Module: Collapsium::EnvironmentOverride
- Extended by:
- Support::ArrayMethods, Support::HashMethods, Support::Methods
- Includes:
- RecursiveDup
- Defined in:
- lib/collapsium/environment_override.rb
Overview
The EnvironmentOverride module wraps read access methods to return the contents of environment variables derived from the key instead of the value contained in the Hash.
The environment variable to use is derived from the key by replacing all consecutive occurrences of non-alphanumeric characters with an underscore (_), and converting the alphabetic characters to upper case. Leading and trailing underscores will be stripped.
For example, the key “[email protected]” will become “SOME_EMAIL_ORG”.
If PathedAccess is also used, the :path_prefix of nested hashes will be consulted after converting it in the same manner. NOTE: include EnvironmentOverride after PathedAccess for both to work well together.
Constant Summary collapse
- ENV_ACCESS_READER =
Returns a proc read access.
proc do |wrapped_method, *args, &block| # If there are no arguments, there's nothing to do with paths. Just # delegate to the hash. if args.empty? next wrapped_method.call(*args, &block) end # The method's receiver is encapsulated in the wrapped_method; we'll # use it a few times so let's reduce typing. This is essentially the # equivalent of `self`. receiver = wrapped_method.receiver # All KEYED_READ_METHODS have a key as the first argument. key = args[0] # Grab matching environment variable names. If PathedAccess is # supported, we'll try environment variables of the path, starting # with the full qualified path and ending with just the last key # component. env_keys = EnvironmentOverride.environment_variables_for_key(receiver, key) # When we have the keys (in priority order), try to see if the # environment yields something useful. value = EnvironmentOverride.override_value(env_keys, receiver, key) if not value.nil? # We can't just return the value, because that doesn't respect the # method being called. We also can't store the value, because that # would not reset the Hash after the environment variable was # cleared. # # We can deal with this by duplicating the receiver, writing the value # we found into the appropriate key, and then sending the # wrapped_method to the duplicate. double = receiver.recursive_dup double[key] = value meth = double.method(wrapped_method.name) next meth.call(*args, &block) end # Otherwise, fall back on the super method. next wrapped_method.call(*args, &block) end.freeze
Constants included from Support::Methods
Support::Methods::BUILTINS, Support::Methods::WRAPPER_HASH
Constants included from Support::ArrayMethods
Support::ArrayMethods::INDEXED_READ_METHODS, Support::ArrayMethods::INDEXED_WRITE_METHODS, Support::ArrayMethods::READ_METHODS, Support::ArrayMethods::WRITE_METHODS
Constants included from Support::HashMethods
Support::HashMethods::KEYED_READ_METHODS, Support::HashMethods::KEYED_WRITE_METHODS, Support::HashMethods::READ_METHODS, Support::HashMethods::WRITE_METHODS
Constants included from ViralCapabilities
ViralCapabilities::DEFAULT_ANCESTORS, ViralCapabilities::ENHANCED_MARKER, ViralCapabilities::READ_METHODS, ViralCapabilities::WRITE_METHODS
Class Method Summary collapse
- .enhance(base) ⇒ Object
- .environment_variables_for_key(receiver, key) ⇒ Object
- .extended(base) ⇒ Object
-
.included(base) ⇒ Object
proc.
- .key_to_env(key) ⇒ Object
- .override_value(variables, receiver, key) ⇒ Object
- .prepended(base) ⇒ Object
Methods included from Support::Methods
builtins, loop_detected?, repeated, resolve_helpers, wrap_method, wrappers
Methods included from RecursiveDup
Methods included from ViralCapabilities
call_virality, copy_mods, enhance_array_value, enhance_hash_value, enhance_value, #extended, #included, #prepended, set_ancestors
Class Method Details
.enhance(base) ⇒ Object
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# File 'lib/collapsium/environment_override.rb', line 103 def enhance(base) # Make the capabilities of classes using EnvironmentOverride viral. base.extend(ViralCapabilities) # Wrap read accessor functions to deal with paths (INDEXED_READ_METHODS + KEYED_READ_METHODS).each do |method| wrap_method(base, method, raise_on_missing: false, &ENV_ACCESS_READER) end end |
.environment_variables_for_key(receiver, key) ⇒ Object
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# File 'lib/collapsium/environment_override.rb', line 113 def environment_variables_for_key(receiver, key) env_keys = [] if receiver.respond_to?(:path_prefix) # If we have a prefix, use it. components = [] if not receiver.path_prefix.nil? components += receiver.path_components(receiver.path_prefix) end # The key has its own components. If the key components and prefix # components overlap (it happens), ignore the duplication. key_comps = receiver.path_components(key.to_s) if key_comps.first == components.last components.pop end components += key_comps # Start with most qualified, shifting off the first component # until we reach just the last component. loop do path = receiver.normalize_path(components) env_keys << path components.shift if components.empty? break end end else env_keys = [key.to_s] end env_keys.map! { |k| key_to_env(k) } env_keys.reject!(&:empty?) env_keys.uniq! return env_keys end |
.extended(base) ⇒ Object
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# File 'lib/collapsium/environment_override.rb', line 95 def extended(base) enhance(base) end |
.included(base) ⇒ Object
proc
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# File 'lib/collapsium/environment_override.rb', line 91 def included(base) enhance(base) end |
.key_to_env(key) ⇒ Object
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# File 'lib/collapsium/environment_override.rb', line 188 def key_to_env(key) # First, convert to upper case env_key = key.upcase # Next, replace non-alphanumeric characters to underscore. This also # collapses them into a single undescore. env_key.gsub!(/[^[:alnum:]]+/, '_') # Strip leading and trailing underscores. env_key.gsub!(/^_*(.*?)_*$/, '\1') return env_key end |
.override_value(variables, receiver, key) ⇒ Object
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# File 'lib/collapsium/environment_override.rb', line 151 def override_value(variables, receiver, key) value = nil variables.each do |env_key| # Grab the environment value; skip if there's nothing there. env_value = ENV[env_key] if env_value.nil? next end # If the environment variable parses as JSON, that's great, we'll use # the parsed result. Otherwise use it as a string. require 'json' # rubocop:disable Lint/HandleExceptions parsed = env_value begin parsed = JSON.parse(env_value) rescue JSON::ParserError # Do nothing. We just use the env_value verbatim. end # rubocop:enable Lint/HandleExceptions # Excellent, we've got an environment variable. Only use it if it # changes something, though. We'll temporarily unset the environment # variable while fetching the old value. ENV.delete(env_key) old_value = receiver[key] ENV[env_key] = env_value # not the parsed value! if parsed != old_value value = parsed end break end return value end |
.prepended(base) ⇒ Object
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# File 'lib/collapsium/environment_override.rb', line 99 def prepended(base) enhance(base) end |