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!
更新:此功能已从gem中移除。
朱利安,你自己的回答很好,我无耻地借鉴了它,但它不能正确地逃脱保留字符,还有一些其他的边缘情况,它会崩溃。
require "addressable/uri"
uri = Addressable::URI.new
uri.query_values = {:a => "a", :b => ["c", "d", "e"]}
uri.query
# => "a=a&b[0]=c&b[1]=d&b[2]=e"
uri.query_values = {:a => "a", :b => [{:c => "c", :d => "d"}, {:e => "e", :f => "f"}]}
uri.query
# => "a=a&b[0][c]=c&b[0][d]=d&b[1][e]=e&b[1][f]=f"
uri.query_values = {:a => "a", :b => {:c => "c", :d => "d"}}
uri.query
# => "a=a&b[c]=c&b[d]=d"
uri.query_values = {:a => "a", :b => {:c => "c", :d => true}}
uri.query
# => "a=a&b[c]=c&b[d]"
uri.query_values = {:a => "a", :b => {:c => "c", :d => true}, :e => []}
uri.query
# => "a=a&b[c]=c&b[d]"
宝石是“可寻址的”
gem install addressable
我知道这是一个老问题,但我只是想张贴这段代码,因为我找不到一个简单的宝石来为我做这个任务。
module QueryParams
def self.encode(value, key = nil)
case value
when Hash then value.map { |k,v| encode(v, append_key(key,k)) }.join('&')
when Array then value.map { |v| encode(v, "#{key}[]") }.join('&')
when nil then ''
else
"#{key}=#{CGI.escape(value.to_s)}"
end
end
private
def self.append_key(root_key, key)
root_key.nil? ? key : "#{root_key}[#{key.to_s}]"
end
end
在这里汇总为宝石:https://github.com/simen/queryparams
偷Merb的东西:
# File merb/core_ext/hash.rb, line 87
def to_params
params = ''
stack = []
each do |k, v|
if v.is_a?(Hash)
stack << [k,v]
else
params << "#{k}=#{v}&"
end
end
stack.each do |parent, hash|
hash.each do |k, v|
if v.is_a?(Hash)
stack << ["#{parent}[#{k}]", v]
else
params << "#{parent}[#{k}]=#{v}&"
end
end
end
params.chop! # trailing &
params
end
参见http://noobkit.com/show/ruby/gems/development/merb/hash/to_params.html
不需要加载臃肿的ActiveSupport或滚动自己的,您可以使用Rack::Utils。build_query和Rack::Utils.build_nested_query。这里有一篇博客文章给出了一个很好的例子:
require 'rack'
Rack::Utils.build_query(
authorization_token: "foo",
access_level: "moderator",
previous: "index"
)
# => "authorization_token=foo&access_level=moderator&previous=index"
它甚至可以处理数组:
Rack::Utils.build_query( {:a => "a", :b => ["c", "d", "e"]} )
# => "a=a&b=c&b=d&b=e"
Rack::Utils.parse_query _
# => {"a"=>"a", "b"=>["c", "d", "e"]}
或者更难嵌套的东西:
Rack::Utils.build_nested_query( {:a => "a", :b => [{:c => "c", :d => "d"}, {:e => "e", :f => "f"}] } )
# => "a=a&b[][c]=c&b[][d]=d&b[][e]=e&b[][f]=f"
Rack::Utils.parse_nested_query _
# => {"a"=>"a", "b"=>[{"c"=>"c", "d"=>"d", "e"=>"e", "f"=>"f"}]}