我想用纯Javascript做无限滚动。我看到了几个教程,但所有的教程都是从某个api中随机获取一些数据,我理解教程中的代码,但我不知道如何按顺序获取数据,而不是随机的。我理解教程中的代码,但我不知道如何按顺序而不是随机地获取数据。
我想做一些类似这里的东西。https:/codepen.ioFlorinPop17penRwwvKYJ。 但我想使用我本地文件中的数据。让我们假设它是data.js,有这样的代码。
data = [{}, {}]
所以它是一个对象数组 我们假设对象的内容是这样的: https:/jsonplaceholder.typicode.composts。
如何将这个codepen的代码改成按顺序一个个显示帖子?我想,函数getPost应该有参数 "id",每次调用这个函数时,参数应该加1?但是怎么做呢?或者我应该在data.js中迭代,每次迭代时检查用户是否滚动到底部?
你只需要改变 getPost()
函数来使用您的内联 blog_data
其中包含所有可用的员额。当前的偏移量被保存在一个全局变量 post_offset
每增加 getPost()
调用,这样订单就会保持不变,不会多次显示帖子。
// all the blog entries that are available
const blog_data = [{
title: "Blog Entry 1",
body: "This is the example body text for entry 1."
},{
title: "This is number two",
body: "Also blog entry number 2 has some content."
},{
title: "Blog entry three",
body: "Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua."
},{
title: "Blog entry four",
body: "Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua."
},{
title: "Blog entry five",
body: "Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua."
},{
title: "Blog entry six",
body: "Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua."
}];
const container = document.getElementById('container');
const loading = document.querySelector('.loading');
let post_offset = 0;
getPost();
getPost();
getPost();
window.addEventListener('scroll', () => {
const { scrollTop, scrollHeight, clientHeight } = document.documentElement;
if(clientHeight + scrollTop >= scrollHeight - 5) {
// show the loading animation
showLoading();
}
});
function showLoading() {
if(post_offset < blog_data.length){
loading.classList.add('show');
// load more data
setTimeout(getPost, 1000)
}
else{
// end has been reached, no more posts available
}
}
async function getPost() {
if(post_offset < blog_data.length){
addDataToDOM(blog_data[post_offset]);
post_offset++;
}
}
function addDataToDOM(data) {
const postElement = document.createElement('div');
postElement.classList.add('blog-post');
postElement.innerHTML = `
<h2 class="title">${data.title}</h2>
<p class="text">${data.body}</p>
`;
container.appendChild(postElement);
loading.classList.remove('show');
}
@import url('https://fonts.googleapis.com/css?family=Open+Sans:300,600&display=swap');
* {
box-sizing: border-box;
}
body {
background-color: #fafafa;
font-family: 'Open Sans', sans-serif;
padding-bottom: 100px;
}
.container {
margin: 0 auto;
max-width: 600px;
}
.blog-post {
background-color: #fff;
box-shadow: 0px 1px 2px rgba(50, 50, 50, .1), 0px 2px 4px rgba(60, 60, 60, 0.1);
border-radius: 4px;
padding: 40px;
margin: 20px 0;
}
.title {
margin: 0;
}
.text {
color: #555;
margin: 20px 0;
}
.loading {
opacity: 0;
display: flex;
position: fixed;
bottom: 50px;
left: 50%;
transform: translateX(-50%);
transition: opacity .3s ease-in;
}
.loading.show {
opacity: 1;
}
.ball {
background-color: #777;
border-radius: 50%;
margin: 5px;
height: 10px;
width: 10px;
animation: jump .5s ease-in infinite;
}
.ball:nth-of-type(2) {
animation-delay: 0.1s;
}
.ball:nth-of-type(3) {
animation-delay: 0.2s;
}
@keyframes jump {
0%, 100% {
transform: translateY(0);
}
50% {
transform: translateY(-10px);
}
}
<div class="container" id="container">
<h1>Blog Posts</h1>
</div>
<div class="loading">
<div class="ball"></div>
<div class="ball"></div>
<div class="ball"></div>
</div>