👩🏿‍🎨 🔺 🤮 DataStore - CRUD (Créer la suppression de la mise à jour en lecture) 🤣 🦐 🧔🏿

Au revoir Redux, MobX, Apollo! La ligne entre le backend et le frontend est rompue! Une étape innovante dans l'évolution des managers d'État.

Magasin de données

L'une des tâches les plus difficiles dans le développement d'applications Web et mobiles est de synchroniser les données entre les appareils et d'effectuer des opérations hors ligne. Idéalement, lorsque l'appareil est hors ligne, vos clients devraient pouvoir continuer à utiliser votre application non seulement pour accéder aux données, mais aussi pour les créer et les modifier. Lorsque l'appareil revient en ligne, l'application doit se reconnecter au backend, synchroniser les données et résoudre les conflits, le cas échéant. La gestion correcte de tous les cas extrêmes nécessite beaucoup de code indifférencié, même lorsque vous utilisez le cache AWS AppSync SDK sur un appareil avec des mutations autonomes et une synchronisation delta.

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DataStore Delta Sync GraphQL .

DataStore AWS Amplify Redux, MobX, Apollo, Relay, , :

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1. Real time

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web sockets?

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, fullStack serverless AWS Amplify, real time , , , , GraphQL . , , , AWS Amplify Store:

type Job
  @model
  @auth(
    rules: [
      {allow: owner, ownerField: "owner", operations: [create, update, delete]},
    ])
{
  id: ID!
  position: String!
  rate: String!
  description: String!
  owner: String
}

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Redux, MobX, Apollo , . AWS Amplify DataStore

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2.

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Old school?

fetch axios?

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npm run amplify-modelgen

models .

graphql , Flow, TS JavaScript.

3. Offline data & cloud sync

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Github.

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git clone https://github.com/fullstackserverless/startup.git

cd startup

Install dependencies

yarn

npm install

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amplify push

All resources are updated in the cloud

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c DataStore — npx- ampify-app.

npx amplify-app@latest

React Native Cli,

yarn add @aws-amplify/datastore @react-native-community/netinfo @react-native-community/async-storage

React Native> 0.60, iOS:

cd ios && pod install && cd ..

API(App Sync)

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, API

amplify add api

GraphQL amplify/backend/api/<datasourcename>/schema.graphql :

type Job
  @model
  @auth(
    rules: [
      {allow: owner, ownerField: "owner", operations: [create, update, delete]},
    ])
{
  id: ID!
  position: String!
  rate: String!
  description: String!
  owner: String
}

, DataStore, — . GraphQL JavaScript, iOS Android , . GraphQL , Automerge AppSync. NPX Amplify CLI.

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npm run amplify-modelgen

src/models

API

DataStore API

amplify update api

amplify push

All resources are updated in the cloud

READ

JobsMain src/screens/Jobs/JobsMain.js

Query, , useQuery , Flatlist.

import React, { useEffect, useState } from 'react'
import { FlatList } from 'react-native'
import { Auth } from 'aws-amplify'
import { AppContainer, CardVacancies, Space, Header } from 'react-native-unicorn-uikit'
import { DataStore } from '@aws-amplify/datastore'
import { Job } from '../../models'
import { goBack, onScreen } from '../../constants'

const JobsMain = ({ navigation }) => {
  const [data, updateJobs] = useState([])

  const fetchJobs = async () => {
    const mess = await DataStore.query(Job)
    updateJobs(mess)
  }

  useEffect(() => {
    fetchJobs()
    const subscription = DataStore.observe(Job).subscribe(() => fetchJobs())
    return () => {
      subscription.unsubscribe()
    }
  }, [data])

  const _renderItem = ({ item }) => {
    const owner = Auth.user.attributes.sub
    const check = owner === item.owner
    return (
      <>
        <CardVacancies obj={item} onPress={onScreen(check ? 'JOB_ADD' : 'JOB_DETAIL', navigation, item)} />
        <Space height={20} />
      </>
    )
  }

