Class: HighLine::Menu

Class | HighLine::Menu
In: | lib/highline/menu.rb
Parent: | Question

Menu objects encapsulate all the details of a call to HighLine.choose(). Using the accessors and Menu.choice() and Menu.choices(), the block passed to HighLine.choose() can detail all aspects of menu display and control.

### Methods

choice choices help hidden index= init_help layout= new options select to_ary to_str update_responses

### 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.

### 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.

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.

help( topic, help )

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

hidden( name, help = nil, &action )

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

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.

init_help( )

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

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`.

options( )

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

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().

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.

to_str( )

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

update_responses( )

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

[Validate]