NgxSignalTranslate

A signal-driven translation service.

Compatibility with Angular Versions

ngx-signal-translate	Angular
2.x	>= 19
1.x	>= 18

Table of contents

• Features
• Installation
• Configuration
• Language file
• Params in the language file
• Usage
  • Component template
  • Typescript files

Features

• Lazy load language JSON files via HTTP request.
• Pipe for translating the template strings. (signal)
• Service with a synchronous, signal and observable translate interface. (The synchronous interface works with computed signal and signal effects.)
• Option for the variable replace in the translated strings.

Installation

npm install ngx-signal-translate
# Or if you use yarn
yarn add ngx-signal-translate

Configuration

Add configuration provider to your app.config.ts as provider.

import { provideSignalTranslateConfig } from 'ngx-signal-translate';

export const appConfig: ApplicationConfig = {
  providers: [
    provideSignalTranslateConfig({path: ''}),
  ],
};

The path is a required config parameter, that will be the json language files base folder.

And finally set the default language in your AppComponent constructor:

import { NgxSignalTranslateService } from 'ngx-signal-translate';

@Component({})
export class AppComponent {
  readonly #signalTranslateService = inject(NgxSignalTranslateService);

  constructor(){
    this.#signalTranslateService.setLanguage('en');
  }
}

A language file

The language files should be JSON files, and the language key should be the file name.

Example:

{
  "DEMO": "Demo"
}

Params in the language file

The language files be able to handle variables in the translation string. When the translation service gets variables for a replacement, it will try to replace these keys in the template string. You need to put the variable key inside brackets.

Example:

{
  "DEMO": "Demo {param}"
}

Usage

Component template

import { NgxSignalTranslatePipe } from 'ngx-signal-translate';

@Component({
  imports: [NgxSignalTranslatePipe]
})
export class DemoComponent {}

without params:

<p>{{('Demo' | signalTranslate)()}}</p>

with params:

<p>{{('Demo' | signalTranslate : {param: 'hello'})()}}</p>

Typescript files

import { NgxSignalTranslateService } from 'ngx-signal-translate';

@Component({})
export class DemoComponent implements ngOnInit{
  readonly #signalTranslateService = inject(NgxSignalTranslateService);
  readonly #translatedText = computed(() => this.#signalTranslateService.translate('DEMO'));

  constructor() {
    effect(() => {
      console.log(this.#signalTranslateService.translate('DEMO'));
    });
    /* The translate function triggers the signal effects. */
  }

  public ngOnInit(): void {
    console.log(this.#signalTranslateService.translate('DEMO'));
    /* If the selected language files were not loaded, then the function will return with the translation key. */

    this.#signalTranslateService.translate$('DEMO').subscribe(console.log);
    /* The translate$ observable will wait for the language file to load. */

    console.log(this.#translatedText());
    /* The translate function works with computed signals. That will trigger the value refresh when the language resource / selected language changed. */
  }
}

The second parameter can be used to pass translate variables to the translate and translate$ function.