Added wiki diff.

Diff can be viewed from the page history, or directly from the project activity page for each edit.
Uses Lars Christensen's diff library.

git-svn-id: http://redmine.rubyforge.org/svn/trunk@583 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/controllers/wiki_controller.rb

@@ -15,6 +15,8 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
+require 'diff'
+
 class WikiController < ApplicationController
   layout 'base'
   before_filter :find_wiki, :check_project_privacy
@@ -84,12 +86,18 @@ class WikiController < ApplicationController
     @versions = @page.content.versions.find :all, 
                                             :select => "id, author_id, comments, updated_on, version",
                                             :order => 'version DESC',
-                                            :limit  =>  @version_pages.items_per_page,
+                                            :limit  =>  @version_pages.items_per_page + 1,
                                             :offset =>  @version_pages.current.offset
 
     render :layout => false if request.xhr?
   end
   
+  def diff
+    @page = @wiki.find_page(params[:page])
+    @diff = @page.diff(params[:version], params[:version_from])
+    render_404 unless @diff
+  end
+  
   # remove a wiki page and its history
   def destroy
     @page = @wiki.find_page(params[:page])

app/helpers/application_helper.rb

@@ -171,6 +171,14 @@ module ApplicationHelper
     text = @do_textilize ? auto_link(RedCloth.new(text, [:hard_breaks]).to_html) : simple_format(auto_link(h(text)))
   end
   
+  # Same as Rails' simple_format helper without using paragraphs
+  def simple_format_without_paragraph(text)
+    text.to_s.
+      gsub(/\r\n?/, "\n").                    # \r\n and \r -> \n
+      gsub(/\n\n+/, "<br /><br />").          # 2+ newline  -> 2 br
+      gsub(/([^\n]\n)(?=[^\n])/, '\1<br />')  # 1 newline   -> br
+  end
+  
   def error_messages_for(object_name, options = {})
     options = options.symbolize_keys
     object = instance_variable_get("@#{object_name}")

app/helpers/wiki_helper.rb

@@ -16,4 +16,41 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 module WikiHelper
+
+  def html_diff(wdiff)
+    words = wdiff.words.collect{|word| h(word)}
+    words_add = 0
+    words_del = 0
+    dels = 0
+    del_off = 0
+    wdiff.diff.diffs.each do |diff|
+      add_at = nil
+      add_to = nil
+      del_at = nil
+      deleted = ""	    
+      diff.each do |change|
+        pos = change[1]
+        if change[0] == "+"
+          add_at = pos + dels unless add_at
+          add_to = pos + dels
+          words_add += 1
+        else
+          del_at = pos unless del_at
+          deleted << ' ' + change[2]
+          words_del	 += 1
+        end
+      end
+      if add_at
+        words[add_at] = '<span class="diff_in">' + words[add_at]
+        words[add_to] = words[add_to] + '</span>'
+      end
+      if del_at
+        words.insert del_at - del_off + dels + words_add, '<span class="diff_out">' + deleted + '</span>'
+        dels += 1
+        del_off += words_del
+        words_del = 0
+      end
+    end
+    simple_format_without_paragraph(words.join(' '))
+  end
 end

app/models/wiki_page.rb

@@ -15,6 +15,8 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
+require 'diff'
+
 class WikiPage < ActiveRecord::Base
   belongs_to :wiki
   has_one :content, :class_name => 'WikiContent', :foreign_key => 'page_id', :dependent => :destroy
@@ -39,6 +41,17 @@ class WikiPage < ActiveRecord::Base
     result
   end
   
+  def diff(version_to=nil, version_from=nil)
+    version_to = version_to ? version_to.to_i : self.content.version
+    version_from = version_from ? version_from.to_i : version_to - 1
+    version_to, version_from = version_from, version_to unless version_from < version_to
+    
+    content_to = content.versions.find_by_version(version_to)
+    content_from = content.versions.find_by_version(version_from)
+    
+    (content_to && content_from) ? WikiDiff.new(content_to, content_from) : nil
+  end
+  
   def self.pretty_title(str)
     (str && str.is_a?(String)) ? str.tr('_', ' ') : str
   end
@@ -47,3 +60,17 @@ class WikiPage < ActiveRecord::Base
     wiki.project
   end
 end
+
+class WikiDiff
+  attr_reader :diff, :words, :content_to, :content_from
+  
+  def initialize(content_to, content_from)
+    @content_to = content_to
+    @content_from = content_from
+    @words = content_to.text.split(/(\s+)/)
+    @words = @words.select {|word| word != ' '}
+    words_from = content_from.text.split(/(\s+)/)
+    words_from = words_from.select {|word| word != ' '}    
+    @diff = words_from.diff @words
+  end
+end

