SilverStripe overwriting URLSegmentFilter static

Question

URLSegmentFilter has a static array $default_replacements which holds, among others, the string to convert ampersands to (from & to -and-) for URL's.

I'm trying to extend the class and overwrite this static to translate the ampersand convert (only value is english and).

How can I overwrite the owner static for this goal?

class URLSegmentFilterExtension extends Extension {

    private static $default_replacements = array(
        '/&/u' => '-and-', // I need to translate this using _t()
        '/&/u' => '-and-', // And this one
        '/\s|\+/u' => '-',
        '/[_.]+/u' => '-', 
        '/[^A-Za-z0-9\-]+/u' => '', 
        '/[\/\?=#]+/u' => '-', 
        '/[\-]{2,}/u' => '-', 
        '/^[\-]+/u' => '',
        '/[\-]+$/u' => ''
    );

}

Answer 1

First of all: The URLSegmentFilter mainly operates in the CMS context, where you usually just have a single locale (depending on the settings of the editing Member). So using _t() alone might not be very helpful? So you'd probably have to get the current editing locale (assuming you're using Fluent or Translatable) and set the locale for translations temporarily.

I don't see a way to hook in translations via an Extension there. I think you'd be better off creating a custom subclass and use it via Injector.

Something like this should work:

<?php
class TranslatedURLSegmentFilter extends URLSegmentFilter
{
    public function getReplacements()
    {
        $currentLocale = i18n::get_locale();
        $contentLocale = Translatable::get_current_locale();
        // temporarily set the locale to the content locale
        i18n::set_locale($contentLocale);

        $replacements = parent::getReplacements();
        // merge in our custom replacements
        $replacements = array_merge($replacements, array(
            '/&amp;/u' => _t('TranslatedURLSegmentFilter.UrlAnd', '-and-'),
            '/&/u' => _t('TranslatedURLSegmentFilter.UrlAnd', '-and-')
        ));

        // reset to CMS locale
        i18n::set_locale($currentLocale);
        return $replacements;
    }
}

Then you have to enable the custom URLSegmentFilter via config by putting something like this in your mysite/_config/config.yml file:

Injector:
  URLSegmentFilter:
    class: TranslatedURLSegmentFilter

Update: The above example assumes you're using the Translatable module. If you're using Fluent, replace the following line:

$contentLocale = Translatable::get_current_locale();

with:

$contentLocale = Fluent::current_locale();

Answer 2

You can update configuration dynamically in mysite/_config.php

$defaultReplacements = Config::inst()->get('URLSegmentFilter', 'default_replacements');

$translatedAnd = _t('URLSegmentFilter.And','-and-');
$defaultReplacements['/&/u'] = $translatedAnd;
$defaultReplacements['/&/u'] = $translatedAnd;

Config::inst()->Update('URLSegmentFilter', 'default_replacements', $defaultReplacements);