Set focus on first invalid input in AngularJs form

Question

I\'ve read several articles and StackOverflow questions relating to the setting of focus in AngularJs.

Unfortunately all the examples that I have read assume that th

Answer 1

I was inspired by chaojidan above to suggest this variation for those who are using nested angular 1.5.9 ng-forms:

class FormFocusOnErr implements ng.IDirective
{
    static directiveId: string = 'formFocusOnErr';

    restrict: string = "A";

    link = (scope: ng.IScope, elem, attrs) =>
    {
        // set up event handler on the form element
        elem.on('submit', function () {

            // find the first invalid element
            var firstInvalid = angular.element(
                elem[0].querySelector('.ng-invalid'))[0];

            // if we find one, set focus
            if (firstInvalid) {
                firstInvalid.focus();
                // ng-invalid appears on ng-forms as well as 
                // the inputs that are responsible for the errors.
                // In such cases, the focus will probably fail 
                // because we usually put the ng-focus attribute on divs 
                // and divs don't support the focus method
                if (firstInvalid.tagName.toLowerCase() === 'ng-form' 
                    || firstInvalid.hasAttribute('ng-form') 
                    || firstInvalid.hasAttribute('data-ng-form')) {
                    // Let's try to put a finer point on it by selecting 
                    // the first visible input, select or textarea 
                    // that has the ng-invalid CSS class
                    var firstVisibleInvalidFormInput = angular.element(firstInvalid.querySelector("input.ng-invalid,select.ng-invalid,textarea.ng-invalid")).filter(":visible")[0];
                    if (firstVisibleInvalidFormInput) {
                        firstVisibleInvalidFormInput.focus();
                    }
                }
            }
        });            
    }
}

// Register in angular app
app.directive(FormFocusOnErr.directiveId, () => new FormFocusOnErr());