How to insert a Build Number or Timestamp at build time in AngularCLI

I want to have a timestamp or build number somewhere on my Angular2 App so I can tell if a user is using an old cached version or not.

How to do this with AngularCLI in Angular2 at AOT compile/build time?

1. Install plugin npm install replace-in-file --save-dev

2. Add to prod environment src/environments/environment.prod.ts new property

   export const environment = {
       production: true,
       version: '{BUILD_VERSION}'
   }
   

3. Add build file replace.build.js to root of your folder

   var replace = require('replace-in-file');
   var buildVersion = process.argv[2];
   const options = {
       files: 'src/environments/environment.prod.ts',
       from: /{BUILD_VERSION}/g,
       to: buildVersion,
       allowEmptyPaths: false,
   };
   
   try {
       let changedFiles = replace.sync(options);
       console.log('Build version set: ' + buildVersion);
   }
   catch (error) {
       console.error('Error occurred:', error);
   }
   

4. add scripts to package.json

   "updateBuild": "node ./replace.build.js"
   

5. Use environment.version in your app

6. Before build call npm run updateBuild -- 1.0.1

PS. You must always remember that {BUILD_VERSION} is never committed.

PS. I wrote a bit better solution in my blog

PS.3 as @julien-100000 mentioned you should not commit environment.prod.ts with updated version. Version update must happen only in build process. And should never be committed.

Add this step to your build (ie Jenkins-Job):

echo export const version = { number: '%SVN_REVISION%' } > src\version.ts

You can access the number like this:

import { version } from "../version";

export class AppComponent {
    constructor() {
        console.log("MyApp version " + version.number);
    }
}

This solution is + lightweight, + easy to read, + robust.