class Vagrant::Plugin::V2::Config
This is the base class for a configuration key defined for V2
. Any configuration key plugins for V2
should inherit from this class.
Constants
- UNSET_VALUE
This constant represents an unset value. This is useful so it is possible to know the difference between a configuration value that was never set, and a value that is nil (explicitly). Best practice is to initialize all variables to this value, then the {#merge} method below will “just work” in many cases.
Public Instance Methods
This returns any automatically detected errors.
@return [Array<String>]
# File lib/vagrant/plugin/v2/config.rb, line 145 def _detected_errors return [] if !@__invalid_methods || @__invalid_methods.empty? return [I18n.t("vagrant.config.common.bad_field", fields: @__invalid_methods.to_a.sort.join(", "))] end
An internal finalize call that no subclass should override.
# File lib/vagrant/plugin/v2/config.rb, line 152 def _finalize! @__finalized = true end
# File lib/vagrant/plugin/v2/config.rb, line 156 def clean_up_config_object(config) # Remote variables that are internal config.delete_if{|k,_| k.start_with?("_") } config end
This is called as a last-minute hook that allows the configuration object to finalize itself before it will be put into use. This is a useful place to do some defaults in the case the user didn’t configure something or so on.
An example of where this sort of thing is used or has been used: the “vm” configuration key uses this to make sure that at least one sub-VM has been defined: the default VM.
The configuration object is expected to mutate itself.
# File lib/vagrant/plugin/v2/config.rb, line 28 def finalize! # Default implementation is to do nothing. end
Returns the instance variables as a hash of key-value pairs.
# File lib/vagrant/plugin/v2/config.rb, line 125 def instance_variables_hash instance_variables.inject({}) do |acc, iv| acc[iv.to_s[1..-1]] = instance_variable_get(iv) acc end end
Merge another configuration object into this one. This assumes that the other object is the same class as this one. This should not mutate this object, but instead should return a new, merged object.
The default implementation will simply iterate over the instance variables and merge them together, with this object overriding any conflicting instance variables of the older object. Instance variables starting with “__” (double underscores) will be ignored. This lets you set some sort of instance-specific state on your configuration keys without them being merged together later.
@param [Object] other The other configuration object to merge from,
this must be the same type of object as this one.
@return [Object] The merged object.
# File lib/vagrant/plugin/v2/config.rb, line 46 def merge(other) result = self.class.new # Set all of our instance variables on the new class [self, other].each do |obj| obj.instance_variables.each do |key| # Ignore keys that start with a double underscore. This allows # configuration classes to still hold around internal state # that isn't propagated. if !key.to_s.start_with?("@__") # Don't set the value if it is the unset value, either. value = obj.instance_variable_get(key) result.instance_variable_set(key, value) if value != UNSET_VALUE end end end # Persist through the set of invalid methods this_invalid = @__invalid_methods || Set.new other_invalid = other.instance_variable_get(:"@__invalid_methods") || Set.new result.instance_variable_set(:"@__invalid_methods", this_invalid + other_invalid) result end
Capture all bad configuration calls and save them for an error message later during validation.
# File lib/vagrant/plugin/v2/config.rb, line 73 def method_missing(name, *args, &block) return super if @__finalized # There are a few scenarios where ruby will attempt to implicity # coerce a given object into a certain type. Configs can end up # in some of these scenarios when they're being shipped around in # callbacks with splats. If method_missing allows these methods to be # called but continues to return Config back, Ruby will raise a # TypeError. Doing the normal thing of raising NoMethodError allows # Config to behave normally as its being passed through splats. # # For a bit more detail and some keywords for further searching, see: # https://ruby-doc.org/core-2.7.2/doc/implicit_conversion_rdoc.html if [:to_hash, :to_ary].include?(name) return super end name = name.to_s name = name[0...-1] if name.end_with?("=") @__invalid_methods ||= Set.new @__invalid_methods.add(name) # Return the dummy object so that anything else works ::Vagrant::Config::V2::DummyConfig.new end
Allows setting options from a hash. By default this simply calls the ‘#{key}=` method on the config class with the value, which is the expected behavior most of the time.
This is expected to mutate itself.
@param [Hash] options A hash of options to set on this configuration
key.
# File lib/vagrant/plugin/v2/config.rb, line 108 def set_options(options) options.each do |key, value| send("#{key}=", value) end end
Converts this configuration object to JSON.
# File lib/vagrant/plugin/v2/config.rb, line 115 def to_json(*a) instance_variables_hash.to_json(*a) end
A default to_s
implementation.
# File lib/vagrant/plugin/v2/config.rb, line 120 def to_s self.class.to_s end
Called after the configuration is finalized and loaded to validate this object.
@param [Machine] machine Access to the machine that is being
validated.
@return [Hash]
# File lib/vagrant/plugin/v2/config.rb, line 138 def validate(machine) return { self.to_s => _detected_errors } end