Mobile Application Development Tutorial - React Native

About This Tutorial

• This tutorial assumes that you have completed the Web Application Development tutorial and built an ABP based application named Acme.BookStore with React Native as the mobile option.. Therefore, if you haven't completed the Web Application Development tutorial, you either need to complete it or download the source code from down below and follow this tutorial.
• In this tutorial, we will only focus on the UI side of the Acme.BookStore application and will implement the CRUD operations.
• Before starting, please make sure that the React Native Development Environment is ready on your machine.

Download the Source Code

You can use the following link to download the source code of the application described in this article:

• Acme.BookStore

If you encounter the "filename too long" or "unzip" error on Windows, please see this guide.

The Book List Page

In react native there is no dynamic proxy generation, that's why we need to create the BookAPI proxy manually under the ./src/api folder.

import api from "./API";

export const getList = () => api.get("/api/app/book").then(({ data }) => data);

export const get = (id) =>
  api.get(`/api/app/book/${id}`).then(({ data }) => data);

export const create = (input) =>
  api.post("/api/app/book", input).then(({ data }) => data);

export const update = (input, id) =>
  api.put(`/api/app/book/${id}`, input).then(({ data }) => data);

export const remove = (id) =>
  api.delete(`/api/app/book/${id}`).then(({ data }) => data);

Add the Book Store menu item to the navigation

For the create menu item, navigate to ./src/navigators/DrawerNavigator.js file and add BookStoreStack to Drawer.Navigator component.

//Other imports..
import BookStoreStackNavigator from "./BookStoreNavigator";

const Drawer = createDrawerNavigator();

export default function DrawerNavigator() {
  return (
    <Drawer.Navigator
      initialRouteName="Home"
      drawerContent={DrawerContent}
      defaultStatus="closed"
    >
      {/*Added Screen*/}
      <Drawer.Screen
        name="BookStoreStack"
        component={BookStoreStackNavigator}
        options={{ header: () => null }}
      />
      {/*Added Screen*/}
    </Drawer.Navigator>
  );
}

Create the BookStoreStackNavigator in ./src/navigators/BookStoreNavigator.js, this navigator will be used for the BookStore menu item.

import React from "react";
import { SafeAreaView } from "react-native-safe-area-context";
import { createNativeStackNavigator } from "@react-navigation/native-stack";
import i18n from "i18n-js";
import HamburgerIcon from "../components/HamburgerIcon/HamburgerIcon";
import BookStoreScreen from "../screens/Books/BookStoreScreen";

const Stack = createNativeStackNavigator();

export default function BookStoreStackNavigator() {
  return (
    <SafeAreaView style={{ flex: 1 }}>
      <Stack.Navigator initialRouteName="BookStore">
        <Stack.Screen
          name="BookStore"
          component={BookStoreScreen}
          options={({ navigation }) => ({
            title: i18n.t("BookStore::Menu:BookStore"),
            headerLeft: () => <HamburgerIcon navigation={navigation} />,
          })}
        />
      </Stack.Navigator>
    </SafeAreaView>
  );
}

• BookStoreScreen will be used to store the books and authors page

Add the BookStoreStack to the screens object in the ./src/components/DrawerContent/DrawerContent.js file. The DrawerContent component will be used to render the menu items.

// Imports..
const screens = {
  HomeStack: { label: "::Menu:Home", iconName: "home" },
  DashboardStack: {
    label: "::Menu:Dashboard",
    requiredPolicy: "BookStore.Dashboard",
    iconName: "chart-areaspline",
  },
  UsersStack: {
    label: "AbpIdentity::Users",
    iconName: "account-supervisor",
    requiredPolicy: "AbpIdentity.Users",
  },
  //Add this property
  BookStoreStack: {
    label: "BookStore::Menu:BookStore",
    iconName: "book",
  },
  //Add this property
  TenantsStack: {
    label: "Saas::Tenants",
    iconName: "book-outline",
    requiredPolicy: "Saas.Tenants",
  },
  SettingsStack: {
    label: "AbpSettingManagement::Settings",
    iconName: "cog",
    navigation: null,
  },
};
// Other codes..

Create Book List page

Before creating the book list page, we need to create the BookStoreScreen.js file under the ./src/screens/BookStore folder. This file will be used to store the books and authors page.

import React from "react";
import i18n from "i18n-js";
import { BottomNavigation } from "react-native-paper";
import BooksScreen from "./Books/BooksScreen";

const BooksRoute = () => <BooksScreen />;

function BookStoreScreen({ navigation }) {
  const [index, setIndex] = React.useState(0);
  const [routes] = React.useState([
    {
      key: "books",
      title: i18n.t("BookStore::Menu:Books"),
      focusedIcon: "book",
      unfocusedIcon: "book-outline",
    },
  ]);

  const renderScene = BottomNavigation.SceneMap({
    books: BooksRoute,
  });

  return (
    <BottomNavigation
      navigationState={{ index, routes }}
      onIndexChange={setIndex}
      renderScene={renderScene}
    />
  );
}
export default BookStoreScreen;

Create the BooksScreen.js file under the ./src/screens/BookStore/Books folder.

import React from "react";
import { useSelector } from "react-redux";
import { View } from "react-native";
import { useTheme, List } from "react-native-paper";
import { getBooks } from "../../api/BookAPI";
import i18n from "i18n-js";
import DataList from "../../components/DataList/DataList";
import { createAppConfigSelector } from "../../store/selectors/AppSelectors";

function BooksScreen({ navigation }) {
  const theme = useTheme();
  const currentUser = useSelector(createAppConfigSelector())?.currentUser;

  return (
    <View style={{ flex: 1, backgroundColor: theme.colors.background }}>
      {currentUser?.isAuthenticated && (
        <DataList
          navigation={navigation}
          fetchFn={getBooks}
          render={({ item }) => (
            <List.Item
              key={item.id}
              title={item.name}
              description={i18n.t("BookStore::Enum:BookType." + item.type)}
            />
          )}
        />
      )}
    </View>
  );
}
export default BooksScreen;

• getBooks function is used to fetch the books from the server.
• i18n API to localize the given key. It uses the incoming resource from the application-localization endpoint.
• DataList component takes the fetchFn property that we'll give to the API request function, it's used to fetch data and maintain the logic of lazy loading etc.

