=head1 USE

The value for the C<date_select_text> keyword is the link text which will
popup a rather old fashioned Javascript based date picker.

For it to work, you must use C<Gantry::Plugins::Calendar> (but you don't have
to use it as a plugin).  Further, you must name your form and add this to its
C<extra_keys>:

    extra_keys
        javascript => `$self->calendar_month_js( 'your_form_name' )`;

Those steps are rather tedious, so tentmaker does them for you when
you enter a value for the C<date_select_text> keyword.

Our current best practice suggestion is to use a Javascript framework like
Yahoo's UI or JQuery.  Both of those, and many similar frameworks, have
more modern and usable date pickers along with a wealth of other gadgets.

=head1 EXAMPLE

To see an example, build:

    bigtop -c example.bigtop all

Change to the newly created Kids directory, start the app server, and add
a child.  When you press 'Select Date', a box should popup.  Click on a
date to fill in the field and close the popup.

To see the code, look in lib/Kids/GEN/Child.pm.  Note the use of the
Calendar plugin, the naming of the form, and the Javascript.