Add bin and edit workflow

bin/gems/kramdown-2.5.1/lib/kramdown/converter/base.rb

@@ -0,0 +1,257 @@
+# -*- coding: utf-8; frozen_string_literal: true -*-
+#
+#--
+# Copyright (C) 2009-2019 Thomas Leitner <t_leitner@gmx.at>
+#
+# This file is part of kramdown which is licensed under the MIT.
+#++
+#
+
+require 'erb'
+require 'kramdown/utils'
+require 'kramdown/document'
+
+module Kramdown
+
+  module Converter
+
+    # == \Base class for converters
+    #
+    # This class serves as base class for all converters. It provides methods that can/should be
+    # used by all converters (like #generate_id) as well as common functionality that is
+    # automatically applied to the result (for example, embedding the output into a template).
+    #
+    # A converter object is used as a throw-away object, i.e. it is only used for storing the needed
+    # state information during conversion. Therefore one can't instantiate a converter object
+    # directly but only use the Base::convert method.
+    #
+    # == Implementing a converter
+    #
+    # Implementing a new converter is rather easy: just derive a new class from this class and put
+    # it in the Kramdown::Converter module (the latter is only needed if auto-detection should work
+    # properly). Then you need to implement the #convert method which has to contain the conversion
+    # code for converting an element and has to return the conversion result.
+    #
+    # The actual transformation of the document tree can be done in any way. However, writing one
+    # method per element type is a straight forward way to do it - this is how the Html and Latex
+    # converters do the transformation.
+    #
+    # Have a look at the Base::convert method for additional information!
+    class Base
+
+      # Can be used by a converter for storing arbitrary information during the conversion process.
+      attr_reader :data
+
+      # The hash with the conversion options.
+      attr_reader :options
+
+      # The root element that is converted.
+      attr_reader :root
+
+      # The warnings array.
+      attr_reader :warnings
+
+      # Initialize the converter with the given +root+ element and +options+ hash.
+      def initialize(root, options)
+        @options = options
+        @root = root
+        @data = {}
+        @warnings = []
+      end
+      private_class_method(:new, :allocate)
+
+      # Returns whether the template should be applied before the conversion of the tree.
+      #
+      # Defaults to false.
+      def apply_template_before?
+        false
+      end
+
+      # Returns whether the template should be applied after the conversion of the tree.
+      #
+      # Defaults to true.
+      def apply_template_after?
+        true
+      end
+
+      # Convert the element tree +tree+ and return the resulting conversion object (normally a
+      # string) and an array with warning messages. The parameter +options+ specifies the conversion
+      # options that should be used.
+      #
+      # Initializes a new instance of the calling class and then calls the #convert method with
+      # +tree+ as parameter.
+      #
+      # If the +template+ option is specified and non-empty, the template is evaluate with ERB
+      # before and/or after the tree conversion depending on the result of #apply_template_before?
+      # and #apply_template_after?. If the template is evaluated before, an empty string is used for
+      # the body; if evaluated after, the result is used as body. See ::apply_template.
+      #
+      # The template resolution is done in the following way (for the converter ConverterName):
+      #
+      # 1. Look in the current working directory for the template.
+      #
+      # 2. Append +.converter_name+ (e.g. +.html+) to the template name and look for the resulting
+      #    file in the current working directory (the form +.convertername+ is deprecated).
+      #
+      # 3. Append +.converter_name+ to the template name and look for it in the kramdown data
+      #    directory (the form +.convertername+ is deprecated).
+      #
+      # 4. Check if the template name starts with 'string://' and if so, strip this prefix away and
+      #    use the rest as template.
+      def self.convert(tree, options = {})
+        converter = new(tree, ::Kramdown::Options.merge(options.merge(tree.options[:options] || {})))
+
+        if !converter.options[:template].empty? && converter.apply_template_before?
+          apply_template(converter, '')
+        end
+        result = converter.convert(tree)
+        if result.respond_to?(:encode!) && result.encoding != Encoding::BINARY
+          result.encode!(tree.options[:encoding] ||
+                         (raise ::Kramdown::Error, "Missing encoding option on root element"))
+        end
+        if !converter.options[:template].empty? && converter.apply_template_after?
+          result = apply_template(converter, result)
+        end
+
+        [result, converter.warnings]
+      end
+
+      # Convert the element +el+ and return the resulting object.
+      #
+      # This is the only method that has to be implemented by sub-classes!
+      def convert(_el)
+        raise NotImplementedError
+      end
+
+      # Apply the +template+ using +body+ as the body string.
+      #
+      # The template is evaluated using ERB and the body is available in the @body instance variable
+      # and the converter object in the @converter instance variable.
