gandra404 gandra404 - 5 months ago 488
Javascript Question

How to fix babel react "Uncaught SyntaxError: Unexpected token <"

I am having problem with react setup via CDN.

Her is my html:

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>

<link rel="stylesheet" type="text/css" href="css/main.css">

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.14.0/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.14.0/react-dom.js"></script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/babel-standalone/6.7.7/babel.min.js"></script>
<script src="js/app.js"></script>

</head>
<body>
<div id="container">
</div>
</body>
</html>


and here my app.js:

var myItems = {
items:
["Widget","Gear","Sprocket","Spring","Crank","Lever","Hose","Tube",
"Wheel","Housing","Case"]
}

var FilteredList = React.createClass({

filterList: function (event) {
var updatedList = this.props.initialItems.items;

updatedList = updatedList.filter(function (item) {
return item.toLowerCase().search(event.target.value.toLowerCase()) !== 1;
});

this.setState({items: updatedList});
},

getInitialState: function(){
return {
items: []
}
},

componentWillMount: function(){
this.setState({items: this.props.initialItems.items})
},

render: function(){
return (
<div className="myList">
<input type="text" placeholder="Search" onChange={this.filterList} />

<List items={this.state.items}/>

</div>
);
}
});

var List = React.createClass({
render: function(){
return (
<ul>
{
this.props.items.map(function (item) {
return <li key={item}>{item}</li>;
})
}
</ul>
);
}
});

ReactDOM.render(<FilteredList initialItems={myItems} />,
document.getElementById('container'));


When run it I get the following error:

app.js:31 Uncaught SyntaxError: Unexpected token <


Any idea how to fix it?

Answer

Even though you have added babel-standalone to your page, you still need to tell it to transpile your app.js file.

You do it by adding type="text/babel" to your script tag:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

    <link rel="stylesheet" type="text/css" href="css/main.css">

    <script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.14.0/react.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.14.0/react-dom.js"></script>
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/babel-standalone/6.7.7/babel.min.js">    </script>
    <script type="text/babel" src="js/app.js"></script>

</head>
<body>
    <div id="container">
    </div>
</body>
</html>

Just for reference you can also transpile your code inline with:

Babel.transform(input, { presets: ['es2015'] }).code;