Wiki Redirects and Page Renaming

Added the ability to rename existing pages.
[[!redirects Some Page Name]] redirects Wikilinks [[Some Page Name]] to
  the current page (assuming "Some Page Name" does not exist).
  Real pages trump redirects (though this may change, depending on 
  user feedback).

app/controllers/file_controller.rb

@@ -129,7 +129,7 @@ class FileController < ApplicationController
             next
           else
             logger.info "Page '#{page_name}' already exists. Adding a new revision to it."
-            wiki.revise_page(@web.address, page_name, page_content, Time.now, @author, PageRenderer.new)
+            wiki.revise_page(@web.address, page_name, page_name, page_content, Time.now, @author, PageRenderer.new)
           end
         else
           wiki.write_page(@web.address, page_name, page_content, Time.now, @author, PageRenderer.new)

app/controllers/revision_sweeper.rb

@@ -22,8 +22,9 @@ class RevisionSweeper < ActionController::Caching::Sweeper
   
   def expire_caches(page)
     expire_cached_summary_pages(page.web)
-    pages_to_expire = ([page.name] + WikiReference.pages_that_reference(page.web, page.name) +  
+    pages_to_expire = ([page.name] + WikiReference.pages_that_reference(page.web, page.name)   
-        WikiReference.pages_that_include(page.web, page.name)).uniq
+        + WikiReference.pages_redirected_to(page.web, page.name) 
+        + WikiReference.pages_that_include(page.web, page.name)).uniq
     pages_to_expire.each { |page_name| expire_cached_page(page.web, page_name) }
   end
 

app/controllers/web_sweeper.rb

@@ -12,7 +12,7 @@ class WebSweeper < ActionController::Caching::Sweeper
       web.pages.each { |page| expire_cached_page(web, page.name) }
       expire_cached_summary_pages(web)
     elsif record.is_a?(WikiFile)
-      record.web.pages_that_link_to(record.file_name).each do |page|
+      record.web.pages_that_link_to_file(record.file_name).each do |page|
         expire_cached_page(record.web, page)
       end
       expire_cached_summary_pages(record.web)

app/controllers/wiki_controller.rb

@@ -268,9 +268,13 @@ class WikiController < ApplicationController
         raise Instiki::ValidationError.new('Your content was not valid utf-8.')
       end
       if @page
-        wiki.revise_page(@web_name, @page_name, the_content, Time.now, 
+        new_name = params['new_name'] || @page_name
+        raise Instiki::ValidationError.new('Your new title was not valid utf-8.') unless new_name.is_utf8?
+        raise Instiki::ValidationError.new('A page named "' + new_name.escapeHTML + '" already exists.') if @page_name != new_name && @web.has_page?(new_name)
+        wiki.revise_page(@web_name, @page_name, new_name, the_content, Time.now, 
             Author.new(author_name, remote_ip), PageRenderer.new)
         @page.unlock
+        @page_name = new_name
       else
         wiki.write_page(@web_name, @page_name, the_content, Time.now, 
             Author.new(author_name, remote_ip), PageRenderer.new)

app/models/page.rb

@@ -4,13 +4,14 @@ class Page < ActiveRecord::Base
   has_many :wiki_references, :order => 'referenced_name'
   has_one :current_revision, :class_name => 'Revision', :order => 'id DESC'
 
-  def revise(content, time, author, renderer)
+  def revise(content, name, time, author, renderer)
     revisions_size = new_record? ? 0 : revisions.size
-    if (revisions_size > 0) and content == current_revision.content
+    if (revisions_size > 0) and content == current_revision.content and name == self.name
       raise Instiki::ValidationError.new(
           "You have tried to save page '#{name}' without changing its content")
     end
     
+    self.name = name
     author = Author.new(author.to_s) unless author.is_a?(Author)
 
     # Try to render content to make sure that markup engine can take it,
@@ -37,7 +38,7 @@ class Page < ActiveRecord::Base
       raise Instiki::ValidationError.new("Revision #{revision_number} not found")
     end
     author = Author.new(roll_back_revision.author.name, author_ip)
-    revise(roll_back_revision.content, time, author, renderer)
+    revise(roll_back_revision.content, self.name, time, author, renderer)
   end
 
   def revisions?
@@ -71,6 +72,10 @@ class Page < ActiveRecord::Base
     web.select.pages_that_link_to(name)
   end
   
