MikeDabrowski/transloco-keys-manager

🦄 The Key to a Better Translation Experience

Translation is a tiresome and repetitive task. Each time we add new text, we need to create a new entry in the translation file, find the correct placement for it, etc. Moreover, when we delete existing keys, we need to remember to remove them from each translation file.

To make the process less burdensome, we've created two tools for the Transloco library, which will do the monotonous work for you.

🍻Features

✅ Extract Translate Keys
✅ Scopes Support
✅ Webpack Plugin
✅ Find Missing and Extra Keys

🌩 Installation

Assuming that you've already added Transloco to your project, run the following schematics command:

ng g @ngneat/transloco:keys-manager

At this point, you'll have to choose whether you want to use the CLI, Webpack Plugin, or both. The project will be updated according to your choice.

Note that if you're going to use the Webpack plugin and you've already defined other Webpack plugins in your project, you should add the Keys Manager plugin to the list, rather than using the schematics command.

The following functionality is available once the installation is complete:

🔑 Keys Extractor

This tool extracts translatable keys from template and typescript files. Transloco Keys Manager provides two ways of using it:

CLI Usage

If you chose the CLI option, you should see the following script in your project's package.json file:

{
  "i18n:extract": "transloco-keys-manager extract"
}

Run npm run i18n:extract, and it'll extract translatable keys from your project.

Webpack Plugin

The TranslocoExtractKeysWebpackPlugin provides you with the ability to extract the keys during development, while you're working on the project.

The angular-cli doesn't support adding a custom Webpack config out of the box. To make it easier for you, when you choose the Webpack Plugin option, it'll do the work for you.

You should see a new file named webpack-dev.config.js configured with TranslocoExtractKeysWebpackPlugin:

// webpack-dev.config.js
const { TranslocoExtractKeysWebpackPlugin } = require('@ngneat/transloco-keys-manager');

module.exports = {
  plugins: [
    new TranslocoExtractKeysWebpackPlugin(config?),
  ]
};

Also, you should see an updated definition of the npm start command:

{
  "start": "ng serve --extra-webpack-config webpack-dev.config.js"
}

Now run npm start and it'll generate new keys whenever a save is made to the project.

Scopes Support

The extractor supports scopes out of the box. When you define a new scope in the providers array:

import { TRANSLOCO_SCOPE } from '@ngneat/transloco';

@Component({
  templateUrl: './admin-page.component.html',
  providers: [{ provide: TRANSLOCO_SCOPE, useValue: 'admin' }]
})
export class AdminPageComponent {}

<ng-container *transloco="let t">{{ t('admin.title') }}</ng-container>

It'll extract the scope (admin in our case) keys into the relevant folder:

📦assets
 ┗ 📂i18n
 ┃ ┣ 📂admin
 ┃ ┃ ┣ 📜en.json
 ┃ ┃ ┗ 📜es.json
 ┃ ┣ 📜en.json
 ┃ ┗ 📜es.json

Inline Loaders

Let's say that we're using the following inline loader:

export const loader = ['en', 'es'].reduce((acc, lang) => {
  acc[lang] = () => import(`../i18n/${lang}.json`);
  return acc;
}, {});

@NgModule({
  imports: [TranslocoModule],
  providers: [
    {
      provide: TRANSLOCO_SCOPE,
      useValue: {
        scope: 'scopeName',
        loader
      }
    }
  ],
  declarations: [YourComponent],
  exports: [YourComponent]
})
export class FeatureModule {}

We can add it to the scopePathMap key in the transloco.config.js file:

module.exports = {
  langs: ['en', 'es'],
  scopePathMap: {
    scopeName: 'src/app/feature/i18n'
  }
};

Now, it'll create the files in the provided folder.

Dynamic Keys

There are times when we need to extract keys with values that may change during runtime. One example can be when you need to use a dynamic expression:

import { TranslocoService } from '@ngneat/transloco';

class MyComponent {
  someMethod() {
    const value = translocoService.translate(`key.${type}.postfix`);
  }
}

To support such cases, you can add a special comment to your code, which tells the CLI to extract it. It can be added to Typescript files:

import { TranslocoService } from '@ngneat/transloco';

class MyComponent {
  /**
   * t(key.typeOne.postfix, key.typeTwo.postfix)
   * t(this.will.be.extracted)
   */
  someMethod() {
    const value = translocoService.translate(`key.${type}.postfix`);
  }
}

Or to templates:

<!-- t(I.am.going.to.extract.it, this.is.cool) -->
<ng-container *transloco="let t">...</ng-container>

When using comments in the templates they will also inherit the read input value (if exists), and will be prefixed with it:

