我的申请表里有几页表格。

如何确保表单的安全性,以便在用户导航离开或关闭浏览器选项卡时,提示他们确认是否确实希望保留未保存数据的表单?


当前回答

通用解决方案无需配置,自动检测所有输入修改,包括可满足的元素:

"use strict";
(() => {
const modified_inputs = new Set;
const defaultValue = "defaultValue";
// store default values
addEventListener("beforeinput", (evt) => {
    const target = evt.target;
    if (!(defaultValue in target || defaultValue in target.dataset)) {
        target.dataset[defaultValue] = ("" + (target.value || target.textContent)).trim();
    }
});
// detect input modifications
addEventListener("input", (evt) => {
    const target = evt.target;
    let original;
    if (defaultValue in target) {
        original = target[defaultValue];
    } else {
        original = target.dataset[defaultValue];
    }
    if (original !== ("" + (target.value || target.textContent)).trim()) {
        if (!modified_inputs.has(target)) {
            modified_inputs.add(target);
        }
    } else if (modified_inputs.has(target)) {
        modified_inputs.delete(target);
    }
});
// clear modified inputs upon form submission
addEventListener("submit", (evt) => {
    modified_inputs.clear();
    // to prevent the warning from happening, it is advisable
    // that you clear your form controls back to their default
    // state with evt.target.reset() or form.reset() after submission
});
// warn before closing if any inputs are modified
addEventListener("beforeunload", (evt) => {
    if (modified_inputs.size) {
        const unsaved_changes_warning = "Changes you made may not be saved.";
        evt.returnValue = unsaved_changes_warning;
        return unsaved_changes_warning;
    }
});
})();

其他回答

下面的一句话对我很管用。

window.onbeforeunload = s => modified ? "" : null;

根据应用程序的状态将modified设置为true或false。

查看JavaScript onbeforeunload事件。它是微软引入的非标准JavaScript,但是它可以在大多数浏览器中运行,他们的onbeforeunload文档有更多的信息和示例。

建在Wasim A的顶部。使用序列化的好主意。这里的问题是,在提交表单时也显示了警告。这里已经修好了。

var isSubmitting = false

$(document).ready(function () {
    $('form').submit(function(){
        isSubmitting = true
    })

    $('form').data('initial-state', $('form').serialize());

    $(window).on('beforeunload', function() {
        if (!isSubmitting && $('form').serialize() != $('form').data('initial-state')){
            return 'You have unsaved changes which will not be saved.'
        }
    });
})

它已经在Chrome和IE 11上进行了测试。

我做了不同的,分享在这里,以便有人可以得到帮助,只测试Chrome。

我想警告用户关闭标签只有当有一些变化。

<input type="text" name="field" value="" class="onchange" />

var ischanged = false;

$('.onchange').change(function () {
    ischanged = true;
});

window.onbeforeunload = function (e) {
    if (ischanged) {
        return "Make sure to save all changes.";
    }        
};

工作很好,但有一个其他的问题,当我提交的形式,我得到不想要的警告,我看到了很多解决方法,这是因为onbeforeunload火灾之前onsubmit,这就是为什么我们不能处理它在onsubmit事件像onbeforeunload = null,但onclick事件提交按钮火灾前这两个事件,所以我更新了代码

var isChanged = false;
var isSubmit = false;

window.onbeforeunload = function (e) {
    if (isChanged && (!isSubmit)) {
        return "Make sure to save all changes.";
    }        
};

$('#submitbutton').click(function () {
    isSubmit = true;
});

$('.onchange').change(function () {
    isChanged = true;
});

通用解决方案无需配置,自动检测所有输入修改,包括可满足的元素:

"use strict";
(() => {
const modified_inputs = new Set;
const defaultValue = "defaultValue";
// store default values
addEventListener("beforeinput", (evt) => {
    const target = evt.target;
    if (!(defaultValue in target || defaultValue in target.dataset)) {
        target.dataset[defaultValue] = ("" + (target.value || target.textContent)).trim();
    }
});
// detect input modifications
addEventListener("input", (evt) => {
    const target = evt.target;
    let original;
    if (defaultValue in target) {
        original = target[defaultValue];
    } else {
        original = target.dataset[defaultValue];
    }
    if (original !== ("" + (target.value || target.textContent)).trim()) {
        if (!modified_inputs.has(target)) {
            modified_inputs.add(target);
        }
    } else if (modified_inputs.has(target)) {
        modified_inputs.delete(target);
    }
});
// clear modified inputs upon form submission
addEventListener("submit", (evt) => {
    modified_inputs.clear();
    // to prevent the warning from happening, it is advisable
    // that you clear your form controls back to their default
    // state with evt.target.reset() or form.reset() after submission
});
// warn before closing if any inputs are modified
addEventListener("beforeunload", (evt) => {
    if (modified_inputs.size) {
        const unsaved_changes_warning = "Changes you made may not be saved.";
        evt.returnValue = unsaved_changes_warning;
        return unsaved_changes_warning;
    }
});
})();