How to pass server data into React component

Question

I'm just learning React, and while I understand many of the basics there is one concept I haven't seen anyone cover: how do I take information loaded via the server-side language (e.g. PHP) and use it when loading up the React view?

I would have expected that I'd just have the RenderDom call in my php view, such as:

// In the pre-compiled JSX file
var Greeting = React.createClass({
    render: function() {
        <div>
            <h1>Hello, { this.props.username }</h1>
        </div>
    }
});

// In my PHP view
<script type="text/jsx">
    ReactDOM.render( <Greeting username="<?php echo $username; ?>"/>, document.body );
</script>

But that doesn't work; nothing is displayed. I'm thinking that's because the text/jsx script area doesn't get executed...but of course if I remove that there's a syntax error.

Soo...I'm just wondering, what's the typical method for taking data loaded up from the DB and passing it into a React component?

Answer 1

Method 1: Define a global variable.

In your main PHP file:

<script>
    window.reactInit = {
        username: <?php echo $username; ?>
    };
</script>

In your component:

class Greeting extends React.Component {
    constructor(props) {
        super(props);
        this.username = reactInit.username;
    }
}

If you use Redux, you may find this method particularly useful. Because ANY of your reducers can access this global variable during building of the initial state.

Method 2: Use data-* attributes.

<div id="app" data-username="<?php echo $username; ?>"></div>

All data-* attributes are passed by using {...app.dataset}.

const app = document.getElementById('app');
ReactDOM.render(<Greeting {...app.dataset} />, app);

Now you can access your server data as ordinary props.

class Greeting extends React.Component {
    constructor(props) {
        super(props);
        console.log(this.props.username);
    }
}

This method is not so flexible as the previous one, but seems to be more consistent with React philosophy.

Answer 2

The React way would be to load in the data via a RESTful API.

However, you could look into serverside rendering of React components with PHP V8JS. Not sure how stable it is, but if, it would be a very good/better alternative to the AJAX call on the client. It would look somewhat like this:

// the library
$react_source = file_get_contents('/path/to/build/react.js');
// all custom code concatenated
$app_source = file_get_contents('/path/to/custom/components.js');

$rjs = new ReactJS($react_source, $app_source);
$rjs->setComponent('MyComponent', array(
  'any'   =>  1,
  'props' =>  2
  )
);

/// ...

// print rendered markup
echo '<div id="here">' . $rjs->getMarkup() . '</div>';

If you actually want to render this in the browser, you can use plain Javascript instead of JSX:

<?php $username = 'Eric Andre'; ?>
<script type="text/javascript">
  ReactDOM.render(React.createElement(Greeting, { username: "<?php echo $username; ?>" }), document.body);
</script>

Another option would be to transform the JSX into plain Javascript with babel-browser and use <script type="text/babel">. Keep in mind that babel-browser is not in active development anymore and also not intended for production use.

<?php $username = 'Eric Andre'; ?>
<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/6.1.19/browser.min.js"></script>
<script type="text/babel">
  ReactDOM.render( <Greeting username="<?php echo $username; ?>"/>, document.body );
</script>