Added a much improved Flash module that allows for finer-grained control on...

Added a much improved Flash module that allows for finer-grained control on expiration and allows you to flash the current action #839 [Caio Chassot]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@942 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/CHANGELOG

 *SVN*
 
+* Added a much improved Flash module that allows for finer-grained control on expiration and allows you to flash the current action #839 [Caio Chassot]. Example of flash.now:
+
+    class SomethingController < ApplicationController
+      def save
+        ...
+        if @something.save
+          # will redirect, use flash
+          flash['message'] = 'Save successful'
+          redirect_to :action => 'list'
+        else
+          # no redirect, message is for current action, use flash.now
+          flash.now['message'] = 'Save failed, review'
+          render_action 'edit'
+        end
+      end    
+    end
+
 * Added to_param call for parameters when composing an url using url_for from something else than strings #812 [Sam Stephenson]. Example:
 
     class Page

actionpack/lib/action_controller/flash.rb

@@ -21,45 +21,141 @@ module ActionController #:nodoc:
   #
   # This example just places a string in the flash, but you can put any object in there. And of course, you can put as many
   # as you like at a time too. Just remember: They'll be gone by the time the next action has been performed.
+  #
+  # See docs on the FlashHash class for more details about the flash.
   module Flash
+
     def self.append_features(base) #:nodoc:
       super
       base.before_filter(:fire_flash)
-      base.after_filter(:clear_flash)
+      base.after_filter(:sweep_flash)
     end
 
-    protected
-      # Access the contents of the flash. Use <tt>flash["notice"]</tt> to read a notice you put there or 
-      # <tt>flash["notice"] = "hello"</tt> to put a new one.
-      def flash #:doc:
-        if @session["flash"].nil?
-          @session["flash"]   = {}
-          @session["flashes"] ||= 0
+    class FlashNow #:nodoc:
+      def initialize flash
+        @flash = flash
+      end
+      
+      def []=(k, v)
+        @flash[k] = v
+        @flash.discard(k)
+        v
+      end
+    end
+    
+    class FlashHash < Hash
+    
+      def initialize #:nodoc:
+        super
+        @used = {}
+      end
+      
+      def []=(k, v) #:nodoc:
+        keep(k)
+        super
+      end
+      
+      def update h #:nodoc:
+        h.keys.each{|k| discard k }
+        super
+      end
+      
+      alias merge! update
+      
+      def replace h #:nodoc:
+        @used = {}
+        super
+      end
+    
+      # Sets a flash that will not be available to the next action, only to the current.
+      #
+      #     flash.now["message"] = "Hello current action"
+      # 
+      # This method enables you to use the flash as a central messaging system in your app.
+      # When you need to pass an object to the next action, you use the standard flash assign (<tt>[]=</tt>).
+      # When you need to pass an object to the current action, you use <tt>now</tt>, and your object will
+      # vanish when the current action is done.
+      #
+      # Entries set via <tt>now</tt> are accessed the same way as standard entries: <tt>flash['my-key']</tt>.
+      def now
+        FlashNow.new self
+      end
+    
+      # Keeps either the entire current flash or a specific flash entry available for the next action:
+      #
+      #    flash.keep            # keeps the entire flash
+      #    flash.keep("notice")  # keeps only the "notice" entry, the rest of the flash is discarded
+      def keep(k=nil)
+        use(k, false)
+      end
+    
+      # Marks the entire flash or a single flash entry to be discarded by the end of the current action
+      #
+      #     flash.keep                 # keep entire flash available for the next action
+      #     flash.discard('warning')   # discard the "warning" entry (it'll still be available for the current action)
+      def discard(k=nil)
+        use(k)
+      end
+    
+      # Mark for removal entries that were kept, and delete unkept ones.
+      #
+      # This method is called automatically by filters, so you generally don't need to care about it.
+      def sweep #:nodoc:
+        keys.each do |k| 
+          unless @used[k]
+            use(k)
+          else
+            delete(k)
+            @used.delete(k)
+          end
         end
-        @session["flash"]
-      end    
-
-      # Can be called by any action that would like to keep the current content of the flash around for one more action.
-      def keep_flash #:doc:
-        @session["flashes"] = 0
-      end    
-
-    private
-      # Records that the contents of @session["flash"] was flashed to the action
-      def fire_flash
-        if @session["flash"]
-          @session["flashes"] += 1 unless @session["flash"].empty?
-          @assigns["flash"] = @session["flash"]
+        (@used.keys - keys).each{|k| @used.delete k } # clean up after keys that could have been left over by calling reject! or shift on the flash
+      end
+    
+      private
+    
+      # Used internally by the <tt>keep</tt> and <tt>discard</tt> methods
+      #     use()               # marks the entire flash as used
+      #     use('msg')          # marks the "msg" entry as used
+      #     use(nil, false)     # marks the entire flash as unused (keeps it around for one more action)
+      #     use('msg', false)   # marks the "msg" entry as unused (keeps it around for one more action)
+      def use(k=nil, v=true)
+        unless k.nil?
+          @used[k] = v
         else
-          @assigns["flash"] = {}
+          keys.each{|key| use key, v }
         end
       end
 
