rss-bridge/lib/FormatAbstract.php

<?php
require_once(__DIR__ . '/FormatInterface.php');
abstract class FormatAbstract implements FormatInterface{
    const DEFAULT_CHARSET = 'UTF-8';

    protected 
        $contentType,
        $charset,
        $items,
        $extraInfos
    ;

    public function setCharset($charset){
        $this->charset = $charset;

        return $this;
    }

    public function getCharset(){
        $charset = $this->charset;

        return is_null($charset) ? self::DEFAULT_CHARSET : $charset;
    }

    protected function setContentType($contentType){
        $this->contentType = $contentType;

        return $this;
    }

    protected function callContentType(){
        header('Content-Type: ' . $this->contentType);
    }

    public function display(){
        echo $this->stringify();

        return $this;
    }

    public function setItems(array $items){
        $this->items = array_map(array($this, 'array_trim'), $items);

        return $this;
    }

    public function getItems(){
        if(!is_array($this->items))
            throw new \LogicException('Feed the ' . get_class($this) . ' with "setItems" method before !');

        return $this->items;
    }

    /**
    * Define common informations can be required by formats and set default value for unknow values
    * @param array $extraInfos array with know informations (there isn't merge !!!)
    * @return this
    */
    public function setExtraInfos(array $extraInfos = array()){    
        foreach(array('name', 'uri') as $infoName){
            if( !isset($extraInfos[$infoName]) ){
                $extraInfos[$infoName] = '';
            }
        }

        $this->extraInfos = $extraInfos;

        return $this;
    }

    /**
    * Return extra infos
    * @return array See "setExtraInfos" detail method to know what extra are disponibles
    */
    public function getExtraInfos(){
        if( is_null($this->extraInfos) ){ // No extra info ?
            $this->setExtraInfos(); // Define with default value
        }

        return $this->extraInfos;
    }
    
    /**
     * Sanitized html while leaving it functionnal.
     * The aim is to keep html as-is (with clickable hyperlinks)
     * while reducing annoying and potentially dangerous things.
     * Yes, I know sanitizing HTML 100% is an impossible task.
     * Maybe we'll switch to http://htmlpurifier.org/
     * or http://www.bioinformatics.org/phplabware/internal_utilities/htmLawed/index.php
     */
    protected function sanitizeHtml($html)
    {
        $html = str_replace('<script','<&zwnj;script',$html); // Disable scripts, but leave them visible.
        $html = str_replace('<iframe','<&zwnj;iframe',$html);
        $html = str_replace('<link','<&zwnj;link',$html);
        // We leave alone object and embed so that videos can play in RSS readers.
        return $html;
    }

    protected function array_trim($elements){
        foreach($elements as $key => $value){
            if(is_string($value))
                $elements[$key] = trim($value);
        }
        return $elements;
    }
}