HTML - 在用户类型时保留占位符

时间:2014-10-12 10:38:54

标签: javascript html css

我有这样的输入:

<input value="My text" placeholder="Placeholder">

当我在输入中输入内容时,占位符文本将消失,这很明显。

现在,我想要做的是我希望占位符文本在用户输入时保留,以便您可以将占位符文本视为原始文本背后的背景文本:

placeholder

编辑:我也希望能够使用JavaScript更改背景文本。

6 个答案:

答案 0 :(得分:10)

很难想到这种行为的良好用法,因为它会阻止一些用户输入。

一种简单的方法是使用input::after,但目前任何浏览器都不支持此功能(感谢@ JukkaK.Korpela)。

但是你可以使用包装元素和数据属性,如下所示:

<div class="placeholder" data-placeholder="my placeholder">
    <input value="My text" />  
</div>

用这个css:

.placeholder
{
    position: relative;
}

.placeholder::after
{
    position: absolute;
    left: 5px;
    top: 3px;
    content: attr(data-placeholder);
    pointer-events: none;
    opacity: 0.6;
}

导致:enter image description here

<强> Click here for jsFiddle demo.


由于您需要进行大量调整以使其看起来不错,您还可以考虑使用包装<div>元素作为输入“看起来相似”:

<div class="editable" data-placeholder="my placeholder">
    <input type="text" value="my Text" />
</div>

CSS:

.editable
{
    position: relative;
    border: 1px solid gray;
    padding: 3px;
    background-color: white;
    box-shadow: rgba(0,0,0,0.4) 2px 2px 2px inset;
}

.editable > input
{
    position: relative;
    z-index: 1;
    border: none;
    background-color: transparent;
    box-shadow: none;
    width: 100%;
}

.editable::after
{
    position: absolute;
    left: 4px;
    top: 5px;
    content: attr(data-placeholder);
    pointer-events: none;
    opacity: 0.5;
    z-index: 1;
}

<强> Click here for the Demo 3. (with mocked <input />)

<强> Click here for the Demo 2. (with contenteditable)

答案 1 :(得分:9)

通过CSS轻松实现更好的解决方案。看看:http://jsfiddle.net/csdtesting/wbqq129q/

  • 在输入之前:

enter image description here

  • 输入时:

enter image description here

<强>代码:

#login {
  font-size: 12px;
  margin: 0 auto;
  width: 700px;
}
#login li {
  float: left;
  list-style: none;
  margin-left: 30px;
  position: relative;
}
#login li:first-child {
  margin-left: 0;
}
label {
  line-height: 40px;
  position: absolute;
  right: 120px;
  top: 0;
  bottom: 0;
  -moz-transition: 0.3s right ease;
  -ms-transition: 0.3s right ease;
  -o-transition: 0.3s right ease;
  -webkit-transition: 0.3s right ease;
  transition: 0.3s right ease;
  z-index: 0
}
input {
  color: transparent;
  font-size: 12px;
  height: 35px;
  -moz-border-radius: 3px;
  -webkit-border-radius: 3px;
  border-radius: 3px;
  -moz-transition: 0.3s all ease;
  -ms-transition: 0.3s all ease;
  -o-transition: 0.3s all ease;
  -webkit-transition: 0.3s all ease;
  transition: 0.3s all ease;
}
input[type="email"],
input[type="password"] {
  border: 1px solid #ccc;
  height: 35px;
  padding: 0 10px;
  width: 240px;
  position: relative;
  -moz-box-shadow: inset 0 0 10px rgba(0, 0, 0, .06);
  -webkit-box-shadow: inset 0 0 10px rgba(0, 0, 0, .06);
  box-shadow: inset 0 0 10px rgba(0, 0, 0, .06);
  z-index: 2;
}
input[type="email"] {
  color: rgba(47, 130, 194, .8);
}
/* Placeholder */

input[type="email"]:-moz-placeholder {
  color: rgba(47, 130, 194, .6);
}
input[type="email"]:-ms-input-placeholder {
  color: rgba(47, 130, 194, .6);
}
input[type="email"]::-webkit-input-placeholder {
  color: rgba(47, 130, 194, .6);
}
/* Label */

input[type="email"] + label {
  color: rgb(47, 130, 194);
}
input:focus + label {
  right: 10px;
}
input[type="email"]:focus,
input[type="password"]:focus {
  background-color: rgba(255, 255, 255, .8);
}
/* Submit */

