class Asciidoctor::Converter::TemplateConverter
A {Converter} implementation that uses templates composed in template languages supported by {github.com/rtomayko/tilt Tilt} to convert {AbstractNode} objects from a parsed AsciiDoc document tree to the backend format.
The converter scans the specified directories for template files that are supported by Tilt. If an engine name (e.g., “slim”) is specified in the options Hash passed to the constructor, the scan is restricted to template files that have a matching extension (e.g., “.slim”). The scanner trims any extensions from the basename of the file and uses the resulting name as the key under which to store the template. When the {Converter#convert} method is invoked, the transform argument is used to select the template from this table and use it to convert the node.
For example, the template file “path/to/templates/paragraph.html.slim” will be registered as the “paragraph” transform. The template is then used to convert a paragraph {Block} object from the parsed AsciiDoc tree to an HTML backend format (e.g., “html5”).
As an optimization, scan results and templates are cached for the lifetime of the Ruby process. If the {rubygems.org/gems/thread_safe thread_safe} gem is installed, these caches are guaranteed to be thread safe. If this gem is not present, there is no such guarantee and a warning will be issued.
Constants
- DEFAULT_ENGINE_OPTIONS
Public Class Methods
# File lib/asciidoctor/converter/template.rb, line 45 def self.caches @caches end
# File lib/asciidoctor/converter/template.rb, line 49 def self.clear_caches @caches[:scans].clear if @caches[:scans] @caches[:templates].clear if @caches[:templates] end
# File lib/asciidoctor/converter/template.rb, line 54 def initialize backend, template_dirs, opts = {} Helpers.require_library 'tilt' unless defined? ::Tilt @backend = backend @templates = {} @template_dirs = template_dirs @eruby = opts[:eruby] @safe = opts[:safe] @active_engines = {} @engine = opts[:template_engine] @engine_options = DEFAULT_ENGINE_OPTIONS.inject({}) do |accum, (engine, default_opts)| accum[engine] = default_opts.dup accum end if opts[:htmlsyntax] == 'html' @engine_options[:haml][:format] = :html5 @engine_options[:slim][:format] = :html end @engine_options[:slim][:include_dirs] = template_dirs.reverse.map {|dir| ::File.expand_path dir } if (overrides = opts[:template_engine_options]) overrides.each do |engine, override_opts| (@engine_options[engine] ||= {}).update override_opts end end case opts[:template_cache] when true @caches = self.class.caches when ::Hash @caches = opts[:template_cache] else @caches = {} # the empty Hash effectively disables caching end scan #create_handlers end
Public Instance Methods
Public: Convert an {AbstractNode} to the backend format using the named template.
Looks for a template that matches the value of the {AbstractNode#node_name} property if a template name is not specified.
node - the AbstractNode to convert template_name - the String name of the template to use, or the value of
the node_name property on the node if a template name is not specified. (optional, default: nil)
opts - an optional Hash that is passed as local variables to the
template. (optional, default: {})
Returns the [String] result from rendering the template
# File lib/asciidoctor/converter/template.rb, line 182 def convert node, template_name = nil, opts = {} template_name ||= node.node_name unless (template = @templates[template_name]) raise %(Could not find a custom template to handle transform: #{template_name}) end # Slim doesn't include helpers in the template's execution scope (like HAML), so do it ourselves node.extend ::Slim::Helpers if (defined? ::Slim::Helpers) && (::Slim::Template === template) # NOTE opts become locals in the template if template_name == 'document' (template.render node, opts).strip else (template.render node, opts).chomp end end
Public: Checks whether there is a Tilt template registered with the specified name.
name - the String template name
Returns a [Boolean] that indicates whether a Tilt template is registered for the specified template name.
