diff options
Diffstat (limited to 'guides/source/active_support_core_extensions.textile')
| -rw-r--r-- | guides/source/active_support_core_extensions.textile | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/guides/source/active_support_core_extensions.textile b/guides/source/active_support_core_extensions.textile index 65fb4d09b4..011a702901 100644 --- a/guides/source/active_support_core_extensions.textile +++ b/guides/source/active_support_core_extensions.textile @@ -156,7 +156,7 @@ NOTE: Defined in +active_support/core_ext/object/duplicable.rb+. h4. +deep_dup+ -The +deep_dup+ method returns deep copy of a given object. Normally, when you +dup+ an object that contains other objects, ruby does not +dup+ them. If you have array with a string, for example, it will look like this: +The +deep_dup+ method returns deep copy of a given object. Normally, when you +dup+ an object that contains other objects, ruby does not +dup+ them. If you have an array with a string, for example, it will look like this: <ruby> array = ['string'] @@ -189,7 +189,7 @@ array #=> ['string'] duplicate #=> ['foo'] </ruby> -If object is not duplicable +deep_dup+ will just return this object: +If object is not duplicable, +deep_dup+ will just return this object: <ruby> number = 1 @@ -201,12 +201,10 @@ NOTE: Defined in +active_support/core_ext/object/deep_dup.rb+. h4. +try+ -There are a lot of situations where you want to call a method on the receiver object if the object is not +nil+, so your code remains safe from unhandled +NoMethodError+ exceptions. The simplest way to achieve this is with conditional statements, which add unnecessary clutter. The alternative is to -use +try+. - -+try+ is like +Object#send+ except that it returns +nil+ if sent to +nil+. +When you want to call a method on an object only if it is not +nil+, the simplest way to achieve it is with conditional statements, adding unnecessary clutter. The alternative is to use +try+. +try+ is like +Object#send+ except that it returns +nil+ if sent to +nil+. Here is an example: + <ruby> # without try unless @number.nil? @@ -217,7 +215,7 @@ end @number.try(:next) </ruby> -Another example is this code from +ActiveRecord::ConnectionAdapters::AbstractAdapter+ +@logger+ could be +nil+, but you don't check it and write in an optimistic style: +Another example is this code from +ActiveRecord::ConnectionAdapters::AbstractAdapter+ where +@logger+ could be +nil+. You can see that the code uses +try+ and avoids an unnecessary check. <ruby> def log_info(sql, name, ms) |