2013-02-26 58 views
0

有一个代码Ruby:该case语句=〜&&〜在 '何时' 状态

file_paths = {nature:[], nature_thumb:[]} 

否则如果版本正常工作:

Find.find('public/uploads') do |path| 
    if path =~ /.*nature.*\.(jpg|png|gif)$/ and path !~ /.*nature\/thumb.*\.(jpg|png|gif)$/ 
    file_paths[:nature] << path 
    elsif 
    path =~ /.*nature\/thumb.*\.(jpg|png|gif)$/ 
    file_paths[:nature_thumb] << path 
    #etc 
    end 
end 

案例版本会导致一个问题

Find.find('public/uploads') do |path| 
    case 
    when path =~ /.*nature.*\.(jpg|png|gif)$/, path !~ /.*nature\/thumb.*\.(jpg|png|gif)$/ 
    file_paths[:nature] << path 
    when path =~ /.*nature\/thumb.*\.(jpg|png|gif)$/ 
    file_paths[:nature_thumb] << path 
    # etc 
    end 
end 

将'& &'替换为逗号会导致错误。逗号工作不正确。如何避免这种情况?

回答

1

变化的情况下的顺序:

Find.find('public/uploads') do |path| 
    case path 
    when /.*nature\/thumb.*\.(jpg|png|gif)$/ 
    file_paths[:nature_thumb] << path 
    when /.*nature.*\.(jpg|png|gif)$/ 
    file_paths[:nature] << path 
    end 
end 
在您的情况

或更好:

Find.find('public/uploads') do |path| 
    file_paths[ 
    case path 
    when /.*nature\/thumb.*\.(jpg|png|gif)$/ then :nature_thumb 
    when /.*nature.*\.(jpg|png|gif)$/  then :nature 
    end 
    ] << path 
end 
+0

辉煌!我应该想到。感谢重构顺便说一句。 – user1201917 2013-02-26 20:45:04

2

您case语句应该是这样的:

Find.find('public/uploads') do |path| 

    case 
     #Surround your statement with parenthesis 
     when ((path =~ /.*nature.*\.(jpg|png|gif)$/) && (path !~ /.*nature\/thumb.*\.(jpg|png|gif)$/)) 
     file_paths[:nature] << path 
     when path =~ /.*nature\/thumb.*\.(jpg|png|gif)$/ 
     file_paths[:nature_thumb] << path 
     # etc 
     end 
    end