Class: Herb::Engine::Compiler

Inherits:
Visitor
  • Object
show all
Defined in:
lib/herb/engine/compiler.rb

Constant Summary collapse

EXPRESSION_TOKEN_TYPES = 
[:expr, :expr_escaped, :expr_block, :expr_block_escaped].freeze
TRAILING_WHITESPACE = 
/[ \t]+\z/
TRAILING_INDENTATION = 
/\n[ \t]+\z/
TRAILING_INDENTATION_CAPTURE = 
/\n([ \t]+)\z/
WHITESPACE_ONLY = 
/\A[ \t]+\z/
WHITESPACE_ONLY_CAPTURE = 
/\A([ \t]+)\z/

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Visitor

#visit, #visit_all, #visit_child_nodes, #visit_erb_node, #visit_erb_render_node, #visit_erb_strict_locals_node, #visit_html_conditional_open_tag_node, #visit_node, #visit_ruby_html_attributes_splat_node, #visit_ruby_parameter_node, #visit_ruby_render_keywords_node, #visit_ruby_render_local_node

Methods included from AST::Helpers

#erb_comment?, #erb_graphql?, #erb_output?, #erb_outputs?, #inline_ruby_comment?

Constructor Details

#initialize(engine, options = {}) ⇒ Compiler

Returns a new instance of Compiler.



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# File 'lib/herb/engine/compiler.rb', line 16

def initialize(engine, options = {})
  super()

  @engine = engine
  @escape = options.fetch(:escape) { options.fetch(:escape_html, false) }
  @tokens = [] #: Array[untyped]
  @element_stack = [] #: Array[String]
  @context_stack = [:html_content]
  @trim_next_whitespace = false
  @last_trim_consumed_newline = false
  @pending_leading_whitespace = nil
  @pending_leading_whitespace_insert_index = 0
  @current_element_source = nil
end

Instance Attribute Details

#tokens ⇒ Object (readonly)

Returns the value of attribute tokens.



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# File 'lib/herb/engine/compiler.rb', line 14

def tokens
  @tokens
end

Instance Method Details

#generate_output ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 31

def generate_output
  optimized_tokens = optimize_tokens(@tokens)

  optimized_tokens.each do |type, value, context, escaped|
    case type
    when :text
      @engine.send(:add_text, value)
    when :code
      @engine.send(:add_code, value)
    when :expr, :expr_escaped
      indicator = indicator_for(type)

      if context_aware_context?(context)
        @engine.send(:add_context_aware_expression, indicator, value, context)
      else
        @engine.send(:add_expression, indicator, value)
      end
    when :expr_block, :expr_block_escaped
      @engine.send(:add_expression_block, indicator_for(type), value)
    when :expr_block_end
      @engine.send(:add_expression_block_end, value, escaped: escaped)
    end
  end
end

#visit_cdata_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 206

def visit_cdata_node(node)
  add_text(node.tag_opening.value)
  visit_all(node.children)
  add_text(node.tag_closing.value)
end

#visit_document_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 56

def visit_document_node(node)
  visit_all(node.children)
end

#visit_erb_begin_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 268

def visit_erb_begin_node(node)
  visit_erb_control_with_parts(node, :statements, :rescue_clause, :else_clause, :ensure_clause, :end_node)
end

#visit_erb_block_end_node(node, escaped: false) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 327

def visit_erb_block_end_node(node, escaped: false)
  remove_trailing_whitespace_from_last_token! if left_trim?(node)

  code = node.content.value.strip

  if at_line_start?
    leading_space = extract_and_remove_leading_space!
    right_space = " \n"

    @tokens << [:expr_block_end, "#{leading_space}#{code}#{right_space}", current_context, escaped]
    @trim_next_whitespace = true
  else
    @tokens << [:expr_block_end, code, current_context, escaped]
  end
end

#visit_erb_block_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 296

def visit_erb_block_node(node)
  opening = node.tag_opening.value

  check_for_escaped_erb_tag!(opening)

  if opening.include?("=")
    should_escape = should_escape_output?(opening)
    code = node.content.value.strip

    @tokens << if should_escape
                 [:expr_block_escaped, code, current_context]
               else
                 [:expr_block, code, current_context]
               end

    @last_trim_consumed_newline = false
    @trim_next_whitespace = true if right_trim?(node)

    visit_all(node.body)
    visit_erb_block_end_node(node.end_node, escaped: should_escape)
  else
    visit_erb_control_node(node) do
      visit_all(node.body)
      visit(node.rescue_clause)
      visit(node.else_clause)
      visit(node.ensure_clause)
      visit(node.end_node)
    end
  end
end

#visit_erb_case_match_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 284

def visit_erb_case_match_node(node)
  visit_erb_control_with_parts(node, :conditions, :else_clause, :end_node)
end

#visit_erb_case_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 248

def visit_erb_case_node(node)
  visit_erb_control_with_parts(node, :conditions, :else_clause, :end_node)
end

#visit_erb_content_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 212

def visit_erb_content_node(node)
  return if inline_ruby_comment?(node)

  process_erb_tag(node)
end

#visit_erb_control_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 218

def visit_erb_control_node(node, &)
  if node.content
    apply_trim(node, node.content.value.strip)
  end

  yield if block_given?
end

#visit_erb_control_with_parts(node, *parts) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 343

def visit_erb_control_with_parts(node, *parts)
  visit_erb_control_node(node) do
    parts.each do |part|
      value = node.send(part)
      case value
      when Array
        visit_all(value)
      when nil
        # Skip nil values
      else
        visit(value)
      end
    end
  end
end

#visit_erb_else_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 234

def visit_erb_else_node(node)
  visit_erb_control_node(node) do
    visit_all(node.statements)
  end
end