app/views/projects/activity.rhtml

@@ -38,7 +38,8 @@
     <% elsif e.is_a? Document %>
       <%= e.created_on.strftime("%H:%M") %> <%=l(:label_document)%>: <%= link_to h(e.title), :controller => 'documents', :action => 'show', :id => e %><br />
     <% elsif e.is_a? WikiContent.versioned_class %>
-      <%= e.created_on.strftime("%H:%M") %> <%=l(:label_wiki_edit)%>: <%= link_to h(WikiPage.pretty_title(e.title)), :controller => 'wiki', :page => e.title %> (<%= link_to '#' + e.version.to_s, :controller => 'wiki', :page => e.title, :version => e.version %>)<br />
+      <%= e.created_on.strftime("%H:%M") %> <%=l(:label_wiki_edit)%>: <%= link_to h(WikiPage.pretty_title(e.title)), :controller => 'wiki', :page => e.title %>
+      (<%= link_to '#' + e.version.to_s, :controller => 'wiki', :page => e.title, :version => e.version %><%= ', ' + link_to('diff', :controller => 'wiki', :action => 'diff', :page => e.title, :version => e.version) if e.version > 1 %>)<br />
       <% unless e.comments.blank? %><em><%=h e.comments %></em><% end %>
     <% elsif e.is_a? Changeset %>
       <%= e.created_on.strftime("%H:%M") %> <%=l(:label_revision)%> <%= link_to h(e.revision), :controller => 'repositories', :action => 'revision', :id => @project, :rev => e.revision %><br />

app/views/wiki/diff.rhtml

@@ -0,0 +1,19 @@
+<div class="contextual">
+<%= link_to(l(:button_edit), {:action => 'edit', :page => @page.title}, :class => 'icon icon-edit') %>
+<%= link_to(l(:label_history), {:action => 'history', :page => @page.title}, :class => 'icon icon-history') %>
+<%= link_to(l(:label_page_index), {:action => 'special', :page => 'Page_index'}, :class => 'icon icon-index') %>
+</div>
+
+<h2><%= @page.pretty_title %></h2>
+
+<p>
+<%= l(:label_version) %> <%= link_to @diff.content_from.version, :action => 'index', :page => @page.title, :version => @diff.content_from.version %>
+<em>(<%= @diff.content_from.author ? @diff.content_from.author.name : "anonyme" %>, <%= format_time(@diff.content_from.updated_on) %>)</em>
+&#8594;
+<%= l(:label_version) %> <%= link_to @diff.content_to.version, :action => 'index', :page => @page.title, :version => @diff.content_to.version %>/<%= @page.content.version %>
+<em>(<%= @diff.content_to.author ? @diff.content_to.author.name : "anonyme" %>, <%= format_time(@diff.content_to.updated_on) %>)</em>
+</p>
+
+<hr />
+
+<%= html_diff(@diff) %>

app/views/wiki/history.rhtml

@@ -6,26 +6,33 @@
 
 <h3><%= l(:label_history) %></h3>
 
+<% form_tag({:action => "diff"}, :method => :get) do %>
 <table class="list">
 <thead><tr>
     <th>#</th>
+    <th></th>
+    <th></th>    
     <th><%= l(:field_updated_on) %></th>
     <th><%= l(:field_author) %></th>
     <th><%= l(:field_comments) %></th>
 </tr></thead>
 <tbody>
+<% show_diff = @versions.size > 1 %>
+<% line_num = 1 %>
 <% @versions.each do |ver| %>
 <tr class="<%= cycle("odd", "even") %>">
     <th align="center"><%= link_to ver.version, :action => 'index', :page => @page.title, :version => ver.version %></th>
+    <td align="center" width="1%"><%= radio_button_tag('version', ver.version, (line_num==1), :id => "cb-#{line_num}", :onclick => "$('cbto-#{line_num+1}').checked=true;") if show_diff && (line_num < @versions.size) %></td>
+    <td align="center" width="1%"><%= radio_button_tag('version_from', ver.version, (line_num==2), :id => "cbto-#{line_num}", :onclick => "if ($('cb-#{line_num}').checked==true || $('version_from').value > #{ver.version}) {$('cb-#{line_num-1}').checked=true;}") if show_diff && (line_num > 1) %></td>
     <td align="center"><%= format_time(ver.updated_on) %></td>
     <td><em><%= ver.author ? ver.author.name : "anonyme" %></em></td>
     <td><%=h ver.comments %></td>
 </tr>
+<% line_num += 1 %>
 <% end %>
 </tbody>
 </table>
-
+<%= submit_tag l(:label_view_diff), :class => 'small' %>
-<p><%= pagination_links_full @version_pages, :page_param => :p %>
+<%= pagination_links_full @version_pages, :page_param => :p %>
-[ <%= @version_pages.current.first_item %> - <%= @version_pages.current.last_item %> / <%= @version_count %> ]</p>
+[ <%= @version_pages.current.first_item %> - <%= @version_pages.current.last_item %> / <%= @version_count %> ]
-
+<% end %>
-<p><%= link_to l(:button_back), :action => 'index', :page => @page.title %></p>

