• collin.garvey

• in reply to: JS performance issues
• January 23, 2014 at 5:53 am

I have run in to this issue as well. It seems like a very serious one, too.

In advanced-custom-fields/js/input.js, in the acf.conditional_logic object, the change event gets called for every single ACF input on the page.

This causes the JS to get slower and slower with each new field (or set) added because it’s checking the conditions for every field instead of just what was added or modified.

In addition to this, there is some display modifications on the elements during these nested loops that is causing a browser recalculate/reflow for every input. This all adds up to an increasingly slow, and at a certain point, unusable experience.

I put some timers in the code to illustrate the time increases with each new set of fields added.