Localize Carbon::diffForHumans in Laravel Models

Article.php

<?php namespace App;

use App\Carbon\LocalizedDiffForHumansTrait;
use Illuminate\Database\Eloquent\Model;

// example model

class Article extends Model
{
    use LocalizedDiffForHumansTrait;
}

CarbonBR.php

<?php namespace App\Carbon;

use Carbon\Carbon;

// extends Carbon\Carbon replacing only the diffForHumans for localized output

class CarbonBR extends Carbon
{
    public function diffForHumans( Carbon $other = NULL, $absolute = FALSE )
    {
        $isNow = $other === NULL;

        if ( $isNow )
        {
            $other = static::now( $this->tz );
        }

        $diffInterval = $this->diff( $other );

        switch ( TRUE )
        {
            case ( $diffInterval->y > 0 ):
                $unit  = 'ano';
                $delta = $diffInterval->y;
                break;

            case ( $diffInterval->m > 0 ):
                $unit  = 'mês';
                $delta = $diffInterval->m;
                break;

            case ( $diffInterval->d > 0 ):
                $unit  = 'dia';
                $delta = $diffInterval->d;
                if ( $delta >= self::DAYS_PER_WEEK )
                {
                    $unit  = 'semana';
                    $delta = floor( $delta / self::DAYS_PER_WEEK );
                }
                break;

            case ( $diffInterval->h > 0 ):
                $unit  = 'hora';
                $delta = $diffInterval->h;
                break;

            case ( $diffInterval->i > 0 ):
                $unit  = 'minuto';
                $delta = $diffInterval->i;
                break;

            default:
                $delta = $diffInterval->s;
                $unit  = 'segundo';
                break;
        }

        if ( $delta == 0 )
        {
            $delta = 1;
        }


        if ($unit === 'mês') {
            $txt = $delta == 1 ? $delta . ' mês' : $delta . ' meses';
        } else {
            $txt = $delta . ' ' . $unit;
            $txt .= $delta == 1 ? '' : 's';
        }

        if ( $absolute )
        {
            return $txt;
        }

        $isFuture = $diffInterval->invert === 1;

        if ( $isNow )
        {
            if ( $isFuture )
            {
                return 'daqui a ' . $txt;
            }

            return $txt . ' atrás';
        }

        if ( $isFuture )
        {
            return $txt . ' depois';
        }

        return $txt . ' antes';
    }
}

LocalizedDiffForHumansTrait.php

<?php  namespace App\Carbon;

use DateTime;

// exact same implementation from Illuminate\Database\Eloquent\Model class, changing only Carbon\Carbon with our extended version

trait LocalizedDiffForHumansTrait {
    /**
     * Return a timestamp as DateTime object.
     *
     * @param  mixed  $value
     * @return \App\Carbon\CarbonBR
     */
    protected function asDateTime($value)
    {
        // If this value is an integer, we will assume it is a UNIX timestamp's value
        // and format a Carbon object from this timestamp. This allows flexibility
        // when defining your date fields as they might be UNIX timestamps here.
        if (is_numeric($value))
        {
            return CarbonBR::createFromTimestamp($value);
        }

        // If the value is in simply year, month, day format, we will instantiate the
        // Carbon instances from that format. Again, this provides for simple date
        // fields on the database, while still supporting Carbonized conversion.
        elseif (preg_match('/^(\d{4})-(\d{2})-(\d{2})$/', $value))
        {
            return CarbonBR::createFromFormat('Y-m-d', $value)->startOfDay();
        }

        // Finally, we will just assume this date is in the format used by default on
        // the database connection and use that format to create the Carbon object
        // that is returned back out to the developers after we convert it here.
        elseif ( ! $value instanceof DateTime)
        {
            $format = $this->getDateFormat();

            return CarbonBR::createFromFormat($format, $value);
        }

        return CarbonBR::instance($value);
    }
}