If you have form fields inside accordion sections, it is goood UX to have those accordions toggle open when they contain an invalid form field. Using Parsley callbacks, this can easily be achieved by adding the following to your script.js file, preferably near the other window.parsley customizations/extensions.
How To - script.js
Add this near the other window.parsley custom extensions.
window.Parsley.on('field:error', function() {
var $isAcc = this.$element.closest(".collapse");
if($isAcc.length>0) { $isAcc.collapse("show"); }
});
Tags: bs3, bs4, parsley, javascript, jquery, js, form, script, accordion