app/views/wiki/show.rhtml

@@ -9,7 +9,8 @@
 <% if @content.version != @page.content.version %>
     <p>    
     <%= link_to(('&#171; ' + l(:label_previous)), :action => 'index', :page => @page.title, :version => (@content.version - 1)) + " - " if @content.version > 1 %>
-    <%= "#{l(:label_version)} #{@content.version}/#{@page.content.version}"  %> - 
+    <%= "#{l(:label_version)} #{@content.version}/#{@page.content.version}" %>
+    <%= '(' + link_to('diff', :controller => 'wiki', :action => 'diff', :page => @page.title, :version => @content.version) + ')' if @content.version > 1 %> - 
     <%= link_to((l(:label_next) + ' &#187;'), :action => 'index', :page => @page.title, :version => (@content.version + 1)) + " - " if @content.version < @page.content.version %>
     <%= link_to(l(:label_current_version), :action => 'index', :page => @page.title) %>
     <br />

lib/diff.rb

@@ -0,0 +1,280 @@
+class Diff
+
+  VERSION = 0.3
+
+  def Diff.lcs(a, b)
+    astart = 0
+    bstart = 0
+    afinish = a.length-1
+    bfinish = b.length-1
+    mvector = []
+    
+    # First we prune off any common elements at the beginning
+    while (astart <= afinish && bstart <= afinish && a[astart] == b[bstart])
+      mvector[astart] = bstart
+      astart += 1
+      bstart += 1
+    end
+    
+    # now the end
+    while (astart <= afinish && bstart <= bfinish && a[afinish] == b[bfinish])
+      mvector[afinish] = bfinish
+      afinish -= 1
+      bfinish -= 1
+    end
+
+    bmatches = b.reverse_hash(bstart..bfinish)
+    thresh = []
+    links = []
+    
+    (astart..afinish).each { |aindex|
+      aelem = a[aindex]
+      next unless bmatches.has_key? aelem
+      k = nil
+      bmatches[aelem].reverse.each { |bindex|
+	if k && (thresh[k] > bindex) && (thresh[k-1] < bindex)
+	  thresh[k] = bindex
+	else
+	  k = thresh.replacenextlarger(bindex, k)
+	end
+	links[k] = [ (k==0) ? nil : links[k-1], aindex, bindex ] if k
+      }
+    }
+
+    if !thresh.empty?
+      link = links[thresh.length-1]
+      while link
+	mvector[link[1]] = link[2]
+	link = link[0]
+      end
+    end
+
+    return mvector
+  end
+
+  def makediff(a, b)
+    mvector = Diff.lcs(a, b)
+    ai = bi = 0
+    while ai < mvector.length
+      bline = mvector[ai]
+      if bline
+	while bi < bline
+	  discardb(bi, b[bi])
+	  bi += 1
+	end
+	match(ai, bi)
+	bi += 1
+      else
+	discarda(ai, a[ai])
+      end
+      ai += 1
+    end
+    while ai < a.length
+      discarda(ai, a[ai])
+      ai += 1
+    end
+    while bi < b.length
+      discardb(bi, b[bi])
+      bi += 1
+    end
+    match(ai, bi)
+    1
+  end
+
+  def compactdiffs
+    diffs = []
+    @diffs.each { |df|
+      i = 0
+      curdiff = []
+      while i < df.length
+	whot = df[i][0]
+	s = @isstring ? df[i][2].chr : [df[i][2]]
+	p = df[i][1]
+	last = df[i][1]
+	i += 1
+	while df[i] && df[i][0] == whot && df[i][1] == last+1
+	  s << df[i][2]
+	  last  = df[i][1]
+	  i += 1
+	end
+	curdiff.push [whot, p, s]
+      end
+      diffs.push curdiff
+    }
+    return diffs
+  end
+
+  attr_reader :diffs, :difftype
+
+  def initialize(diffs_or_a, b = nil, isstring = nil)
+    if b.nil?
+      @diffs = diffs_or_a
+      @isstring = isstring
+    else
+      @diffs = []
+      @curdiffs = []
+      makediff(diffs_or_a, b)
+      @difftype = diffs_or_a.class
+    end
+  end
+  
+  def match(ai, bi)
+    @diffs.push @curdiffs unless @curdiffs.empty?
+    @curdiffs = []
+  end
+
+  def discarda(i, elem)
+    @curdiffs.push ['-', i, elem]
+  end
+
+  def discardb(i, elem)
+    @curdiffs.push ['+', i, elem]
+  end
+
+  def compact
+    return Diff.new(compactdiffs)