+  def redirects_for
+    wiki_references.select { |ref| ref.redirected_page?}.map { |ref| ref.referenced_name }
+  end
+
   def included_from
     web.select.pages_that_include(name)
   end

app/models/web.rb

@@ -14,7 +14,7 @@ class Web < ActiveRecord::Base
   
   def add_page(name, content, time, author, renderer)
     page = page(name) || Page.new(:web => self, :name => name)
-    page.revise(content, time, author, renderer)
+    page.revise(content, name, time, author, renderer)
   end
   
   def authors
@@ -43,6 +43,14 @@ class Web < ActiveRecord::Base
     Page.count(:conditions => ['web_id = ? AND name = ?', id, name]) > 0
   end
   
+  def has_redirect_for?(name)
+     WikiReference.page_that_redirects_for(self, name) 
+  end
+
+  def page_that_redirects_for(name)
+     page(WikiReference.page_that_redirects_for(self, name))
+  end
+
   def has_file?(file_name)
     WikiFile.find_by_file_name(file_name) != nil
   end
@@ -51,7 +59,11 @@ class Web < ActiveRecord::Base
     WikiFile.all(:order => sort_order, :conditions => ['web_id = ?', id])
   end
 
-  def pages_that_link_to(file_name)
+  def pages_that_link_to(page_name)
+    WikiReference.pages_that_link_to(self, page_name)
+  end
+
+  def pages_that_link_to_file(file_name)
     WikiReference.pages_that_link_to_file(self, file_name)
   end
 

app/models/wiki.rb

@@ -60,9 +60,9 @@ class Wiki
     web.remove_pages(pages_in_category.orphaned_pages)
   end
 
-  def revise_page(web_address, page_name, content, revised_at, author, renderer)
+  def revise_page(web_address, page_name, new_name, content, revised_at, author, renderer)
     page = read_page(web_address, page_name)
-    page.revise(content, revised_at, author, renderer)
+    page.revise(content, new_name, revised_at, author, renderer)
   end
 
   def rollback_page(web_address, page_name, revision_number, time, author_id = nil)

app/models/wiki_reference.rb

@@ -2,6 +2,7 @@ class WikiReference < ActiveRecord::Base
 
   LINKED_PAGE = 'L'
   WANTED_PAGE = 'W'
+  REDIRECTED_PAGE = 'R'
   INCLUDED_PAGE = 'I'
   CATEGORY = 'C'
   AUTHOR = 'A'
@@ -9,7 +10,7 @@ class WikiReference < ActiveRecord::Base
   WANTED_FILE = 'E'
 
   belongs_to :page
-  validates_inclusion_of :link_type, :in => [LINKED_PAGE, WANTED_PAGE, INCLUDED_PAGE, CATEGORY, AUTHOR, FILE, WANTED_FILE]
+  validates_inclusion_of :link_type, :in => [LINKED_PAGE, WANTED_PAGE, REDIRECTED_PAGE, INCLUDED_PAGE, CATEGORY, AUTHOR, FILE, WANTED_FILE]
 
   def self.link_type(web, page_name)
     web.has_page?(page_name) ? LINKED_PAGE : WANTED_PAGE
@@ -51,6 +52,28 @@ class WikiReference < ActiveRecord::Base
     names = connection.select_all(sanitize_sql([query, page_name])).map { |row| row['name'] }
   end
 
+  def self.pages_redirected_to(web, page_name)
+    names = []
+    if web.has_page?(page_name) 
+      page = web.page(page_name)
+      redirected_names = page.redirects_for
+      redirected_names.each do |name|
+        names = names | self.pages_that_reference(web, name)
+      end
+    end
+    names
+  end
+
+  def self.page_that_redirects_for(web, page_name)
+    query = 'SELECT name FROM pages JOIN wiki_references ' +
+      'ON pages.id = wiki_references.page_id ' +
+      'WHERE wiki_references.referenced_name = ? ' +
+      "AND wiki_references.link_type = '#{REDIRECTED_PAGE}' " +
+      "AND pages.web_id = '#{web.id}'"
+    names = connection.select_all(sanitize_sql([query, page_name])).map { |row| row['name'] }
+    names[0] 
+  end
+  
   def self.pages_in_category(web, category)
     query = 
       "SELECT name FROM pages JOIN wiki_references " +
@@ -82,6 +105,10 @@ class WikiReference < ActiveRecord::Base
     link_type == LINKED_PAGE
   end
 