Creating a New Book

Add the @react-native-community/datetimepicker package for the date functionality.

yarn expo install @react-native-community/datetimepicker

//or

npx expo install @react-native-community/datetimepicker

Add the CreateUpdateBook Screen to the BookStoreNavigator

Like the BookStoreScreen we need to add the CreateUpdateBookScreen to the ./src/navigators/BookStoreNavigator.js file.

//Other codes

import { Button } from "react-native-paper"; //Added this line

import CreateUpdateBookScreen from "../screens/BookStore/Books/CreateUpdateBook/CreateUpdateBookScreen"; //Added this line

//Other codes

export default function BookStoreStackNavigator() {
  return (
    <SafeAreaView style={{ flex: 1 }}>
      <Stack.Navigator initialRouteName="BookStore">
        {/*Other screens*/}

        {/* Added this screen */}
        <Stack.Screen
          name="CreateUpdateBook"
          component={CreateUpdateBookScreen}
          options={({ route, navigation }) => ({
            title: i18n.t(
              route.params?.bookId ? "BookStore::Edit" : "BookStore::NewBook"
            ),
            headerRight: () => (
              <Button
                mode="text"
                onPress={() => navigation.navigate("BookStore")}
              >
                {i18n.t("AbpUi::Cancel")}
              </Button>
            ),
          })}
        />
      </Stack.Navigator>
    </SafeAreaView>
  );
}

To navigate to the CreateUpdateBookScreen, we need to add the CreateUpdateBook button to the BooksScreen.js file.

//Other imports..

import {
  // rest imports..,
  StyleSheet,
} from "react-native";

import {
  // rest imports..,
  AnimatedFAB,
} from "react-native-paper";

function BooksScreen({ navigation }) {
  //Other codes..

  return (
    <View style={{ flex: 1, backgroundColor: theme.colors.background }}>
      {/* Other codes..*/}

      {/* Included Code */}
      {currentUser?.isAuthenticated && (
        <AnimatedFAB
          icon={"plus"}
          label={i18n.t("BookStore::NewBook")}
          color="white"
          extended={false}
          onPress={() => navigation.navigate("CreateUpdateBook")}
          visible={true}
          animateFrom={"right"}
          iconMode={"static"}
          style={[styles.fabStyle, { backgroundColor: theme.colors.primary }]}
        />
      )}
      {/* Included Code */}
    </View>
  );
}

//Added lines
const styles = StyleSheet.create({
  container: {
    flexGrow: 1,
  },
  fabStyle: {
    bottom: 16,
    right: 16,
    position: "absolute",
  },
});
//Added lines

export default BooksScreen;

After adding the CreateUpdateBook button, we need to add the CreateUpdateBookScreen.js file under the ./src/screens/BookStore/Books/CreateUpdateBook folder.

import PropTypes from "prop-types";
import React from "react";

import { create } from "../../../../api/BookAPI";
import LoadingActions from "../../../../store/actions/LoadingActions";
import { createLoadingSelector } from "../../../../store/selectors/LoadingSelectors";
import { connectToRedux } from "../../../../utils/ReduxConnect";
import CreateUpdateBookForm from "./CreateUpdateBookForm";

function CreateUpdateBookScreen({ navigation, startLoading, clearLoading }) {
  const submit = (data) => {
    startLoading({ key: "save" });

    create(data)
      .then(() => navigation.goBack())
      .finally(() => clearLoading());
  };

  return <CreateUpdateBookForm submit={submit} />;
}

CreateUpdateBookScreen.propTypes = {
  startLoading: PropTypes.func.isRequired,
  clearLoading: PropTypes.func.isRequired,
};

export default connectToRedux({
  component: CreateUpdateBookScreen,
  stateProps: (state) => ({ loading: createLoadingSelector()(state) }),
  dispatchProps: {
    startLoading: LoadingActions.start,
    clearLoading: LoadingActions.clear,
  },
});

• In this page we'll store logic, send post/put requests, get the selected book data and etc.
• This page will wrap the CreateUpdateBookFrom component and pass the submit function with other properties.

Create a CreateUpdateBookForm.js file under the ./src/screens/BookStore/Books/CreateUpdateBook folder and add the following code to it.

import React, { useRef, useState } from "react";
import {
  Platform,
  KeyboardAvoidingView,
  StyleSheet,
  View,
  ScrollView,
} from "react-native";

import { useFormik } from "formik";
import i18n from "i18n-js";
import PropTypes from "prop-types";
import * as Yup from "yup";
import { useTheme, TextInput } from "react-native-paper";
import DateTimePicker from "@react-native-community/datetimepicker";

import { FormButtons } from "../../../../components/FormButtons";
import ValidationMessage from "../../../../components/ValidationMessage/ValidationMessage";
import AbpSelect from "../../../../components/Select/Select";

const validations = {
  name: Yup.string().required("AbpValidation::ThisFieldIsRequired."),
  price: Yup.number().required("AbpValidation::ThisFieldIsRequired."),
  type: Yup.string().nullable().required("AbpValidation::ThisFieldIsRequired."),
  publishDate: Yup.string()
    .nullable()
    .required("AbpValidation::ThisFieldIsRequired."),
};

const props = {
  underlineStyle: { backgroundColor: "transparent" },
  underlineColor: "#333333bf",
};

function CreateUpdateBookForm({ submit }) {
  const theme = useTheme();

  const [bookTypeVisible, setBookTypeVisible] = useState(false);
  const [publishDateVisible, setPublishDateVisible] = useState(false);

