This question already has an answer here:
I am able to pass in arguments as follows:
desc "Testing args"
task: :hello, :user, :message do |t, args|
args.with_defaults(:message => "Thanks for logging on")
puts "Hello #{args[:user]}. #{:message}"
end
I am also able to load the current environment for a Rails application
desc "Testing environment"
task: :hello => :environment do
puts "Hello #{User.first.name}."
end
What I would like to do is be able to have variables and environment
desc "Testing environment and variables"
task: :hello => :environment, :message do |t, args|
args.with_defaults(:message => "Thanks for logging on")
puts "Hello #{User.first.name}. #{:message}"
end
But that is not a valid task call. Does anyone know how I can achieve this?
task :t, [args] => [deps]
When you pass in arguments to rake tasks, you can require the environment using the :needs option. For example:
desc "Testing environment and variables"
task :hello, :message, :needs => :environment do |t, args|
args.with_defaults(:message => "Thanks for logging on")
puts "Hello #{User.first.name}. #{args.message}"
end
Updated per @Peiniau's comment below
As for Rails > 3.1
task :t, arg, :needs => [deps] # deprecated
Please use
task :t, [args] => [deps]
:needs method this way: "That format is still supported for compatability, but it is not recommended for use." (I mention this only for future browsers, since it suggests that eventually :needs won't be supported any longer. The section is called "Deprecated Task Paramaters Format"...) - Telemachustask :hello, [:message] => [:environment] do |t, args|. - Jason Swetttask :hello, [:message1, :message2] => [:environment] do |t, args| works, and to invoke use rake hello['message #1','message #2']. Warning: I found that rake would fail if the argument list contained any clear text, e.g rake hello['message #1', 'message #2'] (note the space after the comma). - Steve Wilhelm
Just to follow up on this old topic; here's what I think a current Rakefile (since a long ago) should do there. It's an upgraded and bugfixed version of the current winning answer (hgimenez):
desc "Testing environment and variables"
task :hello, [:message] => :environment do |t, args|
args.with_defaults(:message => "Thanks for logging on")
puts "Hello #{User.first.name}. #{args.message}" # Q&A above had a typo here : #{:message}
end
This is how you invoke it (http://guides.rubyonrails.org/v4.2/command_line.html#rake):
rake "hello[World]"
For multiple arguments, just add their keywords in the array of the task declaration (task :hello, [:a,:b,:c]...), and pass them comma separated:
rake "hello[Earth,Mars,Sun,Pluto]"
Note: the number of arguments is not checked, so the odd planet is left out:)
rake 'webp:convert["hello", "world"]' .. Warning: I haven't tried this one now, but it should work. - inger
Just for completeness, here the example from the docs mentioned above:
task :name, [:first_name, :last_name] => [:pre_name] do |t, args|
args.with_defaults(:first_name => "John", :last_name => "Dough")
puts "First name is #{args.first_name}"
puts "Last name is #{args.last_name}"
end
Notes:
#with_defaults call, obviously.Array for your arguments, even if there is only one.Array.args is an instance of Rake::TaskArguments.t is an instance of Rake::Task.args.empty? was giving me weird results. args looks like a hash, but it's a Rake::TaskArguments. So if you want special behaviour when no args are passed, call #to_hash or #to_s before checking if args is empty. - Dennis
An alternate way to go about this: use OS environment variables. Benefits of this approach:
I have a rake task which requires three command-line options. Here's how I invoke it:
$ rake eaternet:import country=us region=or agency=multco
That's very clean, simple, and just bash syntax, which I like. Here's my rake task. Also very clean and no magic:
task import: [:environment] do
agency = agency_to_import
puts "Importing data for #{agency}..."
agency.import_businesses
end
def agency_to_import
country_code = ENV['country'] or raise "No country specified"
region_slug = ENV['region'] or raise "No region specified"
agency_slug = ENV['agency'] or raise "No agency specified"
Agency.from_slugs(country_code, region_slug, agency_slug)
end
This particular example doesn't show the use of dependencies. But if the :import task did depend on others, they'd also have access to these options. But using the normal rake options method, they wouldn't.
country=us ruby -e "puts ENV['country']" is not the same as ruby -e "puts ENV['country']" country=us (environment variable in the first versus argument in the second). - Djunzu
While these solutions work, in my opinion this is overly complicated.
Also, if you do it this way in zsh, you'll get errors if the brackets in your array aren't escaped with '\'.
I recommend using the ARGV array, which works fine, is much simpler, and is less prone to error. E.g:
namespace :my_example do
desc "Something"
task :my_task => :environment do
puts ARGV.inspect
end
end
then
rake my_example:my_task 1 2 3
#=> ["my_example:my_task", "1", "2", "3"]
The only thing you need to keep in mind is that ARGV[0] is the process name, so use only ARGV[1..-1].
I realize that strictly speaking this does not answer the question, as it does not make use of :environment as part of the solution. But OP did not state why he included that stipulation so it might still apply to his use case.
:environment is needed to load Rails application code. And trying it on a Rails app I get: ["my_example:my_task", "1", "2", "3"] rake aborted! Don't know how to build task '1' (see --tasks) - Djunzu