Create A WebView-free Blog App with React Native Render HTML, Part I

June 27, 2021 · 5 min read

Developer of React Native Render HTML v6

The Foundry Release beta is out, and I wanted to show you its powerful capabilities with a very common use-case: rendering an article from a Blog. For this case study, we will use the official React Native blog, which is build on Docusaurus. The App will feature:

A list of articles fetched from an RSS Feed;
An aside table of content displayed in a drawer layout;
A scroll-to-section feature when pressing a TOC entry.

This study will be a good opportunity to learn or revisit important techniques to master this library. Also note that the implementation, especially targeted CSS classes are inherently tied to how the website is structured. Since the React Native blog is built on Docusaurus, the implementation should be very easy to transpose in other docusaurus-based blogs.

Now, let's get to the heart of it ❤️

tip

The source code of this case study is available in the main branch of this repo: jsamr/rnrh-blog. The enhanced branch contains a few more features beyond this tutorial, such as a refined UI, dark mode, caching with react-queries... etc. You can try out the enhanced version right now with expo, see the project page for instructions.

tip

If you have any question or remarks regarding this tutorial, you're welcome in our Discord channel.

Introduction#

I propose starting with the end-result, and then explain how we got there. The App has two screens:

The Home screen, displaying a list of articles fetched from a RSS feed.
The Article screen, displaying the body of the article and a side-menu to navigate into sections.

The navigation is handled by React Navigation library, and most of the components come from React Native Paper.

important

The steps laid out in this tutorial won't cover the enhanced implementation such as seen in below gallery. We will focus on simplicity and won't spend much time on theming. But you can always check out the enhanced implementation here: jsamr/rnrh-blog (enhanced branch)

Gallery#

Try Out The React Native Blog App on Expo!

QR code to scan the React Native Blog App in Expo Go

Getting Started#

We will use Expo cli to initiate the project. If you don't have it installed yet, install the cli globally:

npm install -g expo-cli

After which, create the project. We will use TypeScript and yarn, but of course you're free to set a plain JavaScript project instead.

expo init rnrh-blog -t expo-template-blank-typescript --name Blog --yarn

Then we need to install dependencies required for this project:

cd rnrh-blog
expo install @react-navigation/native@^5 @react-navigation/stack@^5 \
     react-native-screens react-native-safe-area-context \
     react-native-rss-parser@^1 react-native-render-html \
     react-native-paper@^4 react-native-gesture-handler events

Now, run

yarn android

to launch the App in an android emulator.

Setting Up Navigation#

Declare the Routes in TypeScript#

Create a new shared-types.ts file in the root of your project with the following definitions:

shared-types.ts

export type RootStackParamList = {
  Home: undefined;
  Article: ArticleParams;
};

export interface ArticleParams {
  url: string;
  title: string;
}

These types define the names of the routes supported by our stack navigator, and the types of their params. Notice that the Article route takes a url and title for display.

Create the Routes Components#

Add two files, screens/HomeScreen.tsx and screens/ArticleScreen.tsx:

screens/HomeScreen.tsx

import React from 'react';
import { Text } from 'react-native';
import { SafeAreaView } from 'react-native-safe-area-context';

export default function HomeScreen() {
  return (
    <SafeAreaView>
      <Text>Welcome to the React Native Blog!</Text>
    </SafeAreaView>
  );
}

screens/ArticleScreen.tsx

import React, { useEffect } from 'react';
import { StackScreenProps } from '@react-navigation/stack';
import { RootStackParamList } from '../shared-types';

type ArticleScreenProps = StackScreenProps<RootStackParamList, 'Article'>;

function useSetTitleEffect({ route, navigation }: ArticleScreenProps) {
  useEffect(
    function setTitle() {
      navigation.setOptions({ title: route.params.title });
    },
    [route.params.title, navigation]
  );
}

export default function ArticleScreen(props: ArticleScreenProps) {
  useSetTitleEffect(props);
  return null;
}

Remarks

In the ArticleScreen component, we define an effect to set the screen title displayed in the header based on a route parameter. The logic is internal to the React Navigation library.

Create the Root Navigator#

Replace the current App.tsx with the following:

App.tsx

import { createStackNavigator } from '@react-navigation/stack';
import { SafeAreaProvider } from 'react-native-safe-area-context';
import React from 'react';
import { NavigationContainer } from '@react-navigation/native';
import { RootStackParamList } from './shared-types';
import HomeScreen from './screens/HomeScreen';
import ArticleScreen from './screens/ArticleScreen';

const Stack = createStackNavigator<RootStackParamList>();

export default function App() {
  return (
    <SafeAreaProvider>
      <NavigationContainer>
        <Stack.Navigator
          screenOptions={{
            headerShown: false
          }}>
          <Stack.Screen
            name="Home"
            options={{ title: 'Blog' }}
            component={HomeScreen}
          />
          <Stack.Screen
            name="Article"
            options={{ headerShown: true }}
            component={ArticleScreen}
          />
        </Stack.Navigator>
      </NavigationContainer>
    </SafeAreaProvider>
  );
}

You should finally see a screen displaying "Welcome to the React Native Blog"! Great, the structure is ready: from now on, we can implement each of those screens.

tip

If you are not familiar with React Navigation, you could benefit from reading its Stack Navigator documentation before going further.

Now, we're ready to implement the RSS feed list. Let's jump to Part II.

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