【问题标题】：Search a table made with JS with for() loop使用 for() 循环搜索用 JS 制作的表格
【发布时间】：2019-06-15 12:41:31
【问题描述】：

我正在尝试设置一个搜索栏，该栏搜索通过按名称或电子邮件从 API 获取的循环数据创建的表格，但我找不到我出错的地方。控制台显示未捕获的 ReferenceError: sBar is not defined at window.onload 请记住，我是 JS 的新手。真的很抱歉这很愚蠢，但我已尽力而为，我对无法看到错误感到非常沮丧

这是我的 HTML

<body>
  <div>
    <label for="finder">Find User:</label>
    <input type="search" id="searchInput" name="sInput" placeholder="Search 
    user">
    <button id="sButton">Search</button>
  </div>
  <table class="table table-responsive">
    <thead class="thead-dark">
      <tr>
        <th scope="col">Id</th>
        <th scope="col">Name</th>
        <th scope="col">Username</th>
        <th scope="col">Email</th>
        <th scope="col">Address</th>
        <th scope="col">Phone</th>
        <th scope="col">Website</th>
        <th scope="col">Company</th>
      </tr>
    </thead>
    <tbody name="tTable">
    </tbody>
  </table>
</body>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jquery.min.js">
</script>
<script src="script.js">
</script>

小米JS

window.onload = function(){    

    let uList = document.querySelector('[name =tTable]');  

    fetchCall('https://jsonplaceholder.typicode.com/users', getUsers);
    sButton.addEventListener('click', 
    fetchCall('https://jsonplaceholder.typicode.com/users', sBar), false);


  function sBar(getObject) {
    let sUser = getObject;
    let inputBar = document.getElementById("searchInput");
    let text = inputBar.textContent;
    let textView = text.toUpperCase();
    for (let i = 0; i < getObject.length; i++) {
         let uObject = sUser[i];
      if (textView == uObject.name || textView == uObject.email) {
        let new_tTable = document.createElement('tbody');
        uList.parentNode.replaceChild(new_tTable, uList)

        let row = uList.insertRow();   
        let idInput = document.createElement('td');
        let nameInput = document.createElement('td');     
        let usernameInput = document.createElement('td');    
        let emailInput = document.createElement('td');      
        let cityInput = document.createElement('td');      
        let phoneInput = document.createElement('td');      
        let websiteInput = document.createElement('td');      
        let companyInput = document.createElement('td');      

        idInput.textContent = uObject.id;
        nameInput.textContent = uObject.name;
        usernameInput.textContent = uObject.username;
        emailInput.textContent = uObject.email;
        cityInput.textContent = uObject.address.city;
        phoneInput.textContent = uObject.phone;
        websiteInput.textContent = uObject.website;
        companyInput.textContent = uObject.company.name;
        row.appendChild(idInput);
        row.appendChild(nameInput);
        row.appendChild(usernameInput);
        row.appendChild(emailInput);
        row.appendChild(cityInput);
        row.appendChild(phoneInput);
        row.appendChild(websiteInput);
        row.appendChild(companyInput);  
     } else {
       alert("User not found");         
     }
   }
} 


  function fetchCall(url, fn){
    fetch(url)
        .then(function(response){
            return response.json();
        })
        .then(function(endPoint){
            fn(endPoint);
        })
        .catch(function(error){
            console.error(error);
        })
    }

  function getUsers(getObject) {
    let user = getObject;      
      for (let i = 0; i < getObject.length; i++) {
        let userObject = user[i];
        let row = uList.insertRow();   
        let idInput = document.createElement('td');
        let nameInput = document.createElement('td');     
        let usernameInput = document.createElement('td');    
        let emailInput = document.createElement('td');      
        let cityInput = document.createElement('td');      
        let phoneInput = document.createElement('td');      
        let websiteInput = document.createElement('td');      
        let companyInput = document.createElement('td');      

        idInput.textContent = userObject.id;
        nameInput.textContent = userObject.name;
        usernameInput.textContent = userObject.username;
        emailInput.textContent = userObject.email;
        cityInput.textContent = userObject.address.city;
        phoneInput.textContent = userObject.phone;
        websiteInput.textContent = userObject.website;
        companyInput.textContent = userObject.company.name;
        row.appendChild(idInput);
        row.appendChild(nameInput);
         row.appendChild(usernameInput);
         row.appendChild(emailInput);
         row.appendChild(cityInput);
         row.appendChild(phoneInput);
         row.appendChild(websiteInput);
         row.appendChild(companyInput);        
        }
      } 
    }

