javascript - 如何重置过滤列表搜索框？

Question

我创建了一个搜索框来过滤this W3Schools guideline之后的列表:

function myFunction() {
    var input, filter, ul, li, a, i, txtValue;
    input = document.getElementById("myInput");
    filter = input.value.toUpperCase();
    ul = document.getElementById("myUL");
    li = ul.getElementsByTagName("li");
    for (i = 0; i < li.length; i++) {
        a = li[i].getElementsByTagName("a")[0];
        txtValue = a.textContent || a.innerText;
        if (txtValue.toUpperCase().indexOf(filter) > -1) {
            li[i].style.display = "";
        } else {
            li[i].style.display = "none";
        }
    }
}

* {
  box-sizing: border-box;
}
#myInput {
  background-image: url('/css/searchicon.png');
  background-position: 10px 12px;
  background-repeat: no-repeat;
  width: 100%;
  font-size: 16px;
  padding: 12px 20px 12px 40px;
  border: 1px solid #ddd;
  margin-bottom: 12px;
}
#myUL {
  list-style-type: none;
  padding: 0;
  margin: 0;
}
#myUL li a {
  border: 1px solid #ddd;
  margin-top: -1px; /* Prevent double borders */
  background-color: #f6f6f6;
  padding: 12px;
  text-decoration: none;
  font-size: 18px;
  color: black;
  display: block
}
#myUL li a:hover:not(.header) {
  background-color: #eee;
}

<h2>My Phonebook</h2>
<input type="text" id="myInput" onkeyup="myFunction()" placeholder="Search for names.." title="Type in a name">
<ul id="myUL">
  <li><a href="#">Adele</a></li>
  <li><a href="#">Agnes</a></li>
  <li><a href="#">Billy</a></li>
  <li><a href="#">Bob</a></li>
  <li><a href="#">Calvin</a></li>
  <li><a href="#">Christina</a></li>
  <li><a href="#">Cindy</a></li>
</ul>

我现在需要一个按钮，只需单击一下即可:
- 重置搜索框
- 并再次显示完整列表

我在 stackoverflow 和互联网上的其他地方进行了搜索，但没有找到解决方案。

如下面的代码所示，我添加了一个链接到应该完成这项工作的 JavaScript 函数的重置按钮。然而，该按钮只会清除搜索框，尽管搜索框显示为空，但我需要单击搜索框并按“删除”一次才能恢复完整列表:

// CREATE A FILTER/SEARCH LIST
function myFunction() {
  // Declare variables
  var input, filter, ul, li, a, i, txtValue;
  input = document.getElementById('myInput');
  filter = input.value.toUpperCase();
  ul = document.getElementById("myUL");
  li = ul.getElementsByTagName('li');

  // Loop through all list items, and hide those who don't match the search query
  for (i = 0; i < li.length; i++) {
    a = li[i].getElementsByTagName("a")[0];
    txtValue = a.textContent || a.innerText;
    if (txtValue.toUpperCase().indexOf(filter) > -1) {
      li[i].style.display = "";
    } else {
      li[i].style.display = "none";
    }
  }
}

  // CLEAR SEARCH BOX
function clearInputFields(divElement) {
        var ele = document.getElementById(divElement);

        // IT WILL READ ALL THE ELEMENTS. <p>, <div>, <input> ETC.
        for (i = 0; i < ele.childNodes.length; i++) {

            // SINCE THE <input> FIELDS ARE INSIDE A <p> TAG, 
            // I'LL USE THE "firstChild" PROPERTY TO GET THE <input> TAG.
            var child = ele.childNodes[i].firstChild;
            //console.log(child);

            // CHECK IF CHILD NOT NULL.
            // THIS IS IMPORTANT AS IT WILL RETURN A TEXT FOR EVERY "Whitespace".
            // 'Whitespace' IS A TEXT OR NODE BETWEEN <div> AND <p> AND AFTER <p>.
            if (child) {
                switch (child.type) {
                    case 'text':
                        child.value = '';
                }
            }
        }
    }

* {
  box-sizing: border-box;
}

#myInput {
  background-image: url('/css/searchicon.png');
  background-position: 10px 12px;
  background-repeat: no-repeat;
  width: 100%;
  font-size: 16px;
  padding: 12px 20px 12px 40px;
  border: 1px solid #ddd;
  margin-bottom: 12px;
}

