Email_Service_Premailer

Email_Service_Premailer.php

<?php
class Email_Service_Premailer {

    /**
     * Process using premailer
     *
     * requires:
     * yum -y install ruby rubygems ruby-devel
     * gem install premailer
     * gem install hpricot
     *
     * @see https://github.com/premailer/premailer/
     * 
     * 
     * @param string $string
     * @return string
     */
    public function process( $string )
    {
        $process = proc_open( '/usr/bin/env premailer', [ ['pipe','r'], ['pipe','w'], ['pipe','a'] ], $pipes, '/tmp' );

        if( is_resource( $process ) ) {
            fwrite( $pipes[0], $string );
            fclose( $pipes[0] );

            $processed = stream_get_contents( $pipes[1] );
            fclose( $pipes[1] );

            fclose( $pipes[2] );
            proc_close( $process );
        }
        
        return empty( $processed ) ? $string : $processed;
    }

}