Merge branch 'master' of git://github.com/lifo/docrails

* 'master' of git://github.com/lifo/docrails: (259 commits)
  Fix a small typo
  ensure authors get warnings about broken links, and ensure end users don't
  in guides generator, warn about duplicate header IDs only if WARN_DUPLICATE_HEADERS
  replace edit distance implementation with one written from scratch to avoid license issues
  removes a wrong comment in the finders guide
  updates fxn picture
  thanks but release notes are mostly frozen once they are published, and provide only an overview of the new stuff
  Added extra notes to nested model forms explanation in 2.3 release notes to cover has_one relationships
  clarifies a bit more what's the issue with check boxes and arrays of parameters
  be even more ambiguous about the order of generation of hidden input for check boxes in form helper guide
  this page referred to an :href_options keyword hash, in fact the correct keyword (the one the code responds to) is :html
  update explanation of check box generation according to f400209
  Hidden field with check box goes first.
  update rack fixture to be ruby 1.9 compat
  Better error message to try to figure out why the CI build is failing
  ruby 1.9 compat: Pathname doesn't support =~
  update rack fixture to be ruby 1.9 compat
  update metal fixtures to be ruby 1.9 compat
  Fix brittle Time.now mock
  Ensure our bundled version of rack is at the front of the load path
  ...

1 files changed, 22 insertions, 4 deletions

diff --git a/railties/guides/rails_guides/generator.rb b/railties/guides/rails_guides/generator.rb
index dd147c4d5f..7807c2c565 100644
--- a/railties/guides/rails_guides/generator.rb
+++ b/railties/guides/rails_guides/generator.rb
@@ -137,16 +137,34 @@ module RailsGuides
     end
 
     def warn_about_broken_links(html)
+      anchors = extract_anchors(html)
+      check_fragment_identifiers(html, anchors)
+    end
+    
+    def extract_anchors(html)
       # Textile generates headers with IDs computed from titles.
-      anchors  = Set.new(html.scan(/<h\d\s+id="([^"]+)/).flatten)
+      anchors = Set.new
+      html.scan(/<h\d\s+id="([^"]+)/).flatten.each do |anchor|
+        if anchors.member?(anchor)
+          puts "*** DUPLICATE HEADER ID: #{anchor}, please consider rewording" if ENV.key?("WARN_DUPLICATE_HEADERS")
+        else
+          anchors << anchor
+        end
+      end
+
       # Also, footnotes are rendered as paragraphs this way.
       anchors += Set.new(html.scan(/<p\s+class="footnote"\s+id="([^"]+)/).flatten)
-      
-      # Check fragment identifiers.
+      return anchors
+    end
+    
+    def check_fragment_identifiers(html, anchors)
       html.scan(/<a\s+href="#([^"]+)/).flatten.each do |fragment_identifier|
         next if fragment_identifier == 'mainCol' # in layout, jumps to some DIV
         unless anchors.member?(fragment_identifier)
-          puts "BROKEN LINK: ##{fragment_identifier}"
+          guess = anchors.min { |a, b|
+            Levenshtein.distance(fragment_identifier, a) <=> Levenshtein.distance(fragment_identifier, b)
+          }
+          puts "*** BROKEN LINK: ##{fragment_identifier}, perhaps you meant ##{guess}." if ENV.key?("WARN_BROKEN_LINKS")
         end
       end
     end