線上書籍

自定義樣式

參考：https://bootstrap5.hexschool.com/docs/5.1/forms/validation/

為了自定義 Bootstrap 表單驗證訊息，您需要將布林屬性 novalidate 添加到 <form> 中。這將會禁用瀏覽器預設的回饋工具提示，不過 JavaScript 的表單驗證 API 依然有效。嘗試提交以下的表單，Bootstrap 的 JavaScript 將會攔截提交按鈕並向您提供回饋。在嘗試提交時，您會看到 :invalid 和 :valid 的樣式被應用於您的表單控制元件。

但仍提供 JavaScript 中表單驗證 API 有效。嘗試提交以下表格；我們的 JavaScript 將攔截提交按鈕並向您提供回饋。嘗試提交時，您會看到 :invalid 和 :valid 的樣式應用於表單控制元件 (form control)。

自定義的回饋樣式將會採用客製化的顏色、邊界、focus 樣式和背景圖示以更好的傳遞回饋。<select> 的背景圖示僅適用於 .form-select 而不可使用於 .form-control。

<form class="row g-3 needs-validation" novalidate> <div class="col-md-4"> <label for="validationCustom01" class="form-label">First name</label> <input type="text" class="form-control" id="validationCustom01" value="Mark" required> <div class="valid-feedback"> Looks good! </div> </div> <div class="col-md-4"> <label for="validationCustom02" class="form-label">Last name</label> <input type="text" class="form-control" id="validationCustom02" value="Otto" required> <div class="valid-feedback"> Looks good! </div> </div> <div class="col-md-4"> <label for="validationCustomUsername" class="form-label">Username</label> <div class="input-group has-validation"> <span class="input-group-text" id="inputGroupPrepend">@</span> <input type="text" class="form-control" id="validationCustomUsername" aria-describedby="inputGroupPrepend" required> <div class="invalid-feedback"> Please choose a username. </div> </div> </div> <div class="col-md-6"> <label for="validationCustom03" class="form-label">City</label> <input type="text" class="form-control" id="validationCustom03" required> <div class="invalid-feedback"> Please provide a valid city. </div> </div> <div class="col-md-3"> <label for="validationCustom04" class="form-label">State</label> <select class="form-select" id="validationCustom04" required> <option selected disabled value="">Choose...</option> <option>...</option> </select> <div class="invalid-feedback"> Please select a valid state. </div> </div> <div class="col-md-3"> <label for="validationCustom05" class="form-label">Zip</label> <input type="text" class="form-control" id="validationCustom05" required> <div class="invalid-feedback"> Please provide a valid zip. </div> </div> <div class="col-12"> <div class="form-check"> <input class="form-check-input" type="checkbox" value="" id="invalidCheck" required> <label class="form-check-label" for="invalidCheck"> Agree to terms and conditions </label> <div class="invalid-feedback"> You must agree before submitting. </div> </div> </div> <div class="col-12"> <button class="btn btn-primary" type="submit">Submit form</button> </div> </form>

JS

<script> // Example starter JavaScript for disabling form submissions if there are invalid fields (function() { 'use strict' // Fetch all the forms we want to apply custom Bootstrap validation styles to var forms = document.querySelectorAll('.needs-validation') // Loop over them and prevent submission Array.prototype.slice.call(forms) .forEach(function(form) { form.addEventListener('submit', function(event) { if (!form.checkValidity()) { event.preventDefault() event.stopPropagation() } form.classList.add('was-validated') }, false) }) })() </script>