  const nameRef = useRef();
  const priceRef = useRef();
  const typeRef = useRef();
  const publishDateRef = useRef();

  const inputStyle = {
    ...styles.input,
    backgroundColor: theme.colors.primaryContainer,
  };
  const bookTypes = new Array(8).fill(0).map((_, i) => ({
    id: i + 1,
    displayName: i18n.t(`BookStore::Enum:BookType.${i + 1}`),
  }));

  const onSubmit = (values) => {
    if (!bookForm.isValid) {
      return;
    }

    submit({ ...values });
  };

  const bookForm = useFormik({
    enableReinitialize: true,
    validateOnBlur: true,
    validationSchema: Yup.object().shape({
      ...validations,
    }),
    initialValues: {
      name: "",
      price: "",
      type: "",
      publishDate: null,
    },
    onSubmit,
  });

  const isInvalidControl = (controlName = null) => {
    if (!controlName) {
      return;
    }

    return (
      ((!!bookForm.touched[controlName] && bookForm.submitCount > 0) ||
        bookForm.submitCount > 0) &&
      !!bookForm.errors[controlName]
    );
  };

  const onChange = (event, selectedDate) => {
    if (!selectedDate) {
      return;
    }

    setPublishDateVisible(false);

    if (event && event.type !== "dismissed") {
      bookForm.setFieldValue("publishDate", selectedDate, true);
    }
  };

  return (
    <View style={{ flex: 1, backgroundColor: theme.colors.background }}>
      <AbpSelect
        key="typeSelect"
        title={i18n.t("BookStore::Type")}
        visible={bookTypeVisible}
        items={bookTypes}
        hasDefualtItem={true}
        hideModalFn={() => setBookTypeVisible(false)}
        selectedItem={bookForm.values.type}
        setSelectedItem={(id) => {
          bookForm.setFieldValue("type", id, true);
          bookForm.setFieldValue(
            "typeDisplayName",
            bookTypes.find((f) => f.id === id)?.displayName || null,
            false
          );
        }}
      />

      {publishDateVisible && (
        <DateTimePicker
          testID="publishDatePicker"
          value={bookForm.values.publishDate || new Date()}
          mode={"date"}
          is24Hour={true}
          onChange={onChange}
        />
      )}

      <KeyboardAvoidingView
        behavior={Platform.OS === "ios" ? "padding" : "margin"}
      >
        <ScrollView keyboardShouldPersistTaps="handled">
          <View style={styles.input.container}>
            <TextInput
              mode="flat"
              ref={nameRef}
              error={isInvalidControl("name")}
              onSubmitEditing={() => priceRef.current.focus()}
              returnKeyType="next"
              onChangeText={bookForm.handleChange("name")}
              onBlur={bookForm.handleBlur("name")}
              value={bookForm.values.name}
              autoCapitalize="none"
              label={i18n.t("BookStore::Name")}
              style={inputStyle}
              {...props}
            />
            {isInvalidControl("name") && (
              <ValidationMessage>{bookForm.errors.name}</ValidationMessage>
            )}
          </View>

          <View style={styles.input.container}>
            <TextInput
              mode="flat"
              ref={priceRef}
              error={isInvalidControl("price")}
              onSubmitEditing={() => typeRef.current.focus()}
              returnKeyType="next"
              onChangeText={bookForm.handleChange("price")}
              onBlur={bookForm.handleBlur("price")}
              value={bookForm.values.price}
              autoCapitalize="none"
              label={i18n.t("BookStore::Price")}
              style={inputStyle}
              {...props}
            />
            {isInvalidControl("price") && (
              <ValidationMessage>{bookForm.errors.price}</ValidationMessage>
            )}
          </View>

          <View style={styles.input.container}>
            <TextInput
              ref={typeRef}
              label={i18n.t("BookStore::Type")}
              right={
                <TextInput.Icon
                  onPress={() => setBookTypeVisible(true)}
                  icon="menu-down"
                />
              }
              style={inputStyle}
              editable={false}
              value={bookForm.values.typeDisplayName}
              {...props}
            />
            {isInvalidControl("type") && (
              <ValidationMessage>{bookForm.errors.type}</ValidationMessage>
            )}
          </View>

          <View style={styles.input.container}>
            <TextInput
              ref={publishDateRef}
              label={i18n.t("BookStore::PublishDate")}
              right={
                <TextInput.Icon
                  onPress={() => setPublishDateVisible(true)}
                  icon="menu-down"
                />
              }
              style={inputStyle}
              editable={false}
              value={bookForm.values.publishDate?.toLocaleDateString()}
              {...props}
            />
            {isInvalidControl("publishDate") && (
              <ValidationMessage>
                {bookForm.errors.publishDate}
              </ValidationMessage>
            )}
          </View>

          <FormButtons style={styles.button} submit={bookForm.handleSubmit} />
        </ScrollView>
      </KeyboardAvoidingView>
    </View>
  );
}

const styles = StyleSheet.create({
  input: {
    container: {
      margin: 8,
      marginLeft: 16,
      marginRight: 16,
    },
    borderRadius: 8,
    borderTopLeftRadius: 8,
    borderTopRightRadius: 8,
  },
  button: {
    marginLeft: 16,
    marginRight: 16,
  },
});

CreateUpdateBookForm.propTypes = {
  submit: PropTypes.func.isRequired,
};

export default CreateUpdateBookForm;

• formik will manage the form state, validation and value changes.
• Yup allows for the build validation schema.
• AbpSelect component is used to select the book type.
• submit method will pass the form values to the CreateUpdateBookScreen component.

Update a Book

We need the navigation parameter for the get bookId and then navigate it again after the Create & Update operation. That's why we'll pass the navigation parameter to the BooksScreen component.

//Imports..

