这对于普通哈希来说很简单
{:a => "a", :b => "b"}
这就意味着
"a=a&b=b"
但是你怎么处理更复杂的东西，比如
{:a => "a", :b => ["c", "d", "e"]}
这应该转化为
"a=a&b[0]=c&b[1]=d&b[2]=e"
或者更糟的是，(该怎么做)像这样的事情:
{:a => "a", :b => [{:c => "c", :d => "d"}, {:e => "e", :f => "f"}]
非常感谢你的帮助!
当前回答
{:a=>"a", :b=>"b", :c=>"c"}.map{ |x,v| "#{x}=#{v}" }.reduce{|x,v| "#{x}&#{v}" }
"a=a&b=b&c=c"
还有另一种方法。对于简单的查询。
其他回答
如果使用Ruby 1.9.2或更高版本，则可以使用URI。Encode_www_form如果你不需要数组。
例如(来自1.9.3的Ruby文档):
URI.encode_www_form([["q", "ruby"], ["lang", "en"]])
#=> "q=ruby&lang=en"
URI.encode_www_form("q" => "ruby", "lang" => "en")
#=> "q=ruby&lang=en"
URI.encode_www_form("q" => ["ruby", "perl"], "lang" => "en")
#=> "q=ruby&q=perl&lang=en"
URI.encode_www_form([["q", "ruby"], ["q", "perl"], ["lang", "en"]])
#=> "q=ruby&q=perl&lang=en"
您会注意到，数组值不是用包含[]的键名来设置的，就像我们在查询字符串中习惯的那样。encode_www_form使用的规范与HTML5对application/x-www-form-urlencoded data的定义一致。
我喜欢使用这个宝石:
https://rubygems.org/gems/php_http_build_query
示例用法:
puts PHP.http_build_query({"a"=>"b","c"=>"d","e"=>[{"hello"=>"world","bah"=>"black"},{"hello"=>"world","bah"=>"black"}]})
# a=b&c=d&e%5B0%5D%5Bbah%5D=black&e%5B0%5D%5Bhello%5D=world&e%5B1%5D%5Bbah%5D=black&e%5B1%5D%5Bhello%5D=world
对于基本的、非嵌套的散列，Rails/ActiveSupport有object# to_query。
>> {:a => "a", :b => ["c", "d", "e"]}.to_query
=> "a=a&b%5B%5D=c&b%5B%5D=d&b%5B%5D=e"
>> CGI.unescape({:a => "a", :b => ["c", "d", "e"]}.to_query)
=> "a=a&b[]=c&b[]=d&b[]=e"
http://api.rubyonrails.org/classes/Object.html#method-i-to_query
如果你在法拉第请求的上下文中，你也可以只是传递params哈希作为第二个参数，法拉第会照顾到正确的param URL部分:
faraday_instance.get(url, params_hsh)
require 'uri'
class Hash
def to_query_hash(key)
reduce({}) do |h, (k, v)|
new_key = key.nil? ? k : "#{key}[#{k}]"
v = Hash[v.each_with_index.to_a.map(&:reverse)] if v.is_a?(Array)
if v.is_a?(Hash)
h.merge!(v.to_query_hash(new_key))
else
h[new_key] = v
end
h
end
end
def to_query(key = nil)
URI.encode_www_form(to_query_hash(key))
end
end
2.4.2 :019 > {:a => "a", :b => "b"}.to_query_hash(nil)
=> {:a=>"a", :b=>"b"}
2.4.2 :020 > {:a => "a", :b => "b"}.to_query
=> "a=a&b=b"
2.4.2 :021 > {:a => "a", :b => ["c", "d", "e"]}.to_query_hash(nil)
=> {:a=>"a", "b[0]"=>"c", "b[1]"=>"d", "b[2]"=>"e"}
2.4.2 :022 > {:a => "a", :b => ["c", "d", "e"]}.to_query
=> "a=a&b%5B0%5D=c&b%5B1%5D=d&b%5B2%5D=e"
