source: trunk/lib/Image.inc.php

<?php
/**
 * The Strangecode Codebase - a general application development framework for PHP
 * For details visit the project site: <http://trac.strangecode.com/codebase/>
 * Copyright 2001-2012 Strangecode, LLC
 *
 * This file is part of The Strangecode Codebase.
 *
 * The Strangecode Codebase is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your option)
 * any later version.
 *
 * The Strangecode Codebase is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * The Strangecode Codebase. If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * Image.inc.php
 *
 * @author  Quinn Comendant <quinn@strangecode.com>
 * @version 1.1
 * @since   14 Apr 2006 20:07:29
 */
class Image
{

    // Object parameters.
    protected $_params = array();

    /**
     * Constructor.
     *
     * @param   array    $params  Set parameters for this object.
     * @author  Quinn Comendant <quinn@strangecode.com>
     * @version 1.1
     * @since   26 Jan 2005 01:54:50
     */
    public function __construct($params=array())
    {
        if (!is_array($params)) {
            trigger_error(sprintf('Parameters not specified properly.', null), E_USER_ERROR);
        }
        $defaults = array(
            // Pattern passed to glob() with $id to match image filenames.
            'filename_pattern' => '%s*',

            // The path to the image source directory. (Ex: /var/www/htdocs/images)
            'base_path' => '',

            // The URL to the image directory. (Ex: /images)
            'base_url' => '',

            // Image to use in the case of a missing image.
            'default_image_file' => '',
        );
        $this->_params = array_merge($defaults, $params);
    }

    /**
     * Tests if an image with specified id exists on the file system.
     *
     * @access  public
     * @param   string  $id     Unique image identifier.
     * @return  bool            Existence of file.
     * @author  Quinn Comendant <quinn@strangecode.com>
     * @version 1.0
     * @since   26 Jan 2005 01:54:50
      */
    public function exists($id)
    {
        $src = $this->oSrc($id);
        $filepath = preg_match('!://!', $src) ? $src : getenv('DOCUMENT_ROOT') . $src;
        // Use exif_imagetype to check not only file existence but that of a valid image.
        // The return value is the same value that getimagesize() returns in index 2 but exif_imagetype() is much faster.
        return false != @exif_imagetype($filepath);
    }

    /**
     * Returns the value from getimagesize().
     *
     * @access  public
     * @param   string  $id     Unique image identifier.
     * @param   int     $key    Which element from the array returned by getimagesize:
     *                   - Index 0 contains the width of the image in pixels.
     *                   - Index 1 contains the height.
     *                   - Index 2 is the type of the image.
     *                   - Index 3 is height="yyy" width="xxx" string.
     * @return  mixed   return value of getimagesize.
     * @author  Quinn Comendant <quinn@strangecode.com>
     * @version 1.0
     * @since   26 Jan 2005 01:54:50
     */
    public function size($id, $key)
    {
        $src = $this->oSrc($id);
        $filepath = preg_match('!://!', $src) ? $src : getenv('DOCUMENT_ROOT') . $src;
        $img_size = @getimagesize($filepath);
        return isset($img_size[$key]) ? $img_size[$key] : false;
    }

    /**
     * Returns the URL to the source of image specified by id.
     *
     * @access  public
     * @param   string  $id     Unique image identifier.
     * @return  string  Absolute URL of image.
     * @author  Quinn Comendant <quinn@strangecode.com>
     * @version 1.1
     * @since   26 Jan 2005 01:56:35
     */
    public function oSrc($id)
    {
        $file_name = '';
        // filename_pattern is a sprintf argument with %s replaced with the image id.
        if ($file_match = glob(sprintf("%s/{$this->_params['filename_pattern']}", $this->_params['base_path'], $id))) {
            $file_name = basename(end($file_match));
        } else if ('' != $this->_params['default_image_file']) {
            $file_name = $this->_params['default_image_file'];
        }
        return sprintf('%s/%s', $this->_params['base_url'], $file_name);
    }

    /**
     * Returns an HTML <img> tag with the src set to an image specified by id.
     * Automatically prints image width and height.
     *
     * @access  public
     * @param   string  $id     Unique image identifier.
     * @param   string  $alt    Text for image alt attribute.
     * @param   string  $extra  Additional tag attributes.
     * @return  HTML image tag.
     * @author  Quinn Comendant <quinn@strangecode.com>
     * @version 1.0
     * @since   26 Jan 2005 01:57:33
     */
    public function oImg($id, $alt='', $extra='')
    {
        $src = $this->oSrc($id);
        $filepath = preg_match('!://!', $src) ? $src : getenv('DOCUMENT_ROOT') . $src;

        if (false === ($gis = @getimagesize($filepath)) || preg_match('/width|height/', $extra)) {
            $image_size = '';
        } else {
            $image_size = $gis[3];
        }

        return sprintf('<img src="%s" %s alt="%s" %s />',
            oTxt($src),
            $image_size,
            oTxt($alt),
            $extra
        );
    }
} // End class