+  def redirected_page?
+    link_type == REDIRECTED_PAGE
+  end
+
   def wanted_page?
     link_type == WANTED_PAGE
   end

app/views/wiki/edit.rhtml

@@ -12,6 +12,16 @@
 	<% form_tag({ :action => 'save', :web => @web.address, :id => @page.name },
 	             { 'id' => 'editForm', 'method' => 'post', 'onsubmit' => 'cleanAuthorName()',
 	               'accept-charset' => 'utf-8' }) do %>
+<% if @page_name != 'HomePage' -%>
+	   <p>
+	      <%= check_box_tag :alter_title, value = "1", checked=false,
+	         'onchange' => "toggleVisibility();" %> <label for="alter_title">Change page name.</label><br/>
+	      <span id="title_change" style="display:none"><label for="new_name">New name:</label> <%= text_field_tag :new_name, h(@page.name.purify),
+			        :onblur => "addRedirect();"  %></span>
+	   </p>
+<% else -%>
+       <%= hidden_field_tag 'new_name', @page_name %>
+<% end%> 
 	   <div>	
 		<textarea name="content" id="content" rows="24" cols="60"><%= h(flash[:content] || 
                          ((params['content'] && params['content'].is_utf8?) ?  params['content'] : @page.content).purify) %></textarea>
@@ -31,10 +41,30 @@
 	<%- end -%>
 
 <script type="text/javascript">
+function toggleVisibility() {
+  var span = document.getElementById('title_change');
+  if (span.style.display =='inline') {
+     span.style.display ='none';
+     document.getElementById('new_name').value = "<%= @page.name %>";
+     var content = document.getElementById('content').value
+     document.getElementById('content').value = content.replace(/\[\[!redirects <%= Regexp.escape(@page.name) %>\]\]\n/, '')
+     }
+  else
+     span.style.display ='inline'
+}
+
+function addRedirect(){
+  if (document.getElementById('new_name').value != "<%= @page.name %>" ) {
+    var content = document.getElementById('content');
+    content.value = '[[!redirects <%= @page.name %>]]\n' + content.value
+    }
+}
+
 function cleanAuthorName() {
   if (document.getElementById('authorName').value == "") {
     document.getElementById('authorName').value = 'AnonymousCoward';
   }
 }
+
 document.forms["editForm"].elements["content"].focus();
 </script>

app/views/wiki/file_list.html.erb

@@ -19,8 +19,8 @@
       <input type="checkbox" name="<%= file.file_name %>" value="delete"/>
       <a href="<%= url_for :web => @web.address, :action => 'files', 
             :id => file.file_name %>"><%= file.file_name%></a> (<%= file.created_at.asctime %>) <span class="linked"><%= "Linked to by: " unless
-            @web.pages_that_link_to(file.file_name).empty? -%>
+            @web.pages_that_link_to_file(file.file_name).empty? -%>
-            <%= @web.pages_that_link_to(file.file_name).collect { |referring_page|  link_to_page(referring_page) }.join(", ") %></span>
+            <%= @web.pages_that_link_to_file(file.file_name).collect { |referring_page|  link_to_page(referring_page) }.join(", ") %></span>
     </li>
   <%- end -%>
   </ul>

lib/chunks/redirect.rb

@@ -0,0 +1,21 @@
+require 'chunks/wiki'
+
+#      [[!redirects Foo]]
+# redirects Wikilinks for the (nonexistent) page "Foo" to this page.
+# If "Foo" exists, then the Redirect has no effect. But if "Foo"
+# does not exist, then a Wikilink [[Foo]] will produce a link to this
+# page, rather than produce a create-a-new-page link. 
+
+class Redirect < WikiChunk::WikiReference
+
+  REDIRECT_PATTERN = /\[\[!redirects\s+([^\]\s][^\]]*?)\s*\]\]/i
+  def self.pattern() REDIRECT_PATTERN end
+
+  def initialize(match_data, content)
+      super
+      @page_name = match_data[1].strip
+      @link_type = :redirect
+      @unmask_text = ''
+  end
+
+end

lib/page_renderer.rb

@@ -173,6 +173,13 @@ class PageRenderer
           :link_type => WikiReference::INCLUDED_PAGE
     end
     