//Add navigation parameter
const BooksRoute = (nav) => <BooksScreen navigation={nav} />;

function BookStoreScreen({ navigation }) {
  //Other codes..

  const renderScene = BottomNavigation.SceneMap({
    books: () => BooksRoute(navigation), //Use this way
  });

  //Other codes..
}

export default BookStoreScreen;

Replace the code below in the BookScreen.js file under the ./src/screens/BookStore/Books folder.

import React from "react";
import { useSelector } from "react-redux";
import { Alert, View, StyleSheet } from "react-native";
import { useTheme, List, IconButton, AnimatedFAB } from "react-native-paper";
import { useActionSheet } from "@expo/react-native-action-sheet";
import i18n from "i18n-js";

import { getList } from "../../../api/BookAPI";
import DataList from "../../../components/DataList/DataList";
import { createAppConfigSelector } from "../../../store/selectors/AppSelectors";

function BooksScreen({ navigation }) {
  const theme = useTheme();
  const currentUser = useSelector(createAppConfigSelector())?.currentUser;
  const { showActionSheetWithOptions } = useActionSheet();

  const openContextMenu = (item) => {
    const options = [];

    options.push(i18n.t("AbpUi::Edit"));
    options.push(i18n.t("AbpUi::Cancel"));

    showActionSheetWithOptions(
      {
        options,
        cancelButtonIndex: options.length - 1,
      },
      (index) => {
        switch (options[index]) {
          case i18n.t("AbpUi::Edit"):
            edit(item);
            break;
        }
      }
    );
  };

  const edit = (item) => {
    navigation.navigate("CreateUpdateBook", { bookId: item.id });
  };

  return (
    <View style={{ flex: 1, backgroundColor: theme.colors.background }}>
      {currentUser?.isAuthenticated && (
        <DataList
          navigation={navigation}
          fetchFn={getList}
          render={({ item }) => (
            <List.Item
              key={item.id}
              title={item.name}
              description={i18n.t("BookStore::Enum:BookType." + item.type)}
              right={(props) => (
                <IconButton
                  {...props}
                  icon="dots-vertical"
                  rippleColor={"#ccc"}
                  size={20}
                  onPress={() => openContextMenu(item)}
                />
              )}
            />
          )}
        />
      )}

      {currentUser?.isAuthenticated && (
        <AnimatedFAB
          icon={"plus"}
          label={i18n.t("BookStore::NewBook")}
          color="white"
          extended={false}
          onPress={() => navigation.navigate("CreateUpdateBook")}
          visible={true}
          animateFrom={"right"}
          iconMode={"static"}
          style={[styles.fabStyle, { backgroundColor: theme.colors.primary }]}
        />
      )}
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flexGrow: 1,
  },
  fabStyle: {
    bottom: 16,
    right: 16,
    position: "absolute",
  },
});

export default BooksScreen;

Replace code below for CreateUpdateBookScreen.js file under the ./src/screens/BookStore/Books/CreateUpdateBook/

import PropTypes from "prop-types";
import React, { useEffect, useState } from "react";

import { get, create, update } from "../../../../api/BookAPI";
import LoadingActions from "../../../../store/actions/LoadingActions";
import { createLoadingSelector } from "../../../../store/selectors/LoadingSelectors";
import { connectToRedux } from "../../../../utils/ReduxConnect";
import CreateUpdateBookForm from "./CreateUpdateBookForm";

function CreateUpdateBookScreen({
  navigation,
  route,
  startLoading,
  clearLoading,
}) {
  const { bookId } = route.params || {};
  const [book, setBook] = useState(null);

  const submit = (data) => {
    startLoading({ key: "save" });

    (data.id ? update(data, data.id) : create(data))
      .then(() => navigation.goBack())
      .finally(() => clearLoading());
  };

  useEffect(() => {
    if (bookId) {
      startLoading({ key: "fetchBookDetail" });

      get(bookId)
        .then((response) => setBook(response))
        .finally(() => clearLoading());
    }
  }, [bookId]);

  return <CreateUpdateBookForm submit={submit} book={book} />;
}

CreateUpdateBookScreen.propTypes = {
  startLoading: PropTypes.func.isRequired,
  clearLoading: PropTypes.func.isRequired,
};

export default connectToRedux({
  component: CreateUpdateBookScreen,
  stateProps: (state) => ({ loading: createLoadingSelector()(state) }),
  dispatchProps: {
    startLoading: LoadingActions.start,
    clearLoading: LoadingActions.clear,
  },
});

• get method is used to fetch the book details from the server.
• update method is used to update the book on the server.
• route parameter will be used to get the bookId from the navigation.

Replace the CreateUpdateBookForm.js file with the code below. We'll use this file for the create and update operations.

//Imports..

//validateSchema

//props

function CreateUpdateBookForm({
  submit,
  book = null, //Add book parameter with default value
}) {
  //Other codes..

  const bookForm = useFormik({
    enableReinitialize: true,
    validateOnBlur: true,
    validationSchema: Yup.object().shape({
      ...validations,
    }),
    initialValues: {
      //Update initialValues
      ...book,
      name: book?.name || "",
      price: book?.price.toString() || "",
      type: book?.type || "",
      typeDisplayName:
        book?.type && i18n.t("BookStore::Enum:BookType." + book.type),
      publishDate: (book?.publishDate && new Date(book?.publishDate)) || null,
      //Update initialValues
    },
    onSubmit,
  });

  //Others codes..
}

//Other codes..

• book is a nullable property. It'll store the selected book, if the book parameter is null then we'll create a new book.

