Nested params (e.g., "post[title]=Hello") [#70]

This is based largely on manveru's example implementation:

http://paste.linuxhelp.tv/pastes/view/15309

NOTE: we should plan on ripping this out once nested params
makes it into Rack.

CHANGES

@@ -8,6 +8,10 @@
    Documentation on using these features is forth-coming; the following
    provides the basic gist: http://gist.github.com/38605
 
+ * Parameters with subscripts are now parsed into a nested/recursive
+   Hash structure. e.g., "post[title]=Hello&post[body]=World" yields
+   params: {'post' => {'title' => 'Hello', 'body' => 'World'}}.
+
  * Regular expressions may now be used in route pattens; captures are
    available at "params[:captures]".
 

lib/sinatra/base.rb

@@ -331,8 +331,7 @@ module Sinatra
       self.class.filters.each {|block| instance_eval(&block)}
       if routes = self.class.routes[@request.request_method]
         path = @request.path_info
-        original_params = Hash.new{ |hash,k| hash[k.to_s] if Symbol === k }
-        original_params.merge! @request.params
+        original_params = nested_params(@request.params)
 
         routes.each do |pattern, keys, conditions, method_name|
           if pattern =~ path
@@ -352,8 +351,7 @@ module Sinatra
               else
                 {}
               end
-            @params = original_params.dup
-            @params.merge!(params)
+            @params = original_params.merge(params)
 
             catch(:pass) {
               conditions.each { |cond|
@@ -366,6 +364,22 @@ module Sinatra
       raise NotFound
     end
 
+    def nested_params(params)
+      return indifferent_hash.merge(params) if !params.keys.join.include?('[')
+      params.inject indifferent_hash do |res, (key,val)|
+        if key =~ /\[.*\]/
+          splat = key.scan(/(^[^\[]+)|\[([^\]]+)\]/).flatten.compact
+          head, last = splat[0..-2], splat[-1]
+          head.inject(res){ |s,v| s[v] ||= indifferent_hash }[last] = val
+        end
+        res
+      end
+    end
+
+    def indifferent_hash
+      Hash.new {|hash,key| hash[key.to_s] if Symbol === key }
+    end
+
     def invoke(handler)
       res = catch(:halt) {
         if handler.respond_to?(:call)

test/routing_test.rb

@@ -119,6 +119,63 @@ describe "Routing" do
     assert ok?
   end
 
+  it "supports basic nested params" do
+    mock_app {
+      get '/hi' do
+        params["person"]["name"]
+      end
+    }
+
+    get "/hi?person[name]=John+Doe"
+    assert ok?
+    assert_equal "John Doe", body
+  end
+
+  it "exposes nested params with indifferent hash" do
+    mock_app {
+      get '/testme' do
+        assert_equal 'baz', params['bar']['foo']
+        assert_equal 'baz', params['bar'][:foo]
+        'well, alright'
+      end
+    }
+    get '/testme?bar[foo]=baz'
+    assert_equal 'well, alright', body
+  end
+
+  it "supports deeply nested params" do
+    input = {
+      'browser[chrome][engine][name]' => 'V8',
+      'browser[chrome][engine][version]' => '1.0',
+      'browser[firefox][engine][name]' => 'spidermonkey',
+      'browser[firefox][engine][version]' => '1.7.0',
+      'emacs[map][goto-line]' => 'M-g g',
+      'emacs[version]' => '22.3.1',
+      'paste[name]' => 'hello world',
+      'paste[syntax]' => 'ruby'
+    }
+    expected = {
+      "emacs" => {
+        "map"     => { "goto-line" => "M-g g" },
+        "version" => "22.3.1"
+      },
+      "browser" => {
+        "firefox" => {"engine" => {"name"=>"spidermonkey", "version"=>"1.7.0"}},
+        "chrome"  => {"engine" => {"name"=>"V8", "version"=>"1.0"}}
+      },
+      "paste" => {"name"=>"hello world", "syntax"=>"ruby"}
+    }
+    mock_app {
+      get '/foo' do
+        assert_equal expected, params
+        'looks good'
+      end
+    }
+    get "/foo?#{param_string(input)}"
+    assert ok?
+    assert_equal 'looks good', body
+  end
+
   it "supports paths that include spaces" do
     mock_app {
       get '/path with spaces' do