2a4db54db9
* Throw away old system * Add new system * Add new example files * Replace all calls * add the most important docs * Add Specs * rename disable_ssl_requirement to require_ssl * cloudfiles isn't used/called in our code * since community_spotlight.list is only used as enable flag replace it with such one and remove all legacy and irelevant codepaths around it * die if session secret is unset and on heroku * First basic infrastructure for version information
65 lines
1.9 KiB
Ruby
65 lines
1.9 KiB
Ruby
module Configuration
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# This object builds a chain of configuration providers to try to find
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# a setting.
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class LookupChain
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def initialize
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@provider = []
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end
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# Add a provider to the chain. Providers are tried in the order
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# they are added, so the order is important.
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#
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# @param provider [#lookup]
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# @param *args the arguments passed to the providers constructor
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# @raise [ArgumentError] if an invalid provider is given
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# @return [void]
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def add_provider(provider, *args)
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unless provider.instance_method_names.include?("lookup")
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raise ArgumentError, "the given provider does not respond to lookup"
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end
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@provider << provider.new(*args)
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end
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# Tries all providers in the order they were added to provide a response
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# for setting.
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#
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# @param setting [#to_s] settings should be underscore_case,
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# nested settings should be separated by a dot
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# @param *args further args passed to the provider
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# @return [Array,String,Boolean,nil] whatever the provider provides
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# is casted to a {String}, except for some special values
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def lookup(setting, *args)
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setting = setting.to_s
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@provider.each do |provider|
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begin
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return special_value_or_string(provider.lookup(setting, *args))
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rescue SettingNotFoundError; end
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end
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nil
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end
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alias_method :[], :lookup
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private
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def special_value_or_string(value)
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if [TrueClass, FalseClass, NilClass, Array, Hash].include?(value.class)
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return value
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elsif value.is_a?(String)
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return case value.strip
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when "true" then true
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when "false" then false
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when "", "nil" then nil
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else value
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end
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elsif value.respond_to?(:to_s)
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return value.to_s
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else
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return value
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end
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end
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end
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end
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