React Native Vs Cordova : Selecting the Better Cross Platform Framework

Selecting React Native vs Cordova is made easy with expert analysis. Must-know things to select the mobile app development framework. 

How to perform CRUD operations and consume RESTful API using React?

How to perform CRUD operations and consume RESTful API using React?

In this post, we go through a tutorial on how to create a React application that can perform CRUD functions and take in data from a RESTful API. Recently we have experienced rapid growth of mobile, Internet-based communication. We have...

In this post, we go through a tutorial on how to create a React application that can perform CRUD functions and take in data from a RESTful API.

Recently we have experienced rapid growth of mobile, Internet-based communication. We have smartphones, tablets, netbooks, and other connected devices that create a need to serve appropriate content for each specific front-end profile. Also, the Internet is becoming available for new regions and social groups, constantly increasing web traffic. On the other side, users' computers and browsers, and JavaScript itself are getting more and more powerful, providing more possibilities for processing data on the web via the client-side. In this situation, the best solution can often be to send data as the response, instead of sending page content. That is, we don't need to reload the whole page on each request, but send back the corresponding data and let the client (front-end stuff) process the data.

We can develop a backend application exposing a remote API (usually based on the REST protocol) and a front-end (usually JavaScript) application, which communicates with the API and renders all the data on the device.

If backend data is consumed by humans, we need to develop a user interface (UI) to provide the possibility for users to manage the data. Modern web applications should have responsive and friendly UIs, ensuring adequate user experience. Also, modern UIs can be arbitrarily complex, with multi-panel, nested layouts, paging, progress bars, etc. In this case, the component model can be the right solution. React.js is a light-weight JavaScript framework, which is oriented toward the creation of component-based web UIs. React doesn't provide any means for communicating with the backend, but we can use any communication library from inside React components.

Before starting development, we need to set up a React.js development environment.

1. React.js Development Environment Set Up

There are several ways to use React.js. The simplest way is just to include React libraries in the

Learn React.js - Full Course for Beginners

Learn React.js - Full Course for Beginners

Learn the complete React-Redux front end system: React.js, Redux, React Router, React Hooks and Auth0

Other courses have made partial updates to older techniques and code, but this course is built from the ground up to include the most latest code and techniques from 2019+. You are getting the complete integrated modern techniques and code for React and Redux that are used in development today.

What you'll learn:

  • The Most Modern Version of React and Redux
  • Modern Authentication and Routing Patterns
  • The Knowledge and Skills to Apply to Front End Jobs
  • How React Works Under the Hood
  • The Knowledge to know how different Front End Technologies work together (enough knowledge to impress other engineers)
  • Modern ES5, ES6, ES7 Javascript Syntax.

Build a React Responsive Navigation Menu with React Hooks and Sass

Build a React Responsive Navigation Menu with React Hooks and Sass

In this video tutorial, we will learn how to build a responsive navbar with React, Reach Router, and Sass.

What Is Responsive Web Design?

Responsive Web design is the approach that suggests that design and development should respond to the user’s behavior and environment based on screen size, platform and orientation.

The practice consists of a mix of flexible grids and layouts, images and an intelligent use of CSS media queries. As the user switches from their laptop to iPad, the website should automatically switch to accommodate for resolution, image size and scripting abilities. One may also have to consider the settings on their devices; if they have a VPN for iOS on their iPad, for example, the website should not block the user’s access to the page. In other words, the website should have the technology to automatically respond to the user’s preferences. This would eliminate the need for a different design and development phase for each new gadget on the market.

Download and Run

git clone https://github.com/syntacticsolutions/react-navigation-menu.git
cd react-navigation-menu

In the project directory, you can run:

npm start

Build a React Responsive Navigation Menu with React Hooks and Sass

Runs the app in the development mode.

Open http://localhost:3000 to view it in the browser.
The page will reload if you make edits.

You will also see any lint errors in the console.

npm test

Launches the test runner in the interactive watch mode.

See the section about running tests for more information.

npm run build

Builds the app for production to the build folder.

It correctly bundles React in production mode and optimizes the build for the best performance.
The build is minified and the filenames include the hashes.

Your app is ready to be deployed!