Delete a Book

Replace the code below in the BooksScreen.js file under the ./src/screens/BookStore/Books folder.

import React, { useState } from "react";
import { useSelector } from "react-redux";
import { Alert, View, StyleSheet } from "react-native";
import { useTheme, List, IconButton, AnimatedFAB } from "react-native-paper";
import { useActionSheet } from "@expo/react-native-action-sheet";
import i18n from "i18n-js";

import { getList, remove } from "../../../api/BookAPI";
import DataList from "../../../components/DataList/DataList";
import { createAppConfigSelector } from "../../../store/selectors/AppSelectors";

function BooksScreen({ navigation }) {
  const theme = useTheme();
  const currentUser = useSelector(createAppConfigSelector())?.currentUser;

  const [refresh, setRefresh] = useState(null);
  const { showActionSheetWithOptions } = useActionSheet();

  const openContextMenu = (item) => {
    const options = [];

    options.push(i18n.t("AbpUi::Delete"));
    options.push(i18n.t("AbpUi::Edit"));
    options.push(i18n.t("AbpUi::Cancel"));

    showActionSheetWithOptions(
      {
        options,
        cancelButtonIndex: options.length - 1,
        destructiveButtonIndex: options.indexOf(i18n.t("AbpUi::Delete")),
      },
      (index) => {
        switch (options[index]) {
          case i18n.t("AbpUi::Edit"):
            edit(item);
            break;
          case i18n.t("AbpUi::Delete"):
            removeOnClick(item);
            break;
        }
      }
    );
  };

  const removeOnClick = (item) => {
    Alert.alert("Warning", i18n.t("BookStore::AreYouSureToDelete"), [
      {
        text: i18n.t("AbpUi::Cancel"),
        style: "cancel",
      },
      {
        style: "default",
        text: i18n.t("AbpUi::Ok"),
        onPress: () => {
          remove(item.id).then(() => {
            setRefresh((refresh ?? 0) + 1);
          });
        },
      },
    ]);
  };

  const edit = (item) => {
    navigation.navigate("CreateUpdateBook", { bookId: item.id });
  };

  return (
    <View style={{ flex: 1, backgroundColor: theme.colors.background }}>
      {currentUser?.isAuthenticated && (
        <DataList
          navigation={navigation}
          fetchFn={getList}
          trigger={refresh}
          render={({ item }) => (
            <List.Item
              key={item.id}
              title={item.name}
              description={i18n.t("BookStore::Enum:BookType." + item.type)}
              right={(props) => (
                <IconButton
                  {...props}
                  icon="dots-vertical"
                  rippleColor={"#ccc"}
                  size={20}
                  onPress={() => openContextMenu(item)}
                />
              )}
            />
          )}
        />
      )}

      {currentUser?.isAuthenticated && (
        <AnimatedFAB
          icon={"plus"}
          label={i18n.t("BookStore::NewBook")}
          color="white"
          extended={false}
          onPress={() => navigation.navigate("CreateUpdateBook")}
          visible={true}
          animateFrom={"right"}
          iconMode={"static"}
          style={[styles.fabStyle, { backgroundColor: theme.colors.primary }]}
        />
      )}
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flexGrow: 1,
  },
  fabStyle: {
    bottom: 16,
    right: 16,
    position: "absolute",
  },
});

export default BooksScreen;

• Delete option is added to context menu list
• removeOnClick method will handle the delete process. It'll show an alert before the delete operation.

Authorization

Hide Books item in tab

Add grantedPolicies to the policies variable from the appConfig store

//Other imports..
import { useSelector } from "react-redux";

function BookStoreScreen({ navigation }) {
  const [index, setIndex] = React.useState(0);
  const [routes, setRoutes] = React.useState([]);

  const currentUser = useSelector((state) => state.app.appConfig.currentUser);
  const policies = useSelector(
    (state) => state.app.appConfig.auth.grantedPolicies
  );

  const renderScene = BottomNavigation.SceneMap({
    books: () => BooksRoute(navigation),
  });

  React.useEffect(() => {
    if (!currentUser?.isAuthenticated || !policies) {
      setRoutes([]);
      return;
    }

    let _routes = [];

    if (!!policies["BookStore.Books"]) {
      _routes.push({
        key: "books",
        title: i18n.t("BookStore::Menu:Books"),
        focusedIcon: "book",
        unfocusedIcon: "book-outline",
      });
    }

    setRoutes([..._routes]);
  }, [Object.keys(policies)?.filter((f) => f.startsWith("BookStore")).length]);

  return (
    routes?.length > 0 && (
      <BottomNavigation
        navigationState={{ index, routes }}
        onIndexChange={setIndex}
        renderScene={renderScene}
      />
    )
  );
}

export default BookStoreScreen;

• In the useEffect function we'll check the currentUser and policies variables.
• useEffect's conditions will be the policies of the BookStore permission group.
• Books tab will be shown if the user has the BookStore.Books permission

Hide the New Book Button

New Book button is placed in the BooksScreen as a + icon button. For the toggle visibility of the button, we need to add the policies variable to the BooksScreen component like the BookStoreScreen component. Open the BooksScreen.js file in the ./src/screens/BookStore/Books folder and include the code below.

//Imports..

function BooksScreen({ navigation }) {
  const policies = useSelector(createAppConfigSelector())?.auth?.grantedPolicies;

  //Other codes..

  return (
    {/*Other codes..*/}

    {currentUser?.isAuthenticated &&
      !!policies['BookStore.Books.Create'] && //Add this line
      (
        <AnimatedFAB
          icon={'plus'}
          label={i18n.t('BookStore::NewBook')}
          color="white"
          extended={false}
          onPress={() => navigation.navigate('CreateUpdateBook')}
          visible={true}
          animateFrom={'right'}
          iconMode={'static'}
          style={[styles.fabStyle, { backgroundColor: theme.colors.primary }]}
        />
      )
    }
  )
}

• Now the + icon button will be shown if the user has the BookStore.Books.Create permission.

