class Fragment

A fragment of a Markly AST document.

Wraps a Markly::Node of type :document and provides rendering helpers. Used for both slide documents and presenter notes so callers can choose their output format without the parser pre-committing to one.

Definitions

EXTENSIONS = [:table, :tasklist, :strikethrough, :autolink]

Markly extensions enabled for all slide Markdown rendering.

def initialize(node)

Initialize a fragment from a Markly document node.

Signature
parameter　node　Markly::Node

A document node containing the fragment content.

Implementation

 
def initialize(node)
	@node = node
end

attr :node

Signature
attribute　Markly::Node

The underlying AST document node.

def initialize_copy(other)

Duplicate this fragment and its underlying AST.

Signature
returns　Fragment

An independently mutable copy.

Implementation

 
def initialize_copy(other)
	super
	@node = other.node.dup
end

def empty?

Whether the fragment has no content.

Signature
returns　Boolean

Implementation

 
def empty?
	@node.first_child.nil?
end

def to_html

Render the fragment to HTML.

Signature
returns　String

The rendered HTML.

Implementation

 
def to_html
	Markly::Renderer::HTML.new(flags: Markly::UNSAFE, extensions: EXTENSIONS).render(@node)
end

def extract(name)

Extract the content belonging to a named H2 placeholder.

The matching heading itself is removed. Following nodes are extracted up to the next heading of the same or a higher level. Lower-level headings remain part of the extracted content.

Signature
parameter　name　String

The heading name to extract.

returns　Fragment | Nil

The extracted content, or nil when not found.

Implementation

 
def extract(name)
	heading = find_heading(name)
	return unless heading
	
	level = heading.header_level
	fragment = Markly::Node.new(:document)
	node = heading.next
	heading.delete
	
	while node
		next_node = node.next
		break if node.type == :header && node.header_level <= level
		
		fragment.append_child(node)
		node = next_node
	end
	
	Fragment.new(fragment)
end

def extract_heading(level = 1)

Extract the first heading at the given level, retaining the heading node.

Signature
parameter　level　Integer

The Markdown heading level.

returns　Fragment | Nil

A fragment containing the extracted heading.

Implementation

 
def extract_heading(level = 1)
	heading = nil
	@node.each do |node|
		if node.type == :header && node.header_level == level
			heading = node
			break
		end
	end
	return unless heading
	
	fragment = Markly::Node.new(:document)
	fragment.append_child(heading)
	Fragment.new(fragment)
end

def to_commonmark

Render the fragment back to CommonMark Markdown.

Signature
returns　String

The CommonMark source.

Implementation

 
def to_commonmark
	@node.to_commonmark
end

def heading_text(level = 1)

Return the plain text of the first heading at the given level.

Signature
parameter　level　Integer

The Markdown heading level.

returns　String | Nil

The heading text, or nil when not found.

Implementation

 
def heading_text(level = 1)
	@node.each do |node|
		if node.type == :header && node.header_level == level
			return node.dup.extract_children.to_plaintext
		end
	end
end