class Vagrant::Plugin::V1::Config
This is the base class for a configuration key defined for V1
. Any configuration key plugins for V1
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 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/v1/config.rb, line 25 def finalize! # Default implementation is to do nothing. end
Returns the instance variables as a hash of key-value pairs.
# File lib/vagrant/plugin/v1/config.rb, line 81 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/v1/config.rb, line 43 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?("@__") result.instance_variable_set(key, obj.instance_variable_get(key)) end end end result 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/v1/config.rb, line 69 def set_options(options) options.each do |key, value| send("#{key}=", value) end end
Converts this configuration object to JSON.
# File lib/vagrant/plugin/v1/config.rb, line 76 def to_json(*a) instance_variables_hash.to_json(*a) end
This is called to upgrade this V1
config to V2
. The parameter given is the full V2
configuration object, so you can do anything to it that you want.
No return value is expected, modifications should be made directly to the new V2
object.
@param [V2::Root] new
# File lib/vagrant/plugin/v1/config.rb, line 96 def upgrade(new) end
Called after the configuration is finalized and loaded to validate this object.
@param [Environment] env Vagrant::Environment
object of the
environment that this configuration has been loaded into. This gives you convenient access to things like the the root path and so on.
@param [ErrorRecorder] errors
# File lib/vagrant/plugin/v1/config.rb, line 107 def validate(env, errors) end