wkimage.php

<?php
/**
 * Provides an http interface to wkhtmltopdf / wkhtmltoimage. 
 * 
 * We use this code to get a combined image of all map layers and
 * tiles of an OpenLayers page 
 *
 * In order for wkhtmltoimage to capture the right extent your
 * OpenLayers map must have a fixed size.
 *  
 *
 * @copyright  2011 geOps
 * @license    http://www.geops.de/license.txt http://www.zend.com/license/3_0.txt   PHP License 3.0
 * @version    $Id$
 * @link       http://www.geops.de
 * @package  
 * @authors    nico mandery, uli mueller
 */

$MAP_URL = "http://fledermaus6.geops.de/print";
$WKHTMLTOPDF = "/opt/install/wkhtmltoimage-amd64";
$TMPDIR = "/tmp/";

// defaults
$params = array(
        "zoom" => 6,
        "lat" => 6621292.72182,
        "lon" => 1001876.417,
        "layers" => "0BFTTTT",
        "format" => "jpg",
        "width" => 400,
        "height" => 400
);


// fetch numeric params
foreach (array('zoom', 'lat', 'lon', 'width', 'height') as $p) {
        if (isset($_GET[$p]) && is_numeric($_GET[$p])) {
                $params[$p] = $_GET[$p];
        }
}

if (isset($_GET['format'])) {
        if (in_array($_GET['format'], array('png', 'jpg'))) {
                $params["format"] = $_GET['format'];
        }
}

if (!empty($_GET['layers'])) {
        $params['layers'] = $_GET['layers'];
}

// build the query string for the map fetching
$get_params = array();
foreach(array('zoom', 'lat', 'lon', 'layers') as $p) {
        $get_params[$p] = $params[$p];
}
$query = $MAP_URL . "?" . http_build_query($get_params);


// create temp file
$tmpfile = tempnam($TMPDIR, 'wkpdf');
@unlink($tmpfile);

// build the command
$cmd = $WKHTMLTOPDF . " " ;
$cmd .= "--height " . $params['height'] . " ";
$cmd .= "--width " . $params['width'] . " ";
$cmd .= "-f " . $params['format'] . " ";
$cmd .= "\"" . $query . "\" ";
$cmd .= "\"".$tmpfile."\"";

system($cmd);
header("Content-Type: image/".$params['format']);
@readfile($tmpfile);
@unlink($tmpfile);