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author | Leonel Galán <leonel@getstealz.com> | 2017-04-03 22:59:43 -0400 |
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committer | GitHub <noreply@github.com> | 2017-04-03 22:59:43 -0400 |
commit | 8648f289f01656b2258687126108c389127108e0 (patch) | |
tree | 1ccb15f72f00d8c30497ad4e48f203545dd3383b /activesupport/lib/active_support/deprecation/constant_accessor.rb | |
parent | 28b3582aa2cd6007c708134b911b3f360ad5d659 (diff) | |
parent | e8c33349bfabca28996ac74d344d69c7aaffec50 (diff) | |
download | rails-8648f289f01656b2258687126108c389127108e0.tar.gz rails-8648f289f01656b2258687126108c389127108e0.tar.bz2 rails-8648f289f01656b2258687126108c389127108e0.zip |
Merge branch 'master' into bug/filtered_parameters_class
Diffstat (limited to 'activesupport/lib/active_support/deprecation/constant_accessor.rb')
-rw-r--r-- | activesupport/lib/active_support/deprecation/constant_accessor.rb | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/deprecation/constant_accessor.rb b/activesupport/lib/active_support/deprecation/constant_accessor.rb new file mode 100644 index 0000000000..2b19de365f --- /dev/null +++ b/activesupport/lib/active_support/deprecation/constant_accessor.rb @@ -0,0 +1,50 @@ +require "active_support/inflector/methods" + +module ActiveSupport + class Deprecation + # DeprecatedConstantAccessor transforms a constant into a deprecated one by + # hooking +const_missing+. + # + # It takes the names of an old (deprecated) constant and of a new constant + # (both in string form) and optionally a deprecator. The deprecator defaults + # to +ActiveSupport::Deprecator+ if none is specified. + # + # The deprecated constant now returns the same object as the new one rather + # than a proxy object, so it can be used transparently in +rescue+ blocks + # etc. + # + # PLANETS = %w(mercury venus earth mars jupiter saturn uranus neptune pluto) + # + # (In a later update, the original implementation of `PLANETS` has been removed.) + # + # PLANETS_POST_2006 = %w(mercury venus earth mars jupiter saturn uranus neptune) + # include ActiveSupport::Deprecation::DeprecatedConstantAccessor + # deprecate_constant 'PLANETS', 'PLANETS_POST_2006' + # + # PLANETS.map { |planet| planet.capitalize } + # # => DEPRECATION WARNING: PLANETS is deprecated! Use PLANETS_POST_2006 instead. + # (Backtrace information…) + # ["Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune"] + module DeprecatedConstantAccessor + def self.included(base) + extension = Module.new do + def const_missing(missing_const_name) + if class_variable_defined?(:@@_deprecated_constants) + if (replacement = class_variable_get(:@@_deprecated_constants)[missing_const_name.to_s]) + replacement[:deprecator].warn(replacement[:message] || "#{name}::#{missing_const_name} is deprecated! Use #{replacement[:new]} instead.", caller_locations) + return ActiveSupport::Inflector.constantize(replacement[:new].to_s) + end + end + super + end + + def deprecate_constant(const_name, new_constant, message: nil, deprecator: ActiveSupport::Deprecation.instance) + class_variable_set(:@@_deprecated_constants, {}) unless class_variable_defined?(:@@_deprecated_constants) + class_variable_get(:@@_deprecated_constants)[const_name.to_s] = { new: new_constant, message: message, deprecator: deprecator } + end + end + base.singleton_class.prepend extension + end + end + end +end |