I have created a ReactJs app with create-react-app and then made the Production build with npm run build. In my www folder created with Cordova I just copy all the files from the create-react-app's build folder and that's fine.

I want to know how do I hook into Cordova's events like for example:

function startApp() {
  // your app logic
}
if (window.cordova) {
  document.addEventListener('deviceready', startApp, false);
} else {
  startApp();
}

For example I want to call the minified JS file inside startApp(). Or is there any other workflow that can be used to make Cordova events work with react app.

A small example would be helpful.

Is it possible to use the build file at all and just use the React App directly inside Cordova? I am unsure how that would work given that there is Webpack settings which transpiles the ES6 code to ES5 and all.

I am new to Cordova and struggling with this integration aspect.


I have found to make the two work and will post here for anyone else looking for the same. There maybe other methods to do this , but this is what worked for me.

So basically we will create a Cordova App using(say) : cordova create testapp com.test.testapp testapp This will give me a Folder Structure as so:

testapp
        --hooks
        --platforms
        --plugins
        --www
        --config.xml

Now inside the testapp folder we run : create-react-app teastappReact Which will add my react app inside testapp folder. Your react app will have a main index.js in the /src directory.

I the index.js make sure to wrap your main logic inside a function and then call the function along with Cordova object like so:

import React from 'react';
import ReactDOM from 'react-dom';
import App from './App';
import './index.css';


const startApp = () => {
ReactDOM.render(
  <App />,
  document.getElementById('root')
);
}

if(!window.cordova) {
  startApp()
} else {
  document.addEventListener('deviceready', startApp, false)
}

That should do now your app will have the Cordova instance along with Device objects like navigator.camera inside your app.

Also in your react apps index.html which can be found in the public folder copy the html from the index.html that you will find in the Codova www folder. Now we can delete all files from www folder. We will later manually or via a script copy all files from react apps build folder to Cordova www folder.

So my index.html would look something like below, notice the cordova.js file thats included as a script.

<!DOCTYPE html>
<!--
    Licensed to the Apache Software Foundation (ASF) under one
    or more contributor license agreements.  See the NOTICE file
    distributed with this work for additional information
    regarding copyright ownership.  The ASF licenses this file
    to you under the Apache License, Version 2.0 (the
    "License"); you may not use this file except in compliance
    with the License.  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing,
    software distributed under the License is distributed on an
    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
     KIND, either express or implied.  See the License for the
    specific language governing permissions and limitations
    under the License.
-->
<html>

<head>
    <!--
        Customize this policy to fit your own app's needs. For more guidance, see:
            https://github.com/apache/cordova-plugin-whitelist/blob/master/README.md#content-security-policy
        Some notes:
            * gap: is required only on iOS (when using UIWebView) and is needed for JS->native communication
            * https://ssl.gstatic.com is required only on Android and is needed for TalkBack to function properly
            * Disables use of inline scripts in order to mitigate risk of XSS vulnerabilities. To change this:
                * Enable inline JS: add 'unsafe-inline' to default-src
        -->
    <meta http-equiv="Content-Security-Policy" content="default-src * 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; media-src *; img-src * data: content:;">
    <meta name="format-detection" content="telephone=no">
    <meta name="msapplication-tap-highlight" content="no">
    <meta name="viewport" content="user-scalable=no, initial-scale=1, maximum-scale=1, minimum-scale=1, width=device-width">
    <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">

    <!-- Latest compiled and minified CSS -->
    <title>React App</title>
</head>

<body>
    <div id="root"></div>
   <script type="text/javascript" src="cordova.js"></script>
</body>

</html>

Finally in your react apps' package.json add the following line: .... "homepage": "../www" .... This will make sure your final build file is pointing at the right path. we can also add the following lines in your package.json build script.

  "scripts": {
    "start": "react-scripts start",
    ***"build": "react-scripts build && robocopy .\\build ..\\www /MIR",***
    "test": "react-scripts test --env=jsdom",
    "eject": "react-scripts eject",
    "deploy": "npm run build&&gh-pages -d build"
  }

It can be robocopy or cp-r based on the OS(Windows/Linux etc)..

We should have our Cordova app ready to be build with cordova build android/ios.


I solved the issue. Here's what I did in a step-by-step format for anyone looking for the solution:

  1. Copy/Create-a-new React project (created using create-react-app) just inside the Cordova app directory.
  2. Clear all the contents of www folder of Cordova app.
  3. cd to React project folder (which you just copied/created) & open package.json.
  4. Before dependencies add "homepage": "./", & inside scripts change build to "build": "react-scripts build && robocopy .\\build ..\\www /MIR",
  5. Do npm run build in same (React's) directory & go back to parent (Cordova) folder then build and emulate your project in desired platform.
  6. Bonus Tip: If you are using <Router> in your project change that to <HashRouter> otherwise you'll see a blank display as nothing will get rendered to the screen.

