Du kan bruge forskellige valideringsklasser til at give værdifuld feedback til brugerne. Tilføj enten .was-validated eller .needs-validation til <form> element, afhængigt af om du vil give valideringsfeedback før eller efter indsendelse af formularen. Indtastningsfelterne vil have en grøn (gyldig) eller rød (ugyldig) kant for at angive, hvad der mangler i formularen. Du kan også tilføje en .valid-feedback- eller .invalid-feedback-meddelelse for at fortælle brugeren eksplicit, hvad der mangler , eller skal gøres, før formularen indsendes.
I dette eksempel bruger vi .was-validated til at angive, hvad der mangler, før formularen indsendes:
<form action="/action_page.php" class="was-validated">
<div class="mb-3 mt-3">
<label for="uname" class="form-label">Username:</label>
<input type="text" class="form-control" id="uname" placeholder="Enter username" name="uname" required>
<div class="valid-feedback">Valid.</div>
<div class="invalid-feedback">Please fill out this field.</div>
</div>
<div class="mb-3">
<label for="pwd" class="form-label">Password:</label>
<input type="password" class="form-control" id="pwd" placeholder="Enter password" name="pswd" required>
<div class="valid-feedback">Valid.</div>
<div class="invalid-feedback">Please fill out this field.</div>
</div>
<div class="form-check mb-3">
<input class="form-check-input" type="checkbox" id="myCheck" name="remember" required>
<label class="form-check-label" for="myCheck">I agree on blabla.</label>
<div class="valid-feedback">Valid.</div>
<div class="invalid-feedback">Check this checkbox to continue.</div>
</div>
<button type="submit" class="btn btn-primary">Submit</button>
</form>Prøv det selv →
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/css/bootstrap.min.css" rel="stylesheet">
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/js/bootstrap.bundle.min.js"></script>
</head>
<body>
<div class="container mt-3">
<h3>Form Validation</h3>
<p>Try to submit the form.</p>
<form action="/action_page.php" class="was-validated">
<div class="mb-3 mt-3">
<label for="uname" class="form-label">Username:</label>
<input type="text" class="form-control" id="uname" placeholder="Enter username" name="uname" required>
<div class="valid-feedback">Valid.</div>
<div class="invalid-feedback">Please fill out this field.</div>
</div>
<div class="mb-3">
<label for="pwd" class="form-label">Password:</label>
<input type="password" class="form-control" id="pwd" placeholder="Enter password" name="pswd" required>
<div class="valid-feedback">Valid.</div>
<div class="invalid-feedback">Please fill out this field.</div>
</div>
<div class="form-check mb-3">
<input class="form-check-input" type="checkbox" id="myCheck" name="remember" required>
<label class="form-check-label" for="myCheck">I agree on blabla.</label>
<div class="valid-feedback">Valid.</div>
<div class="invalid-feedback">Check this checkbox to continue.</div>
</div>
<button type="submit" class="btn btn-primary">Submit</button>
</form>
</div>
</body>
</html>