See the section about deployment for more information.

npm run eject

Note: this is a one-way operation. Once you eject, you can’t go back!

If you aren’t satisfied with the build tool and configuration choices, you can eject at any time. This command will remove the single build dependency from your project.

Instead, it will copy all the configuration files and the transitive dependencies (Webpack, Babel, ESLint, etc) right into your project so you have full control over them. All of the commands except eject will still work, but they will point to the copied scripts so you can tweak them. At this point you’re on your own.

You don’t have to ever use eject. The curated feature set is suitable for small and middle deployments, and you shouldn’t feel obligated to use this feature. However we understand that this tool wouldn’t be useful if you couldn’t customize it when you are ready for it.

Learn More

You can learn more in the Create React App documentation.

To learn React, check out the React documentation.

Code Splitting

This section has moved here: https://facebook.github.io/create-react-app/docs/code-splitting

Analyzing the Bundle Size

This section has moved here: https://facebook.github.io/create-react-app/docs/analyzing-the-bundle-size

Making a Progressive Web App

This section has moved here: https://facebook.github.io/create-react-app/docs/making-a-progressive-web-app

Advanced Configuration

This section has moved here: https://facebook.github.io/create-react-app/docs/advanced-configuration

Deployment

This section has moved here: https://facebook.github.io/create-react-app/docs/deployment

npm run build fails to minify

This section has moved here: https://facebook.github.io/create-react-app/docs/troubleshooting#npm-run-build-fails-to-minify

React-Redux with TypeScript

React-Redux with TypeScript

TypeScript is a typed superset of JavaScript. It has become popular recently in applications due to the benefits it can bring. If you are new to TypeScript it is highly recommended to become familiar with it first before proceeding.

TypeScript is a typed superset of JavaScript. It has become popular recently in applications due to the benefits it can bring. If you are new to TypeScript it is highly recommended to become familiar with it first before proceeding.

TypeScript is a great language to choose if you are a JavaScript developer and interested in moving towards a statically typed language. Using TypeScript is such a logical move for developers that are comfortable with JavaScript but haven’t written in languages that are statically typed (like C, JVM’s, Go, etc).

As I began my journey to TypeScript, (I’m most comfortable with JS, but have written a little bit in Go and C), I found it to be pretty easy to pick up. My initial thought was: “It really isn’t that bad typing all the argument in my function and typing the return value; what’s the fuss all about?” It was nice and simple until we had a project where we needed to create a React/Redux app in TypeScript.

It’s super easy to find material for React + JS, but as you begin to search for React + TS and especially React + Redux + TS, the amount of online tutorials (including YouTube videos) begin to dwindle significantly. I found myself scouring Medium, Stack Overflow, etc. for anything I could find to help explain how to set up the project, how types are flowing between files (especially once Redux is involved), and how to build with Webpack. This article is a way for me to solidify my knowledge of React + Redux + TS, and to hopefully provide some guidance for anyone else who is interested in using this tech stack for the front end. TypeScript is becoming more popular, so I hope this is useful to others in the community.

Prerequisites: I assume you’re aware of how React, Redux, and Webpack work, and also most concepts in TypeScript (at least interfaces and generics).

What are we gonna build? Just to keep it simple, we’ll build the infamous to-do list application. Remember that the purpose is to understand how to set up the project and know how TypeScript integrates with React and Redux. The features that this application will support are:

  1. Add a new item to a list.
  2. Remove an item from the list.

The code for the project can be found here: https://github.com/sterlingdeng/react-redux-ts-boilerplate.

For my project, I didn’t use create-react-app --typescript to get the project started. I found that it was a valuable learning experience to get it started from scratch. I’ll go step by step through the import files and folders needed to get this project up and running. Before we start, let me show you what the final structure looks like.

TS-Redux-React-Boilerplate
├── build
├── node_modules
├── public
│   ├── bundle.js
│   └── index.html
├── src
│   ├── App.tsx
│   ├── index.tsx
│   ├── actions
│   │   ├── actions.ts
│   │   └── index.ts
│   ├── components
│   │   ├── index.ts
│   │   └── TodoItem.tsx
│   ├── containers
│   │   └── TodoContainer.tsx
│   ├── reducers
│   │   ├── index.ts
│   │   └── todoReducers.ts
│   ├── store
│   │   └── store.ts
│   └── types
│       └── types.d.ts
├── .gitignore
├── package-lock.json
├── package.json
├── tslint.json
├── tsconfig.json
├── webpack.config.js
└── README.md

First, let’s look at the package.json file and install these dependencies using npm i.