-      def clear_flash
-        if @session["flash"] && (@session["flashes"].nil? || @session["flashes"] >= 1)
-          @session["flash"]   = {}
-          @session["flashes"] = 0 
-        end
-      end    
+    end
+     
+   
+    protected 
+  
+    # Access the contents of the flash. Use <tt>flash["notice"]</tt> to read a notice you put there or 
+    # <tt>flash["notice"] = "hello"</tt> to put a new one.
+    def flash #:doc:
+      @session['flash'] ||= FlashHash.new
+    end
+  
+    # deprecated. use <tt>flash.keep</tt> instead
+    def keep_flash #:doc:
+      flash.keep
+    end
+  
+  
+    private
+  
+    # marks flash entries as used and expose the flash to the view 
+    def fire_flash
+      flash.discard
+      @assigns["flash"] = flash
+    end
+  
+    # deletes the flash entries that were not marked for keeping
+    def sweep_flash
+      flash.sweep
+    end
+  
   end
 end

actionpack/lib/action_controller/test_process.rb

@@ -168,7 +168,7 @@ def flash
     
     # do we have a flash? 
     def has_flash?
-      !session['flash'].nil?
+      !session['flash'].empty?
     end
 
     # do we have a flash that has contents?
@@ -283,4 +283,4 @@ def assigns(name)
         end
       end
   end
-end
\ No newline at end of file
+end

actionpack/test/controller/action_pack_assertions_test.rb

@@ -179,7 +179,6 @@ def test_flash_assertions_full
   # test the flash-based assertions with no flash at all
   def test_flash_assertions_negative
     process :nothing
-    assert_flash_not_exists
     assert_flash_empty
     assert_flash_has_no 'hello'
     assert_flash_has_no 'qwerty'
@@ -230,7 +229,7 @@ def test_assigned_equal
   # check the empty flashing
   def test_flash_me_naked
     process :flash_me_naked
-    assert @response.has_flash?
+    assert !@response.has_flash?
     assert !@response.has_flash_with_contents?
   end
 

actionpack/test/controller/flash_test.rb

@@ -7,12 +7,26 @@ def set_flash
       render_text "hello"
     end
 
+    def set_flash_now
+      flash.now["that"] = "hello"
+      @flash_copy = {}.update flash
+      render_text "hello"
+    end
+
+    def attempt_to_use_flash_now
+      @flash_copy = {}.update flash
+      @flashy = flash["that"]
+      render_text "hello"
+    end
+
     def use_flash
+      @flash_copy = {}.update flash
       @flashy = flash["that"]
       render_text "hello"
     end
 
     def use_flash_and_keep_it
+      @flash_copy = {}.update flash
       @flashy = flash["that"]
       keep_flash
       render_text "hello"
@@ -33,11 +47,11 @@ def test_flash
 
     @request.action = "use_flash"
     first_response = process_request
-    assert_equal "hello", first_response.template.assigns["flash"]["that"]
+    assert_equal "hello", first_response.template.assigns["flash_copy"]["that"]
     assert_equal "hello", first_response.template.assigns["flashy"]
 
     second_response = process_request
-    assert_nil second_response.template.assigns["flash"]["that"], "On second flash"
+    assert_nil second_response.template.assigns["flash_copy"]["that"], "On second flash"
   end
 
   def test_keep_flash
@@ -46,17 +60,28 @@ def test_keep_flash
     
     @request.action = "use_flash_and_keep_it"
     first_response = process_request
-    assert_equal "hello", first_response.template.assigns["flash"]["that"]
+    assert_equal "hello", first_response.template.assigns["flash_copy"]["that"]
     assert_equal "hello", first_response.template.assigns["flashy"]
 
     @request.action = "use_flash"
     second_response = process_request
-    assert_equal "hello", second_response.template.assigns["flash"]["that"], "On second flash"
+    assert_equal "hello", second_response.template.assigns["flash_copy"]["that"], "On second flash"
 
     third_response = process_request
-    assert_nil third_response.template.assigns["flash"]["that"], "On third flash"
+    assert_nil third_response.template.assigns["flash_copy"]["that"], "On third flash"
   end
   
+  def test_flash_now
+    @request.action = "set_flash_now"
+    response = process_request
+    assert_equal "hello", response.template.assigns["flash_copy"]["that"]
+
+    @request.action = "attempt_to_use_flash_now"
+    first_response = process_request
+    assert_nil first_response.template.assigns["flash_copy"]["that"]
+    assert_nil first_response.template.assigns["flashy"]
+  end 
+  
   private
     def initialize_request_and_response
       @request  = ActionController::TestRequest.new