+      def self.apply_template(converter, body) # :nodoc:
+        erb = ERB.new(get_template(converter.options[:template]))
+        obj = Object.new
+        obj.instance_variable_set(:@converter, converter)
+        obj.instance_variable_set(:@body, body)
+        erb.result(obj.instance_eval { binding })
+      end
+
+      # Return the template specified by +template+.
+      def self.get_template(template) # :nodoc:
+        format_ext = '.' + ::Kramdown::Utils.snake_case(name.split("::").last)
+        shipped = File.join(::Kramdown.data_dir, template + format_ext)
+        if File.exist?(template)
+          File.read(template)
+        elsif File.exist?(template + format_ext)
+          File.read(template + format_ext)
+        elsif File.exist?(shipped)
+          File.read(shipped)
+        elsif template.start_with?('string://')
+          template.delete_prefix("string://")
+        else
+          raise "The specified template file #{template} does not exist"
+        end
+      end
+
+      # Add the given warning +text+ to the warning array.
+      def warning(text)
+        @warnings << text
+      end
+
+      # Return +true+ if the header element +el+ should be used for the table of contents (as
+      # specified by the +toc_levels+ option).
+      def in_toc?(el)
+        @options[:toc_levels].include?(el.options[:level]) && (el.attr['class'] || '') !~ /\bno_toc\b/
+      end
+
+      # Return the output header level given a level.
+      #
+      # Uses the +header_offset+ option for adjusting the header level.
+      def output_header_level(level)
+        [[level + @options[:header_offset], 6].min, 1].max
+      end
+
+      # Extract the code block/span language from the attributes.
+      def extract_code_language(attr)
+        if attr['class'] && attr['class'] =~ /\blanguage-\S+/
+          attr['class'].scan(/\blanguage-(\S+)/).first.first
+        end
+      end
+
+      # See #extract_code_language
+      #
+      # *Warning*: This version will modify the given attributes if a language is present.
+      def extract_code_language!(attr)
+        lang = extract_code_language(attr)
+        attr['class'] = attr['class'].sub(/\blanguage-\S+/, '').strip if lang
+        attr.delete('class') if lang && attr['class'].empty?
+        lang
+      end
+
+      # Highlight the given +text+ in the language +lang+ with the syntax highlighter configured
+      # through the option 'syntax_highlighter'.
+      def highlight_code(text, lang, type, opts = {})
+        return nil unless @options[:syntax_highlighter]
+
+        highlighter = ::Kramdown::Converter.syntax_highlighter(@options[:syntax_highlighter])
+        if highlighter
+          highlighter.call(self, text, lang, type, opts)
+        else
+          warning("The configured syntax highlighter #{@options[:syntax_highlighter]} is not available.")
+          nil
+        end
+      end
+
+      # Format the given math element with the math engine configured through the option
+      # 'math_engine'.
+      def format_math(el, opts = {})
+        return nil unless @options[:math_engine]
+
+        engine = ::Kramdown::Converter.math_engine(@options[:math_engine])
+        if engine
+          engine.call(self, el, opts)
+        else
+          warning("The configured math engine #{@options[:math_engine]} is not available.")
+          nil
+        end
+      end
+
+      # Generate an unique alpha-numeric ID from the the string +str+ for use as a header ID.
+      #
+      # Uses the option +auto_id_prefix+: the value of this option is prepended to every generated
+      # ID.
+      def generate_id(str)
+        str = ::Kramdown::Utils::Unidecoder.decode(str) if @options[:transliterated_header_ids]
+        gen_id = basic_generate_id(str)
+        gen_id = 'section' if gen_id.empty?
+        @used_ids ||= {}
+        if @used_ids.key?(gen_id)
+          gen_id += "-#{@used_ids[gen_id] += 1}"
+        else
+          @used_ids[gen_id] = 0
+        end
+        @options[:auto_id_prefix] + gen_id
+      end
+
+      # The basic version of the ID generator, without any special provisions for empty or unique
+      # IDs.
+      def basic_generate_id(str)
+        gen_id = str.gsub(/^[^a-zA-Z]+/, '')
+        gen_id.tr!('^a-zA-Z0-9 -', '')
+        gen_id.tr!(' ', '-')
+        gen_id.downcase!
+        gen_id
+      end
+
+      SMART_QUOTE_INDICES = {lsquo: 0, rsquo: 1, ldquo: 2, rdquo: 3} # :nodoc:
+
+      # Return the entity that represents the given smart_quote element.
+      def smart_quote_entity(el)
+        res = @options[:smart_quotes][SMART_QUOTE_INDICES[el.value]]
+        ::Kramdown::Utils::Entities.entity(res)
+      end
+
+    end
+
+  end
+
+end