"dependencies": {
    "@types/node": "^12.0.0",
    "@types/react": "^16.8.15",
    "@types/react-dom": "^16.8.4",
    "@types/react-redux": "^7.0.8",
    "react": "^16.8.6",
    "react-dom": "^16.8.6",
    "react-redux": "^7.0.3",
    "redux": "^4.0.1",
    "ts-loader": "^5.4.5",
    "typesafe-actions": "^4.2.0",
    "typescript": "^3.4.5",
    "webpack": "^4.30.0",
    "webpack-cli": "^3.3.1"
  }

Let’s first look at the dependencies with the format @types/[npm module here]. If you aren’t familiar with what these modules are, look up https://github.com/DefinitelyTyped/DefinitelyTyped. Since most modules are written in JavaScript, they aren’t written with proper type definitions. Once you attempt to import a module without any type information into a project that is all typed, TypeScript will complain. To prevent this, the community of contributors at DefinitelyTyped create high-quality type definition of the most commonly used JavaScript modules so that those modules will integrate as seamlessly as possible with TS.

You are probably familiar with the next four. ts-loader is needed because Webpack needs a plugin to parse .ts and .tsx files. (This is similar to babel.)

typesafe-actions is a library I use with Redux + TypeScript. Without it, the files can get quite noisy in terms of declaring types for the Store, Reducer, and Actions. This library provides methods that infer type definition for redux code so that the files are a bit cleaner and focused.

webpack and webpack-cli are used to bundle the .ts and .tsx files into one.js file that can be sent to the front end.

Next, let’s look at thetsconfig.json file. The purpose of this file is to configure how you want the ts compiler to run.

{
  "compilerOptions": {
    "baseUrl": ".",
    "outDir": "build/dist",
    "module": "commonjs",
    "target": "es5",
    "sourceMap": true,
    "allowJs": true,
    "jsx": "react"
  }
}

baseUrl denotes the folder. outDir directs the compiler where it should put the compiled code. module tells the compiler which JavaScript module types to use. target tells the compiler which JS version to target. sourceMap tells the compiler to create a bundle.js.map along with bundle.js. Because bundling will turn multiple files into one large .js file, troubleshooting code will be difficult because you wouldn’t easily know which file and at which line the code failed (since everything is just one big file). The .map file will map the bundled file to the respective unbundled file.

tslint.json provides options on how strict or loose you want the ts linter to be. The various options you can set for the linter can be found online.

Action Creators

Normally when I start projects with Redux, I begin at the action creators. Let’s quickly review the features that we need to implement: Adding an item to a list and removing an item from the list. This means we’ll need two action creators, one for adding and another for removing.

import { action } from "typesafe-actions";

// use typescript enum rather than action constants
export enum actionTypes {
  ADD = "ADD",
  DELETE = "DELETE"
}

export const todoActions = {
  add: (item: string) => action(actionTypes.ADD, item),
  delete: (idx: number) => action(actionTypes.DELETE, idx)
};

In the actions.ts file, I’m using the enum feature in TS to create the action constants. Secondly, I’m using the action method provided from the typesafe-actions module. The first argument you pass into the method is a string which represents that action, and the second argument is the payload. The add method will add an item to the list of to-dos, and the deletemethod will remove an item, based on the provided index, from the list of to-dos.

In terms of type safety, what we want in our reducers file is the proper type of the payload, given a specific action. The feature in TypeScript that provides this support is called discriminated union and type guarding. Consider the example below:

// this is an example of discriminated unions
// this file isn't used in the project

interface ActionAdd {
  type: "ADD",
  payload: string
}

interface ActionDelete {
  type: "DELETE",
  payload: number
}

type Actions = ActionAdd | ActionDelete

function reducer(a: Actions) {
  switch(a.type) {
    case "ADD" : {
      // payload is a string
    }
    case "DELETE" : {
      // payload is a number
    }
  }
}

Given the shape of the two action objects, we can discriminate between them based on the type property. Using control flow analysis, like if-else or switch-case statements, it’s very logical that in line 16, the only type that the payload can be is a string. Since we only have two actions, the remaining payload in line 22 will be a number. If you are interested in learning more about discriminated unions and type guarding, I would recommend learning more about it here and here.

