Class: Trivet::Childset

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Defined in:
lib/trivet.rb

Overview

Objects of this class act like an array of the children of a node. However, unlike an array, attempts to add children result in calling Trivet::Node#allow_child? to check if the child is allowed.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(node) ⇒ Childset

Accepts a Trivet::Node object to which this object will be attached.



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# File 'lib/trivet.rb', line 1109

def initialize(node)
	@node = node
	@children = []
end

Instance Attribute Details

#node ⇒ Object (readonly)

Returns the Trivet::Node object that this object is attached to.



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# File 'lib/trivet.rb', line 1123

def node
  @node
end

Instance Method Details

#<<(new_child) ⇒ Object

Shortcut for append without any options.



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# File 'lib/trivet.rb', line 1186

def <<(new_child)
	return append(new_child)
end

#append(new_child, opts = {}) ⇒ Object

Adds a child to the end of the array. Calls Trivet::Node#allow_child? to check if the child can be added. Does nothing if the node is already a child.



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# File 'lib/trivet.rb', line 1181

def append(new_child, opts={})
	return add_child(new_child, 'last', opts)
end

#clear ⇒ Object

Removes all children.



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# File 'lib/trivet.rb', line 1223

def clear()
	# explicitly unlink childen
	@children.clone.each do |child|
		if child.is_a?(Trivet::Node)
			child.unlink
		end
	end
	
	# remove all other child objects
	@children.clear
end

#have_object?(potential) ⇒ Boolean

Returns true if the @children contains the given object. This method is not quite the same as include?. This method returns true only if @children contains the actual object given, not just an object that matches ==. So, for example, the following use of have_object? would return false, even though it cohtains a string identical to the string in @children.

@children.push 'whatever'
@children.include? 'whatever'     # true
@children.have_object? 'whatever' # false

Returns:

  • (Boolean) 


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# File 'lib/trivet.rb', line 1339

def have_object?(potential)
	@children.each_with_index do |child, idx|
		if child.equal?(potential)
			return idx
		end
	end
	
	return false
end

#insert(index, new_child, opts = {}) ⇒ Object

Inserts the child at the position indicated by index. Calls Trivet::Node#allow_child? to check if the child can be added. Does nothing if the node is already a child.



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# File 'lib/trivet.rb', line 1200

def insert(index, new_child, opts={})
	return add_child(new_child, index, opts)
end

#pop ⇒ Object

Unlinks and returns the last child. Returns nil if there are no children.



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# File 'lib/trivet.rb', line 1266

def pop()
	# remove first element
	removed = @children.pop
	
	# if a node was removed, unlink it
	if removed.is_a?(Trivet::Node)
		removed.unlink 'recurse'=>false
	end
	
	# return
	return removed
end

#push(new_child, opts = {}) ⇒ Object

Adds a child to the end of the array. Calls Trivet::Node#allow_child? to check if the child can be added. Does nothing if the node is already a child.



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# File 'lib/trivet.rb', line 1174

def push(new_child, opts={})
	return add_child(new_child, 'last', opts)
end

#reject! ⇒ Object

Acts like Array#reject!. Rejected children are unlinked.



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# File 'lib/trivet.rb', line 1288

def reject!()
	# If no block, just return an enumerator. This mimics the behavior of
	# Array#reject!.
	if not block_given?
		return enum_for(:each)
	end
	
	# $tm.hrm
	all = @children.clone
	
	# loop through all
	all.each do |child|
		bool = yield(child)
		bool or remove_object(child)
	end
	
	# return
	return self
end

#remove_object(child, opts = {}) ⇒ Object

Removes the given child from the array of children. Does nothing if the child isn’t present.



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# File 'lib/trivet.rb', line 1214

def remove_object(child, opts={})
	# opts = {'recurse'=>true}.merge(opts)
	
	@children.reject!() do |el|
		el.equal? child
	end
end

#shift ⇒ Object

Unlinks and returns the first child. Returns nil if there are no children.



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# File 'lib/trivet.rb', line 1244

def shift()
	# remove first element
	removed = @children.shift
	
	# if a node was removed, unlink it
	if removed.is_a?(Trivet::Node)
		removed.unlink 'recurse'=>false
	end
	
	# return
	return removed
end

#to_a ⇒ Object

Returns an array of the children.



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# File 'lib/trivet.rb', line 1317

def to_a
	return @children.clone
end

#unshift(new_child, opts = {}) ⇒ Object

Adds a child to the beginning of the array. Calls Trivet::Node#allow_child? to check if the child can be added. Does nothing if the node is already a child.



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# File 'lib/trivet.rb', line 1193

def unshift(new_child, opts={})
	return add_child(new_child, 'first', opts)
end