jQuery 计时器（jquery timers）简单应用

/**
 * jQuery.timers - Timer abstractions for jQuery
 * Written by Blair Mitchelmore (blair DOT mitchelmore AT gmail DOT com)
 * Licensed under the WTFPL (http://sam.zoy.org/wtfpl/).
 * Date: 2009/10/16
 *
 * @author Blair Mitchelmore
 * @version 1.2
 *
 **/

jQuery.fn.extend({
    everyTime: function(interval, label, fn, times) {
        return this.each(function() {
            jQuery.timer.add(this, interval, label, fn, times);
        });
    },
    oneTime: function(interval, label, fn) {
        return this.each(function() {
            jQuery.timer.add(this, interval, label, fn, 1);
        });
    },
    stopTime: function(label, fn) {
        return this.each(function() {
            jQuery.timer.remove(this, label, fn);
        });
    }
});

jQuery.extend({
    timer: {
        global: [],
        guid: 1,
        dataKey: "jQuery.timer",
        regex: /^([0-9]+(?:\.[0-9]*)?)\s*(.*s)?$/,
        powers: {
            // Yeah this is major overkill...
            'ms': 1,
            'cs': 10,
            'ds': 100,
            's': 1000,
            'das': 10000,
            'hs': 100000,
            'ks': 1000000
        },
        timeParse: function(value) {
            if (value == undefined || value == null)
                return null;
            var result = this.regex.exec(jQuery.trim(value.toString()));
            if (result[2]) {
                var num = parseFloat(result[1]);
                var mult = this.powers[result[2]] || 1;
                return num * mult;
            } else {
                return value;
            }
        },
        add: function(element, interval, label, fn, times) {
            var counter = 0;
            
            if (jQuery.isFunction(label)) {
                if (!times) 
                    times = fn;
                fn = label;
                label = interval;
            }
            
            interval = jQuery.timer.timeParse(interval);

            if (typeof interval != 'number' || isNaN(interval) || interval < 0)
                return;

            if (typeof times != 'number' || isNaN(times) || times < 0) 
                times = 0;
            
            times = times || 0;
            
            var timers = jQuery.data(element, this.dataKey) || jQuery.data(element, this.dataKey, {});
            
            if (!timers[label])
                timers[label] = {};
            
            fn.timerID = fn.timerID || this.guid++;
            
            var handler = function() {
                if ((++counter > times && times !== 0) || fn.call(element, counter) === false)
                    jQuery.timer.remove(element, label, fn);
            };
            
            handler.timerID = fn.timerID;
            
            if (!timers[label][fn.timerID])
                timers[label][fn.timerID] = window.setInterval(handler,interval);
            
            this.global.push( element );
            
        },
        remove: function(element, label, fn) {
            var timers = jQuery.data(element, this.dataKey), ret;
            
            if ( timers ) {
                
                if (!label) {
                    for ( label in timers )
                        this.remove(element, label, fn);
                } else if ( timers[label] ) {
                    if ( fn ) {
                        if ( fn.timerID ) {
                            window.clearInterval(timers[label][fn.timerID]);
                            delete timers[label][fn.timerID];
                        }
                    } else {
                        for ( var fn in timers[label] ) {
                            window.clearInterval(timers[label][fn]);
                            delete timers[label][fn];
                        }
                    }
                    
                    for ( ret in timers[label] ) break;
                    if ( !ret ) {
                        ret = null;
                        delete timers[label];
                    }
                }
                
                for ( ret in timers ) break;
                if ( !ret ) 
                    jQuery.removeData(element, this.dataKey);
            }
        }
    }
});

jQuery(window).bind("unload", function() {
    jQuery.each(jQuery.timer.global, function(index, item) {
        jQuery.timer.remove(item);
    });
});