javascript - 单选按钮清除文本框

Question

我有两个单选按钮:单击第一个单选按钮，如果他们开始输入信息，然后改变主意并选择第二个单选按钮，则会出现三个文本框，这不会清除他们输入的文本。 So what I am trying to figure out is if there is a way make it clear the text from those textboxes when a new radio button (of the same group) is chosen.任何帮助是极大的赞赏!

http://jsfiddle.net/k0paz2pj/

    <input 
      type="radio" 
      value="Yes" 
      name="lien" 
      id="lien" 
      onchange="showhideForm(this.value);"/><label for="lien">Lien</label>

   <input 
     type="radio" 
     value="None" 
     name="lien" 
     id="nolien" 
     onchange="showhideForm(this.value);"/><label for="nolien">No Lien</label>

    <div id="div1" style="display:none">
    <div class="clearfix">
           <p>
                <label for="lname">Lienholder Name:</label>
                  <input 
                    type="text" 
                    name="lienlname" 
                    id="lienlname">
                </p>
                <p>
                <label for="laddress">Lienholder Address:</label>
                  <input 
                    type="text" 
                    name="lienladdress"  
                    id="lienladdress">
                </p>
                <p>
                <label for="ldate">Date of Lien:</label>
                  <input 
                    type="text" 
                    name="lienldate" 
                    id="datepicker2">
                </p>
               </div>
    </div>
               <div id="div2" style="display:none">
    <!---You are not qualified to see this form.--->
    </div>

   <br>

    <script type="text/javascript">
function showhideForm(lien) {
    if (lien == "Yes") {
        document.getElementById("div1").style.display = 'block';
        document.getElementById("div2").style.display = 'none';
    } 
   else if (lien == "None") {
        document.getElementById("div2").style.display = 'block';
        document.getElementById("div1").style.display = 'none';
    }
}
</script>

Answer 1

一种方法，使用您的问题/JS Fiddle 演示中的纯 JavaScript:

function showhideForm(lien) {
    if (lien == "Yes") {
        document.getElementById("div1").style.display = 'block';
        document.getElementById("div2").style.display = 'none';
    } else if (lien == "None") {
        document.getElementById("div2").style.display = 'block';
        document.getElementById("div1").style.display = 'none';

        // getting all the input elements within '#div1' (using a CSS selector):
        var inputs = document.querySelectorAll('#div1 input');

        // iterating over those elements, using Array.prototype.forEach,
        // and setting the value to '' (clearing them):
        [].forEach.call(inputs, function (input) {
            input.value = '';
        });

    }
}

JS Fiddle demo .

上面的稍微更简洁的形式(或者，如果不是更简洁，重复更少):

function showhideForm(lien) {    
    var isYes = lien.trim().toLowerCase() === 'yes',
        div1 = document.getElementById('div1'),
        div2 = document.getElementById('div2');

    div1.style.display = isYes ? 'block' : 'none';
    div2.style.display = isYes ? 'none' : 'block';

    if (!isYes) {
        [].forEach.call(div1.getElementsByTagName('input'), function (input) {
            input.value = '';
        });
    }
}

JS Fiddle demo .

最后，一个版本摆脱了内联事件处理的干扰性 JavaScript(onclick、onchange 等):

function showhideForm() {
    // 'this' in the function is the radio-element to which
    // the function is bound as an event-handler: 
    var isYes = this.value.trim().toLowerCase() === 'yes',
        div1 = document.getElementById('div1'),
        div2 = document.getElementById('div2');

    div1.style.display = isYes ? 'block' : 'none';
    div2.style.display = isYes ? 'none' : 'block';

    if (!isYes) {
        [].forEach.call(div1.getElementsByTagName('input'), function (input) {
            input.value = '';
        });
    }
}

// finding the elements with the name of 'lien':
var lienRadios = document.getElementsByName('lien');

// iterating over those elements, using forEach (again):
[].forEach.call(lienRadios, function (lien) {
    // adding a listener for the 'change' event, when it
    // occurs the showhideForm function is called:
    lien.addEventListener('change', showhideForm);
});

JS Fiddle demo .

引用资料:

• Array.prototype.forEach() .
• document.getElementsByTagName() .
• document.getElementsByName() .
• document.querySelectorAll() .
• EventTarget.addEventListener() .
• Function.prototype.call() .
• String.prototype.toLowerCase() .
• String.prototype.trim() .