  const _keyExtractor = (obj) => obj.id.toString()

  return (
    <AppContainer onPress={goBack(navigation)} flatlist>
      <FlatList
        scrollEventThrottle={16}
        data={data}
        renderItem={_renderItem}
        keyExtractor={_keyExtractor}
        onEndReachedThreshold={0.5}
        ListHeaderComponent={
          <Header
            onPress={goBack(navigation)}
            onPressRight={onScreen('JOB_ADD', navigation)}
            iconLeft="angle-dobule-left"
            iconRight="plus-a"
          />
        }
        stickyHeaderIndices={[0]}
      />
    </AppContainer>
  )
}

export { JobsMain }

JobDetail src/screens/Jobs/JobDetail.js

import React from 'react'
import { Platform } from 'react-native'
import { AppContainer, CardVacancies, Space, Header } from 'react-native-unicorn-uikit'
import { goBack } from '../../constants'

const JobDetail = ({ route, navigation }) => {
  return (
    <AppContainer>
      <Header onPress={goBack(navigation)} iconLeft="angle-dobule-left" />
      <CardVacancies obj={route.params} detail />
      <Space height={Platform.OS === 'ios' ? 100 : 30} />
    </AppContainer>
  )
}

export { JobDetail }

CREATE UPDATE DELETE

JobAdd src/screens/Jobs/JobAdd.js, CREATE UPDATE DELETE

import React, { useState, useEffect, useRef } from 'react'
import { AppContainer, Input, Space, Button, Header, ButtonLink } from 'react-native-unicorn-uikit'
import { DataStore } from '@aws-amplify/datastore'
import { Formik } from 'formik'
import * as Yup from 'yup'
import { Job } from '../../models'
import { goBack } from '../../constants'

const JobAdd = ({ route, navigation }) => {
  const [loading, setLoading] = useState(false)
  const [check, setOwner] = useState(false)
  const [error, setError] = useState('')

  const [input, setJob] = useState({
    id: '',
    position: '',
    rate: '',
    description: ''
  })

  const formikRef = useRef()

  useEffect(() => {
    const obj = route.params
    if (typeof obj !== 'undefined') {
      setOwner(true)
      setJob(obj)
      const { setFieldValue } = formikRef.current
      const { position, rate, description } = obj
      setFieldValue('position', position)
      setFieldValue('rate', rate)
      setFieldValue('description', description)
    }
  }, [route.params])

  const createJob = async (values) => (await DataStore.save(new Job({ ...values }))) && goBack(navigation)()

  const updateJob = async ({ position, rate, description }) => {
    try {
      setLoading(true)
      const original = await DataStore.query(Job, input.id)
      const update = await DataStore.save(
        Job.copyOf(original, (updated) => {
          updated.position = position
          updated.rate = rate
          updated.description = description
        })
      )
      update && goBack(navigation)()
      setLoading(false)
    } catch (err) {
      setError(err)
    }
  }

  const deleteJob = async () => {
    try {
      setLoading(true)
      const job = await DataStore.query(Job, input.id)
      const del = await DataStore.delete(job)
      del && goBack(navigation)()
      setLoading(false)
    } catch (err) {
      setError(err)
    }
  }