【问题讨论】：

name 属性在大部分元素中是没有意义的，只有表单控件元素和窗口元素被名称识别。将id 用于其他元素。实际出现什么问题，用帖子里的代码是无法复现的。
"sBar is not defined at window.onload" 没有正确描述问题，应该是“sBar is not defined on "Search" button click” ...不要使用内联事件，在window.onload 函数内添加按钮的事件。向sButton 添加点击监听器也会失败，fetchCall 不会返回任何用作事件处理函数的内容。

标签： javascript ajax for-loop html-table search-box

【解决方案1】：

您可能希望单独定义window.onload 和其他函数。

window.onload = function(){    

    let uList = document.querySelector('[name =tTable]');  

    fetchCall('https://jsonplaceholder.typicode.com/users', getUsers);
    sButton.addEventListener('click', 
    fetchCall('https://jsonplaceholder.typicode.com/users', sBar), false);
};

  function sBar(getObject) {
    let sUser = getObject;
    let inputBar = document.getElementById("searchInput");
    let text = inputBar.textContent;
    let textView = text.toUpperCase();
    for (let i = 0; i < getObject.length; i++) {
         let uObject = sUser[i];
        if (textView == uObject.name || textView == 
       uObject.email) {
        let new_tTable = document.createElement('tbody');
        uList.parentNode.replaceChild(new_tTable, uList)


        let row = uList.insertRow();   
        let idInput = document.createElement('td');
        let nameInput = document.createElement('td');     
        let usernameInput = document.createElement('td');    
        let emailInput = document.createElement('td');      
        let cityInput = document.createElement('td');      
        let phoneInput = document.createElement('td');      
        let websiteInput = document.createElement('td');      
        let companyInput = document.createElement('td');      

        idInput.textContent = uObject.id;
        nameInput.textContent = uObject.name;
        usernameInput.textContent = uObject.username;
        emailInput.textContent = uObject.email;
        cityInput.textContent = uObject.address.city;
        phoneInput.textContent = uObject.phone;
        websiteInput.textContent = uObject.website;
        companyInput.textContent = uObject.company.name;
        row.appendChild(idInput);
        row.appendChild(nameInput);
         row.appendChild(usernameInput);
         row.appendChild(emailInput);
         row.appendChild(cityInput);
          row.appendChild(phoneInput);
         row.appendChild(websiteInput);
         row.appendChild(companyInput);  
          } else{
           alert("User not found");
               }
       }
   } 


  function fetchCall(url, fn){
    fetch(url)
        .then(function(response){
            return response.json();
        })
        .then(function(endPoint){
            fn(endPoint);
        })
        .catch(function(error){
            console.error(error);
        })
    }

  function getUsers(getObject) {
    let user = getObject;      
      for (let i = 0; i < getObject.length; i++) {
        let userObject = user[i];
        let row = uList.insertRow();   
        let idInput = document.createElement('td');
        let nameInput = document.createElement('td');     
        let usernameInput = document.createElement('td');    
        let emailInput = document.createElement('td');      
        let cityInput = document.createElement('td');      
        let phoneInput = document.createElement('td');      
        let websiteInput = document.createElement('td');      
        let companyInput = document.createElement('td');      

        idInput.textContent = userObject.id;
        nameInput.textContent = userObject.name;
        usernameInput.textContent = userObject.username;
        emailInput.textContent = userObject.email;
        cityInput.textContent = userObject.address.city;
        phoneInput.textContent = userObject.phone;
        websiteInput.textContent = userObject.website;
        companyInput.textContent = userObject.company.name;
        row.appendChild(idInput);
        row.appendChild(nameInput);
         row.appendChild(usernameInput);
         row.appendChild(emailInput);
         row.appendChild(cityInput);
         row.appendChild(phoneInput);
         row.appendChild(websiteInput);
         row.appendChild(companyInput);        
        }
      }

【讨论】：

【解决方案2】：

您已将回调sBar() 附加到搜索输入的onchange 事件。但是没有sBar() 函数的定义（请注意，它不接受参数/参数）。您只定义了一个具有相同名称“sBar”的函数，它接受（需要）您命名为getObject 的参数。

