SortHelper refactoring:

* multiple columns sort feature (#2871)
* CSS classes instead of an image tag to reflect the state of the column
* examples fixed (#2945)

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@2571 e93f8b46-1217-0410-a6f0-8f06a7374b81

1 files changed, 95 insertions, 61 deletions

diff --git a/app/helpers/sort_helper.rb b/app/helpers/sort_helper.rb
index f5e9bb494..d4d8f721a 100644
--- a/app/helpers/sort_helper.rb
+++ b/app/helpers/sort_helper.rb
@@ -1,11 +1,12 @@
 # Helpers to sort tables using clickable column headers.
 #
 # Author:  Stuart Rackham <srackham@methods.co.nz>, March 2005.
+#          Jean-Philippe Lang, 2009
 # License: This source code is released under the MIT license.
 #
 # - Consecutive clicks toggle the column's sort order.
 # - Sort state is maintained by a session hash entry.
-# - Icon image identifies sort column and state.
+# - CSS classes identify sort column and state.
 # - Typically used in conjunction with the Pagination module.
 #
 # Example code snippets:
@@ -17,7 +18,7 @@
 # 
 #   def list
 #     sort_init 'last_name'
-#     sort_update
+#     sort_update %w(first_name, last_name)
 #     @items = Contact.find_all nil, sort_clause
 #   end
 # 
@@ -28,7 +29,7 @@
 # 
 #   def list
 #     sort_init 'last_name'
-#     sort_update
+#     sort_update %w(first_name, last_name)
 #     @contact_pages, @items = paginate :contacts,
 #       :order_by => sort_clause,
 #       :per_page => 10
@@ -45,88 +46,133 @@
 #     </tr>
 #   </thead>
 #
-# - The ascending and descending sort icon images are sort_asc.png and
-#   sort_desc.png and reside in the application's images directory.
-# - Introduces instance variables: @sort_name, @sort_default.
-# - Introduces params :sort_key and :sort_order.
+# - Introduces instance variables: @sort_default, @sort_criteria
+# - Introduces param :sort
 #
+
 module SortHelper
+  class SortCriteria
+    
+    def initialize
+      @criteria = []
+    end
+    
+    def available_criteria=(criteria)
+      unless criteria.is_a?(Hash)
+        criteria = criteria.inject({}) {|h,k| h[k] = k; h}
+      end
+      @available_criteria = criteria
+    end
+    
+    def from_param(param)
+      @criteria = param.to_s.split(',').collect {|s| s.split(':')[0..1]}
+      normalize!
+    end
+    
+    def to_param
+      @criteria.collect {|k,o| k + (o ? '' : ':desc')}.join(',')
+    end
+    
+    def to_sql
+      sql = @criteria.collect do |k,o|
+        if s = @available_criteria[k]
+          (o ? s.to_a : s.to_a.collect {|c| "#{c} DESC"}).join(', ')
+        end
+      end.compact.join(', ')
+      sql.blank? ? nil : sql
+    end
+    
+    def add!(key, asc)
+      @criteria.delete_if {|k,o| k == key}
+      @criteria = [[key, asc]] + @criteria
+      normalize!
+    end
+    
+    def add(*args)
+      r = self.class.new.from_param(to_param)
+      r.add!(*args)
+      r
+    end
+    
+    def first_key
+      @criteria.first && @criteria.first.first
+    end
+    
+    def first_asc?
+      @criteria.first && @criteria.first.last
+    end
+    
+    private
+    
+    def normalize!
+      @criteria = @criteria.collect {|s| [s.first, (s.last == false || s.last == 'desc') ? false : true]}
+      @criteria = @criteria.select {|k,o| @available_criteria.has_key?(k)} if @available_criteria
+      @criteria.slice!(3)
+      self
+    end
+  end
 
   # Initializes the default sort column (default_key) and sort order
   # (default_order).
   #
   # - default_key is a column attribute name.
   # - default_order is 'asc' or 'desc'.
-  # - name is the name of the session hash entry that stores the sort state,
-  #   defaults to '<controller_name>_sort'.
   #
-  def sort_init(default_key, default_order='asc', name=nil)
-    @sort_name = name || params[:controller] + params[:action] + '_sort'
-    @sort_default = {:key => default_key, :order => default_order}
+  def sort_init(default_key, default_order='asc')
+    @sort_default = "#{default_key}:#{default_order}"
   end
 
