# Using React Helmet to build `` content
## Installation and general usage
See https://github.com/nfl/react-helmet for details. Run `yarn add react-helmet` in your `client` directory to add this package to your application.
## Example
Here is what you need to do in order to configure your Rails application to work with **ReactHelmet**.
Create generator function for server rendering like this:
```javascript
export default (props, _railsContext) => {
const componentHtml = renderToString();
const helmet = Helmet.renderStatic();
const renderedHtml = {
componentHtml,
title: helmet.title.toString(),
};
return { renderedHtml };
};
```
You can add more **helmet** properties to result, e.g. **meta**, **base** and so on. See https://github.com/nfl/react-helmet#server-usage.
Use regular component or generator function for client-side:
```javascript
export default (props, _railsContext) => (
);
```
Put **ReactHelmet** component somewhere in your ``:
```javascript
import { Helmet } from 'react-helmet';
const App = (props) => (
Custom page title
...
);
export default App;
```
Register your generators for client and server sides:
```javascript
import ReactHelmetApp from '../ReactHelmetClientApp';
ReactOnRails.register({
ReactHelmetApp
});
```
```javascript
import ReactHelmetApp from '../ReactHelmetServerApp';
ReactOnRails.register({
ReactHelmetApp
});
```
Now when the `react_component_hash` helper is called with **"ReactHelmetApp"** as a first argument it will return a hash instead of HTML string:
```ruby
<% react_helmet_app = react_component_hash("ReactHelmetApp", prerender: true, props: { hello: "world" }, trace: true) %>
<% content_for :title do %>
<%= react_helmet_app['title'] %>
<% end %>
<%= react_helmet_app["componentHtml"] %>
```
So now we're able to insert received title tag to our application layout:
```ruby
<%= yield(:title) if content_for?(:title) %>
```
Note: Use of `react_component` for this functionality is deprecated. Please use `react_component_hash` instead.