CODEWITHSUNDEEP
javascriptjquerylong-running-processes
THX-1138
THX-1138

Reputation: 21730

Force immediate DOM update modified with jQuery in long-running function

I have a javascript that takes about 2 seconds to execute (complex optimization algorithm). I want to set certain span to "working..." at the beginning of the function. I observe that the span doesn't change until the end of the function.

How can I force DOM changes propagation? or should I approach this differently all together?

I call the function from onclick on the button.

The function is something like:

function optimize() {
    $('#status').text('working...');
    // calculate for 2 seconds
    $('#status').text('done!');
}

Upvotes: 10

Views: 3926

Answers (1)

Brad Daily
Brad Daily

Reputation: 812

Try wrapping the long running code in a setTimeout call:

function optimize() {
    $('#status').text('working...');
    window.setTimeout(function() {
        // calculate for 2 seconds
        $('#status').text('done!');
    }, 0);
}

This forces a new call stack for the long running code, allowing the repaint (changing of the text) to complete before the new call stack begins execution.

Upvotes: 12

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