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-rw-r--r--guides/source/active_record_callbacks.md49
1 files changed, 24 insertions, 25 deletions
diff --git a/guides/source/active_record_callbacks.md b/guides/source/active_record_callbacks.md
index 20959a1a35..aa2ce99f6d 100644
--- a/guides/source/active_record_callbacks.md
+++ b/guides/source/active_record_callbacks.md
@@ -35,11 +35,11 @@ class User < ActiveRecord::Base
before_validation :ensure_login_has_a_value
protected
- def ensure_login_has_a_value
- if login.nil?
- self.login = email unless email.blank?
+ def ensure_login_has_a_value
+ if login.nil?
+ self.login = email unless email.blank?
+ end
end
- end
end
```
@@ -49,8 +49,8 @@ The macro-style class methods can also receive a block. Consider using this styl
class User < ActiveRecord::Base
validates :login, :email, presence: true
- before_create do |user|
- user.name = user.login.capitalize if user.name.blank?
+ before_create do
+ self.name = login.capitalize if name.blank?
end
end
```
@@ -65,13 +65,13 @@ class User < ActiveRecord::Base
after_validation :set_location, on: [ :create, :update ]
protected
- def normalize_name
- self.name = self.name.downcase.titleize
- end
+ def normalize_name
+ self.name = self.name.downcase.titleize
+ end
- def set_location
- self.location = LocationService.query(self)
- end
+ def set_location
+ self.location = LocationService.query(self)
+ end
end
```
@@ -157,7 +157,6 @@ The following methods trigger callbacks:
* `save!`
* `save(validate: false)`
* `toggle!`
-* `update`
* `update_attribute`
* `update`
* `update!`
@@ -168,7 +167,7 @@ Additionally, the `after_find` callback is triggered by the following finder met
* `all`
* `first`
* `find`
-* `find_all_by_*`
+* `find_by`
* `find_by_*`
* `find_by_*!`
* `find_by_sql`
@@ -176,12 +175,12 @@ Additionally, the `after_find` callback is triggered by the following finder met
The `after_initialize` callback is triggered every time a new object of the class is initialized.
-NOTE: The `find_all_by_*`, `find_by_*` and `find_by_*!` methods are dynamic finders generated automatically for every attribute. Learn more about them at the [Dynamic finders section](active_record_querying.html#dynamic-finders)
+NOTE: The `find_by_*` and `find_by_*!` methods are dynamic finders generated automatically for every attribute. Learn more about them at the [Dynamic finders section](active_record_querying.html#dynamic-finders)
Skipping Callbacks
------------------
-Just as with validations, it is also possible to skip callbacks. These methods should be used with caution, however, because important business rules and application logic may be kept in callbacks. Bypassing them without understanding the potential implications may lead to invalid data.
+Just as with validations, it is also possible to skip callbacks by using the following methods:
* `decrement`
* `decrement_counter`
@@ -196,6 +195,8 @@ Just as with validations, it is also possible to skip callbacks. These methods s
* `update_all`
* `update_counters`
+These methods should be used with caution, however, because important business rules and application logic may be kept in callbacks. Bypassing them without understanding the potential implications may lead to invalid data.
+
Halting Execution
-----------------
@@ -344,19 +345,17 @@ By using the `after_commit` callback we can account for this case.
```ruby
class PictureFile < ActiveRecord::Base
- attr_accessor :delete_file
+ after_commit :delete_picture_file_from_disk, on: [:destroy]
- after_destroy do |picture_file|
- picture_file.delete_file = picture_file.filepath
- end
-
- after_commit do |picture_file|
- if picture_file.delete_file && File.exist?(picture_file.delete_file)
- File.delete(picture_file.delete_file)
- picture_file.delete_file = nil
+ def delete_picture_file_from_disk
+ if File.exist?(filepath)
+ File.delete(filepath)
end
end
end
```
+NOTE: the `:on` option specifies when a callback will be fired. If you
+don't supply the `:on` option the callback will fire for every action.
+
The `after_commit` and `after_rollback` callbacks are guaranteed to be called for all models created, updated, or destroyed within a transaction block. If any exceptions are raised within one of these callbacks, they will be ignored so that they don't interfere with the other callbacks. As such, if your callback code could raise an exception, you'll need to rescue it and handle it appropriately within the callback.