Please note that this has been superseded by the calendar_helper and associated code in BoilerPlate. In particular the clumsy RequestProcessor is no longer needed.

----

by MichaelSchuerig

These helper methods are intended to make the use of the DHTML/JavaScript calendar from http://www.dynarch.com/projects/calendar/ as easy as possible. See also RequestPreprocessor.

Lest I forget it. The calendar has a bug that keeps it currently from working correctly in "flat" (in-page) mode. Please have a look at this "patch":http://sourceforge.net/tracker/index.php?func=detail&aid=1196694&group_id=75569&atid=544287

--MichaelSchuerig

<pre>
<code>
# The Calendar Helper methods create HTML code for different variants of the
# Dynarch DHTML/JavaScript Calendar.
#
# Author: Michael Schuerig, michael@schuerig.de, 2005
# Free for all uses. No warranty or anything. Comments welcome.
#
# == Prerequisites
#
# Get the latest version of the calendar package from
# http://www.dynarch.com/projects/calendar/
#
# == Installation
#
# You need to install at least these files from the jscalendar distribution
# in the +public+ directory of your project
#
#  public/
#      images/
#          calendar.gif
#      javascripts/
#          calendar.js
#          calendar-setup.js
#          calendar-en.js
#      stylesheets/
#          calendar-system.css
#
# Then, in the head section of your page templates, possibly in a layout,
# include the necessary files like this:
#
#  <%= stylesheet_link_tag 'calendar-system.css' %>
#  <%= javascript_include_tag 'calendar', 'calendar-en', 'calendar-setup' %>
#
# In controllers of views that use calendars for date editing, you have to
# install a +RequestPreprocessor+ that parses the date string into a +Date+
# object.
#
#  class SomethingController < ApplicationController
#    before_filter(
#      RequestPreprocessor.apply_to('person.birthday') { |d|
#        d && Date.strptime(d, '%c') },
#      :only => [ :create, :update ])
#
# == Common Options
#
# The +html_options+ argument is passed through mostly verbatim to the
# +text_field+, +hidden_field+, and +image_tag+ helpers.
# The +title+ attributes are handled specially, +field_title+ and
# +button_title+ appear only on the respective elements as +title+.
#
# The +calendar_options+ argument accepts all the options of the
# JavaScript +Calendar.setup+ method defined in +calendar-setup.js+.
#
#
module CalendarHelper

  # Returns HTML code for a calendar that pops up when the calendar image is clicked.
  #
  # _Example:_
  #
  #  <%= popup_calendar 'person', 'birthday',
  #        { :class => 'date', :field_title => 'Birthday', :button_title => 'Show calendar' },
  #        { :ifFormat => '%c', :firstDay => 1, :range => [1920, 1990],
  #  	    :step => 1, :showOthers => true, :cache => true }
  #  %>
  #
  def popup_calendar(object, method, html_options = {}, calendar_options = {})
    _calendar(object, method, false, true, html_options, calendar_options)
  end

  # Returns HTML code for a flat calendar.
  #
  # _Example:_
  #
  #  <%= calendar 'person', 'birthday',
  #        { :class => 'date' },
  #        { :ifFormat => '%c', :firstDay => 1, :range => [1920, 1990],
  #  	    :step => 1, :showOthers => true }
  #  %>
  #
  def calendar(object, method, html_options = {}, calendar_options = {})
    _calendar(object, method, false, false, html_options, calendar_options)
  end

  # Returns HTML code for a date field and calendar that pops up when the
  # calendar image is clicked.
  #
  # _Example:_
  #
  #  <%= calendar_field 'person', 'birthday',
  #        { :class => 'date', :field_title => 'Birthday', :button_title => 'Show calendar' },
  #        { :ifFormat => '%c', :firstDay => 1, :range => [1920, 1990],
  #  	    :step => 1, :showOthers => true, :cache => true }
  #  %>
  #
  def calendar_field(object, method, html_options = {}, calendar_options = {})
    _calendar(object, method, true, true, html_options, calendar_options)
  end

  private

  def _calendar(object, method, show_field = true, popup = true, html_options = {}, calendar_options = {})
    button_image = html_options[:button_image] || 'calendar'
    date = value(object, method)

    input_field_id = "#{object}_#{method}"
    calendar_id = "#{object}_#{method}_calendar"

    field_options = html_options.dup
    add_defaults(field_options,
      :value => date && date.strftime(calendar_options[:ifFormat] || '%c'),
      :size => 12
    )
    rename_option(field_options, :field_title, :title)
    remove_option(field_options, :button_title)
    field = if show_field
        text_field(object, method, field_options)
      else
        hidden_field(object, method, field_options)
      end

    if popup
      button_options = html_options.dup
      add_mandatories(button_options, :id => calendar_id)
      rename_option(button_options, :button_title, :title)
      remove_option(button_options, :field_title)
      calendar = image_tag(button_image, button_options)
    else
      calendar = "<div id=\"#{calendar_id}\" class=\"#{html_options[:class]}\"></div>"
    end

    calendar_setup = calendar_options.dup
    add_mandatories(calendar_setup,
      :inputField => input_field_id,
      (popup ? :button : :flat) => calendar_id
    )

<<END
#{field}
#{calendar}
<script type="text/javascript">
  Calendar.setup({ #{format_js_hash(calendar_setup)} })
</script>
END
  end

  def value(object_name, method_name)
    if object = self.instance_variable_get("@#{object_name}")
      object.send(method_name)
    else
      nil
    end
  end

  def add_mandatories(options, mandatories)
    options.merge!(mandatories)
  end

  def add_defaults(options, defaults)
    options.merge!(defaults) { |key, old_val, new_val| old_val }
  end

  def remove_option(options, key)
    options.delete(key)
  end

  def rename_option(options, old_key, new_key)
    if options.has_key?(old_key)
      options[new_key] = options.delete(old_key)
    end
    options
  end

  def format_js_hash(options)
    options.collect { |key,value| key.to_s + ':' + value.inspect }.join(',')
  end

end
</code>
</pre>

category:Helper