Oihana PHP

isLanguageCode.php

Table of Contents

Functions

isLanguageCode()  : bool
Checks whether a value is a language tag safe to use as an identifier.

Functions

isLanguageCode()

Checks whether a value is a language tag safe to use as an identifier.

isLanguageCode(mixed $value) : bool

A language tag rarely stays a value: it names a key of a translations map (alternateName.fr), a directory, a template, or an attribute of a stored document — places where it is written verbatim rather than passed as a parameter. Anything interpolating a tag has to prove it harmless first, and this helper is that proof.

A valid tag is a two or three letter primary subtag, optionally followed by dash-separated subtags (region, script, variant): fr, en, pt-BR, zh-Hant-TW. The primary subtag is lowercase — callers normalise before asking, so FR is rejected rather than silently accepted under two spellings.

⚠ A tag carrying a dash is valid here but is not always reachable through dot notation (alternateName.pt-BR reads as a subtraction in several query languages). The caller emits the bracket form for it; this helper only says the tag is safe.

Parameters
$value : mixed

The value to check.

Tags
example 
use function oihana\controllers\helpers\isLanguageCode;

isLanguageCode( 'fr' );         // true
isLanguageCode( 'pt-BR' );      // true
isLanguageCode( 'zh-Hant-TW' ); // true
isLanguageCode( 'FR' );         // false (normalise first)
isLanguageCode( 'f' );          // false (too short)
isLanguageCode( 'fr"' );        // false
isLanguageCode( 'fr fr' );      // false
isLanguageCode( '' );           // false
isLanguageCode( 42 );           // false (not a string)
since
1.3.0
author

Marc Alcaraz

Return values
bool —

True when $value is a safe language tag.

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