Overview

Since declareVar adds ICU-compatible markers to source text, it can create issues for any existing string-processing logic. The decodeVars function extracts original values from strings that contain declareVar markers.

function getGreeting({ name }) {
  const greeting = "Hello, " + declareVar(name);
  // "Hello, {_gt_, select, other {Brian}}"

  const decodedGreeting = decodeVars(greeting);
  // "Hello, Brian" <- the string as if `declareVar` was never used
  return decodedGreeting;
}

Because declareVar only affects encoded strings, it is only meant for use with source strings and has no effects on translated strings.

Reference

Parameters

Returns

A string with ICU markers removed, containing the original variable values.

Example

Basic Usage

Extract original values from strings with variable markers.

import { declareVar, decodeVars } from 'gt-next';

const encodedVar = declareVar(name);
// "{_gt_, select, other {Alice}}"
const decodedVar = decodeVars(encodedVar);
// "Alice"

Multiple Variables

decodeVars can be used with multiple variables.

import { declareVar, decodeVars } from 'gt-next';

const name1 = "Alice";
const name2 = "Bob";
const encodedVar = "Hello, " + declareVar(name1) + "! My name is " + declareVar(name2);
// "Hello, {_gt_, select, other {Alice}}! My name is {_gt_, select, other {Bob}}"

const decodedVar = decodeVars(encodedVar);
// "Hello, Alice! My name is Bob"

Notes

• Only use decodeVars when you need to process strings containing declareVar markers
• The function specifically targets ICU MessageFormat patterns created by declareVar
• Original variable values are preserved exactly as they were before encoding
• Does not affect translation processing - only removes markers for string manipulation
• decodeVars is not a general ICU MessageFormat parser and should not be used on arbitrary ICU strings

Next steps

• See declareVar for marking dynamic content
• See declareStatic for creating static function calls
• See msg for string encoding and decoding patterns