Add flush option for Sinatra::ContentFor flush content

sinatra-contrib/lib/sinatra/capture.rb

@@ -104,7 +104,7 @@ def capture(*args, &block)
         buffer     = eval '_buf if defined?(_buf)', block.binding
         old_buffer = buffer.dup if buffer
         dummy      = DUMMIES.fetch(current_engine)
-        options    = { :layout => false, :locals => {:args => args, :block => block }}
+        options    = { :layout => false, :locals => {:args => args, :block => block } }
 
         buffer.try :clear
         result = render(current_engine, dummy, options, &block)
@@ -116,7 +116,7 @@ def capture(*args, &block)
 
     def capture_later(&block)
       engine = current_engine
-      proc { |*a| with_engine(engine) { @capture = capture(*a, &block) }}
+      proc { |*a| with_engine(engine) { @capture = capture(*a, &block) } }
     end
   end
 

sinatra-contrib/lib/sinatra/content_for.rb

@@ -128,9 +128,12 @@ module ContentFor
     #
     # Your blocks can also receive values, which are passed to them
     # by <tt>yield_content</tt>
-    def content_for(key, value = nil, &block)
+    def content_for(key, value = nil, options = {}, &block)
+      key = key.to_sym
+
       block ||= proc { |*| value }
-      content_blocks[key.to_sym] << capture_later(&block)
+      clear_content_for(key) if options[:flush]
+      content_blocks[key] << capture_later(&block)
     end
 
     # Check if a block of content with the given key was defined. For
@@ -172,8 +175,10 @@ def clear_content_for(key)
     # Would pass <tt>1</tt> and <tt>2</tt> to all the blocks registered
     # for <tt>:head</tt>.
     def yield_content(key, *args)
-      return yield(*args) if block_given? && content_blocks[key.to_sym].empty?
-      content_blocks[key.to_sym].map { |b| capture(*args, &b) }.join
+      key = key.to_sym
+      return yield(*args) if block_given? && content_blocks[key].empty?
+
+      content_blocks[key].map { |b| capture(*args, &b) }.join
     end
 
     private

sinatra-contrib/spec/content_for_spec.rb

@@ -70,6 +70,22 @@ def render(engine, template)
       content_for(:foo, "foo")
       expect(yield_content(:foo)).to eq("foo")
     end
+
+    context 'when flush option was disabled' do
+      it 'append content' do
+        content_for(:foo, "foo")
+        content_for(:foo, "bar")
+        expect(yield_content(:foo)).to eq("foobar")
+      end
+    end
+
+    context 'when flush option was enabled' do
+      it 'flush first content' do
+        content_for(:foo, "foo")
+        content_for(:foo, "bar", flush: true)
+        expect(yield_content(:foo)).to eq("bar")
+      end
+    end
   end
 
   # TODO: liquid radius markaby builder nokogiri