class Loquacious::Configuration::Help
Generate nicely formatted help messages for a configuration. The Help class iterates over all the attributes in a configuration and outputs the name, value, and description to an IO stream. The format of the messages can be configured, and the description and/or value of the attribute can be shown or hidden independently.
Public Class Methods
Create a new Help instance for the given configuration where config can be either a Configuration instance or a configuration name or symbol. Several options can be provided to determine how the configuration information will be printed to the IO stream.
:name_leader String appearing before the attribute name :name_length Maximum length for an attribute name :name_value_sep String separating the attribute name from the value :desc_leader String appearing before the description :io The IO object where help will be written :nesting_nodes Flag to enable or disable output of nesting nodes (this does not affect display of attributes contained by the nesting nodes) :colorize Flag to colorize the output or not :colors Hash of colors for the name, value, description :name Name color :value Value color :description Description color :leader Leader and spacer color
The description is printed before each attribute name and value on its own line.
# File lib/loquacious/configuration/help.rb, line 58 def initialize( config, opts = {} ) opts = @@defaults.merge opts @config = config.kind_of?(::Loquacious::Configuration) ? config : ::Loquacious::Configuration.for(config) @io = opts[:io] @name_length = Integer(opts[:name_length]) @desc_leader = opts[:desc_leader] @nesting_nodes = opts[:nesting_nodes] @colorize = opts[:colorize] @colors = opts[:colors] unless @name_length > 0 Iterator.new(@config).each do |node| length = node.name.length @name_length = length if length > @name_length end end name_leader = opts[:name_leader] name_value_sep = opts[:name_value_sep] extra_length = name_leader.length + name_value_sep.length name_value_sep = name_value_sep.gsub('%', '%%') @value_length = 78 - @name_length - extra_length @value_leader = "\n" + ' '*(@name_length + extra_length) @format = "#{name_leader}%-#{@name_length}s#{name_value_sep}%s" @name_format = "#{name_leader}%s" if colorize? @desc_leader = self.__send__(@colors[:leader], @desc_leader) name_leader = self.__send__(@colors[:leader], name_leader) name_value_sep = self.__send__(@colors[:leader], name_value_sep) @format = name_leader.dup @format << self.__send__(@colors[:name], "%-#{@name_length}s") @format << name_value_sep.dup @format << self.__send__(@colors[:value], "%s") @name_format = name_leader.dup @name_format << self.__send__(@colors[:name], "%s") end @desc_leader.freeze @value_leader.freeze @format.freeze @name_format.freeze end
Public Instance Methods
Returns true
if the help instance is configured to colorize
the output messages. Returns false
otherwise.
# File lib/loquacious/configuration/help.rb, line 110 def colorize? @colorize end
Format the name of the attribute pointed at by the given node. If
the show_value flag is set to true
, then the
attribute value will also be included in the returned string.
# File lib/loquacious/configuration/help.rb, line 199 def format_name( node, show_value ) name = node.name.reduce @name_length return @name_format % name if node.config? or !show_value sio = StringIO.new PP.pp(node.obj, sio, @value_length) sio.seek 0 obj = sio.read.chomp.gsub("\n", @value_leader) @format % [name, obj] end
Normalize the attribute name.
# File lib/loquacious/configuration/help.rb, line 163 def normalize_attr( name ) case name when String, nil; name.to_s when Symbol; name.to_s when Array; name.join('.') else raise Error, "cannot convert #{name.inspect} into an attribute identifier" end end
Format the attribute name, value, and description and print the results.
The value can be printed or not by setting the show_value flag to
either true
or false
. The description can be
printed or not by setting the show_description flag to either
true
or false
.
# File lib/loquacious/configuration/help.rb, line 179 def print_node( node, show_description, show_value ) desc = node.desc.to_s.dup show_description = false if desc.empty? if show_description if colorize? desc = desc.gsub(/([^\n]+)/, self.__send__(@colors[:description], '\1')) end @io.puts(desc.indent(@desc_leader)) end @io.puts(format_name(node, show_value)) @io.puts if show_description end
Show all attributes for the configuration. The same options allowed by the
show
method are also supported by this method.
# File lib/loquacious/configuration/help.rb, line 156 def show_all( opts = {} ) show_attribute(nil, opts) end
Use this method to show the description for a single attribute or for all the attributes if no name is given. The options allow you to show the values along with the attributes and to hide the descriptions (if all you want to see are the values).
:descriptions => true to show descriptions and false to hide them :values => true to show values and false to hide them
# File lib/loquacious/configuration/help.rb, line 134 def show_attribute( name = nil, opts = {} ) name, opts = nil, name if name.is_a?(Hash) opts = { :descriptions => true, :values => false }.merge!(opts) rgxp = Regexp.new(normalize_attr(name)) show_description = opts[:descriptions] show_value = opts[:values] Iterator.new(@config).each do |node| next unless rgxp =~ node.name next if !show_nesting_nodes? and node.config? print_node(node, show_description, show_value) end end
Returns true
if the help instance is configured to show
nesting configuration nodes when iterating over the attributes. This only
prevents the nesting node name from being displayed. The attributes nested
under the node are still displayed regardless of this setting.
# File lib/loquacious/configuration/help.rb, line 119 def show_nesting_nodes? @nesting_nodes end