BRIGAD Workshop

Welcome everyone 🤗! Today we will learn the basics of several technologies we use everyday at Brigad:

• React-native
• Graphql
• TypeScript

1. Dependencies

We will use expo to build our app.

yarn global add expo-cli

expo-cli init giphyapp (or yourappname)

cd giphyapp (or yourappname)

Let's start our app !

yarn start

Let's also open the current folder in our favorite editor. If you don't have any, check out VSCode

You can start playing with your app by adding any react-native component.

STEP 1 - NETWORK

Let's connect our app to our API. We will use apollo to do so! You can explore the API here: https://giphy-graphql-api.herokuapp.com/

Let's install apollo:

yarn add apollo-client apollo-cache-inmemory apollo-link-http react-apollo graphql-tag graphql

1 - Let's create an apollo Client https://www.apollographql.com/docs/react/api/apollo-client/#apolloclient https://www.apollographql.com/docs/link/links/http/

You can make queries with the client to make sure everything is working fine

Test hint

client
  .query({
    query: gql`
      {
        gifs(search: "banana") {
          id
          title
          urlSmall
       }
     }
    `
  })
  .then(result => console.log(result));

2 - Let's wrap our app inside an ApolloProvider https://www.apollographql.com/docs/react/api/react-apollo/#apolloprovider

You can now use the Query component inside your app, so make sure it's working fine

3 - Let's move our queries to .gql files

yarn add -D @bam.tech/react-native-graphql-transformer@https://github.com/titozzz/react-native-graphql-transformer.git#cbd88cc5524b83f98e4f2cf8d5ed6430aac190a1

Create a metro.config.js

// eslint-disable-next-line import/no-extraneous-dependencies
const { getDefaultConfig } = require('metro-config');

const getSourceExts = async () => [
  ...(await getDefaultConfig()).resolver.sourceExts,
  'gql',
];

const getConfig = async () => ({
  ...(process.env.CI === 'true' ? { maxWorkers: 2 } : {}),
  transformer: {
    babelTransformerPath: require.resolve(
      '@bam.tech/react-native-graphql-transformer',
    ),
  },
  resolver: {
    sourceExts: await getSourceExts(),
  },
});

module.exports = getConfig();

gifs.gql

query gifs($search: String!) {
  gifs(search: $search) {
    id
    title
    urlSmall
  }
}

App.tsx

import gifsQuery from './gifs.gql';

gql.d.ts

declare module '*.gql' {
  const content: DocumentNode;
  export default content;
}

4 - Let's generate types from the back-end

Let's install the apollo CLI:

yarn add -D apollo

Create an apollo.config.js file containing

module.exports = {
  client: {
    service: {
      name: 'giphy',
      url: 'https://giphy-graphql-api.herokuapp.com',
      includes: [`./**/*.gql`],
    },
  },
};

And run:

yarn apollo client:codegen . -c=apollo.config.js --target=typescript --includes=./**/*.gql

Or add a new script in your package.json

"codegen": "yarn apollo client:codegen . -c=apollo.config.js --target=typescript --includes=./**/*.gql"

and run yarn codegen

You should have one generated .ts file per .gql file you have. You should re-run the command everytime you update your .gql files.

Last step: create a React component that will understand the types returned by the servers:

GifsQuery.tsx

import React, { ReactNode, FunctionComponent } from 'react';
import { Query, QueryResult, QueryProps } from 'react-apollo';

import {
  gifs as GifsQueryData,
  gifsVariables as GifsQueryVariables,
  gifs_gifs as Gif,
} from './gifs';

import gifsQuery from './gifs.gql';

class BaseGifsQuery extends Query<GifsQueryData, GifsQueryVariables> {}

interface GifsQueryProps {
  children: (
    result: Omit<QueryResult<GifsQueryData>, 'data'> & {
      gifs: Gif[] | null;
    },
  ) => ReactNode;
  variables: GifsQueryVariables;
}

const GifsQuery: FunctionComponent<
  Omit<QueryProps<GifsQueryData>, 'query' | 'children' | 'variables'> &
    GifsQueryProps
> = ({ children, ...otherProps }) => (
  <BaseGifsQuery {...otherProps} query={gifsQuery}>
    {({ data, ...otherArgs }) =>
      children({
        ...otherArgs,
        gifs: data && data.gifs ? data.gifs : null,
      })
    }
  </BaseGifsQuery>
);

export default GifsQuery;

export { Gif, GifsQueryData, GifsQueryVariables, GifsQuery };

import GifsQuery from './GifsQuery';

STEP 2 - DISPLAY EVERYTHING

1 - You should display a list of gifs inside your app. Feel free to use any component you like to do so, be creative!

Bonus: You can add a text input to search any gifs you want! (if you do that maybe have a look to this.

2 - Let's add some navigation to the app

 yarn add react-navigation

3 - Add some navigators... (stack, tab, etc)

4 - Infinite loading

If you have implemented a FlatList, try onEndReached

                onEndReached={() =>
                  fetchMore({
                    variables: {
                      search: search || 'banana',
                      offset: gifs.length,
                    },
                    updateQuery: (prev, { fetchMoreResult }) => {
                      if (!fetchMoreResult) {
                        return prev;
                      }

                      return {
                        ...prev,
                        gifs: [...prev.gifs, ...fetchMoreResult.gifs],
                      };
                    },
                  })
                }

Don't forget to update gifs.gql with the offset variable

query gifs($search: String!, $offset: Int) {
  gifs(search: $search, offset: $offset) {
    id
    title
    url
    urlSmall
    source
    user {
      displayName
      avatarUrl
    }
  }
}

STEP 3 - BE CREATIVE

You now have enougth tools to build a small app! List of things you could do:

• https://docs.expo.io/versions/latest/react-native/share/
• https://github.com/fram-x/FluidTransitions
• https://facebook.github.io/react-native/docs/animated // https://github.com/kmagiera/react-native-reanimated