Unknown TypeError : Cannot read property "search" of undefined

Question

我正在尝试使用 Youtube 数据进行基本搜索操作 API v3.When 我点击任何一个按钮，字符串被传递给 searchyoutube function.I 想要这个字符串作为搜索查询。

这是名为 app.js 的 JS:

"use strict";
var query;
function searchyoutube (query){

var request = gapi.client.youtube.search.list({
     part: 'snippet',
     type: 'video',
     q: query
});
console.log(query);

request.execute(function(response){
    console.log("Whatever");
});
}

function init()
{
    gapi.client.setApiKey("API KEY");
    gapi.client.load("youtube","v3",function(){
    //api ready
});
}

这是HTML

<html>
<head>
<link rel="stylesheet" type="text/css" href="yy.css">
<link href='https://fonts.googleapis.com/css?family=Roboto:400,300,100' rel='stylesheet' type='text/css'>
<title>Title</title>
<script type="text/javascript" src="http://code.jquery.com/jquery-2.2.0.min.js"></script>
<script type="text/javascript" src="app.js"></script>
<script type="text/javascript" src="https://apis.google.com/js/client.js?onload=init"></script>
</head>

<body>

    <h3>Header</h3>
    <h5>Random Header</h5>

    <form method="post">
    <ul class="youtube-categories" id="youtube-category">
        <li><button onClick ="searchyoutube('music')">Music</li>
        <li><button onClick ="searchyoutube('sports')">Sports</li>
        <li><button onClick ="searchyoutube('gaming')">Gaming</li>
        <li><button onClick ="searchyoutube('movies')">Movies</li>
        <li><button onClick ="searchyoutube('tv shows')">TV Shows</li>
        <li><button onClick ="searchyoutube('news')">News</li>
        <li><button onClick ="searchyoutube('live')">Live</li>
    </ul>
    </form>
    </div>

</body>
</html>

我是 JS 的新手，所以如果我犯了任何愚蠢的错误，请告诉我！

Answer 1

我会删除内联 javascript 并使用在 init 回调中创建的委托点击事件。这个问题可能是由于时间问题，这条路线避免了这个问题。此外，由于 <li> 的所有文本都是搜索词，您可以使用它来获取应该搜索的内容。所以：

<ul class="youtube-categories" id="youtube-category">
  <li>Music</li>
  <li>Sports</li>
  <li>Gaming</li>
  <li>Movies</li>
  <li>TV Shows</li>
  <li>News</li>
  <li>Live</li>
</ul>

并更新了javascript：

function init() {
  gapi.client.setApiKey("API KEY");
  gapi.client.load("youtube","v3",function(){
    document.querySelector('#youtube-category').addEventListener('click', function(event) {
      // it's an <li> tag, get the text and search with it
      if(event.target.tagName === 'LI') {
        var searchTerm = event.target.textContent.toLowerCase();
        var request = gapi.client.youtube.search.list({
             part: 'snippet',
             type: 'video',
             q: searchTerm
        });
        console.log(searchTerm);

        request.execute(function(response){
          console.log(response);
        });
      }
    }, false);
  });
}

Codepen 示例：http://jsbin.com/bezawasuta/edit?html,js,output

Unknown TypeError : Cannot read property "search" of undefined

Unknown TypeError : Cannot read property "search" of undefined

html

javascript

youtube

youtube-api

youtube-data-api