#visit_erb_end_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 280

def visit_erb_end_node(node)
  visit_erb_control_node(node)
end

#visit_erb_ensure_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 276

def visit_erb_ensure_node(node)
  visit_erb_control_with_parts(node, :statements)
end

#visit_erb_for_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 256

def visit_erb_for_node(node)
  visit_erb_control_with_parts(node, :statements, :end_node)
end

#visit_erb_if_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 226

def visit_erb_if_node(node)
  visit_erb_control_node(node) do
    visit_all(node.statements)
    visit(node.subsequent)
    visit(node.end_node)
  end
end

#visit_erb_in_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 288

def visit_erb_in_node(node)
  visit_erb_control_with_parts(node, :statements)
end

#visit_erb_open_tag_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 125

def visit_erb_open_tag_node(node)
  tag_name = node.tag_name&.value

  if tag_name
    is_void = Herb::HTML::Util.void_element?(tag_name)
    uses_self_closing = is_void && @current_element_source != "ActionView::Helpers::TagHelper#tag"

    add_text("<")
    add_text(tag_name)

    node.children.each do |child|
      visit(child)
    end

    add_text(uses_self_closing ? " />" : ">")
  else
    process_erb_tag(node)
  end
end

#visit_erb_rescue_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 272

def visit_erb_rescue_node(node)
  visit_erb_control_with_parts(node, :statements, :subsequent)
end

#visit_erb_unless_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 240

def visit_erb_unless_node(node)
  visit_erb_control_node(node) do
    visit_all(node.statements)
    visit(node.else_clause)
    visit(node.end_node)
  end
end

#visit_erb_until_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 264

def visit_erb_until_node(node)
  visit_erb_control_with_parts(node, :statements, :end_node)
end

#visit_erb_when_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 252

def visit_erb_when_node(node)
  visit_erb_control_with_parts(node, :statements)
end

#visit_erb_while_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 260

def visit_erb_while_node(node)
  visit_erb_control_with_parts(node, :statements, :end_node)
end

#visit_erb_yield_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 292

def visit_erb_yield_node(node)
  process_erb_tag(node, skip_comment_check: true)
end

#visit_html_attribute_name_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 111

def visit_html_attribute_name_node(node)
  visit_all(node.children)
end

#visit_html_attribute_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 98

def visit_html_attribute_node(node)
  add_whitespace(" ")

  visit(node.name)

  return unless node.value

  has_equals = node.equals.value&.include?("=")
  add_text(has_equals ? node.equals.value : "=")

  visit(node.value)
end

#visit_html_attribute_value_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 115

def visit_html_attribute_value_node(node)
  push_context(:attribute_value)

  add_text(node.open_quote&.value || '"') if node.quoted
  visit_all(node.children)
  add_text(node.close_quote&.value || '"') if node.quoted

  pop_context
end

#visit_html_close_tag_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 159

def visit_html_close_tag_node(node)
  tag_name = node.tag_name&.value&.downcase

  if @engine.content_for_head && tag_name == "head"
    escaped_html = @engine.content_for_head.gsub("'", "\\\\'")
    @tokens << [:expr, "'#{escaped_html}'.html_safe", current_context]
  end

  add_text(node.tag_opening&.value)
  add_text(node.tag_name&.value)
  add_text(node.tag_closing&.value)
end

#visit_html_comment_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 188

def visit_html_comment_node(node)
  add_text(node.comment_start.value)
  visit_all(node.children)
  add_text(node.comment_end.value)
end

#visit_html_conditional_element_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 81

def visit_html_conditional_element_node(node)
  with_element_context(node) do
    visit(node.open_conditional)
    visit_all(node.body)
    visit(node.close_conditional)
  end
end

#visit_html_doctype_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 194

def visit_html_doctype_node(node)
  add_text(node.tag_opening.value)
  visit_all(node.children)
  add_text(node.tag_closing.value)
end

#visit_html_element_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 60

def visit_html_element_node(node)
  with_element_context(node) do
    visit(node.open_tag)
    visit_all(node.body)

    tag_name = node.tag_name&.value&.downcase

    if node.open_tag.is_a?(Herb::AST::ERBOpenTagNode) && tag_name && node.close_tag
      if node.close_tag.is_a?(Herb::AST::ERBEndNode)
        remove_trailing_whitespace_from_last_token! if left_trim?(node.close_tag)
        add_text("</#{tag_name}>")
        @trim_next_whitespace = true
      else
        add_text("</#{tag_name}>")
      end
    else
      visit(node.close_tag)
    end
  end
end

#visit_html_omitted_close_tag_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 172

def visit_html_omitted_close_tag_node(node)
  # no-op
end

#visit_html_open_tag_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 89

def visit_html_open_tag_node(node)
  add_text(node.tag_opening&.value || "<")
  add_text(node.tag_name.value) if node.tag_name

  visit_all(node.children)

  add_text(node.tag_closing&.value || ">")
end

#visit_html_text_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 176

def visit_html_text_node(node)
  add_text(node.content)
end

#visit_html_virtual_close_tag_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 145

def visit_html_virtual_close_tag_node(node)
  tag_name = node.tag_name&.value

  return unless tag_name

  add_text("</")
  add_text(tag_name)
  add_text(">")
end

#visit_literal_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 180

def visit_literal_node(node)
  add_text(node.content)
end

#visit_ruby_literal_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 155

def visit_ruby_literal_node(node)
  add_expression(node.content)
end

#visit_whitespace_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 184

def visit_whitespace_node(node)
  add_whitespace(node.value.value)
end

#visit_xml_declaration_node(node) ⇒ Object 



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# File 'lib/herb/engine/compiler.rb', line 200

def visit_xml_declaration_node(node)
  add_text(node.tag_opening.value)
  visit_all(node.children)
  add_text(node.tag_closing.value)
end