I thought it was quite hard to find a complete guide how to fix this. I solved it like this, start to finish, to be able to run Create React App on an emulated Android device on Windows:

Start by creating a react app or use your existing app.

npx create-react-app my-app

https://github.com/facebook/create-react-app#creating-an-app

Then install Cordova:

npm install -g cordova

https://cordova.apache.org/docs/en/latest/guide/cli/

Create a new cordova application inside the my-app folder in my case:

cordova create hello com.example.hello HelloWorld

Change directory to hello or what you called your Cordova application.

cordova platform add ios
cordova platform add android

Run cordova requirements to see what you need to build the project.

enter image description here

Since I'm on Windows I will only build it for Android in this example.

cordova platform remove ios

and confirm I have only Android with cordova platform ls

enter image description here

Install what you need based on cordova requirements command. Since I had a fresh install I needed everything: Java Development Kit (JDK) 8, Gradle and Android SDK. Links can be found here:

https://cordova.apache.org/docs/en/latest/guide/platforms/android/index.html#requirements-and-support

Or:

https://www.oracle.com/java/technologies/javase/javase-jdk8-downloads.html

https://gradle.org/install/

https://developer.android.com/studio/index.html

Open Android Studio after it is installed. I choose a standard installation but it failed with the following warning:

Failed to install Intel HAXM. For details, please check the installation log: "C:\Users\Oscar\AppData\Local\Temp\haxm_log.txt" Intel® HAXM installation failed. To install Intel® HAXM follow the instructions found at: https://software.intel.com/android/articles/installation-instructions-for-intel-hardware-accelerated-execution-manager-windows Installer log is located at

C:\Users\Oscar\AppData\Local\Temp\haxm_log.txt Installer log contents: === Logging started: 2020-07-10 16:39:27 === This computer does not support Intel Virtualization Technology (VT-x) or it is being exclusively used by Hyper-V. HAXM cannot be installed. Please ensure Hyper-V is disabled in Windows Features, or refer to the Intel HAXM documentation for more information.

I could however start the application anyway and add an Android Virtual Device (AVD) found under Configure.

enter image description here

I choose to add a Pixel XL with R system image.

However running cordova requirements again I could see I needed an Android target with API level 28. R is level 30.

enter image description here

I therefore installed Pie with API level 28 x86_64 and created a new virtual device.

enter image description here

Instead of opening AVD Manager i opened SDK manager and also downloaded the Android 9.0 Pie SDK.

enter image description here

Now everything looked good:

enter image description here

Then run cordova emulate android to test the default Cordova application.

If it works it should look like this:

enter image description here

Change directory to my-app.

Edit package.json and add "homepage": "./", before dependencies:

enter image description here

Thanks to @BlackBeard for that. Source: https://stackoverflow.com/a/46785362/3850405

Run npm run build

Clear everything in my-app\hello\www then copy everything from my-app\build to my-app\hello\www.

Voilà:

enter image description here

If you don't edit my-app package.json and add "homepage": "./", it will look like this:

enter image description here

Lessons learnt:

1.

If you are using <Router> in your project change that to <HashRouter> otherwise you'll see a blank display as nothing will get rendered to the screen. Works for both iOS and Android.

Source: https://stackoverflow.com/a/46785362/3850405

2.

You need a whitelist to allow URLs. From documentation:

By default navigations are only allowed to file:// URLs. To allow others URLs, you must add tags to your config.xml:

https://cordova.apache.org/docs/en/latest/reference/cordova-plugin-whitelist/

Install like this:

cordova plugin add cordova-plugin-whitelist

Then edit config.xml which is located in your application's root directory and add any of the following:

<!-- Allow links to example.com -->
<allow-navigation href="http://example.com/*" />

<!-- Wildcards are allowed for the protocol, as a prefix
     to the host, or as a suffix to the path -->
<allow-navigation href="*://*.example.com/*" />

<!-- A wildcard can be used to whitelist the entire network,
     over HTTP and HTTPS.
     *NOT RECOMMENDED* -->
<allow-navigation href="*" />

Source: https://stackoverflow.com/a/30327204/3850405

3.

Even though you are using a whitelist you may still need to access an http API that does not support https. By default this is not allowed and can cause some real headache. Solve this as well by editing config.xml and add the following under <platform name="android">:

<edit-config xmlns:android="http://schemas.android.com/apk/res/android"  file="app/src/main/AndroidManifest.xml" mode="merge" target="/manifest/application">     <application android:usesCleartextTraffic="true" /></edit-config>

Given that you do not browse to a URL any API call must specify the actual server. I normally use Axios so we only needed to add our server to the default URL. Example:

import axios, { AxiosPromise, AxiosRequestConfig, Method } from 'axios';

const getConfig = (url: string, method: Method, params?: any, data?: any) => {
     const config: AxiosRequestConfig = {
         url: 'http://192.168.1.249' + url,
         method: method,
         responseType: 'json',
         params: params,
         data: data,
         headers: { 'X-Requested-With': 'XMLHttpRequest' },
    }
    return config;
}

export const sendRequest = (url: string, method: Method, params?: any, data?: any): AxiosPromise<any> => {
    return axios(getConfig(url, method))
}

Then called like this:

const path = '/api/test/'

export const initialLoad = (number: number): AxiosPromise<InitialLoadDto> => {
    return sendRequest(path + 'InitialLoad/' + number, 'get');
}

I created CLI for this.

npm i -g react.cordova

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