book: generate cross-references correctly

Currently, the cross references in the book are handled incorrectly: the
links contain a bogus reference to the current section, and the
`ch00/*.html` files are not written correctly.

As a consequences, most of the links in the books are wrong.

Let's fix this.

Reported-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

script/book.rb

@@ -41,6 +41,7 @@ def self.all_books
   end
 
   attr_accessor :chapters
+  attr_accessor :xrefs
   attr_accessor :ebook_pdf
   attr_accessor :ebook_epub
   attr_accessor :ebook_mobi
@@ -50,6 +51,7 @@ def initialize(edition, language_code)
     @edition = edition
     @language_code = language_code
     @chapters = []
+    @xrefs = {}
   end
 
   def front_matter
@@ -138,6 +140,15 @@ def save
         file.write("---\nredirect_to: \"book/#{@language_code}/v#{@edition}\"\n---\n")
       end
     end
+
+    FileUtils.mkdir_p(self.absolute_path("ch00"))
+    @xrefs.each do |id_xref, section|
+      path = self.absolute_path("ch00/#{id_xref}.html")
+      relurl = "#{section.relative_url(nil)}##{id_xref}"
+      File.open(path, 'w') do |file|
+        file.write("---\nredirect_to: \"#{relurl}\"\n---\n")
+      end
+    end
   end
 end
 

script/update-book2.rb

@@ -115,10 +115,8 @@ def genbook(language_code, &get_content)
     schapter.save
 
     # create xref
-    # csection = schapter.sections[1]
-    # xref = Xref.where(book_id: book.id, name: id_xref).first_or_create
-    # xref.section = csection
-    # xref.save
+    csection = schapter.sections[1] = Section.new(schapter, 1)
+    book.xrefs[id_xref] = csection
 
     book_prefix = "book/#{language_code}/v#{edition}/"
 
@@ -141,7 +139,7 @@ def genbook(language_code, &get_content)
       xlink&.each do |link|
         xref = link.first
         begin
-          html.gsub!(/href="1-.*?\.html\##{xref}"/, "href=\"ch00/#{xref}\"")
+          html.gsub!(/href="1-.*?\.html\##{xref}"/, "href=\"{{< relurl \"#{book_prefix}ch00/#{xref}\" >}}\"")
         rescue StandardError
           nil
         end
@@ -151,7 +149,7 @@ def genbook(language_code, &get_content)
       xlink&.each do |link|
         xref = link.first
         begin
-          html.gsub!(/href="\##{xref}"/, "href=\"ch00/#{xref}\"")
+          html.gsub!(/href="\##{xref}"/, "href=\"{{< relurl \"#{book_prefix}ch00/#{xref}\" >}}\"")
         rescue StandardError
           nil
         end
@@ -185,17 +183,13 @@ def genbook(language_code, &get_content)
         puts "::error::referenced image #{path} does not exit!"
       end
 
-      # xref = Xref.where(book_id: book.id, name: id_xref).first_or_create
-      # xref.section = csection
-      # xref.save
+      book.xrefs[id_xref] = csection
 
       # record all the xrefs
-      # sec.search(".//*[@id]").each do |id|
-      #   id_xref = id.attribute("id").to_s
-      #   xref = Xref.where(book_id: book.id, name: id_xref).first_or_create
-      #   xref.section = csection
-      #   xref.save
-      # end
+      sec.search(".//*[@id]").each do |id|
+        id_xref = id.attribute("id").to_s
+	book.xrefs[id_xref] = csection
+      end
 
       section += 1
       pretext = ""