+    redirect_chunks = rendering_result.find_chunks(Redirect)
+    redirects = redirect_chunks.map { |c| ( c.escaped? ? nil : c.page_name ) }.compact.uniq
+    redirects.each do |redirected_page_name|
+      references.build :referenced_name => redirected_page_name, 
+          :link_type => WikiReference::REDIRECTED_PAGE
+    end
+
     categories = rendering_result.find_chunks(Category).map { |cat| cat.list }.flatten
     categories.each do |category|
       references.build :referenced_name => category, :link_type => WikiReference::CATEGORY

lib/url_generator.rb

@@ -10,23 +10,30 @@ class AbstractUrlGenerator
   # Create a link for the given page (or file) name and link text based
   # on the render mode in options and whether the page (file) exists
   # in the web.
-  def make_link(name, web, text = nil, options = {})
+  def make_link(asked_name, web, text = nil, options = {})
     mode = (options[:mode] || :show).to_sym
     link_type = (options[:link_type] || :show).to_sym
 
     if (link_type == :show)
-      known_page = web.has_page?(name)
+      page_exists = web.has_page?(asked_name)
+      known_page = page_exists || web.has_redirect_for?(asked_name)
+      if known_page && !page_exists
+        name = web.page_that_redirects_for(asked_name)
       else
+        name = asked_name
+      end
+    else
+      name = asked_name
       known_page = web.has_file?(name)
       description = web.description(name)
       description = description.unescapeHTML.escapeHTML if description
     end
-    if (text == name)
+    if (text == asked_name)
       text = description || text
     else
       text = text || description
     end
-    text = (text || WikiWords.separate(name)).unescapeHTML.escapeHTML
+    text = (text || WikiWords.separate(asked_name)).unescapeHTML.escapeHTML
     
     case link_type
     when :show

lib/wiki_content.rb

@@ -2,6 +2,7 @@ require 'cgi'
 require 'chunks/engines'
 require 'chunks/category'
 require_dependency 'chunks/include'
+require_dependency 'chunks/redirect'
 require_dependency 'chunks/wiki'
 require_dependency 'chunks/literal'
 require 'chunks/nowiki'
@@ -38,7 +39,7 @@ require 'sanitizer'
 module ChunkManager
   attr_reader :chunks_by_type, :chunks_by_id, :chunks, :chunk_id
 
-  ACTIVE_CHUNKS = [ NoWiki, Category, WikiChunk::Link,
+  ACTIVE_CHUNKS = [ NoWiki, Category, Redirect, WikiChunk::Link,
                     WikiChunk::Word ]
 
   HIDE_CHUNKS = [ Literal::Pre, Literal::Tags, Literal::Math ]

test/functional/file_controller_test.rb

@@ -118,7 +118,7 @@ class FileControllerTest < ActionController::TestCase
     # edit and re-render a page so that it has an "unknown file" link to 'rails-e2e.gif'
     PageRenderer.setup_url_generator(StubUrlGenerator.new)
     renderer = PageRenderer.new
-    @wiki.revise_page('wiki1', 'Oak', '[[rails-e2e.gif:pic]]', 
+    @wiki.revise_page('wiki1', 'Oak', 'Oak', '[[rails-e2e.gif:pic]]', 
         Time.now, 'AnonymousBrave', renderer)
     assert_equal "<p><span class='newWikiWord'>rails-e2e.gif<a href='../file/rails-e2e.gif'>" +
         "?</a></span></p>",
@@ -146,7 +146,7 @@ class FileControllerTest < ActionController::TestCase
     assert @web.has_file?('rails-e2e.gif')
     assert_equal(picture, WikiFile.find_by_file_name('rails-e2e.gif').content)
     PageRenderer.setup_url_generator(StubUrlGenerator.new)
-    @wiki.revise_page('wiki1', 'Oak', 'Try [[rails-e2e.gif:pic]] again.',
+    @wiki.revise_page('wiki1', 'Oak', 'Oak', 'Try [[rails-e2e.gif:pic]] again.',
         Time.now, 'AnonymousBrave', renderer)
     assert_equal "<p>Try <img alt='Rails, end-to-end' src='../file/rails-e2e.gif'/> again.</p>",
         renderer.display_content

test/unit/page_test.rb

@@ -32,7 +32,7 @@ class PageTest < ActiveSupport::TestCase
   end
 
   def test_revise
-    @page.revise('HisWay would be MyWay in kinda lame', Time.local(2004, 4, 4, 16, 55), 
+    @page.revise('HisWay would be MyWay in kinda lame', @page.name, Time.local(2004, 4, 4, 16, 52), 
         'MarianneSyhler', test_renderer)
     @page.reload
 
@@ -44,14 +44,14 @@ class PageTest < ActiveSupport::TestCase
   end
   
   def test_revise_continous_revision
-    @page.revise('HisWay would be MyWay in kinda lame', Time.local(2004, 4, 4, 16, 55), 
+    @page.revise('HisWay would be MyWay in kinda lame', @page.name, Time.local(2004, 4, 4, 16, 55), 
         'MarianneSyhler', test_renderer)
     @page.reload
     assert_equal 2, @page.revisions.length
     assert_equal 'HisWay would be MyWay in kinda lame', @page.content
 
