try-catch-loader v1.0.2

try-catch loader

A Webpack loader that wraps required JS in a try/catch.

Why would I use that?

Some client-side JS libraries don't like being loaded on the server - ones that do something like check navigator.userAgent when loading, for example. This causes problems when you're trying to do server-side rendering of a React component (for example) as the require statement will fail.

What doesn't it do?

Fix the library. It'll just cause the require statement to return null, so the module will be inaccessible. You either need it to be inside a function that doesn't get run on the server, or wrap it in an if statement that checks what it is.

Give me an example

Fine. Consider the following React component:

var someClientsideLibrary = require('some-client-side-library);
var React = require('react');

module.exports = React.createClass({
    render: function() {
        return <div>Hello.</div>
    },
    componentDidMount: function() {
        someClientsideLibrary.doThing(this.findDOMNode());
    }
})

If someClientsideLibrary uses document, navigator, window etc. on load it will break any attempt at server-side rendering of this component. When wrapped in try-catch it won't - it will just return null. Normally that would be a problem, but server-side rendered React components never run componentDidMount (instead running it client-side on load), so the render won't actually throw an error.

How do I use it?

Glad you asked. I recommend not hard-coding this in your webpack config, as try/catching every library will add a performance penalty. Instead, add it in the require statement, like so:

require("try-catch!a-troublesome-library");

Then submit a pull request to that library with a suggestion on how to make it server friendly (like, moving the use of window to the first time the library is used rather than when it is loaded).