Give access to GET/POST params in filters

lib/sinatra/base.rb

@@ -329,6 +329,8 @@ module Sinatra
 
   private
     def dispatch!
+      @params = original_params = nested_params(@request.params)
+
       self.class.filters.each do |block|
         res = catch(:halt) { instance_eval(&block) ; :continue }
         return unless res == :continue
@@ -336,7 +338,6 @@ module Sinatra
 
       if routes = self.class.routes[@request.request_method]
         path = @request.path_info
-        original_params = nested_params(@request.params)
 
         routes.each do |pattern, keys, conditions, method_name|
           if match = pattern.match(path)

test/filter_test.rb

@@ -72,4 +72,15 @@ describe "Filters" do
     assert ok?
     assert_equal 'cool', body
   end
+
+  it "gives you access to params" do
+    mock_app {
+      before { @foo = params['foo'] }
+      get('/foo') { @foo }
+    }
+
+    get '/foo?foo=cool'
+    assert ok?
+    assert_equal 'cool', body
+  end
 end