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Unify `cattr_*` interface: allow to pass a block to `cattr_reader`.

Example:

    class A
      cattr_reader(:defr) { 'default_reader_value' }
    end
    A.defr # => 'default_reader_value'
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1 parent 8147553 commit 0e953c94b152abf0de1c04dba74c22f935bc85c7 @907th 907th committed Jun 5, 2013
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@@ -1,3 +1,14 @@
+* Unify `cattr_*` interface: allow to pass a block to `cattr_reader`.
+
+ Example:
+
+ class A
+ cattr_reader(:defr) { 'default_reader_value' }
+ end
+ A.defr # => 'default_reader_value'
+
+ *Alexey Chernenkov*
+
* Improved compatibility with the stdlib JSON gem.
Previously, calling `::JSON.{generate,dump}` sometimes causes unexpected
@@ -29,6 +29,16 @@ class Class
# end
#
# Person.new.hair_colors # => NoMethodError
+ #
+ # Also, you can pass a block to set up the attribute with a default value.
+ #
+ # class Person
+ # cattr_reader :hair_colors do
+ # [:brown, :black, :blonde, :red]
+ # end
+ # end
+ #
+ # Person.hair_colors # => [:brown, :black, :blonde, :red]
def cattr_reader(*syms)
options = syms.extract_options!
syms.each do |sym|
@@ -50,6 +60,7 @@ def #{sym}
end
EOS
end
+ class_variable_set("@@#{sym}", yield) if block_given?
end
end
@@ -8,6 +8,9 @@ def setup
cattr_accessor :bar, :instance_writer => false
cattr_reader :shaq, :instance_reader => false
cattr_accessor :camp, :instance_accessor => false
+ cattr_accessor(:defa) { 'default_accessor_value' }
+ cattr_reader(:defr) { 'default_reader_value' }
+ cattr_writer(:defw) { 'default_writer_value' }
end
@object = @class.new
end
@@ -58,4 +61,10 @@ def test_should_raise_name_error_if_attribute_name_is_invalid
end
assert_equal "invalid class attribute name: 1nvalid", exception.message
end
+
+ def test_should_use_default_value_if_block_passed
+ assert_equal 'default_accessor_value', @class.defa
+ assert_equal 'default_reader_value', @class.defr
+ assert_equal 'default_writer_value', @class.class_variable_get('@@defw')
+ end
end
@@ -1093,6 +1093,15 @@ end
we can access `field_error_proc` in views.
+Also, you can pass a block to `cattr_*` to set up the attribute with a default value:
+
+```ruby
+class MysqlAdapter < AbstractAdapter
+ # Generates class methods to access @@emulate_booleans with default value of true.
+ cattr_accessor(:emulate_booleans) { true }
+end
+```
+
The generation of the reader instance method can be prevented by setting `:instance_reader` to `false` and the generation of the writer instance method can be prevented by setting `:instance_writer` to `false`. Generation of both methods can be prevented by setting `:instance_accessor` to `false`. In all cases, the value must be exactly `false` and not any false value.
```ruby

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