Reducer

After defining our action creators, let’s create the reducer for this project.

import * as MyTypes from "MyTypes";
import { actionTypes } from "../actions/";

interface ITodoModel {
  count: number;
  list: string[];
}

export const initialState: ITodoModel = {
  count: 2,
  list: ["Do the laundry", "Do the dishes"]
};

export const todoReducer = (state: ITodoModel = initialState, action: MyTypes.RootAction) => {
  switch (action.type) {
    case actionTypes.ADD: {
      return {
        ...state,
        count: state.count + 1,
        list: [...state.list, action.payload]
      };
    }
    case actionTypes.DELETE: {
      const oldList = [...state.list];
      oldList.splice(action.payload, 1);
      const newList = oldList;

      return {
        ...state,
        count: state.count - 1,
        list: newList
      };
    }
    default:
      return state;
  }
};

In lines four through seven, I’m defining the model (or schema) of our Todostore. It will keep track of how many to-do items we have, as well as the array of strings. Lines nine through 12 are the initial state when the application first starts. Within the todoReducer function, we want type safety within the casestatements. Based on the earlier gist, we accomplished that by discriminated unions and type guarding, done by typing the action parameter. We have to first define an interface for every action object, and then create a union of them all and assign that to a type. This can get tedious if we have a lot of action creators — luckily, typesafe-actions has methods to help create the proper typing of the action creators without having to actually write out all the interfaces.

declare module "MyTypes" {
  import { StateType, ActionType } from "typesafe-actions";
  // 1 for reducer, 1 for action creators
  export type ReducerState = StateType<typeof import("../reducers").default>;
  export type RootAction = ActionType<typeof import("../actions/actions")>;
}

Ignoring line four for now and focusing on line five, we use a method called ActionType from the module, and import the actions from actions.ts to create the discriminated union types, which are then assigned to a type called RootAction. In line one of the todoReducers.ts, we import MyTypes and in line 14, we type the action parameter with MyTypes.RootAction. This allows us to have IntelliSense and autocompletion within the reducers!

Now that we have the reducer set up, the ReducerState type from the types.d.ts file allows TypeScript to infer the shape of the state object in the reducer function. This will provide IntelliSense when we try to access the payload object within the Reducer. An example of what that looks like is in the picture below.

IntelliSense in the Reducer

Redux Store

Finally, let’s hook up the reducer to the redux store.

import { createStore } from "redux";
import rootReducer from "../reducers";

const store = createStore(rootReducer);

export default store;

Let’s recap what we have accomplished up until this point. We have created and typed our action creators using the action method from typesafe-actions. We have created our types.d.ts file which provide type information on our action creators and reducer state. The reducer has been created and the actions are typed by using MyTypes.RootAction, which provide invaluable auto-completion information of the payload within the reducer’s case statements. And lastly, we created our Redux store.

React and TS

Let’s change gears and begin working on creating and typing our React components. I’ll go over examples of how to properly type both function and class based components, along with instructions on how to type both the props and state (for stateful components).

App.tsx

import * as React from "react";
import TodoContainer from "./containers/TodoContainer";

export const App: React.FC<{}> = () => {
  return (
    <>
      <h1>React Redux Typescript</h1>
      <TodoContainer />
    </>
  );
};

App is a functional component that is typed by writing const App: React.FC<{}>. (FC refers to functional component.) If you aren’t familiar with generics (which is the <{}> ), I think of them like variables but for types. Since the shape of props and state can differ based on different use cases, generics are a way for us to, well, make the component generic! In this case, App doesn’t take any props; therefore, we pass in an empty object as the generic. How do we know that the generic is specifically for props? If you use VS code, IntelliSense will let you know what type it needs.

Where it says <P = {}> , it means type {} has been assigned to P, where Pstands for props. For class-based components, React will use S to refer to state. App is a functional component that receives no props and is not connected to the Redux store. Let’s go for something a little more complicated.