+  end
+
+  def compact!
+    @diffs = compactdiffs
+  end
+
+  def inspect
+    @diffs.inspect
+  end
+
+end
+
+module Diffable
+  def diff(b)
+    Diff.new(self, b)
+  end
+
+  # Create a hash that maps elements of the array to arrays of indices
+  # where the elements are found.
+
+  def reverse_hash(range = (0...self.length))
+    revmap = {}
+    range.each { |i|
+      elem = self[i]
+      if revmap.has_key? elem
+	revmap[elem].push i
+      else
+	revmap[elem] = [i]
+      end
+    }
+    return revmap
+  end
+
+  def replacenextlarger(value, high = nil)
+    high ||= self.length
+    if self.empty? || value > self[-1]
+      push value
+      return high
+    end
+    # binary search for replacement point
+    low = 0
+    while low < high
+      index = (high+low)/2
+      found = self[index]
+      return nil if value == found
+      if value > found
+	low = index + 1
+      else
+	high = index
+      end
+    end
+
+    self[low] = value
+    # $stderr << "replace #{value} : 0/#{low}/#{init_high} (#{steps} steps) (#{init_high-low} off )\n"
+    # $stderr.puts self.inspect
+    #gets
+    #p length - low
+    return low
+  end
+
+  def patch(diff)
+    newary = nil
+    if diff.difftype == String
+      newary = diff.difftype.new('')
+    else
+      newary = diff.difftype.new
+    end
+    ai = 0
+    bi = 0
+    diff.diffs.each { |d|
+      d.each { |mod|
+	case mod[0]
+	when '-'
+	  while ai < mod[1]
+	    newary << self[ai]
+	    ai += 1
+	    bi += 1
+	  end
+	  ai += 1
+	when '+'
+	  while bi < mod[1]
+	    newary << self[ai]
+	    ai += 1
+	    bi += 1
+	  end
+	  newary << mod[2]
+	  bi += 1
+	else
+	  raise "Unknown diff action"
+	end
+      }
+    }
+    while ai < self.length
+      newary << self[ai]
+      ai += 1
+      bi += 1
+    end
+    return newary
+  end
+end
+
+class Array
+  include Diffable
+end
+
+class String
+  include Diffable
+end
+
+=begin
+= Diff
+(({diff.rb})) - computes the differences between two arrays or
+strings. Copyright (C) 2001 Lars Christensen
+
+== Synopsis
+
+    diff = Diff.new(a, b)
+    b = a.patch(diff)
+
+== Class Diff
+=== Class Methods
+--- Diff.new(a, b)
+--- a.diff(b)
+      Creates a Diff object which represent the differences between
+      ((|a|)) and ((|b|)). ((|a|)) and ((|b|)) can be either be arrays
+      of any objects, strings, or object of any class that include
+      module ((|Diffable|))
+
+== Module Diffable
+The module ((|Diffable|)) is intended to be included in any class for
+which differences are to be computed. Diffable is included into String
+and Array when (({diff.rb})) is (({require}))'d.
+
+Classes including Diffable should implement (({[]})) to get element at
+integer indices, (({<<})) to append elements to the object and
+(({ClassName#new})) should accept 0 arguments to create a new empty
+object.
+
+=== Instance Methods
+--- Diffable#patch(diff)
+      Applies the differences from ((|diff|)) to the object ((|obj|))
+      and return the result. ((|obj|)) is not changed. ((|obj|)) and
+      can be either an array or a string, but must match the object
+      from which the ((|diff|)) was created.
+=end

public/stylesheets/application.css

@@ -647,6 +647,14 @@ div.wiki img {
     margin: 6px;
 }
 
+.diff_out{
+  background: #fcc;
+}
+
+.diff_in{
+  background: #cfc;
+}
+
 #preview .preview { background: #fafbfc url(../images/draft.png); }
 
 #ajax-indicator {

public/stylesheets/scm.css

@@ -26,11 +26,3 @@ table.list thead th.list-filename {
 	font-weight: bolder;
 	text-align: left;
 }
-
-.diff_out{
-  background: #fdd;
-}
-
-.diff_in{
-  background: #dfd;
-}