view app/helpers/sort_helper.rb @ 1082:997f6d7738f7 bug_531

In repo controller entry action, show the page for the file even if it's binary (so user still has access to history etc links). This makes it possible to use the entry action as the default when a file is clicked on

# encoding: utf-8
#
# Helpers to sort tables using clickable column headers.
#
# Author:  Stuart Rackham <[e-mail]>, 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.
# - CSS classes identify sort column and state.
# - Typically used in conjunction with the Pagination module.
#
# Example code snippets:
#
# Controller:
#
#   helper :sort
#   include SortHelper
#
#   def list
#     sort_init 'last_name'
#     sort_update %w(first_name last_name)
#     @items = Contact.find_all nil, sort_clause
#   end
#
# Controller (using Pagination module):
#
#   helper :sort
#   include SortHelper
#
#   def list
#     sort_init 'last_name'
#     sort_update %w(first_name last_name)
#     @contact_pages, @items = paginate :contacts,
#       :order_by => sort_clause,
#       :per_page => 10
#   end
#
# View (table header in list.rhtml):
#
#   <thead>
#     <tr>
#       <%= sort_header_tag('id', :title => 'Sort by contact ID') %>
#       <%= sort_header_tag('last_name', :caption => 'Name') %>
#       <%= sort_header_tag('phone') %>
#       <%= sort_header_tag('address', :width => 200) %>
#     </tr>
#   </thead>
#
# - 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 criteria=(arg)
      @criteria = arg
      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| append_desc(c)}).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

    def empty?
      @criteria.empty?
    end

    private

    def normalize!
      @criteria ||= []
      @criteria = @criteria.collect {|s| s = s.to_a; [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

    # Appends DESC to the sort criterion unless it has a fixed order
    def append_desc(criterion)
      if criterion =~ / (asc|desc)$/i
        criterion
      else
        "#{criterion} DESC"
      end
    end
  end

  def sort_name
    controller_name + '_' + action_name + '_sort'
  end

  # Initializes the default sort.
  # Examples:
  #
  #   sort_init 'name'
  #   sort_init 'id', 'desc'
  #   sort_init ['name', ['id', 'desc']]
  #   sort_init [['name', 'desc'], ['id', 'desc']]
  #
  def sort_init(*args)
    case args.size
    when 1
      @sort_default = args.first.is_a?(Array) ? args.first : [[args.first]]
    when 2
      @sort_default = [[args.first, args.last]]
    else
      raise ArgumentError
    end
  end

  # Updates the sort state. Call this in the controller prior to calling
  # sort_clause.
  # - criteria can be either an array or a hash of allowed keys
  #
  def sort_update(criteria)
    @sort_criteria = SortCriteria.new
    @sort_criteria.available_criteria = criteria
    @sort_criteria.from_param(params[:sort] || session[sort_name])
    @sort_criteria.criteria = @sort_default if @sort_criteria.empty?
    session[sort_name] = @sort_criteria.to_param
  end

  # Clears the sort criteria session data
  #
  def sort_clear
    session[sort_name] = nil
  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_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.
  # - 2 CSS classes reflect the state of the link: sort and asc or desc
  #
  def sort_link(column, caption, default_order)
    css, order = nil, default_order

    if column.to_s == @sort_criteria.first_key
      if @sort_criteria.first_asc?
        css = 'sort asc'
        order = 'desc'
      else
        css = 'sort desc'
        order = 'asc'
      end
    end
    caption = column.to_s.humanize unless caption

    sort_options = { :sort => @sort_criteria.add(column.to_s, order).to_param }
    url_options = params.merge(sort_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_content_update(h(caption), url_options, :class => css)
  end

  # Returns a table header <th> tag with a sort link for the named column
  # attribute.
  #
  # Options:
  #   :caption     The displayed link name (defaults to titleized column name).
  #   :title       The tag's 'title' attribute (defaults to 'Sort by :caption').
  #
  # Other options hash entries generate additional table header tag attributes.
  #
  # Example:
  #
  #   <%= sort_header_tag('id', :title => 'Sort by contact ID', :width => 40) %>
  #
  def sort_header_tag(column, options = {})
    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]
    content_tag('th', sort_link(column, caption, default_order), options)
  end
end