jquery/jquery.schedule.js
/*
** jquery.schedule.js -- jQuery plugin for scheduled/deferred actions
** Copyright (c) 2007 Ralf S. Engelschall <rse@engelschall.com>
** Licensed under GPL <http://www.gnu.org/licenses/gpl.txt>
**
** $LastChangedDate$
** $LastChangedRevision$
*/
/*
* <div id="button">TEST BUTTON</div>
* <div id="test"></div>
*
* <script type="text/javascript">
* $(document).ready(
* function(){
* $('#button').click(function () {
* $(this).css("color", "blue").schedule(2000, function (x) {
* $(this).css("color", "red");
* $("#test").html("test: x = " + x);
* }, 42);
* });
* });
* </script>
*/
(function($) {
/* object constructor */
$.scheduler = function () {
this.bucket = {};
return;
};
/* object methods */
$.scheduler.prototype = {
/* schedule a task */
schedule: function () {
/* schedule context with default parameters */
var ctx = {
"id": null, /* unique identifier of high-level schedule */
"time": 1000, /* time in milliseconds after which the task is run */
"repeat": false, /* whether schedule should be automatically repeated */
"protect": false, /* whether schedule should be protected from double scheduling */
"obj": null, /* function context object ("this") */
"func": function(){}, /* function to call */
"args": [] /* function arguments to pass */
};
/* helper function: portable checking whether something is a function */
function _isfn (fn) {
return (
!!fn
&& typeof fn != "string"
&& typeof fn[0] == "undefined"
&& RegExp("function", "i").test(fn + "")
);
};
/* parse arguments into context parameters (part 1/4):
detect an override object (special case to support jQuery method) */
var i = 0;
var override = false;
if (typeof arguments[i] == "object" && arguments.length > 1) {
override = true;
i++;
}
/* parse arguments into context parameters (part 2/4):
support the flexible way of an associated array */
if (typeof arguments[i] == "object") {
for (var option in arguments[i])
if (typeof ctx[option] != "undefined")
ctx[option] = arguments[i][option];
i++;
}
/* parse arguments into context parameters (part 3/4):
support: schedule([time [, repeat], ]{{obj, methodname} | func}[, arg, ...]); */
if ( typeof arguments[i] == "number"
|| ( typeof arguments[i] == "string"
&& arguments[i].match(RegExp("^[0-9]+[smhdw]$"))))
ctx["time"] = arguments[i++];
if (typeof arguments[i] == "boolean")
ctx["repeat"] = arguments[i++];
if (typeof arguments[i] == "boolean")
ctx["protect"] = arguments[i++];
if ( typeof arguments[i] == "object"
&& typeof arguments[i+1] == "string"
&& _isfn(arguments[i][arguments[i+1]])) {
ctx["obj"] = arguments[i++];
ctx["func"] = arguments[i++];
}
else if ( typeof arguments[i] != "undefined"
&& ( _isfn(arguments[i])
|| typeof arguments[i] == "string"))
ctx["func"] = arguments[i++];
while (typeof arguments[i] != "undefined")
ctx["args"].push(arguments[i++]);
/* parse arguments into context parameters (part 4/4):
apply parameters from override object */
if (override) {
if (typeof arguments[1] == "object") {
for (var option in arguments[0])
if ( typeof ctx[option] != "undefined"
&& typeof arguments[1][option] == "undefined")
ctx[option] = arguments[0][option];
}
else {
for (var option in arguments[0])
if (typeof ctx[option] != "undefined")
ctx[option] = arguments[0][option];
}
i++;
}
/* annotate context with internals */
ctx["_scheduler"] = this; /* internal: back-reference to scheduler object */
ctx["_handle"] = null; /* internal: unique handle of low-level task */
/* determine time value in milliseconds */
var match = String(ctx["time"]).match(RegExp("^([0-9]+)([smhdw])$"));
if (match && match[0] != "undefined" && match[1] != "undefined")
ctx["time"] = String(parseInt(match[1]) *
{ s: 1000, m: 1000*60, h: 1000*60*60,
d: 1000*60*60*24, w: 1000*60*60*24*7 }[match[2]]);
/* determine unique identifier of task */
if (ctx["id"] == null)
ctx["id"] = ( String(ctx["repeat"]) + ":"
+ String(ctx["protect"]) + ":"
+ String(ctx["time"]) + ":"
+ String(ctx["obj"]) + ":"
+ String(ctx["func"]) + ":"
+ String(ctx["args"]) );
/* optionally protect from duplicate calls */
if (ctx["protect"])
if (typeof this.bucket[ctx["id"]] != "undefined")
return this.bucket[ctx["id"]];
/* support execution of methods by name and arbitrary scripts */
if (!_isfn(ctx["func"])) {
if ( ctx["obj"] != null
&& typeof ctx["obj"] == "object"
&& typeof ctx["func"] == "string"
&& _isfn(ctx["obj"][ctx["func"]]))
/* method by name */
ctx["func"] = ctx["obj"][ctx["func"]];
else
/* arbitrary script */
ctx["func"] = eval("function () { " + ctx["func"] + " }");
}
/* pass-through to internal scheduling operation */
ctx["_handle"] = this._schedule(ctx);
/* store context into bucket of scheduler object */
this.bucket[ctx["id"]] = ctx;
/* return context */
return ctx;
},
/* re-schedule a task */
reschedule: function (ctx) {
if (typeof ctx == "string")
ctx = this.bucket[ctx];
/* pass-through to internal scheduling operation */
ctx["_handle"] = this._schedule(ctx);
/* return context */
return ctx;
},
/* internal scheduling operation */
_schedule: function (ctx) {
/* closure to act as the call trampoline function */
var trampoline = function () {
/* jump into function */
var obj = (ctx["obj"] != null ? ctx["obj"] : ctx);
(ctx["func"]).apply(obj, ctx["args"]);
/* either repeat scheduling and keep in bucket or
just stop scheduling and delete from scheduler bucket */
if ( /* not cancelled from inside... */
typeof (ctx["_scheduler"]).bucket[ctx["id"]] != "undefined"
&& /* ...and repeating requested */
ctx["repeat"])
(ctx["_scheduler"])._schedule(ctx);
else
delete (ctx["_scheduler"]).bucket[ctx["id"]];
};
/* schedule task and return handle */
return setTimeout(trampoline, ctx["time"]);
},
/* cancel a scheduled task */
cancel: function (ctx) {
if (typeof ctx == "string")
ctx = this.bucket[ctx];
/* cancel scheduled task */
if (typeof ctx == "object") {
clearTimeout(ctx["_handle"]);
delete this.bucket[ctx["id"]];
}
}
};
/* integrate a global instance of the scheduler into the global jQuery object */
$.extend({
scheduler$: new $.scheduler(),
schedule: function () { return $.scheduler$.schedule.apply ($.scheduler$, arguments) },
reschedule: function () { return $.scheduler$.reschedule.apply($.scheduler$, arguments) },
cancel: function () { return $.scheduler$.cancel.apply ($.scheduler$, arguments) }
});
/* integrate scheduling convinience method into all jQuery objects */
$.fn.extend({
schedule: function () {
var a = [ {} ];
for (var i = 0; i < arguments.length; i++)
a.push(arguments[i]);
return this.each(function () {
a[0] = { "id": this, "obj": this };
return $.schedule.apply($, a);
});
}
});
})(jQuery);
![Ralf S. Engelschall's Train of Thoughts [.org]](/repo/theme/tot-img/tot-2-CUT-typo-T.png)