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Diffstat (limited to 'guides')
| -rw-r--r-- | guides/source/form_helpers.md | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/guides/source/form_helpers.md b/guides/source/form_helpers.md index b8681d493a..817a732051 100644 --- a/guides/source/form_helpers.md +++ b/guides/source/form_helpers.md @@ -906,7 +906,21 @@ 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 +951,16 @@ 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. |