如何在ruby中跳過require？

Question

我可以有條件地跳過在Ruby中需要文件嗎？

begin 
    require 'aws-sdk' 
rescue LoadError 
    puts "aws-sdk gem not found" 
end 

namespace :db do 
    desc "import local postgres database to heroku. user and database name is hardcoded" 
    task :import_to_heroku => [:environment, "db:dump_for_heroku"] do 
    # code using aws-sdk gem 
    end 
end 

在上面的代碼，我可以問紅寶石不讀後rescue LoadError
我可以包裝在有條件的整個代碼，但是這是不雅。我試過next和return。

編輯：在Can I conditionally skip loading "further" ruby code in the same file?增加了一個新問題。抱歉。沒有問這個問題的正確

Answer 1

我有救了LoadError，但我想如果LoadError被執行，進一步的代碼不應該被執行。在上述例子中，rake任務分貝：import_to_heroku不應該叫

然後做：

begin 
    require 'aws-sdk' 

    namespace :db do 
    desc "import local postgres database to heroku. user and database name is hardcoded" 
    task :import_to_heroku => [:environment, "db:dump_for_heroku"] do 
     # code using aws-sdk gem 
    end 
    end 
rescue LoadError 
    puts "aws-sdk gem not found" 
end 

Answer 2

日誌後，也許增加一個exit：

begin 
    require 'aws-sdk' 
rescue LoadError 
    puts "aws-sdk gem not found" 
    exit 
end 

namespace :db do 
    desc "import local postgres database to heroku. user and database name is hardcoded" 
    task :import_to_heroku => [:environment, "db:dump_for_heroku"] do 
    # code using aws-sdk gem 
    end 
end 

而且中止功能是登錄和退出在同一呼叫：

abort("aws-sdk gem not found")