Team:Tongji Shanghai/js/count-to.js

(function ($) { $.fn.countTo = function (options) { options = options || {};

return $(this).each(function () { // set options for current element var settings = $.extend({}, $.fn.countTo.defaults, { from: $(this).data('from'), to: $(this).data('to'), speed: $(this).data('speed'), refreshInterval: $(this).data('refresh-interval'), decimals: $(this).data('decimals') }, options);

// how many times to update the value, and how much to increment the value on each update var loops = Math.ceil(settings.speed / settings.refreshInterval), increment = (settings.to - settings.from) / loops;

// references & variables that will change with each update var self = this, $self = $(this), loopCount = 0, value = settings.from, data = $self.data('countTo') || {};

$self.data('countTo', data);

// if an existing interval can be found, clear it first if (data.interval) { clearInterval(data.interval); } data.interval = setInterval(updateTimer, settings.refreshInterval);

// initialize the element with the starting value render(value);

function updateTimer() { value += increment; loopCount++;

render(value);

if (typeof(settings.onUpdate) == 'function') { settings.onUpdate.call(self, value); }

if (loopCount >= loops) { // remove the interval $self.removeData('countTo'); clearInterval(data.interval); value = settings.to;

if (typeof(settings.onComplete) == 'function') { settings.onComplete.call(self, value); } } }

function render(value) { var formattedValue = settings.formatter.call(self, value, settings); $self.html(formattedValue); } }); };

$.fn.countTo.defaults = { from: 0, // the number the element should start at to: 0, // the number the element should end at speed: 1000, // how long it should take to count between the target numbers refreshInterval: 100, // how often the element should be updated decimals: 0, // the number of decimal places to show formatter: formatter, // handler for formatting the value before rendering onUpdate: null, // callback method for every time the element is updated onComplete: null // callback method for when the element finishes updating };

function formatter(value, settings) { return value.toFixed(settings.decimals); } }(jQuery));