How to display the app version in Angular?

Question

If you want to use/show the version number in your angular app please do the following:

Prerequisites:

• Angular file and folder structure created via Angular CLI

• TypeScript 2.9 or later! (Supported from Angular 6.1 upwards)

Steps:

1. In your /tsconfig.json (sometimes also necessary in /src/tsconfig.app.json) enable the resolveJsonModule option (webpack dev server restart required afterwards):

    "compilerOptions": {
      ...
      "resolveJsonModule": true
      ...

2. Then in your component, for example /src/app/app.component.ts use the version info:

    import { version } from '../../package.json';
    ...
    export class AppComponent {
      public version: string = version;
    }

It's also possible to do step 2 in your environment.ts file, making the version info accessible from there.

Thx @Ionaru and @MarcoRinck for helping out.

This solution will not include the package.json contents, only the version number.
Tested w/Angular8/Node10/TypeScript3.4.3.

Please update your apps to use this solution cause depending on the contents of your package.json the original solution may implicate security issues.

If you're using webpack or angular-cli (which uses webpack), you can just require package.json in your component and display that prop.

const { version: appVersion } = require('../../package.json')
// this loads package.json
// then you destructure that object and take out the 'version' property from it
// and finally with ': appVersion' you rename it to const appVersion

And then you have your component

@Component({
  selector: 'stack-overflow',
  templateUrl: './stack-overflow.component.html'
})
export class StackOverflowComponent {
  public appVersion

  constructor() {
    this.appVersion = appVersion
  }
}

Using the tsconfig option --resolveJsonModule you can import json files in Typescript.

In the environment.ts file:

import { version } from '../../package.json';

export const environment = {
    VERSION: version,
};

You can now use environment.VERSION in your application.

Trying DyslexicDcuk's answer resulted in cannot find name require

Then, reading 'Optional Module Loading and Other Advanced Loading Scenarios' section in https://www.typescriptlang.org/docs/handbook/modules.html helped me solve this. (Mentioned by Gary here https://stackoverflow.com/a/41767479/7047595)

Use the below declaration to require package.json.

declare function require(moduleName: string): any;

const {version : appVersion} = require('path-to-package.json');

Simplist solution for angular cli users.

Add declare module '*.json'; on src/typings.d.ts

And then on src/environments/environment.ts:

import * as npm from '../../package.json';

export const environment = {
  version: npm.version
};

Done :)

Typescript

import { Component, OnInit } from '@angular/core';
declare var require: any;

@Component({
  selector: 'app-version',
  templateUrl: './version.component.html',
  styleUrls: ['./version.component.scss']
})
export class VersionComponent implements OnInit {
  version: string = require( '../../../../package.json').version;

  constructor() {}

  ngOnInit() {

  }
}

HTML

<div class="row">
    <p class="version">{{'general.version' | translate}}: {{version}}</p>
</div>

It is a good idea to declare version as environment variable So you can use it everywhere in your project. (specially in case of loading files to be cached based on version e.g. yourCustomjsonFile.json?version=1.0.0)
In order to prevent security issues (as @ZetaPR mentioned) we can use this approach (on @sgwatgit 's comment)
In short: we create a yourProjectPath\PreBuild.js file. Like this:

const path = require('path');
const colors = require('colors/safe');
const fs = require('fs');
const dada = require.resolve('./package.json');
const appVersion = require('./package.json').version;

console.log(colors.cyan('\nRunning pre-build tasks'));

const versionFilePath = path.join(__dirname + '/src/environments/version.ts');

const src = `export const version = '${appVersion}';
`;
console.log(colors.green(`Dada ${colors.yellow(dada)}`));

// ensure version module pulls value from package.json
fs.writeFile(versionFilePath, src, { flat: 'w' }, function (err) {
if (err) {
    return console.log(colors.red(err));
}

console.log(colors.green(`Updating application version         
${colors.yellow(appVersion)}`));
console.log(`${colors.green('Writing version module to 
')}${colors.yellow(versionFilePath)}\n`);
});

Above snippet will create a new file /src/environments/version.ts which contains a constant named version and set it by extracted value from package.json file.

In order to run content of PreBuild.json on build, We add this file into Package.json -> "scripts": { ... }" section like following. So we can run project using this code: npm start:

{
  "name": "YourProject",
  "version": "1.0.0",
  "license": "...",
  "scripts": {
    "ng": "...",
    "start": "node PreBuild.js & ng serve",
  },...
}

Now we can simply import version and use it wherever we want:

import { version } from '../../../../environments/version';
...
export class MyComponent{
  ...
  public versionUseCase: string = version;
}