TodoContainer.tsx

import * as React from "react";
import { connect } from "react-redux";
import { Dispatch } from "redux";
import * as MyTypes from "MyTypes";
import { actionTypes } from "../actions";
import { TodoItem } from "../components";

interface TodoContainerState {
  todoInput: string;
}

interface TodoContainerProps {
  count: number;
  todoList: string[];
  addToDo: (item: string) => object;
  deleteToDo: (idx: number) => object;
}

class TodoContainer extends React.Component<TodoContainerProps, TodoContainerState> {
  constructor(props) {
    super(props);
    this.state = {
      todoInput: ""
    };
  }

  handleTextChange = e => {
    this.setState({
      todoInput: e.target.value
    });
  };

  handleButtonClick = () => {
    this.props.addToDo(this.state.todoInput);
    this.setState({
      todoInput: ""
    });
  };

  handleDeleteButtonClick = (idx: number) => {
    console.log("deleting", idx);
    this.props.deleteToDo(idx);
  };

  render() {
    let todoJSX: JSX.Element[] | JSX.Element;
    if (!this.props.todoList.length) {
      todoJSX = <p>No to do</p>;
    } else {
      todoJSX = this.props.todoList.map((item, idx) => {
        return (
          <TodoItem item={item} key={idx} idx={idx} handleDelete={this.handleDeleteButtonClick} />
        );
      });
    }

    return (
      <div>
        {todoJSX}
        <input
          onChange={this.handleTextChange}
          placeholder={"New To Do Here"}
          value={this.state.todoInput}
        />
        <button onClick={this.handleButtonClick}>Add To Do</button>
      </div>
    );
  }
}

const MapStateToProps = (store: MyTypes.ReducerState) => {
  return {
    count: store.todo.count,
    todoList: store.todo.list
  };
};

const MapDispatchToProps = (dispatch: Dispatch<MyTypes.RootAction>) => ({
  addToDo: (item: string) => dispatch({ type: actionTypes.ADD, payload: item }),
  deleteToDo: (idx: number) => dispatch({ type: actionTypes.DELETE, payload: idx })
});

export default connect(
  MapStateToProps,
  MapDispatchToProps
)(TodoContainer);

OK, TodoContainer.tsx is the most complicated of them all, but I’ll walk you through what’s going on in the code. TodoContainer is a React Class Component because I need it to hold in its state the value for the input box. It is also connected to the redux store, so it’ll have MapStateToProps and MapDispatchToProps . First, I’ve definedTodoContainerState . Since I’ll be holding the value of the input box in state, I’ll type the property as a string.

Next, I’ve defined TodoContainerProps, which will be the shape of the Container’s props.

Because class-based components can have both state and props, we should expect that there should be at least two generics that we need to pass into React.Component.

P for Props and S for State

If you mouse over React.Component, you can see that it takes in three generics, P, S, and SS. The first two generics are props and state. I’m not quite sure whatSS is and what the use case is. If anyone knows, please let me know in the comments below.

After passing in the generics into React.Component , IntelliSense and autocompletion will work within this.state and for props.

Next, we want to type MapStateToProps and MapDispatchToProps. This is easily achievable by leveraging the MyTypes module that we built in the redux section. For MapStateToProps, we assign the store type to be MyTypes.ReducerState. An example of the IntelliSense it will provide is in the below screenshot.

IntelliSense for MapStateToProps

Lastly, we want to have type safety within MapDispatchToProps. The benefit that is provided is a type-safe payload given an action type.

Type-safe payloads

In the screenshot above, I purposely typed item as a boolean. Immediately, the TSServer will pick up that the boolean payload within MapDispatchToProps is not correct because it’s expecting the payload to be a string, given that the type is actionTypes.ADD. TodoContainer.tsx has the most going on since it is a class based React component, with both state and props, and is also connected to the store.

Before we wrap up, let’s look at our last component: TodoItem.tsx

TodoItem.tsx

This component is a functional component with props — code below.

import * as React from "react";

interface TodoItemProps {
  item: string;
  idx: number;
  handleDelete: (idx: number) => void;
}

export const TodoItem: React.FC<TodoItemProps> = props => {
  return (
    <span>
      {props.item}
      <button onClick={() => props.handleDelete(props.idx)}>X</button>
    </span>
  );
};

The shape of the props are defined in the interface TodoItemProps. The type information is passed into as a generic in React.FC. Doing so will provide auto-completion for props within the component. Awesome.

