Added option `:force_non_association_create`.

This option will allow users to use `link_to_add_association`
in the nested fields loop, since it will not add
the new object to the association. Fixes #66.
By default we will still create the object in the
association, as I believe that is the cleanest.

README.markdown

@@ -217,6 +217,7 @@ It takes four parameters:
   - `render_options` : options passed through to the form-builder function (e.g. `simple_fields_for`, `semantic_fields_for` or `fields_for`).
                        If it contains a `:locals` option containing a hash, that is handed to the partial.
   - `wrap_object` : a proc that will allow to wrap your object, especially useful if you are using decorators (e.g. draper). See example lower.
+  - `force_non_association_create`: if true, it will _not_ create the new object using the association (see lower)
 
 Optionally you could also leave out the name and supply a block that is captured to give the name (if you want to do something more complicated).
 
@@ -288,6 +289,22 @@ link_to_add_association('add something', @form_obj, :comments,
                         :wrap_object => Proc.new { |comment| comment.name = current_user.name; comment })
 ```
 
+#### :force_non_association_create
+
+In normal cases we create a new nested object using the association relation itself. This is the cleanest way to create
+a new nested object. But this has a side-effect: for each call of `link_to_add_association` a new element is added to the association.
+
+In most cases this is not a problem, but if you want to render a `link_to_add_association` for each nested element this will result
+in an infinite loop.
+
+To resolve this, specify that `:force_non_association_create` should be `true`, as follows:
+
+```
+link_to_add_association('add something', @form_obj, :comments, :force_non_association_create => true)
+```
+
+By default `:force_non_association_create` is `false`.
+
 > A cleaner option would be to call a function that performs this initialisation and returns `self` at the end.
 
 ### link_to_remove_association

lib/cocoon/view_helpers.rb

@@ -50,6 +50,8 @@ module Cocoon
     #          - *:render_options* : options passed to `simple_fields_for, semantic_fields_for or fields_for`
     #              - *:locals*     : the locals hash in the :render_options is handed to the partial
     #          - *:partial*        : explicitly override the default partial name
+    #          - *:wrap_object     : !!! document more here !!!
+    #          - *!!!add some option to build in collection or not!!!*
     # - *&block*:        see <tt>link_to</tt>
 
     def link_to_add_association(*args, &block)
@@ -68,16 +70,14 @@ module Cocoon
         render_options ||= {}
         override_partial = html_options.delete(:partial)
         wrap_object = html_options.delete(:wrap_object)
+        force_non_association_create = html_options.delete(:force_non_association_create) || false
 
         html_options[:class] = [html_options[:class], "add_fields"].compact.join(' ')
         html_options[:'data-association'] = association.to_s.singularize
         html_options[:'data-associations'] = association.to_s.pluralize
 
-        if wrap_object.respond_to?(:call)
+        new_object = create_object(f, association, force_non_association_create)
-          new_object = wrap_object.call(create_object(f, association))
+        new_object = wrap_object.call(new_object) if wrap_object.respond_to?(:call)
-        else
-          new_object = create_object(f, association)
-        end
 
         html_options[:'data-association-insertion-template'] = CGI.escapeHTML(render_association(association, f, new_object, render_options, override_partial)).html_safe
 
@@ -89,10 +89,10 @@ module Cocoon
     # `` has_many :admin_comments, class_name: "Comment", conditions: { author: "Admin" }
     # will create new Comment with author "Admin"
 
-    def create_object(f, association)
+    def create_object(f, association, force_non_association_create=false)
       assoc = f.object.class.reflect_on_association(association)
 
-      assoc ? create_object_on_association(f, association, assoc) : create_object_on_non_association(f, association)
+      assoc ? create_object_on_association(f, association, assoc, force_non_association_create) : create_object_on_non_association(f, association)
     end
 
     def get_partial_path(partial, association)
@@ -107,13 +107,12 @@ module Cocoon
       raise "Association #{association} doesn't exist on #{f.object.class}"
     end
 
-    def create_object_on_association(f, association, instance)
+    def create_object_on_association(f, association, instance, force_non_association_create)
-      if instance.class.name == "Mongoid::Relations::Metadata"
+      if instance.class.name == "Mongoid::Relations::Metadata" || force_non_association_create
-        conditions = instance.respond_to?(:conditions) ? instance.conditions.flatten : []
+        create_object_with_conditions(instance)
-        instance.klass.new(*conditions)
       else
         # assume ActiveRecord or compatible
-        if  instance.collection?
+        if instance.collection?
           f.object.send(association).build
         else
           f.object.send("build_#{association}")
@@ -121,5 +120,10 @@ module Cocoon
       end
     end
 
+    def create_object_with_conditions(instance)
+      conditions = instance.respond_to?(:conditions) ? instance.conditions.flatten : []
+      instance.klass.new(*conditions)
+    end
+
   end
 end

spec/cocoon_spec.rb

@@ -10,11 +10,15 @@ describe Cocoon do
   it { should respond_to(:link_to_add_association) }
   it { should respond_to(:link_to_remove_association) }
 
+  before(:each) do
+    @tester = TestClass.new
+    @post = Post.new
+    @form_obj = stub(:object => @post, :object_name => @post.class.name)
+  end
+
+
   context "link_to_add_association" do
     before(:each) do
-      @tester = TestClass.new
-      @post = Post.new
-      @form_obj = stub(:object => @post)
       @tester.stub(:render_association).and_return('form<tag>')
