Class: Template

Inherits:
Object show all
Defined in:
lib/volt/server/template_parser.rb

Overview

TODO: The section_name that we’re passing in should probably be abstracted out. Possibly this whole thing needs a rewrite.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(template_parser, section_name, template, scope = Scope.new) ⇒ Template

Returns a new instance of Template.



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# File 'lib/volt/server/template_parser.rb', line 11

def initialize(template_parser, section_name, template, scope=Scope.new)
   @binding_number = 0

	@template_parser = template_parser
   @section_name = section_name
	@template = template
   @scopes = [scope]
   @current_scope = @scopes.first
end

Instance Attribute Details

#current_scope ⇒ Object

Returns the value of attribute current_scope.



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# File 'lib/volt/server/template_parser.rb', line 9

def current_scope
  @current_scope
end

#section_name ⇒ Object

Returns the value of attribute section_name.



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# File 'lib/volt/server/template_parser.rb', line 9

def section_name
  @section_name
end

Instance Method Details

#add_attribute_binding(node, attribute, content) ⇒ Object

Attribute bindings support multiple handlebar listeners Exvoltle:

<button click="{_primary} {_important}">...

To accomplish this, we create a new listener from the existing ones in the Proc that we pass to the binding when it is created.



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# File 'lib/volt/server/template_parser.rb', line 175

def add_attribute_binding(node, attribute, content)
	setup_node_id(node)
   
   if content =~ /^\{[^\{]+\}$/
     # Getter is the content inside of { ... }
     add_single_getter(node, attribute, content)
   else
     add_multiple_getters(node, attribute, content)
   end

end

#add_binding(node, content) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 39

def add_binding(node, content)
	if content[0] == '/'
		add_close_mustache(node)
	elsif content[0] == '#'
		command, *content = content.split(/ /)
		content = content.join(' ')

		case command
	  when '#template'
	    return add_template(node, content)
		when '#each'
			return add_each_binding(node, content)
		when '#if'
			return add_if_binding(node, content)
     when '#elsif'
       return add_else_binding(node, content)
     when '#else'
       if content.present?
         # TODO: improve error, include line/file
         raise "#else should not include a condition, use #elsif instead.  #{content} was passed as a condition."
       end
       
       return add_else_binding(node, nil)
		else
			# TODO: Handle invalid command
			raise "Invalid Command"
		end
	else
		# text binding
		return add_text_binding(content)
	end
end

#add_close_mustache(node, close_if = true) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 134

def add_close_mustache(node, close_if=true)
	scope = @scopes.pop
	@current_scope = @scopes.last
   
   # Close an outstanding if binding (if it exists)
   @current_scope.close_if_binding! if close_if
   
	# Track that this scope was closed out
	@current_scope.add_closed_child_scope(scope)

	html = "<!-- $/#{scope.outer_binding_number} -->"

	return html
end

#add_each_binding(node, content) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 81

def add_each_binding(node, content)
	html = "<!-- $#{@binding_number} -->"
   
   content, variable_name = content.strip.split(/ as /)

   template_name = "#{@template_parser.template_path}/#{section_name}/__template/#{@binding_number}"
	@current_scope.add_binding(@binding_number, "lambda { |target, context, id| EachBinding.new(target, context, id, Proc.new { #{content} }, #{variable_name.inspect}, #{template_name.inspect}) }")

	# Add the node, the binding number, then store the location where the
	# bindings for this block starts.
	@current_scope = Scope.new(@binding_number)
	@scopes << @current_scope

	@binding_number += 1
	return html
end

#add_else_binding(node, content) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 116

def add_else_binding(node, content)
  html = add_close_mustache(node, false)
  
html += "<!-- $#{@binding_number} -->"
  template_name = "#{@template_parser.template_path}/#{section_name}/__template/#{@binding_number}"
  
  @current_scope.current_if_binding[1].add_branch(content, template_name)
  
# Add the node, the binding number, then store the location where the
# bindings for this block starts.
@current_scope = Scope.new(@binding_number)
@scopes << @current_scope

@binding_number += 1
  
  return html
end

#add_event_binding(node, attribute_name, content) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 230

def add_event_binding(node, attribute_name, content)
  setup_node_id(node)
  
  event = attribute_name[2..-1]
  
  if node.name == 'a'
    # For links, we need to add blank href to make it clickable.
    node['href'] ||= ''
  end

  @current_scope.add_binding(node['id'], "lambda { |target, context, id| EventBinding.new(target, context, id, #{event.inspect}, Proc.new {|event| #{content} })}")
end

