Class: DSLCompose::Reader

Inherits:
Object
  • Object
show all
Defined in:
lib/dsl_compose/reader.rb,
lib/dsl_compose/reader/execution_reader.rb,
lib/dsl_compose/reader/execution_reader/arguments_reader.rb

Overview

This class is a decorator for DSL executions.

When a dynamically defined DSL is executed on a class, it creates an execution object which represents the argument values, and any methods and subsequent method argument values which were provided. This class provides a clean and simple API to access those vaues

Defined Under Namespace

Classes: DSLNotFound, ExecutionReader, NoDSLExecutionFound

Instance Method Summary collapse

Constructor Details

#initialize(klass, dsl_name) ⇒ Reader

given a class and the DSL name, finds and creates a reference to the DSL and the ancestor class where the DSL was originally defined



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# File 'lib/dsl_compose/reader.rb', line 19

def initialize klass, dsl_name
  # a reference to the class and dsl_name which we want to read values for
  @klass = klass
  @dsl_name = dsl_name

  # Move up through this classes ancestors until we find the class which defined
  # the DSL with the provided name. When we reach the top of the ancestor chain we
  # exit the loop.
  while klass
    # if we find a DSL with this name, then store a reference to the DSL and the
    # ancestor class where it was defined
    if DSLs.class_dsl_exists?(klass, dsl_name)
      @dsl = DSLs.class_dsl(klass, dsl_name)
      @dsl_defining_class = klass
      # stop once we find the DSL
      break
    end

    # the DSL was not found here, so traverse up the provided classes hierachy
    # and keep looking for where this DSL was initially defined
    klass = klass.superclass
  end

  # if no DSL was found, then raise an error
  if @dsl.nil? && @dsl_defining_class.nil?
    raise DSLNotFound, "No DSL named `#{dsl_name}` was found for class `#{klass}`"
  end
end

Instance Method Details

#all_executions ⇒ Object

Returns an array of ExecutionReaders to represent each time the DSL was used on the provided class or ancestors of the provided class. The executions will be returned in the order they were executed, which is the earliest ancestor first and if the DSL was used more than once on a class then the order they were used.



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# File 'lib/dsl_compose/reader.rb', line 111

def all_executions
  @dsl_defining_class.dsls.class_dsl_executions(@klass, @dsl_name, true, true).map do |execution|
    ExecutionReader.new execution
  end
end

#ancestor_executions ⇒ Object

Returns an array of ExecutionReaders to represent each time the DSL was used on the ancestors of the provided class, but not on the provided class itself. The executions will be returned in the order they were executed, which is the earliest ancestor first and if the DSL was used more than once on a class then the order they were used.



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# File 'lib/dsl_compose/reader.rb', line 101

def ancestor_executions
  @dsl_defining_class.dsls.class_dsl_executions(@klass, @dsl_name, false, true).map do |execution|
    ExecutionReader.new execution
  end
end

#dsl_used? ⇒ Boolean

Returns true if dsl has been executed once or more on the provided class, otherwise returns false.

Returns:

  • (Boolean) 


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# File 'lib/dsl_compose/reader.rb', line 50

def dsl_used?
  executions.any?
end

#dsl_used_on_ancestors? ⇒ Boolean

Returns true if dsl has been executed once or more on one of the ancestors of the provided class, otherwise returns false.

Returns:

  • (Boolean) 


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# File 'lib/dsl_compose/reader.rb', line 56

def dsl_used_on_ancestors?
  ancestor_executions.any?
end

#dsl_used_on_class_or_ancestors? ⇒ Boolean

Returns true if dsl has been executed once or more on the provided class or any of its ancestors, otherwise returns false.

Returns:

  • (Boolean) 


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# File 'lib/dsl_compose/reader.rb', line 62

def dsl_used_on_class_or_ancestors?
  all_executions.any?
end

#executions ⇒ Object

Returns an array of ExecutionReaders to represent each time the DSL was used on the provided class.



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# File 'lib/dsl_compose/reader.rb', line 90

def executions
  @dsl_defining_class.dsls.class_dsl_executions(@klass, @dsl_name, true, false).map do |execution|
    ExecutionReader.new execution
  end
end

#last_execution ⇒ Object

Returns an ExecutionReader class which exposes a simple API to access the arguments, methods and method arguments provided when using this DSL.

If the dsl has been executed once or more on the provided class, then a reader for the last (most recent) execution will be returned. If the DSL was not executed on the provided class, then we traverse up the classes ancestors and look for the last time it was executed on each ancestor. If no execution of the DSL is found, then nil will be returned



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# File 'lib/dsl_compose/reader.rb', line 74

def last_execution
  execution = @dsl_defining_class.dsls.get_last_dsl_execution(@klass, @dsl_name)
  if execution.nil?
    nil
  else
    ExecutionReader.new execution
  end
end

#last_execution! ⇒ Object

A wrapper for last_execution which raises an error if no execution exists



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# File 'lib/dsl_compose/reader.rb', line 84

def last_execution!
  last_execution || (raise NoDSLExecutionFound, "No execution of the `#{@dsl_name}` dsl was found on `#{@klass}` or any of its ancestors")
end