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Diffstat (limited to 'activerecord/CHANGELOG.md')
-rw-r--r-- | activerecord/CHANGELOG.md | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md index 5a289a5aac..46031e7c13 100644 --- a/activerecord/CHANGELOG.md +++ b/activerecord/CHANGELOG.md @@ -1,5 +1,36 @@ ## Rails 4.0.0 (unreleased) ## +* Deprecate eager-evaluated scopes. + + Don't use this: + + scope :red, where(color: 'red') + default_scope where(color: 'red') + + Use this: + + scope :red, -> { where(color: 'red') } + default_scope { where(color: 'red') } + + The former has numerous issues. It is a common newbie gotcha to do + the following: + + scope :recent, where(published_at: Time.now - 2.weeks) + + Or a more subtle variant: + + scope :recent, -> { where(published_at: Time.now - 2.weeks) } + scope :recent_red, recent.where(color: 'red') + + Eager scopes are also very complex to implement within Active + Record, and there are still bugs. For example, the following does + not do what you expect: + + scope :remove_conditions, except(:where) + where(...).remove_conditions # => still has conditions + + *Jon Leighton* + * Remove IdentityMap IdentityMap has never graduated to be an "enabled-by-default" feature, due |