Class: Saxxy::ContextTree

Inherits:
Object
  • Object
show all
Defined in:
lib/saxxy/context_tree.rb

Overview

ContextTree describes the tree of contexts that the user eventually constructs by constraining NodeActions to be active under some Context.

Author:

  • rubymaniac

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(ctx = nil, &block) ⇒ ContextTree

Initializes a ContextTree by passing an optional context to be used by the actions in order to execute their action block and a block that will be evaluated in order to create the intenal tree structure.

Parameters:

  • ctx (Object) (defaults to: nil) —

    an object to be used by the NodeActions in order to evaluate their block

  • block (Proc) —

    a block that will get evaluated and create the context tree structure



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# File 'lib/saxxy/context_tree.rb', line 33

def initialize(ctx = nil, &block)
  self.root = Saxxy::Context.new
  @ctx = ctx || eval("self", block.binding)
  eval_subtree!(&block)
end

Instance Attribute Details

#root ⇒ Context

Returns the root context of the tree.

Returns:

  • (Context) —

    the root context of the tree



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# File 'lib/saxxy/context_tree.rb', line 20

class ContextTree
  attr_accessor :root

  # Initializes a ContextTree by passing an optional context to be used
  # by the actions in order to execute their action block and a block that
  # will be evaluated in order to create the intenal tree structure.
  #
  # @param ctx [Object] an object to be used by the NodeActions
  #   in order to evaluate their block
  #
  # @param block [Proc] a block that will get evaluated and create
  #   the context tree structure
  #
  def initialize(ctx = nil, &block)
    self.root = Saxxy::Context.new
    @ctx = ctx || eval("self", block.binding)
    eval_subtree!(&block)
  end

  # Creates a Context and uses the arguments to create its activation rule. After
  # creating the context it registers it under the current root context and returns it.
  #
  # @param regexp_or_string [String|Regexp] the activation rule's name
  # @param attributes [Hash] the activation rule's attributes
  # @param block [Proc] a block that will get evaluated and register
  #   the child contexts and the actions
  #
  # @return [Context] the registered Context
  def under(regexp_or_string, attributes = {}, &block)
    Saxxy::Context.new(Saxxy::NodeRule.new(regexp_or_string, attributes)).tap do |context|
      __register_context(context, &block)
    end
  end

  # Creates a NodeAction and uses the arguments to create its activation rule and registers
  # it under the current root context.
  #
  # @param regexp_or_string [String|Regexp] the activation rule's name
  # @param attributes [Hash] the activation rule's attributes
  # @param block [Proc] the NodeAction's action block that will get
  #   evaluated on the passed context at construction
  #
  # @return [NodeAction] the registered NodeAction
  def on(regexp_or_string, attributes = {}, &block)
    Saxxy::NodeAction.new(Saxxy::NodeRule.new(regexp_or_string, attributes), @ctx, &block).tap do |action|
      __register_action(action)
    end
  end

  private
  def eval_subtree!(&block)
    instance_eval(&block) if block_given?
    self.root = root.parent_context if root.has_parent?
  end

  def __register_action(action)
    root.register(action)
  end

  def __register_context(context, &block)
    root.register(self.root = context)
    eval_subtree!(&block)
  end
end

Instance Method Details

#on(regexp_or_string, attributes = {}, &block) ⇒ NodeAction

Creates a NodeAction and uses the arguments to create its activation rule and registers it under the current root context.

Parameters:

  • regexp_or_string (String|Regexp) —

    the activation rule’s name

  • attributes (Hash) (defaults to: {}) —

    the activation rule’s attributes

  • block (Proc) —

    the NodeAction’s action block that will get evaluated on the passed context at construction

Returns:



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# File 'lib/saxxy/context_tree.rb', line 63

def on(regexp_or_string, attributes = {}, &block)
  Saxxy::NodeAction.new(Saxxy::NodeRule.new(regexp_or_string, attributes), @ctx, &block).tap do |action|
    __register_action(action)
  end
end

#under(regexp_or_string, attributes = {}, &block) ⇒ Context

Creates a Context and uses the arguments to create its activation rule. After creating the context it registers it under the current root context and returns it.

Parameters:

  • regexp_or_string (String|Regexp) —

    the activation rule’s name

  • attributes (Hash) (defaults to: {}) —

    the activation rule’s attributes

  • block (Proc) —

    a block that will get evaluated and register the child contexts and the actions

Returns:

  • (Context) —

    the registered Context



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# File 'lib/saxxy/context_tree.rb', line 48

def under(regexp_or_string, attributes = {}, &block)
  Saxxy::Context.new(Saxxy::NodeRule.new(regexp_or_string, attributes)).tap do |context|
    __register_context(context, &block)
  end
end