#add_if_binding(node, content) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 98

def add_if_binding(node, content)
	html = "<!-- $#{@binding_number} -->"

   template_name = "#{@template_parser.template_path}/#{section_name}/__template/#{@binding_number}"
   if_binding_setup = IfBindingSetup.new
   if_binding_setup.add_branch(content, template_name)
   
	@current_scope.start_if_binding(@binding_number, if_binding_setup)

	# Add the node, the binding number, then store the location where the
	# bindings for this block starts.
	@current_scope = Scope.new(@binding_number)
	@scopes << @current_scope

	@binding_number += 1
	return html
end

#add_multiple_getters(node, attribute, content) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 200

def add_multiple_getters(node, attribute, content)
  case attribute
  when 'checked', 'value'
    if parts.size > 1
      # Multiple ReactiveValue's can not be passed to value or checked attributes.
      raise "Multiple bindings can not be passed to a #{attribute} binding."
    end
  end
  
  reactive_template_path = add_reactive_template(content)
  
  @current_scope.add_binding(node['id'], "lambda { |target, context, id| AttributeBinding.new(target, context, id, #{attribute.inspect}, Proc.new { ReactiveTemplate.new(context, #{reactive_template_path.inspect}) }) }")
end

#add_reactive_template(content) ⇒ Object

Returns a path to a template for the content. This can be passed into ReactiveTemplate.new, along with the current context.



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# File 'lib/volt/server/template_parser.rb', line 216

def add_reactive_template(content)
  # Return a template path instead
  template_name = "__attribute/#{@binding_number}"
  full_template_path = "#{@template_parser.template_path}/#{section_name}/#{template_name}"
  @binding_number += 1

  attribute_template = Template.new(@template_parser, section_name, Nokogiri::HTML::DocumentFragment.parse(content))
  @template_parser.add_template("#{section_name}/#{template_name}", attribute_template)
  attribute_template.start_walk
  attribute_template.pull_closed_block_scopes

  return full_template_path
end

#add_single_getter(node, attribute, content) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 187

def add_single_getter(node, attribute, content)
  if attribute == 'checked' || true
    # For a checkbox, we don't want to add
    getter = content[1..-2]
  else
    # Otherwise we should combine them
    # TODO: We should make .or handle assignment
    getter = "_tmp = #{content[1..-2]}.or('') ; _tmp.reactive_manager.setter! { |val| self.#{content[1..-2]} = val } ; _tmp"
  end
  
  @current_scope.add_binding(node['id'], "lambda { |target, context, id| AttributeBinding.new(target, context, id, #{attribute.inspect}, Proc.new { #{getter} }) }")
end

#add_template(node, content) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 72

def add_template(node, content)
	html = "<!-- $#{@binding_number} --><!-- $/#{@binding_number} -->"

	@current_scope.add_binding(@binding_number, "lambda { |target, context, id| TemplateBinding.new(target, context, id, #{@template_parser.template_path.inspect}, Proc.new { [#{content}] }) }")

	@binding_number += 1
	return html
end

#add_text_binding(content) ⇒ Object

When we find a binding, we pass it’s content in here and replace it with the return value



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# File 'lib/volt/server/template_parser.rb', line 151

def add_text_binding(content)
	html = "<!-- $#{@binding_number} --><!-- $/#{@binding_number} -->"

	@current_scope.add_binding(@binding_number, "lambda { |target, context, id| ContentBinding.new(target, context, id, Proc.new { #{content} }) }")

	@binding_number += 1
	return html
end

#find_by_comment(name) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 280

def find_by_comment(name)
  return @template.xpath("descendant::comment()[. = ' #{name} ']").first
end

#html ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 21

def html
   if @template.respond_to?(:name) && @template.name[0] == ':'
     # Don't return the <:section> tags
     return @template.children.to_html
   else
     # if @template.class == Nokogiri::XML::NodeSet
     #   result = ''
     #   @template.each do |node|
     #     result << node.to_html
     #   end
     # else
   		result = @template.to_html
     # end
     result
   end
end

#move_nodes_to_new_template(start_node, end_node, scope) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 259

def move_nodes_to_new_template(start_node, end_node, scope)
   # TODO: currently this doesn't handle spanning nodes within seperate containers.
   # so doing tr's doesn't work for some reason.
   
	start_parent = start_node.parent
	start_parent = start_parent.children if start_parent.is_a?(Nokogiri::HTML::DocumentFragment) || start_parent.is_a?(Nokogiri::XML::Element)
	start_index = start_parent.index(start_node) + 1

	end_parent = end_node.parent
	end_parent = end_parent.children if end_parent.is_a?(Nokogiri::HTML::DocumentFragment) || end_parent.is_a?(Nokogiri::XML::Element)
	end_index = end_parent.index(end_node) - 1

	move_nodes = start_parent[start_index..end_index]
	move_nodes.remove

   new_template = Template.new(@template_parser, section_name, move_nodes, scope)
   
   @template_parser.add_template("#{section_name}/__template/#{scope.outer_binding_number}", new_template)
end

#parse_component(node) ⇒ Object

We provide a quick way to render components with tags starting with a : Count the number of /‘s in the path, if we are at the root node we can ignore it, since this is the template its self. TODO: Root node might not be the template if we parsed directly without a subtemplate specifier. We need to find a good way to parse only within the subtemplate.