     end
 
@@ -41,6 +45,25 @@ describe Cocoon do
         @tester.should_receive(:render_association).with(anything(), anything(), kind_of(CommentDecorator), anything(), anything()).and_return('partiallll')
         @tester.link_to_add_association('add something', @form_obj, :comments, :wrap_object => Proc.new {|comment| CommentDecorator.new(comment) })
       end
+
+      context "force non association create" do
+        it "default it uses the association" do
+          @tester.should_receive(:create_object).with(anything, :comments , false)
+          result = @tester.link_to_add_association('add something', @form_obj, :comments)
+          result.to_s.should == '<a href="#" class="add_fields" data-association-insertion-template="form&lt;tag&gt;" data-association="comment" data-associations="comments">add something</a>'
+        end
+        it "specifying false is the same as default: create object on association" do
+          @tester.should_receive(:create_object).with(anything, :comments , false)
+          result = @tester.link_to_add_association('add something', @form_obj, :comments, :force_non_association_create => false)
+          result.to_s.should == '<a href="#" class="add_fields" data-association-insertion-template="form&lt;tag&gt;" data-association="comment" data-associations="comments">add something</a>'
+        end
+        it "specifying true will not create objects on association but using the conditions" do
+          @tester.should_receive(:create_object).with(anything, :comments , true)
+          result = @tester.link_to_add_association('add something', @form_obj, :comments, :force_non_association_create => true)
+          result.to_s.should == '<a href="#" class="add_fields" data-association-insertion-template="form&lt;tag&gt;" data-association="comment" data-associations="comments">add something</a>'
+        end
+
+      end
     end
 
     context "with a block" do
@@ -146,12 +169,6 @@ describe Cocoon do
   end
 
   context "link_to_remove_association" do
-    before(:each) do
-      @tester = TestClass.new
-      @post = Post.new
-      @form_obj = stub(:object => @post, :object_name => @post.class.name)
-    end
-
     context "without a block" do
       it "accepts a name" do
         result = @tester.link_to_remove_association('remove something', @form_obj)
@@ -180,44 +197,50 @@ describe Cocoon do
         result.to_s.should == "<input id=\"Post__destroy\" name=\"Post[_destroy]\" type=\"hidden\" /><a href=\"#\" class=\"add_some_class remove_fields dynamic\" data-something=\"bla\">remove some long name</a>"
       end
     end
+  end
 
-    context "create_object" do
+  context "create_object" do
-      it "should create correct association with conditions" do
+    it "creates correct association with conditions" do
-        result = @tester.create_object(@form_obj, :admin_comments)
+      @tester.should_not_receive(:create_object_with_conditions)
-        result.author.should == "Admin"
+      result = @tester.create_object(@form_obj, :admin_comments)
-      end
+      result.author.should == "Admin"
-
-      it "should create correct association for belongs_to associations" do
-        result = @tester.create_object(stub(:object => Comment.new), :post)
-        result.should be_a Post
-      end
-
-      it "should raise error if cannot reflect on association" do
-        expect { @tester.create_object(stub(:object => Comment.new), :not_existing) }.to raise_error /association/i
-      end
-
-      it "should create an association if object responds to 'build_association' as singular" do
-        object = Comment.new
-        object.should_receive(:build_custom_item).and_return 'custom'
-        @tester.create_object(stub(:object => object), :custom_item).should == 'custom'
-      end
-
-      it "should create an association if object responds to 'build_association' as plural" do
-        object = Comment.new
-        object.should_receive(:build_custom_item).and_return 'custom'
-        @tester.create_object(stub(:object => object), :custom_items).should == 'custom'
-      end
     end
 
-    context "get_partial_path" do
+    it "creates correct association for belongs_to associations" do
-      it "generates the default partial name if no partial given" do
+      result = @tester.create_object(stub(:object => Comment.new), :post)
-        result = @tester.get_partial_path(nil, :admin_comments)
+      result.should be_a Post
-        result.should == "admin_comment_fields"
+    end
-      end
+
-      it "uses the given partial name" do
+    it "raises an error if cannot reflect on association" do
-        result = @tester.get_partial_path("comment_fields", :admin_comments)
+      expect { @tester.create_object(stub(:object => Comment.new), :not_existing) }.to raise_error /association/i
-        result.should == "comment_fields"
+    end
-      end
+
+    it "creates an association if object responds to 'build_association' as singular" do
+      object = Comment.new
+      object.should_receive(:build_custom_item).and_return 'custom'
+      @tester.create_object(stub(:object => object), :custom_item).should == 'custom'
+    end
+
+    it "creates an association if object responds to 'build_association' as plural" do
+      object = Comment.new
+      object.should_receive(:build_custom_item).and_return 'custom'
+      @tester.create_object(stub(:object => object), :custom_items).should == 'custom'
+    end
+
+    it "can create using only conditions not the association" do
+      @tester.should_receive(:create_object_with_conditions).and_return('flappie')
+      @tester.create_object(@form_obj, :comments, true).should == 'flappie'
+    end
+  end
+
+  context "get_partial_path" do
+    it "generates the default partial name if no partial given" do
+      result = @tester.get_partial_path(nil, :admin_comments)
+      result.should == "admin_comment_fields"
+    end
+    it "uses the given partial name" do
+      result = @tester.get_partial_path("comment_fields", :admin_comments)
+      result.should == "comment_fields"
     end
   end