# File lib/asciidoctor/converter/template.rb, line 205 def handles? name @templates.key? name end
Internal: Load the eRuby implementation
name - the String name of the eRuby implementation
Returns an [Array] containing the Tilt template Class for the eRuby implementation and a Hash of additional options to pass to the initializer
# File lib/asciidoctor/converter/template.rb, line 294 def load_eruby name if !name || name == 'erb' require 'erb' unless defined? ::ERB [::Tilt::ERBTemplate, {}] elsif name == 'erubis' Helpers.require_library 'erubis' unless defined? ::Erubis::FastEruby [::Tilt::ErubisTemplate, { :engine_class => ::Erubis::FastEruby }] else raise ::ArgumentError, %(Unknown ERB implementation: #{name}) end end
Public: Registers a Tilt template with this converter.
name - the String template name template - the Tilt template object to register
Returns the Tilt template object
# File lib/asciidoctor/converter/template.rb, line 222 def register name, template @templates[name] = if (template_cache = @caches[:templates]) template_cache[template.file] = template else template end #create_handler name, template end
Internal: Scans the template directories specified in the constructor for Tilt-supported templates, loads the templates and stores the in a Hash that is accessible via the {TemplateConverter#templates} method.
Returns nothing
# File lib/asciidoctor/converter/template.rb, line 101 def scan path_resolver = PathResolver.new backend = @backend engine = @engine @template_dirs.each do |template_dir| # FIXME need to think about safe mode restrictions here next unless ::File.directory?(template_dir = (path_resolver.system_path template_dir, nil)) # NOTE last matching template wins for template name if no engine is given file_pattern = '*' if engine file_pattern = %(*.#{engine}) # example: templates/haml if ::File.directory?(engine_dir = (::File.join template_dir, engine)) template_dir = engine_dir end end # example: templates/html5 or templates/haml/html5 if ::File.directory?(backend_dir = (::File.join template_dir, backend)) template_dir = backend_dir end pattern = ::File.join template_dir, file_pattern if (scan_cache = @caches[:scans]) template_cache = @caches[:templates] unless (templates = scan_cache[pattern]) templates = (scan_cache[pattern] = (scan_dir template_dir, pattern, template_cache)) end templates.each do |name, template| @templates[name] = template_cache[template.file] = template end else @templates.update scan_dir(template_dir, pattern, @caches[:templates]) end nil end end
Internal: Scan the specified directory for template files matching pattern and instantiate a Tilt template for each matched file.
Returns the scan result as a [Hash]
# File lib/asciidoctor/converter/template.rb, line 235 def scan_dir template_dir, pattern, template_cache = nil result, helpers = {}, nil # Grab the files in the top level of the directory (do not recurse) ::Dir.glob(pattern).select {|match| ::File.file? match }.each do |file| if (basename = ::File.basename file) == 'helpers.rb' helpers = file next elsif (path_segments = basename.split '.').size < 2 next end if (name = path_segments[0]) == 'block_ruler' name = 'thematic_break' elsif name.start_with? 'block_' name = name.slice 6, name.length end unless template_cache && (template = template_cache[file]) template_class, extra_engine_options, extsym = ::Tilt, {}, path_segments[-1].to_sym case extsym when :slim unless @active_engines[extsym] # NOTE slim doesn't get automatically loaded by Tilt Helpers.require_library 'slim' unless defined? ::Slim # align safe mode of AsciiDoc embedded in Slim template with safe mode of current document # NOTE safe mode won't get updated if using template cache and changing safe mode (@engine_options[extsym][:asciidoc] ||= {})[:safe] ||= @safe if @safe && ::Slim::VERSION >= '3.0' # load include plugin when using Slim >= 2.1 require 'slim/include' unless (defined? ::Slim::Include) || ::Slim::VERSION < '2.1' @active_engines[extsym] = true end when :haml unless @active_engines[extsym] Helpers.require_library 'haml' unless defined? ::Haml # NOTE Haml 5 dropped support for pretty printing @engine_options[extsym].delete :ugly if defined? ::Haml::TempleEngine @active_engines[extsym] = true end when :erb template_class, extra_engine_options = (@active_engines[extsym] ||= (load_eruby @eruby)) when :rb next else next unless ::Tilt.registered? extsym.to_s end template = template_class.new file, 1, (@engine_options[extsym] ||= {}).merge(extra_engine_options) end result[name] = template end if helpers || ::File.file?(helpers = (::File.join template_dir, 'helpers.rb')) require helpers end result end
Public: Retrieves the templates that this converter manages.
Returns a [Hash] of Tilt template objects keyed by template name.
# File lib/asciidoctor/converter/template.rb, line 212 def templates @templates.dup end