<!-- t(this.is.cool) -->
<ng-container *transloco="let m; read: 'messages'">
    ...
    <!-- t(success, error) -->
    <ng-container *transloco="let g; read: 'general'">
        ...
        <!-- t(ok, cancel) -->
    </ng-container>
</ng-container>

The extracted keys for the code above will be:

{
  "this.is.cool": "",
  "messages.success": "",
  "messages.error": "",
  "general.ok": "",
  "general.cancel": ""
}

Notes:

When using a Typescript file, you must have an import { } from '@ngneat/transloco' statement in it.
When using comments in your HTML files, they must contain only the markers without additional text.
Here's an example for invalid comment:

Extra Support

Supports for the read input:

<ng-container *transloco="let t; read: 'dashboard'">
  <h1>{{ t('title') }}</h1>
  
  <p>{{ t('desc') }}</p>
</ng-container>

The extracted keys for the code above will be:

{
  "dashboard.title": "",
  "dashboard.desc": ""
}

Supports static ternary operators:

<comp [placeholder]="condition ? 'keyOne' : 'keyTwo' | transloco"></comp>
<h1>{{ condition ? 'keyOne' : 'keyTwo' | transloco }}</h1>

🕵️‍ Keys Detective

This tool detects two things: First, it detects any key that exists in one of your translation files but is missing in any of the others. Secondly, it detects any key that exists in the translation files but is missing from any of the templates or typescript files. After installing the library, you should see the following script in your project's package.json file:

{
  "i18n:find": "transloco-keys-manager find"
}

Run npm run i18n:find, and you'll get a lovely list that summarizes the keys found.

🕹 Options

project*: The targeted project (defaults to defaultProject). The sourceRoot of this project will be extracted from the angular.json file and will prefix the input, output, and translationPath properties.
In addition, the transloco config file will be searched in the project's sourceRoot (unless the config option is passed):

transloco-keys-manager extract --project first-app

* Note: If no angular.json file is present, sourceRoot will be src.

config: The root search directory for the transloco config file: (defaults to process.cwd())

transloco-keys-manager extract --config src/my/path
transloco-keys-manager extract -c src/my/path

input: The source directory for all files using the translation keys: (defaults to app)

transloco-keys-manager extract --input src/my/path
transloco-keys-manager extract --input src/my/path,project/another/path
transloco-keys-manager extract -i src/my/path

output: The target directory for all generated translation files: (defaults to assets/i18n)

transloco-keys-manager extract --output my/path
transloco-keys-manager extract -o my/path

langs: The languages files to generate: (defaults to [en])

transloco-keys-manager extract --langs en es it
transloco-keys-manager extract -l en es it

marker: The marker sign for dynamic values: (defaults to t)

transloco-keys-manager extract --marker _
transloco-keys-manager extract -m  _

sort: Whether to sort the keys using JS sort() method: (defaults to false)

transloco-keys-manager extract --sort

unflat: Whether to unflat instead of flat: (defaults to flat)

transloco-keys-manager extract --unflat
transloco-keys-manager extract -u

If you are using unflat files keep in mind that “parent” keys won't be usable for a separate translation value, i.e. if you have two keys first and first.second you cannot assign a value to first as the translation file will look like { "first": { "second": "…" } }.

During key extraction you will get a warning with a list of concerned keys you have to check for.

defaultValue: The default value of a generated key: (defaults to Missing value for {{key}})

transloco-keys-manager extract --default-value missingValue
transloco-keys-manager extract -d "{{key}} translation is missing"

replace: Replace the contents of a translation file (if it exists) with the generated one (default value is false, in which case files are merged)

transloco-keys-manager extract --replace
transloco-keys-manager extract -r

addMissingKeys: Add missing keys that were found by the detective (defaults to false)

transloco-keys-manager find --add-missing-keys
transloco-keys-manager find -a

emitErrorOnExtraKeys: Emit an error and exit the process if extra keys were found (defaults to false)

transloco-keys-manager find --emit-error-on-extra-keys
transloco-keys-manager find -e

translationsPath: The path for the root directory of the translation files (defaults to assets/i18n)

transloco-keys-manager find --translations-path my/path
transloco-keys-manager find -p my/path

help:

transloco-keys-manager --help
transloco-keys-manager -h

Transloco Config File

One more option to define the config object for this library is to create a transloco.config.js file in the project's root folder and add the configuration in it:

// transloco.config.js
module.exports = {
  rootTranslationsPath?: string;
  langs?: string[];
  keysManager: {
    input?: string | string[];
    output?: string;
    marker?: string;
    addMissingKeys?: boolean;
    emitErrorOnExtraKeys?: boolean;
    replace?: boolean;
    defaultValue?: string | undefined;
    unflat?: boolean;
  };
}