@ngx-env/builder
Easily inject environment variables into your Angular applications
Quick start
- Add @ngx-env to your CLI project
ng add @ngx-env/builder
- Define Environment Variables in
.env
NG_APP_ENABLE_ANALYTICS=false
NG_APP_VERSION=$npm_package_version
- Run CLI commands
npm start
NG_APP_BRANCH_NAME=`git branch --show-current` npm run build
- Use in TypeScript
@Component({
selector: "app-footer",
})
export class FooterComponent {
public version = process.env.NG_APP_VERSION;
public branch = process.env.NG_APP_BRANCH_NAME;
public analyticsFlag = process.env.NG_APP_ENABLE_ANALYTICS;
}
Using Environment Variables
Your project can consume variables declared in your environment as if they were declared locally in your JS files.
These environment variables can be useful for:
- displaying information conditionally based on where the project is deployed
- consuming sensitive data that lives outside of version control.
The environment variables will be defined for you on process.env
. For example, having an environment variable named NG_APP_NOT_SECRET_CODE
will be exposed in your JS as process.env.NG_APP_NOT_SECRET_CODE
.
The environment variables are embedded during the build time.
⚠ Important
Do not store any secrets (such as private API keys) in your Angular app!
Environment variables are embedded into the build, meaning anyone can view them by inspecting your app's files.
NG_APP*
You must create custom environment variables beginning with NG_APP_
.
Any other variables (except NODE_ENV
) will be ignored to avoid accidentally exposing a private key on the machine that could have the same name. See how to use system environment variables.
Changing any environment variables will require you to restart the development server if it is running.
NODE_ENV
There is also a built-in environment variable called NODE_ENV
. You can read it from process.env.NODE_ENV
.
NODE_ENV is set for you. You cannot override NODE_ENV
manually. This prevents developers from accidentally deploying a slow development build to production.
Command | value |
---|
ng serve | development |
ng test | test |
ng build | production |
ng extract-i18n | production |
ng serve | production |
Having access to the NODE_ENV
is also useful for performing actions conditionally:
if (process.env.NODE_ENV !== "production") {
analytics.disable();
}
When you compile the app with npm run build
, the minification step will strip out this condition, and the resulting bundle will be smaller.
Usage In Templates
You have two options to consume an environment variable in your component's template.
- From your component class
@Component({
selector: "app-footer",
})
export class FooterComponent {
public version = process.env.NG_APP_VERSION;
}
{{ version }}
- Using the
env
pipe
npm install @ngx-env/core
import { NgxEnvModule } from "@ngx-env/core";
@NgModule({
declarations: [FoooterComponent],
imports: [CommonModule, NgxEnvModule],
})
export class FooterModule {}
{{ 'process.env.NODE_ENV' | env }}
{{ 'NODE_ENV' | env }}
Usage in Index.html
You can also access the environment variables starting with NG_APP_
in the index.html
.
<!DOCTYPE html>
<html lang="en">
<head>
<title>NgApp on %NG_APP_BRANCH_NAME%</title>
</head>
<body>
<app-root></app-root>
</body>
</html>
Defining Environment Variables
Command Line
Defining environment variables can vary between OSes. It’s also important to know that this manner is temporary for the life of the shell session.
Windows (cmd.exe)
set "NG_APP_NOT_SECRET_CODE=abcdef" && npm start
(Note: Quotes around the variable assignment are required to avoid a trailing whitespace.)
Windows (Powershell)
($env:NG_APP_NOT_SECRET_CODE = "abcdef") -and (npm start)
Linux, macOS (Bash)
NG_APP_NOT_SECRET_CODE=abcdef npm start
In .env
@ngx-env/builder
uses dotenv to support loading environment variables from .env
files.
.env
files are to be stored alongside the package.json
.
@ngx-env/builder
loads .env
files with these specific names for the following NODE_ENV
values, files on the bottom have less priority than files on the top.
valid .env filenames | NODE_ENV=* | NODE_ENV=test |
---|
.env | ✔️ | ✔️ |
.env.local | ✔️ | ✖️ |
.env.${NODE_ENV} | ✔️ | ✔️ |
.env.${NODE_ENV}.local | ✔️ | ✔️ |
Expanding .env
You can expand variables already available on your machine for use in your .env
For example:
NG_APP_VERSION=$npm_package_version
NG_APP_HOSTNAME=$HOSTNAME
Or expand variables local to the current .env
file:
DOMAIN=www.example.com
NG_APP_FOO=$DOMAIN/foo
NG_APP_BAR=$DOMAIN/bar
Credits