#myUL {
  list-style-type: none;
  padding: 0;
  margin: 0;
}

#myUL li a {
  border: 1px solid #ddd;
  margin-top: -1px; /* Prevent double borders */
  background-color: #f6f6f6;
  padding: 12px;
  text-decoration: none;
  font-size: 18px;
  color: black;
  display: block
}

#myUL li a:hover:not(.header) {
  background-color: #eee;
}

<h2>My Phonebook</h2>

<div id="searchbox">
<p><input type="text" id="myInput" onkeyup="myFunction()" placeholder="Search for names..">
<p/>
</div>

<ul id="myUL">
  <li><a href="#">Adele</a></li>
  <li><a href="#">Agnes</a></li>
  <li><a href="#">Billy</a></li>
  <li><a href="#">Bob</a></li>
  <li><a href="#">Calvin</a></li>
  <li><a href="#">Christina</a></li>
  <li><a href="#">Cindy</a></li>
</ul>

<div id="title">
<a href="#216" onclick="clearInputFields('searchbox');">RESET</a>
</div>

有人可以告诉我我的代码有什么问题或建议更好的代码吗？

Answer 1

您可以使用 dispatchEvent() 触发 keyup 事件来通知更改已完成。

child.dispatchEvent(new Event('keyup'));

参见Creating and triggering events 。

function myFunction() {
  // Declare variables
  var input, filter, ul, li, a, i, txtValue;
  input = document.getElementById('myInput');
  filter = input.value.toUpperCase();
  ul = document.getElementById("myUL");
  li = ul.getElementsByTagName('li');

  // Loop through all list items, and hide those who don't match the search query
  for (i = 0; i < li.length; i++) {
    a = li[i].getElementsByTagName("a")[0];
    txtValue = a.textContent || a.innerText;
    if (txtValue.toUpperCase().indexOf(filter) > -1) {
      li[i].style.display = "";
    } else {
      li[i].style.display = "none";
    }
  }
}

// CLEAR SEARCH BOX
function clearInputFields(divElement) {
  var ele = document.getElementById(divElement);

  // IT WILL READ ALL THE ELEMENTS. <p>, <div>, <input> ETC.
  for (i = 0; i < ele.childNodes.length; i++) {

    // SINCE THE <input> FIELDS ARE INSIDE A <p> TAG, 
    // I'LL USE THE "firstChild" PROPERTY TO GET THE <input> TAG.
    var child = ele.childNodes[i].firstChild;
    //console.log(child);

    // CHECK IF CHILD NOT NULL.
    // THIS IS IMPORTANT AS IT WILL RETURN A TEXT FOR EVERY "Whitespace".
    // 'Whitespace' IS A TEXT OR NODE BETWEEN <div> AND <p> AND AFTER <p>.
    if (child) {
      switch (child.type) {
        case 'text':
          child.value = '';
          child.dispatchEvent(new Event('keyup'));
      }
    }
  }
}

* {
  box-sizing: border-box;
}

#myInput {
  background-image: url('/css/searchicon.png');
  background-position: 10px 12px;
  background-repeat: no-repeat;
  width: 100%;
  font-size: 16px;
  padding: 12px 20px 12px 40px;
  border: 1px solid #ddd;
  margin-bottom: 12px;
}

#myUL {
  list-style-type: none;
  padding: 0;
  margin: 0;
}

#myUL li a {
  border: 1px solid #ddd;
  margin-top: -1px;
  /* Prevent double borders */
  background-color: #f6f6f6;
  padding: 12px;
  text-decoration: none;
  font-size: 18px;
  color: black;
  display: block
}

#myUL li a:hover:not(.header) {
  background-color: #eee;
}

<h2>My Phonebook</h2>

<div id="searchbox">
  <p><input type="text" id="myInput" onkeyup="myFunction()" placeholder="Search for names..">
    <p/>
</div>

<ul id="myUL">
  <li><a href="#">Adele</a></li>
  <li><a href="#">Agnes</a></li>
  <li><a href="#">Billy</a></li>
  <li><a href="#">Bob</a></li>
  <li><a href="#">Calvin</a></li>
  <li><a href="#">Christina</a></li>
  <li><a href="#">Cindy</a></li>
</ul>

<div id="title">
  <a href="#216" onclick="clearInputFields('searchbox');">RESET</a>
</div>