily.

If set to either :one_line, or :menu_only, index will default to :none and flow will default to :inline.

[Source]

# File lib/highline/menu.rb, line 250
    def layout=( new_layout )
      @layout = new_layout
      
      # Default settings.
      case @layout
      when :one_line, :menu_only
        self.index = :none
        @flow  = :inline
      end
    end

options( )

This method returns all possible options for auto-completion, based on the settings of index and select_by.

[Source]

# File lib/highline/menu.rb, line 265
    def options(  )
      # add in any hidden menu commands
      @items.concat(@hidden_items)
      
      by_index = if @index == :letter
        l_index = "`"
        @items.map { "#{l_index.succ!}" }
      else
        (1 .. @items.size).collect { |s| String(s) }
      end
      by_name = @items.collect { |c| c.first }

      case @select_by
      when :index then
        by_index
      when :name
        by_name
      else
        by_index + by_name
      end
    ensure
      # make sure the hidden items are removed, before we return
      @items.slice!(@items.size - @hidden_items.size, @hidden_items.size)
    end

select( highline_context, selection, details = nil )

This method processes the auto-completed user selection, based on the rules for this Menu object. If an action was provided for the selection, it will be executed as described in Menu.choice().

[Source]

# File lib/highline/menu.rb, line 295
    def select( highline_context, selection, details = nil )
      # add in any hidden menu commands
      @items.concat(@hidden_items)
      
      # Find the selected action.
      name, action = if selection =~ /^\d+$/
        @items[selection.to_i - 1]
      else
        l_index = "`"
        index = @items.map { "#{l_index.succ!}" }.index(selection)
        @items.find { |c| c.first == selection } or @items[index]
      end
      
      # Run or return it.
      if not @nil_on_handled and not action.nil?
        @highline = highline_context
        if @shell
          action.call(name, details)
        else
          action.call(name)
        end
      elsif action.nil?
        name
      else
        nil
      end
    ensure
      # make sure the hidden items are removed, before we return
      @items.slice!(@items.size - @hidden_items.size, @hidden_items.size)
    end

to_ary( )

Allows Menu objects to pass as Arrays, for use with HighLine.list(). This method returns all menu items to be displayed, complete with indexes.

[Source]

# File lib/highline/menu.rb, line 331
    def to_ary(  )
      case @index
      when :number
        @items.map { |c| "#{@items.index(c) + 1}#{@index_suffix}#{c.first}" }
      when :letter
        l_index = "`"
        @items.map { |c| "#{l_index.succ!}#{@index_suffix}#{c.first}" }
      when :none
        @items.map { |c| "#{c.first}" }
      else
        @items.map { |c| "#{index}#{@index_suffix}#{c.first}" }
      end
    end

to_str( )

Allows Menu to behave as a String, just like Question. Returns the layout to be rendered, which is used by HighLine.say().

[Source]

# File lib/highline/menu.rb, line 349
    def to_str(  )
      case @layout
      when :list
        '<%= if @header.nil? then '' else "#{@header}:\n" end %>' +
        "<%= list( @menu, #{@flow.inspect},
                          #{@list_option.inspect} ) %>" +
        "<%= @prompt %>"
      when :one_line
        '<%= if @header.nil? then '' else "#{@header}:  " end %>' +
        "<%= @prompt %>" +
        "(<%= list( @menu, #{@flow.inspect},
                           #{@list_option.inspect} ) %>)" +
        "<%= @prompt[/\s*$/] %>"
      when :menu_only
        "<%= list( @menu, #{@flow.inspect},
                          #{@list_option.inspect} ) %><%= @prompt %>"
      else
        @layout
      end
    end

update_responses( )

This method will update the intelligent responses to account for Menu specific differences. This overrides the work done by Question.build_responses().

[Source]

# File lib/highline/menu.rb, line 375
    def update_responses(  )
      append_default unless default.nil?
      @responses = @responses.merge(
                     :ambiguous_completion =>
                       "Ambiguous choice.  " +
                       "Please choose one of #{options.inspect}.",
                     :ask_on_error         =>
                       "?  ",
                     :invalid_type         =>
                       "You must enter a valid #{options}.",
                     :no_completion        =>
                       "You must choose one of " +
                       "#{options.inspect}.",
                     :not_in_range         =>
                       "Your answer isn't within the expected range " +
                       "(#{expected_range}).",
                     :not_valid            =>
                       "Your answer isn't valid (must match " +
                       "#{@validate.inspect})."
                   )
    end

Methods

Attributes

Public Class methods

Public Instance methods