https://www.commabooks.com.tw/sites/all/modules/civicrm/packages/j…/plugins/jquery.chainedSelects.js?tlw1p7

1/**
2*    Chained Selects for jQuery 
3*    Copyright (C) 2008 Ziadin Givan www.CodeAssembly.com  
4*
5*    This program is free software: you can redistribute it and/or modify
6*    it under the terms of the GNU General Public License as published by
7*    the Free Software Foundation, either version 3 of the License, or
8*    (at your option) any later version.
9*
10*    This program is distributed in the hope that it will be useful,
11*    but WITHOUT ANY WARRANTY; without even the implied warranty of
12*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13*    GNU General Public License for more details.
14*
15*    You should have received a copy of the GNU General Public License
16*    along with this program.  If not, see http://www.gnu.org/licenses/
17*
18*    
19*   settings = { usePost : true, before:function() {}, after: function() {}, default: null, parameters : { parameter1 : 'value1', parameter2 : 'value2'} }	
20*   if usePost is true, then the form will use POST to pass the parameters to the target, otherwise will use GET
21*   "before" function is called before the ajax request and "after" function is called after the ajax request.
22*   If defaultValue is not null then the specified option will be selected.
23*   You can specify additional parameters to be sent to the the server in settings.parameters.
24*
25*/
26;(function($) {
27    
28jQuery.fn.chainSelect = function( target, url, settings ) 
29{
30  return this.each( function()
31  {
32	$(this).change( function( ) 
33	{
34		settings = $.extend(
35		{
36			after : null,
37			before : null,
38			usePost : false,
39			defaultValue : null,
40			parameters : {'_id' : $(this).attr('id'), '_name' : $(this).attr('name')}
41        } , settings);
42
43		settings.parameters._value =  $(this).val();
44
45		if (settings.before != null) 
46		{
47			settings.before( target );
48		}
49
50		ajaxCallback = function(data, textStatus) 
51		{
52			$(target).html(""); //clear old options
53			data = JSON.parse(data); //get json array
54                        if ( data != null ) {
55			    for (i = 0; i < data.length; i++) {
56				$(target).get(0).add(new Option(data[i].name, data[i].value), document.all ? i : null);
57			    }
58			} else {
59				$(target).get(0).add(new Option('- select a country -', 0), document.all ? i : null);
60			}
61
62			if (settings.defaultValue != null)
63			{
64				$(target).val(settings.defaultValue);//select default value
65			} else
66			{
67				$("option:first", target).attr( "selected", "selected" );//select first option
68			}
69
70			if (settings.after != null) 
71			{
72				settings.after(target);
73			}
74
75			$(target).change();//call next chain
76		};
77
78		if (settings.usePost == true)
79		{
80			$.post( url, settings.parameters, ajaxCallback );
81		} else
82		{
83			$.get( url, settings.parameters, ajaxCallback );
84		}
85	});
86  });
87};
88
89})(jQuery);