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Diffstat (limited to 'guides/source/active_record_callbacks.md')
| -rw-r--r-- | guides/source/active_record_callbacks.md | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/guides/source/active_record_callbacks.md b/guides/source/active_record_callbacks.md index ebdee446f9..614737c342 100644 --- a/guides/source/active_record_callbacks.md +++ b/guides/source/active_record_callbacks.md @@ -239,13 +239,12 @@ Skipping Callbacks Just as with validations, it is also possible to skip callbacks by using the following methods: -* `decrement` +* `decrement!` * `decrement_counter` * `delete` * `delete_all` -* `increment` +* `increment!` * `increment_counter` -* `toggle` * `update_column` * `update_columns` * `update_all` @@ -310,7 +309,7 @@ end ### Using `:if` and `:unless` with a `Proc` -Finally, it is possible to associate `:if` and `:unless` with a `Proc` object. This option is best suited when writing short validation methods, usually one-liners: +It is possible to associate `:if` and `:unless` with a `Proc` object. This option is best suited when writing short validation methods, usually one-liners: ```ruby class Order < ApplicationRecord @@ -338,6 +337,20 @@ class Comment < ApplicationRecord end ``` +### Combining Callback Conditions + +When multiple conditions define whether or not a callback should happen, an `Array` can be used. Moreover, you can apply both `:if` and `:unless` to the same callback. + +```ruby +class Comment < ApplicationRecord + after_create :send_email_to_author, + if: [Proc.new { |c| c.user.allow_send_email? }, :author_wants_emails?], + unless: Proc.new { |c| c.article.ignore_comments? } +end +``` + +The callback only runs when all the `:if` conditions and none of the `:unless` conditions are evaluated to `true`. + Callback Classes ---------------- |