input[type="submit"] {
  background-color: #333;
  background: -moz-linear-gradient(bottom, #333, #444);
  background: -ms-linear-gradient(bottom, #333, #444);
  background: -o-linear-gradient(bottom, #333, #444);
  background: -webkit-linear-gradient(bottom, #333, #444);
  background: linear-gradient(bottom, #333, #444);
  border: 1px solid #222;
  color: #fff;
  cursor: pointer;
  height: 35px;
  width: 110px;
}
<form id="login">
  <ul>
    <li>
      <input id="email" name="email" placeholder="Your Email" title="Your Email" type="email" required />
      <label for="email">Your Email</label>
    </li>
  </ul>
</form>

答案 2 :(得分:0)

这可以通过使用&#39; onchange&#39;处理程序。您可以编写一个花哨的函数,将占位符的其余部分连接到用户键入的内容,并将光标放在用户文本的末尾。

这里有一些未经测试的,不完整的js / psuedocode给你一个想法:

userTextLength: 0, // measure of how many chars the user has typed; need this because the length itself won't be a valid measure, since we're modifying it in place. Note that we're using the DOM as a source of truth here... alternative method would be to store the user's text itself here, but let's run with this.
placeholder: "xx/yy/zz",
onchange: function() {
  boxText = document.querySelector('#elem').value;
  if (boxText.length === 1) { // special handling for the first character they type. (Using placeholder text at first.)
    this.userTextLength++;
    placeholder = boxText.slice(userTextLength);
    userText = boxText.slice(0, userTextLength);
    document.querySelector('#elem').innerHTML = userText + placeholder;
  }
  if (boxText.length < placeholder.length) { // this would mean they used backspace, which also needs to be handled.

  }
  else { // the normal case, should look quite similar to the first if block
    this.userTextLength += 1;
    userInput = 
  }
}

我在这里处理的是光标聚焦。这将需要一个“焦点”&#39; event,并将使用userTextLength属性来决定放置它的位置。对于这方面的一些帮助,this answer看起来应该有用。

答案 3 :(得分:0)

如果它是不可能的话,它将是非常不具吸引力的。但我有一个想法可以帮助你jquery支持。

您可以在此处查看演示:http://hangaumy.com/order/

当您键入时,它会自动添加单词(看起来像占位符)

答案 4 :(得分:0)

您可以尝试执行以下操作:

HTML:

<div class="wrapper">
  <input type="text">
  <span class="placeholder">Placeholder</span>
</div>

CSS:

.wrapper{
  position: relative;
}

input {
  font-size: 14px;
  height: 40px;
}

.placeholder {
  position: absolute;
  font-size:25px;
  pointer-events: none;
  left: 1px;
  top: 1px;
  transition: 0.1s ease all;
}

input:focus ~ .placeholder{
  top: 1px;
  font-size: 11px;
}

JSFiddle

答案 5 :(得分:0)

.box {
  border: 1px solid;
  border-radius: 10px;
  padding: .25rem 1rem 1rem;
  color: #555;
  font-family: sans-serif;
  display: flex;
  flex-direction: column;
  width: max-content;
}

.wrapper {
  position: relative;
  width: 450px;
}

.wrapper * {
  font-size: 1.25rem;
  letter-spacing: 2px;
  font-family: monospace;
  padding: .125rem .25rem;
  display: flex;
  width: calc(100% - 1rem);
}

input {
  width: 4000px;
  border: 0;
}

.placeholder {
  position: absolute;
  pointer-events: none;
  left: 0;
  top: 0;
  width: min-content;
}
<div class="box">
  <h2>Short Homepage Headline</h2>
  <p>Use up tp 30 characters</p>
  <div class="wrapper">
    <input type="text">
    <span class="placeholder">
      ______________________________
    </span>
  </div>
</div>

这对于功能、良好的用例及其吸引力如何。
(试图消除上述一些负面因素,哈)

  1. 占位符文本是有限数量的下划线 (30)?
  2. 相同的字体大小、等宽和字母间距

firestore rules docs

这为标题作家提供了一个整洁的无 js 字符观察器。通过这种方式,他们将能够看到它何时会破坏模板。但您不一定非要受其限制,才能达到硬性限制。