Why are the event handlers fired twice?
Question
If I collapse or expand "id-1" then the handlers work correctly.
If I collapse or expand "id-1-1" then two handlers are triggered: one for "id-1" and the second for "id-1-1".
Why is the event fired for "id-1" even though no action is taking place?
const myCollapsible = document.querySelectorAll('.collapse'); myCollapsible.forEach(myOne => { myOne.addEventListener('shown.bs.collapse', function() { console.log('shown ' + this.id); }); myOne.addEventListener('hidden.bs.collapse', function() { console.log('hidden ' + this.id); }); });
<!doctype html> <html lang="en"> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.2.0-beta1/dist/css/bootstrap.min.css" rel="stylesheet"> <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-icons@1.8.2/font/bootstrap-icons.css"> </head> <body> <div> <a class="bi-caret-right-fill link-dark text-decoration-none me-2" data-bs-toggle="collapse" href="#id-1"></a> <a href="#">id-1</a> <div class="collapse ms-4" id="id-1"> <div> <a class="bi-caret-right-fill link-dark text-decoration-none me-2" data-bs-toggle="collapse" href="#id-1-1"></a> <a href="#">id-1-1</a> <div class="collapse ms-4" id="id-1-1"> text </div> </div> <div> <a class="bi-caret-right-fill link-dark text-decoration-none me-2" data-bs-toggle="collapse" href="#id-1-2"></a> <a href="#">id-1-2</a> <div class="collapse ms-4" id="id-1-2"> text </div> </div> <div> <a class="bi-caret-right-fill link-dark text-decoration-none me-2" data-bs-toggle="collapse" href="#id-1-3"></a> <a href="#">id-1-3</a> <div class="collapse ms-4" id="id-1-3"> text </div> </div> </div> </div> <div> <a class="bi-caret-right-fill link-dark text-decoration-none me-2" data-bs-toggle="collapse" href="#id-2"></a> <a href="#">id-2</a> <div class="collapse ms-4" id="id-2"> text </div> </div> <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.2.0-beta1/dist/js/bootstrap.bundle.min.js"></script> </body> </html>
1 answers
solution1
1 ACCPTED 2022-05-19 14:10:13
You need to e.stopPropagation() from your child to top level parent.
You can find more on stopPropagation
const myCollapsible = document.querySelectorAll('.collapse'); myCollapsible.forEach(myOne => { myOne.addEventListener('shown.bs.collapse', function(e) { e.stopPropagation(); console.log('shown ' + this.id); }); myOne.addEventListener('hidden.bs.collapse', function(e) { e.stopPropagation(); console.log('hidden ' + this.id); }); });
<!doctype html> <html lang="en"> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.2.0-beta1/dist/css/bootstrap.min.css" rel="stylesheet"> <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-icons@1.8.2/font/bootstrap-icons.css"> </head> <body> <div> <a class="bi-caret-right-fill link-dark text-decoration-none me-2" data-bs-toggle="collapse" href="#id-1"></a> <a href="#">id-1</a> <div class="collapse ms-4" id="id-1"> <div> <a class="bi-caret-right-fill link-dark text-decoration-none me-2" data-bs-toggle="collapse" href="#id-1-1"></a> <a href="#">id-1-1</a> <div class="collapse ms-4" id="id-1-1"> text </div> </div> <div> <a class="bi-caret-right-fill link-dark text-decoration-none me-2" data-bs-toggle="collapse" href="#id-1-2"></a> <a href="#">id-1-2</a> <div class="collapse ms-4" id="id-1-2"> text </div> </div> <div> <a class="bi-caret-right-fill link-dark text-decoration-none me-2" data-bs-toggle="collapse" href="#id-1-3"></a> <a href="#">id-1-3</a> <div class="collapse ms-4" id="id-1-3"> text </div> </div> </div> </div> <div> <a class="bi-caret-right-fill link-dark text-decoration-none me-2" data-bs-toggle="collapse" href="#id-2"></a> <a href="#">id-2</a> <div class="collapse ms-4" id="id-2"> text </div> </div> <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.2.0-beta1/dist/js/bootstrap.bundle.min.js"></script> </body> </html>
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