Hide the Edit and Delete Actions

Update your code as below in the ./src/screens/BookStore/Books/BooksScreen.js file. We'll check the policies variables for the Edit and Delete actions.

function BooksScreen() {
  //...

  const openContextMenu = (item) => {
    const options = [];

    if (policies["BookStore.Books.Delete"]) {
      options.push(i18n.t("AbpUi::Delete"));
    }

    if (policies["BookStore.Books.Update"]) {
      options.push(i18n.t("AbpUi::Edit"));
    }

    options.push(i18n.t("AbpUi::Cancel"));
  };

  //...
}

Author

Create API Proxy

./src/api/AuthorAPI.js

import api from './API';

export const getList = () => api.get('/api/app/author').then(({ data }) => data);

export const get = id => api.get(`/api/app/author/${id}`).then(({ data }) => data);

export const create = input => api.post('/api/app/author', input).then(({ data }) => data);

export const update = (input, id) => api.put(`/api/app/author/${id}`, input).then(({ data }) => data);

export const remove = id => api.delete(`/api/app/author/${id}`).then(({ data }) => data);

The Author List Page

Add Authors Tab to BookStoreScreen

Open the ./src/screens/BookStore/BookStoreScreen.js file and update it with the code below.

//Other imports
import AuthorsScreen from "./Authors/AuthorsScreen";

//Other Routes..
const AuthorsRoute = (nav) => <AuthorsScreen navigation={nav} />;

function BookStoreScreen({ navigation }) {
  //Other codes..

  const renderScene = BottomNavigation.SceneMap({
    books: () => BooksRoute(navigation),
    authors: () => AuthorsRoute(navigation), //Added this line
  });

  //Added this
  if (!!policies["BookStore.Authors"]) {
    _routes.push({
      key: "authors",
      title: i18n.t("BookStore::Menu:Authors"),
      focusedIcon: "account-supervisor",
      unfocusedIcon: "account-supervisor-outline",
    });
  }
  //Added this
}

export default BookStoreScreen;

Create a AuthorsScreen.js file under the ./src/screens/BookStore/Authors folder and add the code below to it.

import React, { useState } from "react";
import { useSelector } from "react-redux";
import { Alert, View, StyleSheet } from "react-native";
import { useTheme, List, IconButton, AnimatedFAB } from "react-native-paper";
import { useActionSheet } from "@expo/react-native-action-sheet";
import i18n from "i18n-js";

import { getList, remove } from "../../../api/AuthorAPI";
import DataList from "../../../components/DataList/DataList";
import { createAppConfigSelector } from "../../../store/selectors/AppSelectors";

function AuthorsScreen({ navigation }) {
  const theme = useTheme();
  const currentUser = useSelector(createAppConfigSelector())?.currentUser;
  const policies = useSelector(createAppConfigSelector())?.auth
    ?.grantedPolicies;

  const [refresh, setRefresh] = useState(null);
  const { showActionSheetWithOptions } = useActionSheet();

  const openContextMenu = (item) => {
    const options = [];

    if (policies["BookStore.Authors.Delete"]) {
      options.push(i18n.t("AbpUi::Delete"));
    }

    if (policies["BookStore.Authors.Edit"]) {
      options.push(i18n.t("AbpUi::Edit"));
    }

    options.push(i18n.t("AbpUi::Cancel"));

    showActionSheetWithOptions(
      {
        options,
        cancelButtonIndex: options.length - 1,
        destructiveButtonIndex: options.indexOf(i18n.t("AbpUi::Delete")),
      },
      (index) => {
        switch (options[index]) {
          case i18n.t("AbpUi::Edit"):
            edit(item);
            break;
          case i18n.t("AbpUi::Delete"):
            removeOnClick(item);
            break;
        }
      }
    );
  };

  const removeOnClick = ({ id } = {}) => {
    Alert.alert("Warning", i18n.t("BookStore::AreYouSureToDelete"), [
      {
        text: i18n.t("AbpUi::Cancel"),
        style: "cancel",
      },
      {
        style: "default",
        text: i18n.t("AbpUi::Ok"),
        onPress: () => {
          remove(id).then(() => {
            setRefresh((refresh ?? 0) + 1);
          });
        },
      },
    ]);
  };

  const edit = ({ id } = {}) => {
    navigation.navigate("CreateUpdateAuthor", { authorId: id });
  };

  return (
    <View style={{ flex: 1, backgroundColor: theme.colors.background }}>
      {currentUser?.isAuthenticated && (
        <DataList
          navigation={navigation}
          fetchFn={getList}
          trigger={refresh}
          render={({ item }) => (
            <List.Item
              key={item.id}
              title={item.name}
              description={
                item.shortBio || new Date(item.birthDate)?.toLocaleDateString()
              }
              right={(props) => (
                <IconButton
                  {...props}
                  icon="dots-vertical"
                  rippleColor={"#ccc"}
                  size={20}
                  onPress={() => openContextMenu(item)}
                />
              )}
            />
          )}
        />
      )}

      {currentUser?.isAuthenticated && policies["BookStore.Authors.Create"] && (
        <AnimatedFAB
          icon={"plus"}
          label={i18n.t("BookStore::NewAuthor")}
          color="white"
          extended={false}
          onPress={() => navigation.navigate("CreateUpdateAuthor")}
          visible={true}
          animateFrom={"right"}
          iconMode={"static"}
          style={[styles.fabStyle, { backgroundColor: theme.colors.primary }]}
        />
      )}
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flexGrow: 1,
  },
  fabStyle: {
    bottom: 16,
    right: 16,
    position: "absolute",
  },
});

export default AuthorsScreen;

Create a CreateUpdateAuthorScreen.js file under the ./src/screens/BookStore/Authors/CreateUpdateAuthor folder and add the code below to it.

