我有一个相对简单的问题，试图将内联脚本添加到React组件。到目前为止我有:
'use strict';
import '../../styles/pages/people.scss';
import React, { Component } from 'react';
import DocumentTitle from 'react-document-title';
import { prefix } from '../../core/util';
export default class extends Component {
render() {
return (
<DocumentTitle title="People">
<article className={[prefix('people'), prefix('people', 'index')].join(' ')}>
<h1 className="tk-brandon-grotesque">People</h1>
<script src="https://use.typekit.net/foobar.js"></script>
<script dangerouslySetInnerHTML={{__html: 'try{Typekit.load({ async: true });}catch(e){}'}}></script>
</article>
</DocumentTitle>
);
}
};
我也试过:
<script src="https://use.typekit.net/foobar.js"></script>
<script>try{Typekit.load({ async: true });}catch(e){}</script>
这两种方法似乎都不能执行所需的脚本。我猜我错过了一件简单的事。有人能帮忙吗?
PS:忽略foobar，我有一个真正的id实际上在使用，我不想分享。
要获得支持加载状态和错误处理的更完整的useScript实现，请查看useHooks。
使用
function App() {
const status = useScript(
"https://pm28k14qlj.codesandbox.io/test-external-script.js"
);
return (
<div>
<div>
Script status: <b>{status}</b>
</div>
{status === "ready" && (
<div>
Script function call response: <b>{TEST_SCRIPT.start()}</b>
</div>
)}
</div>
);
}
Hook
function useScript(src) {
// Keep track of script status ("idle", "loading", "ready", "error")
const [status, setStatus] = useState(src ? "loading" : "idle");
useEffect(
() => {
// Allow falsy src value if waiting on other data needed for
// constructing the script URL passed to this hook.
if (!src) {
setStatus("idle");
return;
}
// Fetch existing script element by src
// It may have been added by another intance of this hook
let script = document.querySelector(`script[src="${src}"]`);
if (!script) {
// Create script
script = document.createElement("script");
script.src = src;
script.async = true;
script.setAttribute("data-status", "loading");
// Add script to document body
document.body.appendChild(script);
// Store status in attribute on script
// This can be read by other instances of this hook
const setAttributeFromEvent = (event) => {
script.setAttribute(
"data-status",
event.type === "load" ? "ready" : "error"
);
};
script.addEventListener("load", setAttributeFromEvent);
script.addEventListener("error", setAttributeFromEvent);
} else {
// Grab existing script status from attribute and set to state.
setStatus(script.getAttribute("data-status"));
}
// Script event handler to update status in state
// Note: Even if the script already exists we still need to add
// event handlers to update the state for *this* hook instance.
const setStateFromEvent = (event) => {
setStatus(event.type === "load" ? "ready" : "error");
};
// Add event listeners
script.addEventListener("load", setStateFromEvent);
script.addEventListener("error", setStateFromEvent);
// Remove event listeners on cleanup
return () => {
if (script) {
script.removeEventListener("load", setStateFromEvent);
script.removeEventListener("error", setStateFromEvent);
}
};
},
[src] // Only re-run effect if script src changes
);
return status;
}
以下是我如何最终能够在React JS代码中添加两个外部JavaScript文件:
以下是我遵循的步骤。
步骤1:
我在react-app文件夹路径中使用npm I React-Helmet从终端安装了React-Helmet。
步骤2:
然后我添加了import {Helmet} from "react-helmet";头在我的代码。
步骤3:
最后，在我的代码中这是
我如何使用Helment添加外部JS文件
<Helmet>
<script src = "path/to/my/js/file1.js" type = "text/javascript" />
<script src = "path/to/my/js/file2.js" type = "text/javascript" />
</Helmet>
有点晚了，但我决定创建我自己的@Alex Macmillan的答案后，这是通过传递两个额外的参数;放置脚本的位置，如或和设置async为true/false，这里是:
import { useEffect } from 'react';
const useScript = (url, position, async) => {
useEffect(() => {
const placement = document.querySelector(position);
const script = document.createElement('script');
script.src = url;
script.async = typeof async === 'undefined' ? true : async;
placement.appendChild(script);
return () => {
placement.removeChild(script);
};
}, [url]);
};
export default useScript;
调用它的方式与本文中接受的答案完全相同，但有两个额外的参数(再次):
// First string is your URL
// Second string can be head or body
// Third parameter is true or false.
useScript("string", "string", bool);
要在head tag <head>中添加脚本标签或代码，请使用react-helmet包。它很轻，有很好的文档。
在script标签中添加Js代码
function htmlDecode(html) {
return html.replace(/&([a-z]+);/ig, (match, entity) => {
const entities = { amp: '&', apos: '\'', gt: '>', lt: '<', nbsp: '\xa0', quot: '"' };
entity = entity.toLowerCase();
if (entities.hasOwnProperty(entity)) {
return entities[entity];
}
return match;
});
}
render() {
const scriptCode = `<script type="text/javascript">
{(function() {
window.hello={
FIRST_NAME: 'firstName',
LAST_NAME: 'lastName',
};
})()}
</script>`
return(
<div dangerouslySetInnerHTML={{ __html: this.htmlDecode(scriptCode) }} />;
);
}
这段代码可以通过console.log(windows.hello)进行测试。
编辑:事情变化很快，这是过时的-见更新
您是希望在每次呈现该组件时，还是在将该组件挂载到DOM时，一次又一次地获取并执行脚本?
也许可以试试这样的方法:
componentDidMount () {
const script = document.createElement("script");
script.src = "https://use.typekit.net/foobar.js";
script.async = true;
document.body.appendChild(script);
}
但是，只有当你想要加载的脚本不能作为模块/包使用时，这才真正有用。首先，我总是:
在npm上查找包
下载并安装在我的项目包(npm install typekit)
导入我需要的包(import Typekit from ' Typekit ';)
这可能就是你安装例子中的react和react-document-title包的方式，npm上有一个Typekit包可用。
更新:
现在我们有了钩子，一个更好的方法可能是像这样使用useEffect:
useEffect(() => {
const script = document.createElement('script');
script.src = "https://use.typekit.net/foobar.js";
script.async = true;
document.body.appendChild(script);
return () => {
document.body.removeChild(script);
}
}, []);
这使得它成为自定义钩子(例如:hooks/useScript.js)的一个很好的候选人:
import { useEffect } from 'react';
const useScript = url => {
useEffect(() => {
const script = document.createElement('script');
script.src = url;
script.async = true;
document.body.appendChild(script);
return () => {
document.body.removeChild(script);
}
}, [url]);
};
export default useScript;
可以这样使用:
import useScript from 'hooks/useScript';
const MyComponent = props => {
useScript('https://use.typekit.net/foobar.js');
// rest of your component
}