去掉参数“getObject”，修改前几行，用于在搜索输入中获取当前输入的文本。获取搜索输入值的示例代码是：

var value = document.getElementById("searchInput").value;

旁注：

您可能需要使用另一个事件发射器而不是onchange。仅当您将焦点放在输入元素上而不是实际输入上时才会触发。

如果您想在输入时跟踪更改，请使用"onkeydown"。如果您需要用鼠标捕获粘贴操作，请使用"onpaste"（IE、FF3）和"oninput"（FF、Opera、Chrome、Safari¹）。

请从this链接查看

【讨论】：

【解决方案3】：

设置事件时调用函数，但需要绑定。

sButton.addEventListener('click', fetchCall.bind(this, 'https://jsonplaceholder.typicode.com/users', sBar), false);

我还建议在全局范围内创建一个函数。

uList = document.querySelector('[name =tTable]');

window.onload = function () {
    fetchCall('https://jsonplaceholder.typicode.com/users', getUsers);
    sButton.addEventListener('click', fetchCall.bind(this, 'https://jsonplaceholder.typicode.com/users', sBar), false);
}

function sBar(getObject) {
    let sUser = getObject;
    let inputBar = document.getElementById("searchInput");
    let text = inputBar.textContent;
    let textView = text.toUpperCase();
    for (let i = 0; i < getObject.length; i++) {
        let uObject = sUser[i];
        if (textView == uObject.name || textView ==
            uObject.email) {
            let new_tTable = document.createElement('tbody');
            uList.parentNode.replaceChild(new_tTable, uList)


            let row = uList.insertRow();
            let idInput = document.createElement('td');
            let nameInput = document.createElement('td');
            let usernameInput = document.createElement('td');
            let emailInput = document.createElement('td');
            let cityInput = document.createElement('td');
            let phoneInput = document.createElement('td');
            let websiteInput = document.createElement('td');
            let companyInput = document.createElement('td');

            idInput.textContent = uObject.id;
            nameInput.textContent = uObject.name;
            usernameInput.textContent = uObject.username;
            emailInput.textContent = uObject.email;
            cityInput.textContent = uObject.address.city;
            phoneInput.textContent = uObject.phone;
            websiteInput.textContent = uObject.website;
            companyInput.textContent = uObject.company.name;
            row.appendChild(idInput);
            row.appendChild(nameInput);
            row.appendChild(usernameInput);
            row.appendChild(emailInput);
            row.appendChild(cityInput);
            row.appendChild(phoneInput);
            row.appendChild(websiteInput);
            row.appendChild(companyInput);
        } else {
            alert("User not found");
        }
    }
}


function fetchCall(url, fn) {
    fetch(url)
        .then(function (response) {
            return response.json();
        })
        .then(function (endPoint) {
            fn(endPoint);
        })
        .catch(function (error) {
            console.error(error);
        })
}

function getUsers(getObject) {
    let user = getObject;
    for (let i = 0; i < getObject.length; i++) {
        let userObject = user[i];
        let row = uList.insertRow();
        let idInput = document.createElement('td');
        let nameInput = document.createElement('td');
        let usernameInput = document.createElement('td');
        let emailInput = document.createElement('td');
        let cityInput = document.createElement('td');
        let phoneInput = document.createElement('td');
        let websiteInput = document.createElement('td');
        let companyInput = document.createElement('td');

        idInput.textContent = userObject.id;
        nameInput.textContent = userObject.name;
        usernameInput.textContent = userObject.username;
        emailInput.textContent = userObject.email;
        cityInput.textContent = userObject.address.city;
        phoneInput.textContent = userObject.phone;
        websiteInput.textContent = userObject.website;
        companyInput.textContent = userObject.company.name;
        row.appendChild(idInput);
        row.appendChild(nameInput);
        row.appendChild(usernameInput);
        row.appendChild(emailInput);
        row.appendChild(cityInput);
        row.appendChild(phoneInput);
        row.appendChild(websiteInput);
        row.appendChild(companyInput);
    }
}