Another great feature that TypeScript provides when used with React is IntelliSense for props when rendering React Components within JSX. As an example, if you delete idx:number from TodoItemProps and then you navigate to TodoContainer.tsx, an error will appear at the place where you render <TodoItem />.

Property ‘idx’ does not exist

Because we removed idx from the TodoItemProps interface, TypeScript is letting us know that we have provided an additional prop that it couldn’t find, idx, into the component.

Lastly, let’s build the project using Webpack. In the command line, type npm run build. In the public folder within the root directory, you should see bundle.js alongsideindex.html. Open index.html in any browser and you should see a very simple, unstyled, to-do app.

After webpack build

I hope that I was able to demonstrate the power of TypeScript coupled with React and Redux. It may seem a bit overkill for our simple to-do list app — you just need to imagine the benefit of TS + React + Redux at scale. It will help new developers read the code quicker, provide more confidence in refactoring, and ultimately improve development speed.

If you need more reference and material, I used the following two Git repos to teach myself

Both these repos have proved invaluable for my learning, and I hope they will be the same for you.

Ionic 4, Angular 7 and Cordova Crop and Upload Image

Ionic 4, Angular 7 and Cordova Crop and Upload Image

The comprehensive step by step tutorial on crop, and upload Image using Ionic 4, Angular 7 and Cordova

The comprehensive step by step tutorial on crop, and upload Image using Ionic 4, Angular 7 and Cordova. We will use Native Ionic Cordova Crop, File Transfer plugins and it’s dependencies. In this tutorial, we will use our existing uploader API that you can find on our GitHub which it uses Node.js, Express.js, and Multer. Or, you can use your own backend or API that using HTML Form Encoding multipart/form-data. The scenario is in the Ionic 4 App, click the Camera button inside the preview image then it will open image picker. After image picked then it will go to cropping popup that you can crop anyway you like then upload to the API. After the successful upload, the Ionic 4 app will preview the Image by URL that saved to the API server.

Table of Contents:

The following tools, frameworks, and modules are required for this tutorial:

Before going to the main steps, we assume that you have to install Node.js. Next, upgrade or install new Ionic 4 CLI by open the terminal or Node command line then type this command.

sudo npm install -g ionic

You will get the latest Ionic CLI in your terminal or command line. Check the version by type this command.

ionic --version
4.12.0

1. Create a New Ionic 4, Angular 7 and Cordova App

To create a new Ionic 4 App, type this command in your terminal.

ionic start ionic4-crop blank --type=angular

If you see this question, just type N for because we will installing or adding Cordova later.

Install the free Ionic Appflow SDK and connect your app? (Y/n) N

Next, go to the newly created app folder.

cd ./ionic4-crop

As usual, run the Ionic 4 App for the first time, but before run as lab mode, type this command to install @ionic/lab.

npm install --save-dev @ionic/lab
ionic serve -l

Now, open the browser and you will the Ionic 4 App with the iOS, Android, or Windows view. If you see a normal Ionic 4 blank application, that’s mean you ready to go to the next steps.

2. Install and Configure Image Crop, File Transfer Plugins, and Dependencies

We will install all required plugins for this tutorial. First, we have to install Native Cordova plugins and Ionic 4 Angular 7 Modules by running these commands.

ionic cordova plugin add cordova-plugin-crop
npm install @ionic-native/crop
ionic cordova plugin add cordova-plugin-camera
npm install @ionic-native/camera
ionic cordova plugin add cordova-plugin-file-transfer
npm install @ionic-native/file-transfer
ionic cordova plugin add cordova-plugin-file
npm install @ionic-native/file

Next, open and edit src/app/app.module.ts then add these imports.

import { ImagePicker } from '@ionic-native/image-picker/ngx';

Add that import to @NgModule Providers.

providers: [
&nbsp; StatusBar,
&nbsp; SplashScreen,
&nbsp; { provide: RouteReuseStrategy, useClass: IonicRouteStrategy },
&nbsp; ImagePicker
],

3. Implementing Image Crop and File Upload/Transfer

We will be using the existing Home component or page to implementing Image Preview, Picker, Crop and Upload. For that, open and edit src/app/home/home.page.html then replace all HTML tags with these.

