rss_feed_writer.inc

<?php
class RSS_Feed_Writer
{

    var $items = Array();

    var $image = Array();

    var $channel = Array();

    var $rss = '';

    var $type = '';

    var $version = '';


    function RSS_Feed_Writer()
    {

    }//end constructor


    function addItems($items)
    {
        if (empty($items)) {
            return TRUE;
        }
        if ($this->_isTypeVersionSet()) {
            if (!is_array($items)) {
                trigger_error('You can assign Associative Arrays only to the items', E_USER_ERROR);
                return FALSE;
            }
            $this->items = $items;
            return TRUE;
        } else {
            return FALSE;
        }

    }//end addItems()


    function addChannel($channel)
    {
        if (empty($channel)) {
            trigger_error('You cannot set empty values to channel', E_USER_ERROR);
            return FALSE;
        }
        if ($this->_isTypeVersionSet()) {
            if (!is_array($channel)) {
                trigger_error('You can assign Associative Arrays only to the items', E_USER_ERROR);
                return FALSE;
            }
            $this->channel = $channel;
            return TRUE;
        } else {
            return FALSE;
        }

    }//end addChannel()


    function addImage($image)
    {
        if (empty($image)) {
            trigger_error('You cannot set empty values to image ', E_USER_ERROR);
            return FALSE;
        }
        if ($this->_isTypeVersionSet()) {
            if (!is_array($image)) {
                trigger_error('You can assign Associative Arrays only to the items', E_USER_ERROR);
                return FALSE;
            }
            $this->image = $image;
            return TRUE;
        } else {
            return FALSE;
        }

    }//end addImage()


    function setTypeVersion($type='', $version='')
    {
        if (empty($type)  || empty($version)) {
            trigger_error('You Have To Set The Type And The Version Of RSS Before Adding the element', E_USER_WARNING);
            return FALSE;
        } else {
            if (!is_string($type) || !is_string($version)) {
                trigger_error('The Type And Version Of The RSS Feed To Be Generated Have To Be Strings', E_USER_WARNING);
                return FALSE;
            }
            $type_version = $type.'_'.$version;
            switch ($type_version) {
                case 'rss_1.0':
                break;
                case 'rss_2.0':
                break;
                case 'atom_1.0':
                break;
                default:
                    trigger_error('The Type The RSS Feed Can Only Be Either rss Or atom', E_USER_ERROR);
                return FALSE;
            }
            $this->type = $type;
            $this->version = $version;
            return TRUE;
        }

    }//end setTypeVersion()


    function getRSSString($header=TRUE, $encoding='iso-8859-1')
    {
        $channel = $this->channel;
        $image = $this->image;
        $items = $this->items;
        $type = $this->type;
        $version = $this->version;
        // if no type or version is specified then trigger error
        // we NEED TYPE AND VERSION as this writer can build rss1.0, rss2.0, atom 1.0 versions
        if (empty($type) || empty($version)) {
            trigger_error('There Is No Type Or Version Set.. Please Set the Type And Version And Try Again', E_USER_WARNING);
            return;
        }
        // if the channel is empty ir the items is empoty then trigger error as there is no feed without items or channel
        if (empty($channel)) {
            trigger_error('Channel Info Required As Per The RSS Standards', E_USER_WARNING);
            return;
        }

        $name = 'item';
        ob_start();
        if ($header) header('Content-type: text/xml');
        echo '<?xml version="1.0" encoding="'.$encoding.'"?>';

        // open tag for atom is feed
        // for rss 1.0 it is rdf:RDF
        // for rss 2.0 it is rss version 2.0
        if (strcasecmp($type, 'atom') == 0) {
            $type = 'feed';
            $name = 'entry';
        }
        if (($type == 'rss') && ($version == '1.0')) {
            echo '<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns="http://purl.org/rss/1.0/">';
        } else {
            echo '<'.$type;
            if ($type == 'feed') {
                echo ' xml:lang="en" xmlns="http://www.w3.org/2005/Atom"';
            } else {
                echo ' version="'.$version.'"';
            }
            echo '>';
        }
        // you do not have channel tag in atom 1.0 Instead we use feed tag itself
        if ($type != 'feed') {
            $type .= ' '.$version;

