Text manager

Lightweight, extensible text manager for managing texts, such as localizing texts in a web application

Installation

npm i text-manager -S

TL;DR

// 1. initialize
import { createDefaultTextManager } from 'text-manager';
const textManager = createDefaultTextManager();

// 2. register texts
const buttonTexts = {
  'button.open': 'Open',
  'button.open_in': 'Open in {{0}} seconds',
  'button.close_in': 'Close in {{seconds}} seconds',
};
textManager.addTexts('buttons', buttonTexts);

// 3. use
textManager.getText('button.open') === 'Open'; // get a text without parameters
textManager.getText('button.open_in', [5]) === 'Open in 5 seconds'; // get a text with ordered parameters
textManager.getText('button.close_in', { seconds: 5 }) === 'Close in 5 seconds'; // get a text with named parameters

Getting started

Text manager is used to get a text or a parameterized text by the code. It can also be extended for additional text changes or modifications via middleware, e.g. hiding sensitive information.

Texts set

Texts set is a plain object where a key is the code and a value is the text. Text may contain or may not contain parameters. Parameter must be surrounded with double braces {{<parameter>}}. Parameter must be specified by the name or a sequence number.

Example:

{
  "button.open": "Open",
  "button.open_in": "Open in {{0}} seconds",
  "button.close_in": "Close in {{seconds}} seconds"
}

Default text manager

Default TextManager is used get a parameterized text by the code. If a text is not found it returns the code.

Example:

import { createDefaultTextManager } from 'text-manager';
const textManager = createDefaultTextManager();
textManager.addTexts('buttons', buttonTexts);

textManager.getText('button.open'); // 'Open'
textManager.getText('button.open_in', [5]); // 'Open in 5 seconds'
textManager.getText('button.close_in', { seconds: 5 }); // 'Close in 5 seconds'
textManager.getText('button.save'); // 'button.save' - there is no text for the code

Middleware

In some cases addition text modifications are needed, e.g. parsing markdown, formatting numbers, dates and etc. This can be reached by extending TextManager with a custom list of middleware.

Middleware is a function which receives text, parameters and code and must return a text. Middleware functions are being executed one by one in sequence. Each of them receives text from the previous one. The first one receives original text or undefined if it doesn't exist. The result of the last one will be returned by TextManger.getText.

The following middleware functions are built-in and used in createDefaultTextManager

• import { insert-params } from 'text-manage' - inserts params in the text
• import { no-text-fallback } from 'text-manage' - returns the code if a text is not found

Example:

import TextManager from 'text-manager';

function CustomMiddleware1(code, text) {
  return text + ' Hello';
}

function CustomMiddleware2(code, text) {
  return text + ' World!';
}

const buttonTexts = {
  'button.open': 'Open',
};
const textManager = new TextManager([CustomMiddleware1, CustomMiddleware2]);
textManager.addTexts('buttons', buttonTexts);

// get text
textManager.getText('button.open') === 'Open Hello World!';

API

TextManager

• constructor(middleware)

  • middleware, array of middleware functions

• addTexts(id, texts)

  • id, string - required, the id of a texts
  • texts, object - required, a flat object where key is a code and value is a text, e.g. { 'button.open': 'Open' }

• getText(code, parameters)

  • code, string - required, the code of a text
  • parameters, array/object - parameters, e.g. [5, 'abc'], { seconds: 5 }

Middleware

• function(code, text, parameters) - returns string
  • code, string - the code of a text
  • text, string - initial text or text from previous middleware
  • parameters, object/array - parameters