Tagging uploaded files

[SamWM]

Created a new plugin File Meta Info, which allows you to store extra (meta) information about files. Data is stored in an XML file (data/other/file_meta.xml) and you can define what meta data to store by changing the array $file_meta_fields.

To display the data in a page, use <?php echo file_meta_data('filename.pdf', 'tags') ?>.

Code:

Code:

<?php
/*
Plugin Name: File Meta Info
Description: Store additional information about uploaded files
Version: 1.0
Author: Sam Collett
*/

# get correct id for plugin
$thisfile=basename(__FILE__, ".php");

# register plugin
register_plugin(
    $thisfile,
    'File Meta Info',    
    '1.0',        
    'Sam Collett',
    'http://www.texotela.co.uk',
    'Save additional meta information for uploaded files',
    '',
    ''  
);

# "Text to display" => "metakey" (no spaces)
$file_meta_fields = array("Tags" => "tags");

# activate filter
add_action('index-pretemplate', 'file_meta_preload');
add_action('header', 'file_meta_header');
add_action('file-extras','file_meta_extras');

# path to xml file
$file_meta_path = GSDATAOTHERPATH.'file_meta.xml';
# xml data
$file_meta_xml;

# functions
function file_meta_preload()
{
    global $file_meta_xml, $file_meta_path;
    if(is_file($file_meta_path)) {
        $file_meta_xml = getXML($file_meta_path);
    }
    else {
        $file_meta_xml = @new SimpleXMLElement('<?xml version="1.0" encoding="UTF-8"?><files></files>');
        XMLsave($file_meta_xml, $file_meta_path);
    }
    if (isset($_REQUEST["file_meta"]))
    {
        file_meta_update();
    }
}

function file_meta_header()
{
    // preload data
    file_meta_preload();
    echo '<style type="text/css">tr.file_meta { font-size: 0.875em } tr.file_meta input.meta { font-size: 0.875em; width: 200px } tr.file_meta td { padding: 0 18px }</style>';
}

function file_meta_extras() {
    global $file_meta_fields, $upload;
    echo '<tr class="file_meta"><td colspan="4">
    <form method="post" action="'.htmlentities($_SERVER['PHP_SELF'], ENT_QUOTES).'">';
    foreach($file_meta_fields as $text => $metakey)
    {
        echo $text.': <input name="meta_'.$metakey.'" value="'.file_meta_data($upload['name'], $metakey).'" class="'.$metakey.' meta" />';
    }
    echo '<input type="hidden" name="file" value="'.$upload['name'].'" />
    <input type="submit" value="Save" name="file_meta" />
    </form>
    </td></tr>';
}

function file_meta_data($file, $meta)
{
    global $file_meta_xml;
    $meta_data = '';
    if(is_object($file_meta_xml))
    {
        $current = $file_meta_xml->xpath('//files/file[@name="'.$file.'"]');
        if(count($current) !== 0) {
            $children = $current[0]->xpath($meta);
            if(count($children) > 0)
            {
                $meta_data = $children[0];
            }
        }
    }
    return $meta_data;
}

function file_meta_update()
{
    global $file_meta_xml, $file_meta_path;
    $file = '';
    // meta data to update
    $meta_update = array();
    foreach($_REQUEST as $key => $value)
    {
        // temp array for storing meta key and its value
        $ar = array();
        // if request key is file
        if($key == "file") $file = $value;
        if(strpos($key, "meta_") === 0) {
            $ar = explode('_',$key);
            $meta_update[$ar[1]] = $value;
        }
    }
    // find the file in the XML document
    $file_item = $file_meta_xml->xpath('//files/file[@name="'.$file.'"]');
    // if the file is not found
    if(count($file_item) === 0) {
        $file_item = $file_meta_xml->addChild('file');
        $file_item->addAttribute('name', $file);
    }
    
    // loop through all meta keys to update
    foreach($meta_update as $key => $value)
    {
        $children = $file_item[0]->xpath($key);
        if(count($children) > 0)
        {
            // remove existing tag
            unset($children[0][0]);
        }
        $file_item[0]->addChild($key, $value);
        
    }
    
    XMLsave($file_meta_xml, $file_meta_path);
}