1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
# Helpers to sort tables using clickable column headers.
#
# Author: Stuart Rackham <srackham@methods.co.nz>, March 2005.
# 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.
# - Typically used in conjunction with the Pagination module.
#
# Example code snippets:
#
# Controller:
#
# helper :sort
# include SortHelper
#
# def list
# sort_init 'last_name'
# sort_update
# @items = Contact.find_all nil, sort_clause
# end
#
# Controller (using Pagination module):
#
# helper :sort
# include SortHelper
#
# def list
# sort_init 'last_name'
# sort_update
# @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>
#
# - 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.
#
module SortHelper
# 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}
end
# Updates the sort state. Call this in the controller prior to calling
# sort_clause.
#
def sort_update()
if @params[:sort_key]
sort = {:key => @params[:sort_key], :order => @params[:sort_order]}
elsif @session[@sort_name]
sort = @session[@sort_name] # Previous sort.
else
sort = @sort_default
end
@session[@sort_name] = sort
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()
@session[@sort_name][:key] + ' ' + @session[@sort_name][:order]
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.
#
def sort_link(column, caption=nil)
key, order = @session[@sort_name][:key], @session[@sort_name][:order]
if key == column
if order.downcase == 'asc'
icon = 'sort_asc'
order = 'desc'
else
icon = 'sort_desc'
order = 'asc'
end
else
icon = nil
order = 'desc' # changed for desc order by default
end
caption = titleize(Inflector::humanize(column)) unless caption
params = {:params => {:sort_key => column, :sort_order => order}}
link_to_remote(caption,
{:update => "content", :url => { :sort_key => column, :sort_order => order}},
{:href => url_for(:params => { :sort_key => column, :sort_order => order})}) +
(icon ? nbsp(2) + image_tag(icon) : '')
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) %>
#
# Renders:
#
# <th title="Sort by contact ID" width="40">
# <a href="/contact/list?sort_order=desc&sort_key=id">Id</a>
# <img alt="Sort_asc" src="/images/sort_asc.png" />
# </th>
#
def sort_header_tag(column, options = {})
if options[:caption]
caption = options[:caption]
options.delete(:caption)
else
caption = titleize(Inflector::humanize(column))
end
options[:title]= "Sort by #{caption}" unless options[:title]
content_tag('th', sort_link(column, caption), options)
end
private
# Return n non-breaking spaces.
def nbsp(n)
' ' * n
end
# Return capitalized title.
def titleize(title)
title.split.map {|w| w.capitalize }.join(' ')
end
end
|
