Class: Opto::Resolver

Inherits:
Object
  • Object
show all
Defined in:
lib/opto/resolver.rb

Overview

Base for resolvers.

Resolvers are scripts that can retrieve or generate a value for an option. Such resolvers are for example Env, which can try to find the value for the option from an environment variable. An example of generators is RandomString, which can generate random strings of defined length.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(hint = nil, option = nil) ⇒ Opto::Resolver

Initialize an instance of a resolver.

Parameters:

  • hint (defaults to: nil) —

    A “hint” for the resolver, for example. the environment variable name or a set of rules for generators.

  • option (Opto::Option) (defaults to: nil) —

    The option parent of this resolver instance



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# File 'lib/opto/resolver.rb', line 43

def initialize(hint = nil, option = nil)
  @hint = hint
  @option = option
  @tried = false
end

Instance Attribute Details

#hint ⇒ Object

Returns the value of attribute hint.



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# File 'lib/opto/resolver.rb', line 15

def hint
  @hint
end

#option ⇒ Object

Returns the value of attribute option.



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# File 'lib/opto/resolver.rb', line 16

def option
  @option
end

Class Method Details

.for(origin) ⇒ Object

Find a resolver using an origin_name definition, such as :env or :file

Parameters:

  • origin (Symbol, String)

Raises:

  • (NameError) 


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# File 'lib/opto/resolver.rb', line 21

def for(origin)
  raise NameError, "Unknown resolver: #{origin}" unless resolvers[origin]
  resolvers[origin]
end

.inherited(where) ⇒ Object 



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# File 'lib/opto/resolver.rb', line 26

def inherited(where)
  resolvers[where.origin] = where
end

.origin ⇒ Object 



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# File 'lib/opto/resolver.rb', line 34

def origin
  name.to_s.split('::').last.snakecase.to_sym
end

.resolvers ⇒ Object 



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# File 'lib/opto/resolver.rb', line 30

def resolvers
  @resolvers ||= {}
end

Instance Method Details

#origin ⇒ Object

The origin “tag” of this resolver, for example: ‘random_string’ or ‘env’



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# File 'lib/opto/resolver.rb', line 76

def origin
  self.class.origin
end

#reset_tried ⇒ Object 



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# File 'lib/opto/resolver.rb', line 57

def reset_tried
  @tried = false
end

#resolve ⇒ Object

This is a “base” class, you’re supposed to inherit from this in your resolver and define a #resolve method.

Raises:

  • (RuntimeError) 


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# File 'lib/opto/resolver.rb', line 71

def resolve
  raise RuntimeError, "#{self.class}.resolve not defined"
end

#set_tried ⇒ Object 



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# File 'lib/opto/resolver.rb', line 53

def set_tried
  @tried = true
end

#tried? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/opto/resolver.rb', line 49

def tried?
  !!@tried
end

#try_resolve ⇒ Object 



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# File 'lib/opto/resolver.rb', line 61

def try_resolve
  return nil if tried?
  set_tried
  self.respond_to?(:before) && self.before
  result = resolve
  self.respond_to?(:after) && self.after
  result
end