While trying to develop a simple gem to learn the process, I happened to stumble on this issue: Thor DSL takes in options to a command using the syntax: option :some_option, :type => :boolean
, just prior to the method definition.
I am trying to have a dynamic set of options loaded from a file. I do this file read operation in the constructor, but it seems the option
keyword for the Thor class is getting processed before the initialize
method.
Any ideas to resolve this? Also it would be great if someone can explain how the option keyword works? I mean is option
a method call? I don't get the design. (This is the first DSL I am trying out and am a total newbie to Ruby Gems)
#!/usr/bin/env ruby
require 'thor'
require 'yaml'
require 'tinynews'
class TinyNewsCLI < Thor
attr_reader :sources
@sources = {}
def initialize *args
super
f = File.open( "sources.yml", "r" ).read
@sources = YAML::load( f )
end
desc "list", "Lists the available news feeds."
def list
puts "List of news feed sources: "
@sources.each do |symbol, source|
puts "- #{source[:title]}"
end
end
desc "show --source SOURCE", "Show news from SOURCE feed"
option :source, :required => true
def show
if options[:source]
TinyNews.print_to_cli( options[:source].to_sym )
end
end
desc "tinynews --NEWS_SOURCE", "Show news for NEWS_SOURCE"
@sources.keys.each do |source_symbol| # ERROR: States that @sources.keys is nil
#[:hindu, :cnn, :bbc].each do |source_symbol| # I expected the above to work like this
option source_symbol, :type => :boolean
end
def news_from_option
p @sources.keys
TinyNews.print_to_cli( options.keys.last.to_sym )
end
default_task :news_from_option
end
TinyNewsCLI.start( ARGV )
After a bit of tweaking, I think I ended upon a solution that doesn't look too bad. But not sure placing code in module like that is a good practice. But anyways:
#!/usr/bin/env ruby
require 'thor'
require 'yaml'
require 'tinynews'
module TinyNews
# ***** SOLUTION *******
f = File.open( "../sources.yml", "r" ).read
SOURCES = YAML::load( f )
class TinyNewsCLI < Thor
default_task :news_from_source
desc "list", "Lists the available news feeds."
def list
puts "List of news feed sources: "
SOURCES.each do |symbol, source|
puts "- #{source[:title]}"
end
end
desc "--source NEWS_SOURCE", "Show news for NEWS_SOURCE"
option :source, :required => true, :aliases => :s
def news_from_source
TinyNews.print_to_cli( options[:source].to_sym )
end
end
end
TinyNews::TinyNewsCLI.start( ARGV )
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.