# class RDoc::Markup::ToHtmlCrossref

Subclass of the RDoc::Markup::ToHtml class that supports looking up method names, classes, etc to create links. RDoc::CrossReference is used to generate those links based on the current context.

### Attributes

context[RW]

RDoc::CodeObject for generating references

show_hash[RW]

Should we show ‘#’ characters on method references?

### Public Class Methods

new(from_path, context, show_hash, hyperlink_all = false, markup = nil) click to toggle source

Creates a new crossref resolver that generates links relative to `context` which lives at `from_path` in the generated files. ‘#’ characters on references are removed unless `show_hash` is true. Only method names preceded by ‘#’ or ‘::’ are linked, unless `hyperlink_all` is true.

    # File lib/rdoc/markup/to_html_crossref.rb, line 31
    def initialize(from_path, context, show_hash, hyperlink_all = false,
                   markup = nil)
      raise ArgumentError, 'from_path cannot be nil' if from_path.nil?
      super markup

      crossref_re = hyperlink_all ? ALL_CROSSREF_REGEXP : CROSSREF_REGEXP

      @cross_reference = RDoc::CrossReference.new context

      @markup.add_special crossref_re, :CROSSREF

      @context       = context
      @from_path     = from_path
      @hyperlink_all = hyperlink_all
      @show_hash     = show_hash
    end

### Public Instance Methods

cross_reference(name, text = nil) click to toggle source

Creates a link to the reference `name` if the name exists. If `text` is given it is used as the link text, otherwise `name` is used.

    # File lib/rdoc/markup/to_html_crossref.rb, line 52
    def cross_reference name, text = nil
      lookup = name

      name = name[1..-1] unless @show_hash if name[0, 1] == '#'

      name = "#{CGI.unescape $'} at #{$1}" if name =~ %r(.*[^#:])@/

      text = name unless text

      link lookup, text
    end

gen_url(url, text) click to toggle source

Generates links for `rdoc-ref:` scheme URLs and allows RDoc::Markup::ToHtml to handle other schemes.

    # File lib/rdoc/markup/to_html_crossref.rb, line 117
    def gen_url url, text
      return super unless url =~ %r\Ardoc-ref:/

      cross_reference $', text
    end

handle_special_CROSSREF(special) click to toggle source

We’re invoked when any text matches the CROSSREF pattern. If we find the corresponding reference, generate a link. If the name we’re looking for contains no punctuation, we look for it up the module/class chain. For example, ToHtml is found, even without the `RDoc::Markup::` prefix, because we look for it in module Markup first.

    # File lib/rdoc/markup/to_html_crossref.rb, line 71
    def handle_special_CROSSREF(special)
      name = special.text

      unless @hyperlink_all then
        # This ensures that words entirely consisting of lowercase letters will
        # not have cross-references generated (to suppress lots of erroneous
        # cross-references to "new" in text, for instance)
        return name if name =~ %r\A[a-z]*\z/
      end

      cross_reference name
    end

handle_special_HYPERLINK(special) click to toggle source

Handles `rdoc-ref:` scheme links and allows RDoc::Markup::ToHtml to handle other schemes.

    # File lib/rdoc/markup/to_html_crossref.rb, line 88
    def handle_special_HYPERLINK special
      return cross_reference $' if special.text =~ %r\Ardoc-ref:/

      super
    end

handle_special_RDOCLINK(special) click to toggle source

`special` is an rdoc-schemed link that will be converted into a hyperlink. For the rdoc-ref scheme the cross-reference will be looked up and the given name will be used.

All other contents are handled by the superclass

    # File lib/rdoc/markup/to_html_crossref.rb, line 102
    def handle_special_RDOCLINK special
      url = special.text

      case url
      when %r\Ardoc-ref:/ then
        cross_reference $'
      else
        super
      end
    end

link(name, text) click to toggle source

Creates an HTML link to `name` with the given `text`.

    # File lib/rdoc/markup/to_html_crossref.rb, line 126
    def link name, text
      original_name = name

      if name =~ %r(.*[^#:])@/ then
        name = $1
        label = $'
      end

      ref = @cross_reference.resolve name, text

      text = ref.output_name @context if
        RDoc::MethodAttr === ref and text == original_name

      case ref
      when String then
        ref
      else
        path = ref.as_href @from_path

        if path =~ %r#/ then
          path << "-label-#{label}"
        else
          path << "#label-#{label}"
        end if label

        "<a href=\"#{path}\">#{text}</a>"
      end
    end