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# File 'lib/volt/server/template_parser.rb', line 322

def parse_component(node)
  template_path = node.name[1..-1].gsub(':', '/')

  # Take the attributes and turn them into a hash
  attribute_hash = {}
  node.attribute_nodes.each do |attribute_node|
    content = attribute_node.value
    
    if !content.index('{')
      # passing in a string
      value = content.inspect
    elsif content =~ /^\{[^\}]+\}$/
      # Has one binding, just get it
      value = "Proc.new { #{content[1..-2]} }"
    else
      # Has multiple bindings, we need to render a template here
      attr_template_path = add_reactive_template(content)
      
      value = "Proc.new { ReactiveTemplate.new(context, #{attr_template_path.inspect}) }"
    end
    
    attribute_hash[attribute_node.name] = value
  end
  
  attributes_string = attribute_hash.to_a.map do |key, value|
    "#{key.inspect} => #{value}"
  end.join(', ')

  # Setup the arguments string, which goes to the TemplateBinding
  args_str = "#{template_path.inspect}"
  args_str << ", {#{attributes_string}}" if attribute_hash.size > 0

new_html = add_template(node, args_str)
  
  node.swap(new_html)#Nokogiri::HTML::DocumentFragment.parse(new_html))
end

#parse_html_node(node) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 371

def parse_html_node(node)
node.attribute_nodes.each do |attribute_node|
  if attribute_node.name =~ /^e\-/
      # We have an e- binding
      add_event_binding(node, attribute_node.name, attribute_node.value)

      # remove the attribute
      attribute_node.remove
	elsif attribute_node.value.match(/\{[^\}]+\}/)
      # Has bindings
		add_attribute_binding(node, attribute_node.name, attribute_node.value)

		# remove the attribute
		attribute_node.remove
	end
end    
end

#parse_textarea(node) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 359

def parse_textarea(node)
  # The contents of textareas should really be treated like a 
  # value= attribute.  So here we pull the content into a value attribute
  # if the textarea has bindings in the content.
  if node.inner_html =~ /\{[^\}]+\}/
    node[:value] = node.inner_html
    node.children.remove
  end
  
  parse_html_node(node)
end

#pull_closed_block_scopes(scope = @current_scope) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 243

def pull_closed_block_scopes(scope=@current_scope)
  if scope.closed_block_scopes
    scope.closed_block_scopes.each do |sub_scope|
      # Loop through any subscopes first, pull them in.
      pull_closed_block_scopes(sub_scope)
      
      # Grab everything between the start/end html comments
      start_node = find_by_comment("$#{sub_scope.outer_binding_number}")
      end_node = find_by_comment("$/#{sub_scope.outer_binding_number}")

      move_nodes_to_new_template(start_node, end_node, sub_scope)
    end
  end
end

#setup_node_id(node) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 160

def setup_node_id(node)
  id = node['id']
# First assign this node an id if it doesn't have one
unless id
	id = node['id'] = "id#{@binding_number}"
	@binding_number += 1
end
end

#start_walk ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 284

def start_walk
	walk(@template)
end

#walk(node) ⇒ Object

We implement a dom walker that can walk down the dom and spit out output html as we go



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# File 'lib/volt/server/template_parser.rb', line 290

def walk(node)
	case node.type
	when 1
		# html node
     walk_html_node(node)
	when 3
		# text node
     walk_text_node(node)
	end

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

#walk_html_node(node) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 305

def walk_html_node(node)
  if node.name[0] == ':' && node.path.count('/') > 1
    parse_component(node)
  elsif node.name == 'textarea'
    parse_textarea(node)
  else
    parse_html_node(node)
  end
end

#walk_text_node(node) ⇒ Object 



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# File 'lib/volt/server/template_parser.rb', line 389

def walk_text_node(node)
new_html = node.content.gsub(/\{([^\}]+)\}/) do |template_binding|
	add_binding(node, $1)
end

  # puts "------! #{new_html.inspect} - #{node.class.inspect} - #{node.inspect}"

  # TODO: Broke here in jruby
  node.swap(new_html)# if new_html.blank?
  
  #Nokogiri::HTML::DocumentFragment.parse(new_html))
end