            if ($type == 'rss 2.0') {
                echo '<channel>';
            } else {
                if (isset($channel['rdf:about'])) {
                    echo '<channel rdf:about="'.$channel['rdf:about'].'">';
                } else {
                    trigger_error('A required attribute "rdf:about" is undefined for the Channel tag', E_USER_ERROR);
                    ob_end_clean();
                    return '';
                }
            }
        }
        // add data to the chaannel or the feed tags
        foreach ($channel as $key => $info) {
            if ($key == 'rdf:about') continue;
            if (is_array($info)) {
                if ($type != 'feed') {
                    trigger_error('Attributes And SubTags In Channel Not Allowed For RSS Versions', E_USER_ERROR);
                    ob_end_clean();
                    return '';
                }
                $keys = array_keys($info);
                if (in_array('ATTRIBUTES', $keys)) {
                    echo '<'.$key.' ';
                    $attributes = $info['ATTRIBUTES'];
                    foreach ($attributes as $sub => $sub_info) {
                        // change the tags if any present in the info
                        $sub_info = str_replace('&', '&amp;', $sub_info);
                        $sub_info = str_replace('<', '&lt;', $sub_info);
                        $sub_info = str_replace('>', '&gt;', $sub_info);
                        echo $sub.'="'.$sub_info.'" ';
                    }
                    echo '>';
                }
                if (in_array('SUBTAGS', $keys)) {
                    echo '<'.$key.'>';
                    $sub_tags = $info['SUBTAGS'];
                    foreach ($sub_tags as $sub => $sub_info) {
                        // change the tags if any present in the info
                        $sub_info = str_replace('&', '&amp;', $sub_info);
                        $sub_info = str_replace('<', '&lt;', $sub_info);
                        $sub_info = str_replace('>', '&gt;', $sub_info);
                        echo '<'.$sub.'>'.$sub_info.'</'.$sub.'>';
                    }
                }
                echo '</'.$key.'>';
            } else {
                // change the tags if any present in the info
                $info = str_replace('&', '&amp;', $info);
                $info = str_replace('<', '&lt;', $info);
                $info = str_replace('>', '&gt;', $info);
                echo '<'.$key.'>'.$info.'</'.$key.'>';
            }
        }//end foreach channnel

        if ($type == 'rss 1.0') {
            echo '<items><rdf:Seq>';
            foreach ($items as $item) {
                echo '<rdf:li rdf:resource="'.$item['rdf:about'].'"/>';
            }
            echo '</rdf:Seq></items></channel>';
        }

        if (!empty($image)) {
            if ($type == 'feed') {
                echo '<logo>';
            } else {
                echo '<image>';
            }
            foreach ($image as $key => $info) {
                // change the tags if any present in the info
                $info = str_replace('&', '&amp;', $info);
                $info = str_replace('<', '&lt;', $info);
                $info = str_replace('>', '&gt;', $info);
                if (is_array($info)) {
                    echo '<'.$key.'>';
                    foreach ($info as $sub => $sub_info) {
                        echo '<'.$sub.'>'.$sub_info.'</'.$sub.'>';
                    }
                    echo '</'.$key.'>';
                } else {
                    echo '<'.$key.'>'.$info.'</'.$key.'>';
                }
            }
            if ($type == 'feed') {
                echo '</logo>';
            } else {
                echo '</image>';
            }
        }

            foreach ($items as $item) {
                if ($type != 'rss 1.0') {
                    echo '<'.$name.'>';
                } else {
                    echo '<item rdf:about="'.$item['rdf:about'].'">';
                    unset($item['rdf:about']);
                }
                foreach ($item as $key => $info) {
                    if (is_array($info)) {
                        $keys = array_keys($info);
                        if (in_array('ATTRIBUTES', $keys)) {
                            echo '<'.$key.' ';
                            $attributes = $info['ATTRIBUTES'];
                            foreach ($attributes as $sub => $sub_info) {
                                // change the tags if any present in the info
                                $sub_info = str_replace('&', '&amp;', $sub_info);
                                $sub_info = str_replace('<', '&lt;', $sub_info);
                                $sub_info = str_replace('>', '&gt;', $sub_info);
                                echo $sub.'="'.$sub_info.'" ';
                            }
                            echo '>';
                        }
                        if (in_array('SUBTAGS', $keys)) {
                            echo '<'.$key.'>';
                            $sub_tags = $info['SUBTAGS'];
                            foreach ($sub_tags as $sub => $sub_info) {
                                // change the tags if any present in the info
                                $sub_info = str_replace('&', '&amp;', $sub_info);
                                $sub_info = str_replace('<', '&lt;', $sub_info);
                                $sub_info = str_replace('>', '&gt;', $sub_info);
                                echo '<'.$sub.'>'.$sub_info.'</'.$sub.'>';
                            }
                        }
                        echo '</'.$key.'>';
                    } else {
                        // change the tags if any present in the info
                        $info = str_replace('&', '&amp;', $info);
                        $info = str_replace('<', '&lt;', $info);
                        $info = str_replace('>', '&gt;', $info);
                        echo '<'.$key.'>'.$info.'</'.$key.'>';
                    }
                }//end foreach item
                echo '</'.$name.'>';
            }//end foreach items

        if ($type != 'rss 1.0') {
            if ($type != 'feed') {
                // rss 2.0
                echo '</channel>';
                echo '</'.$this->type.'>';
            } else {
                // atom 1.0
                echo '</feed>';
            }
        } else {
            // rss 1.0
            echo '</rdf:RDF>';
        }

        $rss = ob_get_contents();
        ob_end_clean();
        return $rss;

    }//end getRSSString()


//--        PRIVATE OR INTERNAL FUNCTIONS        --//


    function _isTypeVersionSet()
    {
        if (!empty($this->type) && (!empty($this->version))) {
            return TRUE;
        } else {
            trigger_error('You Have To Set The Type And The Version Of RSS Before Adding the element', E_USER_WARNING);
            return FALSE;
        }

    }//end _isTypeVersionSet()


}//end class


?>