【讨论】：

刚刚进行了更改，但我仍然有相同的 sBar 未定义错误。试过 IE、FF 和 Chrome

【解决方案4】：

`async`/`await` & `fetch()`

核心函数是基于async/await和fetch()，特殊语法请到上面的链接。

老实说，我不知道如何处理 OP（O原始 Post）代码的所有问题。一般来说，您应该分步考虑该过程：

从 URL 获取 JSON。你确定fetchAll() 有效吗？
一旦您可以使用 fetchCall() 获取 JSON，请将 JSON 传递给 getUser()
如果fetchCall() 返回一个值（看起来确实如此...），则使用整个函数作为一个值。
事件侦听器和处理程序具有您必须遵守的特定签名，并且使用命名回调或匿名回调很重要：

命名回调（无参数*）

DOMObj.addEventListener('event', namedFunction);
function namedFunction(e) {...

命名回调（带参数）

DOMObj.addEventListener('event', function(e) {
  namedFunction(num, str);
});
function namedFunction(num, str) {...

匿名回调

DOMObj.addEventListener('event', function(e) {...

以下演示使用async function getUser(url, id) 来简化Promises，使用fetch()，并一次提取一个用户ID 的JSON。 function getData(json) 与 JSON 一起由 getUser() 返回。

搜索输入已更改为type='number'，因为用户的user.id 属性引用了用户。它还包含在<form> 标记中，因此回调function findUser(url, id) 将由提交事件触发。它基本上是getUser() 的函数包装器。

演示

<!DOCTYPE html>
<html>
<head>
<meta charset='utf-8'>
<link href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.2.1/css/bootstrap.min.css" rel="stylesheet">
<style>
fieldset.fieldset {width:max-content;padding: 10px 0 0}
input.input, label.label {display:inline-block;font:inherit;width:9ch;height:30px;line-height:30px;vertical-align:middle;text-align:center;}
input.input {width:6ch;padding-right:0;margin-right:8px}
input.button {font:inherit;height: 30px;line-height:20px;}
</style>
</head>
<body>
  <main class='container'>
    <section class='row'>
      <form id='main' class='form inline-form'>
        <fieldset class='fieldset form-group'>
          <label class='label control-label float-left' for="find">User ID:</label>
          <input id="find" class='input form-control float-left' type="number" min='1' max='10'>
          <input class="button btn btn-dark btn-sm float-left" type='submit' value='Find'>
       </fieldset>
    </form>
  </section>
  <section class='row'>
  <table class="table table-responsive">
    <thead class="thead-dark">
      <tr>
        <th scope="col">ID</th>
        <th scope="col">Name</th>
        <th scope="col">Username</th>
        <th scope="col">Email</th>
        <th scope="col">Phone</th>
        <th scope="col">Company</th>
        <th scope="col">City</th>
        <th scope="col">Website</th>
      </tr>
    </thead>
  </table>
 </section>
</main>
<script>

const main = document.forms[0];

const getData = (user) => {
  const uList = document.querySelector('.table');
  let row = uList.insertRow();  
  let cell = idx => row.insertCell(idx);
  
  for (let i = 0; i < 8; i++) {
    let C = cell(i);
    switch(i) {
      case 0:
      user.id = user.id > 9 ? "" + user.id: "0" + user.id;
      C.textContent = user.id;
      break;
      case 1:
      C.textContent = user.name;
      break;
      case 2:
      C.textContent = user.username;
      break;
      case 3:
      C.textContent = user.email;
      break;
      case 4:
      C.textContent = user.phone;
      break;
      case 5:
      C.textContent = user.company.name;
      break;
      case 6:
      C.textContent = user.address.city;
      break;
      case 7:
      C.textContent = user.website;
      break;
      default:
      break;
    }
  } 
};

const getUser = async (url, id) => { 
  const response = await fetch(`${url}${id}`);
  const json = await response.json();
  return getData(json);
};

/*/ For debugging -- an IIFE variables are private. Parameters are required.
(async (u, i) => {
  const json = await getUser(u, i);
  console.log(json);
})(url, id);
/*/

const findUser = (e) => {
  e.preventDefault();
  const url = 'https://jsonplaceholder.typicode.com/users/';
  let id = Number(e.currentTarget.find.value);
  getUser(url, id);
};

main.addEventListener('submit', findUser);

</script>
</body>
</html>

【讨论】：

async/await & fetch()

命名回调（无参数*）

命名回调（带参数）

匿名回调

演示

`async`/`await` & `fetch()`