import PropTypes from "prop-types";
import React, { useEffect, useState } from "react";

import { get, create, update } from "../../../../api/AuthorAPI";
import LoadingActions from "../../../../store/actions/LoadingActions";
import { createLoadingSelector } from "../../../../store/selectors/LoadingSelectors";
import { connectToRedux } from "../../../../utils/ReduxConnect";
import CreateUpdateAuthorForm from "./CreateUpdateAuthorForm";

function CreateUpdateAuthorScreen({
  navigation,
  route,
  startLoading,
  clearLoading,
}) {
  const { authorId } = route.params || {};
  const [author, setAuthor] = useState(null);

  const submit = (data) => {
    startLoading({ key: "save" });

    (data.id ? update(data, data.id) : create(data))
      .then(() => navigation.goBack())
      .finally(() => clearLoading());
  };

  useEffect(() => {
    if (authorId) {
      startLoading({ key: "fetchAuthorDetail" });

      get(authorId)
        .then((response) => setAuthor(response))
        .finally(() => clearLoading());
    }
  }, [authorId]);

  return <CreateUpdateAuthorForm submit={submit} author={author} />;
}

CreateUpdateAuthorScreen.propTypes = {
  startLoading: PropTypes.func.isRequired,
  clearLoading: PropTypes.func.isRequired,
};

export default connectToRedux({
  component: CreateUpdateAuthorScreen,
  stateProps: (state) => ({ loading: createLoadingSelector()(state) }),
  dispatchProps: {
    startLoading: LoadingActions.start,
    clearLoading: LoadingActions.clear,
  },
});

Create a CreateUpdateAuthorForm.js file under the ./src/screens/BookStore/Authors/CreateUpdateAuthor folder and add the code below to it.

import React, { useRef, useState } from "react";
import {
  Platform,
  KeyboardAvoidingView,
  StyleSheet,
  View,
  ScrollView,
} from "react-native";

import { useFormik } from "formik";
import i18n from "i18n-js";
import PropTypes from "prop-types";
import * as Yup from "yup";
import { useTheme, TextInput } from "react-native-paper";
import DateTimePicker from "@react-native-community/datetimepicker";

import { FormButtons } from "../../../../components/FormButtons";
import ValidationMessage from "../../../../components/ValidationMessage/ValidationMessage";

const validations = {
  name: Yup.string().required("AbpValidation::ThisFieldIsRequired."),
  birthDate: Yup.string()
    .nullable()
    .required("AbpValidation::ThisFieldIsRequired."),
};

const props = {
  underlineStyle: { backgroundColor: "transparent" },
  underlineColor: "#333333bf",
};

function CreateUpdateAuthorForm({ submit, author = null }) {
  const theme = useTheme();

  const [birthDateVisible, setPublishDateVisible] = useState(false);

  const nameRef = useRef();
  const birthDateRef = useRef();
  const shortBioRef = useRef();

  const inputStyle = {
    ...styles.input,
    backgroundColor: theme.colors.primaryContainer,
  };

  const onSubmit = (values) => {
    if (!authorForm.isValid) {
      return;
    }

    submit({ ...values });
  };

  const authorForm = useFormik({
    enableReinitialize: true,
    validateOnBlur: true,
    validationSchema: Yup.object().shape({
      ...validations,
    }),
    initialValues: {
      ...author,
      name: author?.name || "",
      birthDate: (author?.birthDate && new Date(author?.birthDate)) || null,
      shortBio: author?.shortBio || "",
    },
    onSubmit,
  });

  const isInvalidControl = (controlName = null) => {
    if (!controlName) {
      return;
    }

    return (
      ((!!authorForm.touched[controlName] && authorForm.submitCount > 0) ||
        authorForm.submitCount > 0) &&
      !!authorForm.errors[controlName]
    );
  };

  const onChange = (event, selectedDate) => {
    if (!selectedDate) {
      return;
    }

    setPublishDateVisible(false);

    if (event && event.type !== "dismissed") {
      authorForm.setFieldValue("birthDate", selectedDate, true);
    }
  };

  return (
    <View style={{ flex: 1, backgroundColor: theme.colors.background }}>
      {birthDateVisible && (
        <DateTimePicker
          testID="birthDatePicker"
          value={authorForm.values.birthDate || new Date()}
          mode={"date"}
          is24Hour={true}
          onChange={onChange}
        />
      )}

      <KeyboardAvoidingView
        behavior={Platform.OS === "ios" ? "padding" : "margin"}
      >
        <ScrollView keyboardShouldPersistTaps="handled">
          <View style={styles.input.container}>
            <TextInput
              mode="flat"
              ref={nameRef}
              error={isInvalidControl("name")}
              onSubmitEditing={() => birthDateRef.current.focus()}
              returnKeyType="next"
              onChangeText={authorForm.handleChange("name")}
              onBlur={authorForm.handleBlur("name")}
              value={authorForm.values.name}
              autoCapitalize="none"
              label={i18n.t("BookStore::Name")}
              style={inputStyle}
              {...props}
            />
            {isInvalidControl("name") && (
              <ValidationMessage>{authorForm.errors.name}</ValidationMessage>
            )}
          </View>

          <View style={styles.input.container}>
            <TextInput
              ref={birthDateRef}
              label={i18n.t("BookStore::BirthDate")}
              onSubmitEditing={() => shortBioRef.current.focus()}
              right={
                <TextInput.Icon
                  onPress={() => setPublishDateVisible(true)}
                  icon="menu-down"
                />
              }
              style={inputStyle}
              editable={false}
              value={authorForm.values.birthDate?.toLocaleDateString()}
              {...props}
            />
            {isInvalidControl("birthDate") && (
              <ValidationMessage>
                {authorForm.errors.birthDate}
              </ValidationMessage>
            )}
          </View>

          <View style={styles.input.container}>
            <TextInput
              mode="flat"
              ref={shortBioRef}
              error={isInvalidControl("shortBio")}
              onSubmitEditing={() => authorForm.handleSubmit()}
              returnKeyType="next"
              onChangeText={authorForm.handleChange("shortBio")}
              onBlur={authorForm.handleBlur("shortBio")}
              value={authorForm.values.shortBio}
              autoCapitalize="none"
              label={i18n.t("BookStore::ShortBio")}
              style={inputStyle}
              {...props}
            />
          </View>

