Google chart loading message

Question

I have the following script which works, but has one annoying issue:

Answer 1

I would use an onload handler to call the chart functions. It should wait for the page to load, then add the chart.

$(function(){
    google.load("visualization", "1", {packages:["corechart"]});
    google.setOnLoadCallback(drawChartAjax);
});

If this doesn't work, perhaps you could add a load handler to the footer div.

Answer 2

You can also take advantage of Google Chart events to listen for when the chart has loaded and perform an action. It may require you to initially hide the chart container or overlay a loading icon. Example:

google.visualization.events.addListener(chart, 'ready', function() {
            // Do something like ...
            /* $('#chart_div').css('visibility', 'visible'); // provided this was already hidden
            $('.loading-icon').hide(); // if it exists in your HTML */
        });

Answer 3

Does Google Charts clear the chart div on load?

/* style.css */
.preloader {
    height:350px; background:url(../images/spinner.gif) center center no-repeat;
}

Set the height of the preloader equal to the resulting chart.

<!-- HTML -->
<div id="chart_div"><div class="preloader">&nbsp;</div></div>

If it doesn't clear the preloader, you should add a callback on chart load to clear it.

Answer 4

Put the script at the bottom of the HTML file. This won't do a loading screen, but this will prevent the browser from blocking while the chart loads.

To get a loading effect, Google's Charts will overwrite the innerHTML of the div you're pointing it to, so you can keep a loading message in there (in whatever format you desire) and it will get overwritten when the chart loads.