     # consecutive revision by the same author within 30 minutes doesn't create a new revision
-    @page.revise('HisWay would be MyWay in kinda update', Time.local(2004, 4, 4, 16, 57), 
+    @page.revise('HisWay would be MyWay in kinda update', @page.name, Time.local(2004, 4, 4, 16, 57), 
         'MarianneSyhler', test_renderer)
     @page.reload
     assert_equal 2, @page.revisions.length
@@ -59,7 +59,7 @@ class PageTest < ActiveSupport::TestCase
     assert_equal Time.local(2004, 4, 4, 16, 57), @page.revised_at
 
     # but consecutive revision by another author results in a new revision
-    @page.revise('HisWay would be MyWay in the house', Time.local(2004, 4, 4, 16, 58), 
+    @page.revise('HisWay would be MyWay in the house', @page.name, Time.local(2004, 4, 4, 16, 58), 
         'DavidHeinemeierHansson', test_renderer)
     @page.reload
     assert_equal 3, @page.revisions.length
@@ -67,18 +67,31 @@ class PageTest < ActiveSupport::TestCase
 
     # consecutive update after 30 minutes since the last one also creates a new revision, 
     # even when it is by the same author
-    @page.revise('HisWay would be MyWay in my way', Time.local(2004, 4, 4, 17, 30), 
+    @page.revise('HisWay would be MyWay in my way', @page.name, Time.local(2004, 4, 4, 17, 30), 
         'DavidHeinemeierHansson', test_renderer)
     @page.reload
     assert_equal 4, @page.revisions.length
   end
   
+  def test_change_name
+    @page.revise('HisWay would be MyWay in my way', 'SecondPage', Time.local(2004, 4, 5, 17, 56), 
+        'MarianneSyhler', test_renderer)
+    @page.reload
+
+    assert_equal "Second Page", @page.plain_name
+    assert_equal 2, @page.revisions.length, 'Should have two revisions'
+    assert_equal 'MarianneSyhler', @page.current_revision.author.to_s, 
+        'Marianne should be the author now'
+    assert_equal 'DavidHeinemeierHansson', @page.revisions.first.author.to_s, 
+        'David was the first author'
+  end
+
   def test_revise_content_unchanged
     last_revision_before = @page.current_revision
     revisions_number_before = @page.revisions.size
   
     assert_raises(Instiki::ValidationError) { 
-      @page.revise(@page.current_revision.content, Time.now, 'AlexeyVerkhovsky', test_renderer)
+      @page.revise(@page.current_revision.content, @page.name, Time.now, 'AlexeyVerkhovsky', test_renderer)
     }
     
     assert_equal last_revision_before, @page.current_revision(true)
@@ -88,7 +101,7 @@ class PageTest < ActiveSupport::TestCase
   def test_revise_changes_references_from_wanted_to_linked_for_new_pages
     web = Web.find(1)
     new_page = Page.new(:web => web, :name => 'NewPage')
-    new_page.revise('Reference to WantedPage, and to WantedPage2', Time.now, 'AlexeyVerkhovsky', 
+    new_page.revise('Reference to WantedPage, and to WantedPage2', 'NewPage', Time.now, 'AlexeyVerkhovsky', 
         test_renderer)
     
     references = new_page.wiki_references(true)
@@ -99,7 +112,7 @@ class PageTest < ActiveSupport::TestCase
     assert_equal WikiReference::WANTED_PAGE, references[1].link_type
 
     wanted_page = Page.new(:web => web, :name => 'WantedPage')
-    wanted_page.revise('And here it is!', Time.now, 'AlexeyVerkhovsky', test_renderer)
+    wanted_page.revise('And here it is!', 'WantedPage', Time.now, 'AlexeyVerkhovsky', test_renderer)
 
     # link type stored for NewPage -> WantedPage reference should change from WANTED to LINKED
     # reference NewPage -> WantedPage2 should remain the same
@@ -112,8 +125,8 @@ class PageTest < ActiveSupport::TestCase
   end
 
   def test_rollback
-    @page.revise("spot two", Time.now, "David", test_renderer)
+    @page.revise("spot two", @page.name, Time.now, "David", test_renderer)
-    @page.revise("spot three", Time.now + 2000, "David", test_renderer)
+    @page.revise("spot three", @page.name, Time.now + 2000, "David", test_renderer)
     assert_equal 3, @page.revisions(true).length, "Should have three revisions"
     @page.current_revision(true)
     @page.rollback(0, Time.now, '127.0.0.1', test_renderer)