          <FormButtons style={styles.button} submit={authorForm.handleSubmit} />
        </ScrollView>
      </KeyboardAvoidingView>
    </View>
  );
}

const styles = StyleSheet.create({
  input: {
    container: {
      margin: 8,
      marginLeft: 16,
      marginRight: 16,
    },
    borderRadius: 8,
    borderTopLeftRadius: 8,
    borderTopRightRadius: 8,
  },
  button: {
    marginLeft: 16,
    marginRight: 16,
  },
});

CreateUpdateAuthorForm.propTypes = {
  author: PropTypes.object,
  submit: PropTypes.func.isRequired,
};

export default CreateUpdateAuthorForm;

Add Author Relation To Book

Update BookAPI proxy file and include getAuthorLookup method

import api from "./API";

export const getList = () => api.get("/api/app/book").then(({ data }) => data);

//Add this
export const getAuthorLookup = () =>
  api.get("/api/app/book/author-lookup").then(({ data }) => data);
//Add this

export const get = (id) =>
  api.get(`/api/app/book/${id}`).then(({ data }) => data);

export const create = (input) =>
  api.post("/api/app/book", input).then(({ data }) => data);

export const update = (input, id) =>
  api.put(`/api/app/book/${id}`, input).then(({ data }) => data);

export const remove = (id) =>
  api.delete(`/api/app/book/${id}`).then(({ data }) => data);

Add AuthorName to the Book List

Open BooksScreen.js file under the ./src/screens/BookStore/Books and update code below.

//Improts

function BooksScreen({ navigation }) {
  //Other codes..

  return (
    //Other codes
    <DataList
      navigation={navigation}
      fetchFn={getList}
      trigger={refresh}
      render={({ item }) => (
        <List.Item
          key={item.id}
          title={item.name}
          //Update here
          description={`${item.authorName} | ${i18n.t(
            "BookStore::Enum:BookType." + item.type
          )}`}
          //Update here
          right={(props) => (
            <IconButton
              {...props}
              icon="dots-vertical"
              rippleColor={"#ccc"}
              size={20}
              onPress={() => openContextMenu(item)}
            />
          )}
        />
      )}
    />
    //Other codes
  );
}

• item.authorName placed beside book type in the book list.

Pass authors to the CreateUpdateBookForm

import {
  getAuthorLookup, //Add this line
  get,
  create,
  update,
} from "../../../../api/BookAPI";
import CreateUpdateBookForm from "./CreateUpdateBookForm";

function CreateUpdateBookScreen({
  navigation,
  route,
  startLoading,
  clearLoading,
}) {
  //Add this variable
  const [authors, setAuthors] = useState([]);

  //Fetch authors from author-lookup endpoint
  useEffect(() => {
    getAuthorLookup().then(({ items } = {}) => setAuthors(items));
  }, []);

  //Pass author list to Form
  return <CreateUpdateBookForm submit={submit} book={book} authors={authors} />;
}
//Other codes..

• We'll define authors prop in the CreateUpdateBookForm component and it will be used for Authors dropdown.
• In the useEffect function we'll fetch authors from the server and set authors variable.

Add authorId field to Book Form

const validations = {
  authorId: Yup.string()
    .nullable()
    .required("AbpValidation::ThisFieldIsRequired."),
  //Other validators
};

//Add `authors` parameter
function CreateUpdateBookForm({ submit, book = null, authors = [] }) {
  //Add this variable for authors list
  const [authorSelectVisible, setAuthorSelectVisible] = useState(false);

  const authorIdRef = useRef(); //Add this line

  //Update form
  const bookForm = useFormik({
    enableReinitialize: true,
    validateOnBlur: true,
    validationSchema: Yup.object().shape({
      ...validations,
    }),
    initialValues: {
      //Add these
      authorId: book?.authorId || "",
      author: authors.find((f) => f.id === book?.authorId)?.name || "",
      //Add these
    },
    onSubmit,
  });

  //Other codes..

  //Add `AbpSelect` component and TextInput for authors
  return (
    <View style={{ flex: 1, backgroundColor: theme.colors.background }}>
      <AbpSelect
        key="authorSelect"
        title={i18n.t("BookStore::Authors")}
        visible={authorSelectVisible}
        items={authors.map(({ id, name }) => ({ id, displayName: name }))}
        hasDefualtItem={true}
        hideModalFn={() => setAuthorSelectVisible(false)}
        selectedItem={bookForm.values.authorId}
        setSelectedItem={(id) => {
          bookForm.setFieldValue("authorId", id, true);
          bookForm.setFieldValue(
            "author",
            authors.find((f) => f.id === id)?.name || null,
            false
          );
        }}
      />

      <KeyboardAvoidingView
        behavior={Platform.OS === "ios" ? "padding" : "margin"}
      >
        <ScrollView keyboardShouldPersistTaps="handled">
          <View style={styles.input.container}>
            <TextInput
              ref={authorIdRef}
              error={isInvalidControl("authorId")}
              label={i18n.t("BookStore::Author")}
              right={
                <TextInput.Icon
                  onPress={() => setAuthorSelectVisible(true)}
                  icon="menu-down"
                />
              }
              style={inputStyle}
              editable={false}
              value={bookForm.values.author}
              {...props}
            />
            {isInvalidControl("authorId") && (
              <ValidationMessage>{bookForm.errors.authorId}</ValidationMessage>
            )}
          </View>
        </ScrollView>
      </KeyboardAvoidingView>
    </View>
  );
}
CreateUpdateBookForm.propTypes = {
  authors: PropTypes.array.isRequired, //Include this
};

export default CreateUpdateBookForm;

• Create authors dropdown input with AbpSelect component.
• Display selected author in the TextInput

That's all. Just run the application and try to create or edit an author.