1 files changed, 28 insertions, 7 deletions
diff --git a/guides/source/form_helpers.md b/guides/source/form_helpers.md
index b8681d493a..a4dab39d55 100644
--- a/guides/source/form_helpers.md
+++ b/guides/source/form_helpers.md
@@ -221,7 +221,7 @@ Upon form submission the value entered by the user will be stored in `params[:pe
 
 WARNING: You must pass the name of an instance variable, i.e. `:person` or `"person"`, not an actual instance of your model object.
 
-Rails provides helpers for displaying the validation errors associated with a model object. These are covered in detail by the [Active Record Validations and Callbacks](./active_record_validations_callbacks.html#displaying-validation-errors-in-the-view) guide.
+Rails provides helpers for displaying the validation errors associated with a model object. These are covered in detail by the [Active Record Validations](./active_record_validations.html#displaying-validation-errors-in-views) guide.
 
 ### Binding a Form to an Object
 
@@ -423,7 +423,7 @@ Whenever Rails sees that the internal value of an option being generated matches
 
 TIP: The second argument to `options_for_select` must be exactly equal to the desired internal value. In particular if the value is the integer 2 you cannot pass "2" to `options_for_select` — you must pass 2. Be aware of values extracted from the `params` hash as they are all strings.
 
-WARNING: when `:inlude_blank` or `:prompt:` are not present, `:include_blank` is forced true if the select attribute `required` is true, display `size` is one and `multiple` is not true.
+WARNING: when `:include_blank` or `:prompt` are not present, `:include_blank` is forced true if the select attribute `required` is true, display `size` is one and `multiple` is not true.
 
 You can add arbitrary attributes to the options using hashes:
 
@@ -836,17 +836,14 @@ Active Record provides model level support  via the `accepts_nested_attributes_f
 class Person < ActiveRecord::Base
   has_many :addresses
   accepts_nested_attributes_for :addresses
-
-  attr_accessible :name, :addresses_attributes
 end
 
 class Address < ActiveRecord::Base
   belongs_to :person
-  attr_accessible :kind, :street
 end
 ```
 
-This creates an `addresses_attributes=` method on `Person` that allows you to create, update and (optionally) destroy addresses. When using `attr_accessible` or `attr_protected` you must mark `addresses_attributes` as accessible as well as the other attributes of `Person` and `Address` that should be mass assigned.
+This creates an `addresses_attributes=` method on `Person` that allows you to create, update and (optionally) destroy addresses.
 
 ### Building the Form
 
@@ -906,7 +903,21 @@ If the associated object is already saved, `fields_for` autogenerates a hidden i
 
 ### The Controller
 
-You do not need to write any specific controller code to use nested attributes. Create and update records as you would with a simple form.
+As usual you need to
+[whitelist the parameters](action_controller_overview.html#strong-parameters) in
+the controller before you pass them to the model:
+
+```ruby
+def create
+  @person = Person.new(person_params)
+  # ...
+end
+
+private
+def person_params
+  params.require(:person).permit(:name, addresses_attributes: [:id, :kind, :street])
+end
+```
 
 ### Removing Objects
 
@@ -937,6 +948,16 @@ If the hash of attributes for an object contains the key `_destroy` with a value
 <% end %>
 ```
 
+Don't forget to update the whitelisted params in your controller to also include
+the `_destroy` field:
+
+```ruby
+def person_params
+  params.require(:person).
+    permit(:name, addresses_attributes: [:id, :kind, :street, :_destroy])
+end
+```
+
 ### Preventing Empty Records
 
 It is often useful to ignore sets of fields that the user has not filled in. You can control this by passing a `:reject_if` proc to `accepts_nested_attributes_for`. This proc will be called with each hash of attributes submitted by the form. If the proc returns `false` then Active Record will not build an associated object for that hash. The example below only tries to build an address if the `kind` attribute is set.