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| author | Xavier Noria <fxn@hashref.com> | 2009-06-13 00:52:27 +0200 |
|---|---|---|
| committer | Xavier Noria <fxn@hashref.com> | 2009-06-13 01:10:22 +0200 |
| commit | fe0cf9213ce227730ece1b92f9828dcc6ad43977 (patch) | |
| tree | 5d51e528d983008fc1f0e9161d717315e3758dff /railties/guides/source | |
| parent | e20e0c8c4260e3718a77367f1b3d7546305defaa (diff) | |
| download | rails-fe0cf9213ce227730ece1b92f9828dcc6ad43977.tar.gz rails-fe0cf9213ce227730ece1b92f9828dcc6ad43977.tar.bz2 rails-fe0cf9213ce227730ece1b92f9828dcc6ad43977.zip | |
AS guide: explains acts_like?
Diffstat (limited to 'railties/guides/source')
| -rw-r--r-- | railties/guides/source/active_support_overview.textile | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/railties/guides/source/active_support_overview.textile b/railties/guides/source/active_support_overview.textile index ab9390883b..a88432dc3b 100644 --- a/railties/guides/source/active_support_overview.textile +++ b/railties/guides/source/active_support_overview.textile @@ -78,6 +78,23 @@ class Proc end </ruby> +h4. +acts_like?(duck)+ + +The method +acts_like+ provides a way to check whether some class acts like some other class based on a simple convention: a class that provides the same interface as +String+ defines + +<ruby> +def acts_like_string? +end +</ruby> + +which is only a marker, its body or return value are irrelevant. Then, client code can query for duck-type-safeness this way: + +<ruby> +some_klass.acts_like?(:string) +</ruby> + +Rails has classes that act like +Date+ or +Time+ and follow this contract. + h3. Extensions to +Module+ ... |