Resources tool 🧰

Resources tool (Locals) y part of the NodeTskeleton template project.

NodeTskeleton is a Clean Architecture based template project for NodeJs using TypeScript to implement with any web server framework or even any user interface.

Go to NodeTskeleton

Using Resources

Resources is a basic internationalization tool that will allow you to manage and administer the local messages of your application, even with enriched messages, for example:

Using Resources

The first thing to note is that your resource files must be in json or js format as shown in an example below:

// ./locals/resources/en.local.ts
// Resource file for English.
import { LocalMessageDictionary } from "./keys";

const enMessages: LocalMessageDictionary = {
  SOMETHING_WENT_WRONG: "Oh sorry, something went wrong with current action!",
  SOME_PARAMETERS_ARE_MISSING: "Some parameters are missing: {{missingParams}}.",
  YOUR_OWN_NEED: "You are the user {{name}}, your last name is {{lastName}} and you are {{age}} years old."
  /* others as you needed */
};
export default enMessages;

// ./locals/resources/es.local.ts
// Resource file for Spanish.
import { LocalMessageDictionary } from "./keys";

const esMessages: LocalMessageDictionary = {
  SOMETHING_WENT_WRONG: "Oh lo sentimos, algo salió mal con esta acción!",
  SOME_PARAMETERS_ARE_MISSING: "Faltan algunos parámetros: {{missingParams}}.",
  YOUR_OWN_NEED: "Usted es {{name}}, su apellido es {{lastName}} y su edad es {{age}} años."
  /* others as you needed */
};
export default esMessages;

Important note

The parameters to be replaced in the messages should be in brackets like this, {{paramName}}.

As a second step you must have the file that corresponds to the mapping of the keys containing your resource files as shown below:

// ./locals/resources/keys.ts
export enum KeysDictionaryEnum {
  SOMETHING_WENT_WRONG: "SOMETHING_WENT_WRONG",
  SOME_PARAMETERS_ARE_MISSING: "SOME_PARAMETERS_ARE_MISSING",
  YOUR_OWN_NEED: "YOUR_OWN_NEED"
};
// This type name is according to your like
export type LocalMessageDictionary = { [key in keyof typeof KeysDictionaryEnum]: string };

So now we can set up our index file which we will use to manage our internationalization resources:

// ./locals/index.ts
import { KeysDictionaryEnum, LocalMessageDictionary } from "./resources/keys";
import esLocal from "./resources/es.local.ts";
import enLocal from "./resources/en.local.ts";
import { Resources } from "resources-tsk";

export enum LocaleTypeEnum {
  ES = "es_ES",
  EN = "en_US",
}

type LocaleType = {
  [K in LocaleTypeEnum]: LocalMessageDictionary;
};

const locals: LocaleType = {
  [LocaleTypeEnum.ES]: esLocal,
  [LocaleTypeEnum.EN]: enLocal,
};

const defaultLanguage = LocaleTypeEnum.ES;
// The types are for strict control to improve inference and avoid errors
const resources = new Resources<LocaleTypeEnum, KeysDictionaryEnum, LocalMessageDictionary, LocaleType>(locals, KeysDictionaryEnum, defaultLanguage);

export default resources;

Okay, so now you can use your resources where you need them, an example would be this:

import resources from "../locals/index";

const simpleMessage = resources.get(resources.keys.ITEM_PRODUCT_DOES_NOT_EXIST);

const enrichedMessage = resources.getWithParams(resources.keys.SOME_PARAMETERS_ARE_MISSING, {
	missingParams: keysNotFound.join(", "),
});

// You can add enriched messages according to your own needs, for example:
const yourEnrichedMessage = resources.getWithParams(resources.keys.YOUR_OWN_NEED, {
	name: firstName, lastName, age: userAge
});
/*
	Output:
	You are the user John, your last name is Doe and you are 24 yeard old.
*/

And you can add all the parameters you need with as many messages in your application as required.

The resource files can be local or you can get them from an external service.

Important

Don't forget to perform the language initialization for your resource manager in the localization middleware as following:

import resources from "../locals/index";

// add this line into your localization function considering the web framework you're using
resources.init(req.headers["accept-language"] || defaultLang);

But if you prefer, applying the concept of pure function, you have the option to pass the optional language parameter in the functions to get the parameters as shown below:

const message = resources.get(localKeys.SOMETHING_WENT_WRONG, user.language);
// Or
const enrichedMessage = resources.getWithParams(
	resources.keys.NOT_VALID_EMAIL,
	{ email: user.email },
	user.language,
);

Replace function

The library provides a static function to replace keys into text as follow:

import { Resources } from "resources-tsk";

const text = "This is a text with {{name}} and {{lastName}}.";
const params = { 
	name: "Carl",
	lastName: "Sagan",
};

const textReady = Resources.replaceParams(text, params);
console.log(textReady);
// This is a text with Carl and Sagan.

RunKit demo

Go to this Link or click in Try on RunKit button on the right side of the page.

Warning 💀

Use this resource at your own risk.