<ion-header>
&nbsp; <ion-toolbar>
&nbsp; &nbsp; <ion-title>
&nbsp; &nbsp; &nbsp; Ionic 4 Crop Upload
&nbsp; &nbsp; </ion-title>
&nbsp; </ion-toolbar>
</ion-header>

<ion-content padding>
&nbsp; <ion-card>
&nbsp; &nbsp; <img *ngIf="!fileUrl" src="assets/no-image.jpeg"/>
&nbsp; &nbsp; <img *ngIf="fileUrl" src="{{fileUrl}}"/>
&nbsp; &nbsp; <ion-card-content>
&nbsp; &nbsp; &nbsp; <ion-button color="medium" size="large" (click)="cropUpload()">
&nbsp; &nbsp; &nbsp; &nbsp; <ion-icon slot="icon-only" name="camera"></ion-icon>
&nbsp; &nbsp; &nbsp; </ion-button>
&nbsp; &nbsp; </ion-card-content>
&nbsp; </ion-card>
</ion-content>

Next, open and edit src/app/home/home.page.ts then add these imports.

import { Crop } from '@ionic-native/crop/ngx';
import { ImagePicker } from '@ionic-native/image-picker/ngx';
import { FileTransfer, FileUploadOptions, FileTransferObject } from '@ionic-native/file-transfer/ngx';

Inject those imports to the constructor.

constructor(private imagePicker: ImagePicker,
&nbsp; private crop: Crop,
&nbsp; private transfer: FileTransfer) { }

Add the variables for hold image URL and response data.

fileUrl: any = null;
respData: any;

Create a function for crop and upload an image file to the API server.

cropUpload() {
&nbsp; this.imagePicker.getPictures({ maximumImagesCount: 1, outputType: 0 }).then((results) => {
&nbsp; &nbsp; for (let i = 0; i < results.length; i++) {
&nbsp; &nbsp; &nbsp; &nbsp; console.log('Image URI: ' + results[i]);
&nbsp; &nbsp; &nbsp; &nbsp; this.crop.crop(results[i], { quality: 100 })
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .then(
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; newImage => {
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; console.log('new image path is: ' + newImage);
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; const fileTransfer: FileTransferObject = this.transfer.create();
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; const uploadOpts: FileUploadOptions = {
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;fileKey: 'file',
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;fileName: newImage.substr(newImage.lastIndexOf('/') + 1)
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; };

&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; fileTransfer.upload(newImage, 'http://192.168.0.7:3000/api/upload', uploadOpts)
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;.then((data) => {
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;console.log(data);
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;this.respData = JSON.parse(data.response);
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;console.log(this.respData);
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;this.fileUrl = this.respData.fileUrl;
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;}, (err) => {
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;console.log(err);
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;});
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; },
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; error => console.error('Error cropping image', error)
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; );
&nbsp; &nbsp; }
&nbsp; }, (err) => { console.log(err); });
}

As you can see, we use the IP address to access Express.js API from the device. The uploaded image file accessible from the device through [http://192.168.0.7:3000/images/filename](http://192.168.0.7:3000/images/filename "http://192.168.0.7:3000/images/filename") URL.

4. Run and Test Ionic 4, Angular 7 and Cordova App on iOS/Android Devices

We assume that you have cloned the Node.js, Express.js and Multer image uploader here https://github.com/didinj/node-express-image-uploader.git. Next, open a new Terminal or cmd-tab then go to the cloned Express image uploader.

npm install
nodemon

Next, to run on Android devices type this command while the device connected.

ionic cordova platform add android
ionic cordova run android

To run on iOS simulator or device, we have to build it first.

ionic cordova platform add ios
ionic cordova build ios

Then open and run the iOS app from the XCode. You will this view from your Android device or iOS simulator.

That it’s, the Ionic 4, Angular 7 and Cordova Crop and Upload Image tutorial. You can get the full source code from out GitHub.