diff options
Diffstat (limited to 'railties/guides/source/active_support_core_extensions.textile')
| -rw-r--r-- | railties/guides/source/active_support_core_extensions.textile | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/railties/guides/source/active_support_core_extensions.textile b/railties/guides/source/active_support_core_extensions.textile index a0ed85cf01..781d3d08cd 100644 --- a/railties/guides/source/active_support_core_extensions.textile +++ b/railties/guides/source/active_support_core_extensions.textile @@ -78,12 +78,14 @@ The following values are considered to be blank in a Rails application: * +nil+ and +false+, -* strings composed only of whitespace, i.e. matching +/\A\s*\z/+, +* strings composed only of whitespace (see note below), * empty arrays and hashes, and * any other object that responds to +empty?+ and it is empty. +INFO: In Ruby 1.9 the predicate for strings uses the Unicode-aware character class <tt>[:space:]</tt>, so for example U+2029 (paragraph separator) is considered to be whitespace. In Ruby 1.8 whitespace is considered to be <tt>\s</tt> together with the ideographic space U+3000. + WARNING: Note that numbers are not mentioned, in particular 0 and 0.0 are *not* blank. For example, this method from +ActionDispatch::Session::AbstractStore+ uses +blank?+ for checking whether a session key is present: @@ -498,7 +500,7 @@ ActionController::TestCase.class_eval do end </ruby> -Rails uses +alias_method_chain+ all over the code base. For example validations are added to +ActiveRecord::Base#save+ by wrapping the method that way in a separate module specialised in validations. +Rails uses +alias_method_chain+ all over the code base. For example validations are added to +ActiveRecord::Base#save+ by wrapping the method that way in a separate module specialized in validations. NOTE: Defined in +active_support/core_ext/module/aliasing.rb+. |