Class: Puppet::Pal::PlanSignature

Inherits:
Object
  • Object
show all
Defined in:
lib/puppet/pal/plan_signature.rb

Overview

A PlanSignature is returned from `plan_signature`. Its purpose is to answer questions about the plans's parameters and if it can be called with a hash of named parameters.

Instance Method Summary collapse

Constructor Details

#initialize(plan_function) ⇒ PlanSignature

Returns a new instance of PlanSignature


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# File 'lib/puppet/pal/plan_signature.rb', line 9

def initialize(plan_function)
  @plan_func = plan_function
end

Instance Method Details

#callable_with?(args_hash) ⇒ Boolean

Returns true or false depending on if the given PlanSignature is callable with a set of named arguments or not In addition to returning the boolean outcome, if a block is given, it is called with a string of formatted error messages that describes the difference between what was given and what is expected. The error message may have multiple lines of text, and each line is indented one space.

Examples:

Checking if signature is acceptable


signature = pal.plan_signature('myplan')
signature.callable_with?({x => 10}) { |errors| raise ArgumentError("Ooops: given arguments does not match\n#{errors}") }

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# File 'lib/puppet/pal/plan_signature.rb', line 25

def callable_with?(args_hash)
  dispatcher = @plan_func.class.dispatcher.dispatchers[0]

  param_scope = {}
  # Assign all non-nil values, even those that represent non-existent parameters.
  args_hash.each { |k, v| param_scope[k] = v unless v.nil? }
  dispatcher.parameters.each do |p|
    name = p.name
    arg = args_hash[name]
    if arg.nil?
      # Arg either wasn't given, or it was undef
      if p.value.nil?
        # No default. Assign nil if the args_hash included it
        param_scope[name] = nil if args_hash.include?(name)
      else
        # parameter does not have a default value, it will be assigned its default when being called
        # we assume that the default value is of the correct type and therefore simply skip
        # checking this
        # param_scope[name] = param_scope.evaluate(name, p.value, closure_scope, @evaluator)
      end
    end
  end

  errors = Puppet::Pops::Types::TypeMismatchDescriber.singleton.describe_struct_signature(dispatcher.params_struct, param_scope).flatten
  return true if errors.empty?
  if block_given?
    yield errors.map {|e| e.format }.join("\n")
  end
  false
end

#params_typePuppet::Pops::Types::PStructType

Returns a PStructType describing the parameters as a puppet Struct data type Note that a `to_s` on the returned structure will result in a human readable Struct datatype as a description of what a plan expects.


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# File 'lib/puppet/pal/plan_signature.rb', line 64

def params_type
  dispatcher = @plan_func.class.dispatcher.dispatchers[0]
  dispatcher.params_struct
end