   # Updates the sort state. Call this in the controller prior to calling
   # sort_clause.
-  # sort_keys can be either an array or a hash of allowed keys
-  def sort_update(sort_keys)
-    sort_key = params[:sort_key]
-    sort_key = nil unless (sort_keys.is_a?(Array) ? sort_keys.include?(sort_key) : sort_keys[sort_key])
-
-    sort_order = (params[:sort_order] == 'desc' ? 'DESC' : 'ASC')
-    
-    if sort_key
-      sort = {:key => sort_key, :order => sort_order}
-    elsif session[@sort_name]
-      sort = session[@sort_name]   # Previous sort.
-    else
-      sort = @sort_default
-    end
-    session[@sort_name] = sort
+  # - criteria can be either an array or a hash of allowed keys
+  #
+  def sort_update(criteria)
+    sort_name = controller_name + '_' + action_name + '_sort'
     
-    sort_column = (sort_keys.is_a?(Hash) ? sort_keys[sort[:key]] : sort[:key])
-    @sort_clause = (sort_column.blank? ? nil : [sort_column].flatten.collect {|s| "#{s} #{sort[:order]}"}.join(','))
+    @sort_criteria = SortCriteria.new
+    @sort_criteria.available_criteria = criteria
+    @sort_criteria.from_param(params[:sort] || session[sort_name] || @sort_default)
+    session[sort_name] = @sort_criteria.to_param
   end
 
   # Returns an SQL sort clause corresponding to the current sort state.
   # Use this to sort the controller's table items collection.
   #
   def sort_clause()
-    @sort_clause
+    @sort_criteria.to_sql
   end
 
   # Returns a link which sorts by the named column.
   #
   # - column is the name of an attribute in the sorted record collection.
-  # - The optional caption explicitly specifies the displayed link text.
-  # - A sort icon image is positioned to the right of the sort link.
+  # - the optional caption explicitly specifies the displayed link text.
+  # - 2 CSS classes reflect the state of the link: sort and asc or desc
   #
   def sort_link(column, caption, default_order)
-    key, order = session[@sort_name][:key], session[@sort_name][:order]
-    if key == column
-      if order.downcase == 'asc'
-        icon = 'sort_asc.png'
+    css, order = nil, default_order
+    
+    if column.to_s == @sort_criteria.first_key
+      if @sort_criteria.first_asc?
+        css = 'sort asc'
         order = 'desc'
       else
-        icon = 'sort_desc.png'
+        css = 'sort desc'
         order = 'asc'
       end
-    else
-      icon = nil
-      order = default_order
     end
-    caption = titleize(Inflector::humanize(column)) unless caption
+    caption = column.to_s.humanize unless caption
     
-    sort_options = { :sort_key => column, :sort_order => order }
+    sort_options = { :sort => @sort_criteria.add(column.to_s, order).to_param }
     # don't reuse params if filters are present
     url_options = params.has_key?(:set_filter) ? sort_options : params.merge(sort_options)
     
-    # Add project_id to url_options
+     # Add project_id to url_options
     url_options = url_options.merge(:project_id => params[:project_id]) if params.has_key?(:project_id)
-    
+
     link_to_remote(caption,
                   {:update => "content", :url => url_options, :method => :get},
-                  {:href => url_for(url_options)}) +
-    (icon ? nbsp(2) + image_tag(icon) : '')
+                  {:href => url_for(url_options),
+                   :class => css})
   end
 
   # Returns a table header <th> tag with a sort link for the named column
@@ -150,22 +196,10 @@ module SortHelper
   #   </th>
   #
   def sort_header_tag(column, options = {})
-    caption = options.delete(:caption) || titleize(Inflector::humanize(column))
+    caption = options.delete(:caption) || column.to_s.humanize
     default_order = options.delete(:default_order) || 'asc'
-    options[:title]= l(:label_sort_by, "\"#{caption}\"") unless options[:title]
+    options[:title] = l(:label_sort_by, "\"#{caption}\"") unless options[:title]
     content_tag('th', sort_link(column, caption, default_order), options)
   end
-
-  private
-
-    # Return n non-breaking spaces.
-    def nbsp(n)
-      '&nbsp;' * n
-    end
-
-    # Return capitalized title.
-    def titleize(title)
-      title.split.map {|w| w.capitalize }.join(' ')
-    end
-
 end
+