  return (
    <AppContainer onPress={goBack(navigation)} loading={loading} error={error}>
      <Header onPress={goBack(navigation)} iconLeft="angle-dobule-left" />
      <Space height={20} />
      <Formik
        innerRef={formikRef}
        initialValues={input}
        onSubmit={(values) => (check ? updateJob(values) : createJob(values))}
        validationSchema={Yup.object().shape({
          position: Yup.string().min(3).required(),
          rate: Yup.string().min(3).required(),
          description: Yup.string().min(3).required()
        })}
      >
        {({ values, handleChange, errors, setFieldTouched, touched, isValid, handleSubmit }) => (
          <>
            <Input
              name="position"
              value={values.position}
              onChangeText={handleChange('position')}
              onBlur={() => setFieldTouched('position')}
              placeholder="Position"
              touched={touched}
              errors={errors}
            />
            <Input
              name="rate"
              keyboardType="numeric"
              value={`${values.rate}`}
              onChangeText={handleChange('rate')}
              onBlur={() => setFieldTouched('rate')}
              placeholder="Rate"
              touched={touched}
              errors={errors}
            />
            <Input
              name="description"
              value={values.description}
              onChangeText={handleChange('description')}
              onBlur={() => setFieldTouched('description')}
              placeholder="Description"
              touched={touched}
              errors={errors}
              multiline
              numberOfLines={5}
            />
            <Space height={40} />
            <Button title={check ? 'Update' : 'Create'} disabled={!isValid} onPress={handleSubmit} formik />
            {check && (
              <>
                <Space height={10} />
                <ButtonLink title="or" textStyle={{ alignSelf: 'center' }} />
                <Space height={15} />
                <Button title="DELETE" onPress={deleteJob} cancel />
              </>
            )}
          </>
        )}
      </Formik>
      <Space height={100} />
    </AppContainer>
  )
}

export { JobAdd }

screens/Jobs/index.js

export * from './JobsMain'
export * from './JobDetail'
export * from './JobAdd'

Jobs StackNavigator

import * as React from 'react'
import { createStackNavigator } from '@react-navigation/stack'
import { enableScreens } from 'react-native-screens' // eslint-disable-line
import { Hello, SignUp, SignIn, ConfirmSignUp, User, Forgot, ForgotPassSubmit } from './screens/Authenticator'
import { JobsMain, JobDetail, JobAdd } from './screens/Jobs'

enableScreens()

const Stack = createStackNavigator()

const AppNavigator = () => {
  return (
    <Stack.Navigator
      screenOptions={{
        headerShown: false
      }}
      initialRouteName="HELLO"
    >
      <Stack.Screen name="HELLO" component={Hello} />
      <Stack.Screen name="SIGN_UP" component={SignUp} />
      <Stack.Screen name="SIGN_IN" component={SignIn} />
      <Stack.Screen name="FORGOT" component={Forgot} />
      <Stack.Screen name="FORGOT_PASSWORD_SUBMIT" component={ForgotPassSubmit} />
      <Stack.Screen name="CONFIRM_SIGN_UP" component={ConfirmSignUp} />
      <Stack.Screen name="USER" component={User} />
      <Stack.Screen name="JOBS_MAIN" component={JobsMain} />
      <Stack.Screen name="JOB_DETAIL" component={JobDetail} />
      <Stack.Screen name="JOB_ADD" component={JobAdd} />
    </Stack.Navigator>
  )
}

export default AppNavigator

Jobs

User screens/Authenticator/User/index.js

import React, { useState, useEffect } from 'react'
import { Auth } from 'aws-amplify'
import * as Keychain from 'react-native-keychain'
import { AppContainer, Button } from 'react-native-unicorn-uikit'
import { goHome, onScreen } from '../../../constants'

const User = ({ navigation }) => {
  const [loading, setLoading] = useState(false)
  const [error, setError] = useState('')

  useEffect(() => {
    const checkUser = async () => {
      await Auth.currentAuthenticatedUser()
    }
    checkUser()
  })

  const _onPress = async () => {
    setLoading(true)
    try {
      await Auth.signOut()
      await Keychain.resetInternetCredentials('auth')
      goHome(navigation)()
    } catch (err) {
      setError(err.message)
    }
  }

  const _onPressJob = () => onScreen('JOBS_MAIN', navigation)() //    JOBS_MAIN

  return (
    <AppContainer message={error} loading={loading}>
      <Button title="Sign Out" onPress={_onPress} />
      <Button title="Jobs" onPress={_onPressJob} />
    </AppContainer>
  )
}

export { User }