Transcoder

Introduction

This is a wrapper around PHP’s mb_convert_encoding and iconv functions. This library adds:

• fallback from mb to iconv for unknown encodings
• conversion of warnings to proper exceptions.

Installation

The recommended way to install the Transcoder library is through Composer:

$ composer require ddeboer/transcoder

This command requires you to have Composer installed globally, as explained in the installation chapter of the Composer documentation.

Usage

Basics

Create the right transcoder for your platform and translate some strings:

use Ddeboer\Transcoder\Transcoder;

$transcoder = Transcoder::create();
$result = $transcoder->transcode('España');

You can also manually instantiate a transcoder of your liking:

use Ddeboer\Transcoder\MbTranscoder;

$transcoder = new MbTranscoder();

Or:

use Ddeboer\Transcoder\IconvTranscoder;

$transcoder = new IconvTranscoder();

Source encoding

By default, the source encoding is detected automatically. However, you get much more reliable results when you specify it explicitly:

$transcoder->transcode('España', 'iso-8859-1');

Target encoding

Specify a default target encoding as the first argument to create():

use Ddeboer\Transcoder\Transcoder;

$isoTranscoder = Transcoder::create('iso-8859-1');

Alternatively, specify a target encoding as the third argument in a transcode() call:

use Ddeboer\Transcoder\Transcoder;

$transcoder->transcode('España', null, 'UTF-8'); 

Error handling

PHP’s mv_convert_encoding and iconv are inconvenient to use because they generate notices and warnings instead of proper exceptions. This library fixes that:

use Ddeboer\Transcoder\Exception\UndetectableEncodingException;
use Ddeboer\Transcoder\Exception\UnsupportedEncodingException;
use Ddeboer\Transcoder\Exception\IllegalCharacterException;

$input = 'España';
 
try {
    $transcoder->transcode($input);
} catch (UndetectableEncodingException $e) {
    // Failed to automatically detect $input’s encoding 
}

try {
    $transcoder->transcode($input, null, 'not-a-real-encoding');
} catch (UnsupportedEncodingException $e) {
    // ‘not-a-real-encoding’ is an unsupported encoding 
}

try {
    $transcoder->transcode('Illegal quotes: ‘ ’', null, 'iso-8859-1');
} catch (IllegalCharacterException $e) {
    // Curly quotes ‘ ’ are illegal in ISO-8859-1
}

Transcoder fallback

In general, mb_convert_encoding is faster than iconv. However, as iconv supports more encodings than mb_convert_encoding, it makes sense to combine the two.

So, the Transcoder returned from create():

• uses mb_convert_encoding if the mbstring PHP extension is installed;
• if not, it uses iconv instead if the iconv extension is installed;
• if both the mbstring and iconv extension are available, the Transcoder will first try mb_convert_encoding and fall back to iconv.