CSC220 Homework 6 Solution 2010

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Revision as of 14:40, 5 November 2010 by Thiebaut (talk | contribs) (→‎Option 1)
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--D. Thiebaut 19:28, 5 November 2010 (UTC)

Solution for Homework #6

Contents

Option 1

  • In this approach, the two files showMap.htm and outputKml.php have been replaced by one program, now called showMap.php.
  • In order to better pass information from the database to GoogleMaps, and to go around the caching that GGeoXml implements, the program works in the following fashion:
    • It gets the Id that the user is interested and saves it in the $Id variable
    • It fetches a KML file from the database at that $Id
    • It stores the KML contents in a local file that is stored in a subdirectory called uploads, which is world-writeable (not very secure solution!)
    • The name of that local file is made random by adding a random number to it (before the ".kml" extension). This will force GoogleMaps to load it, as it will never have it in its cache.
    • GoogleMaps loads the file from a URL pointing to our own Website.
  • The source code is below:

<?php
session_start();
?>

<html>
<head> 
<meta http-equiv="content-type" content="text/html; charset=utf-8"/> 
<title>Google Maps API Example: GGeoXml KML Overlay</title> 
<!-- =================================================================
                          J A V A S C R I P T 
     =================================================================
-->
<script src="http://maps.google.com/maps?file=api&amp;v=2&amp;key=xxxxxxxxxxxxxxxxxxx"
      type="text/javascript"></script> 
<script type="text/javascript"> 
   
   var map;
   var geoXml; 
   var toggleState = 1;

   function initialize2() { 
     if (GBrowserIsCompatible()) { 
         map = new GMap2(document.getElementById( "map_canvas" ) ); 
         map.setCenter(new GLatLng( 42.32012788333333, -72.6431288999999 ), 11 ); 
         map.setUIToDefault(); 
         //map.addControl(new GLargeMapControl());
         var exml;
         exml = new EGeoXml( "exml", map, "uploads/dft.kml"  );
         exml.parse(); 
         exml.show(); 
     } 
   } 

   function initialize() {

     if (GBrowserIsCompatible()) {
       var url;
       url = "http://cs.smith.edu/~220a/mysql/GoogleMaps/uploads/" + "<?php echo $_SESSION[ 'kmlFile' ];?>"; 
       //alert( url );
       geoXml = new GGeoXml( url );
       map = new GMap2(document.getElementById( "map_canvas" ) ); 
       map.setCenter(new GLatLng(42.32012788333333,-72.6431288999999), 11); 
       geoXml.gotoDefaultViewport( map );
       map.setUIToDefault();
       map.addControl(new GLargeMapControl());
       map.addOverlay( geoXml );
     }
   } 
 
   function toggleMyKml() {
       return;
       if (toggleState == 1) {
           map.removeOverlay(geoXml);
           toggleState = 0;
       } else {
           map.addOverlay(geoXml);
           toggleState = 1;
       }
    }
</script> 
</head> 


<?php 
// ==================================================
//                      P  H  P
// ==================================================
 
//-----------------------------------------------------
// logit: logs information to a text file.  Debugging
//-----------------------------------------------------
date_default_timezone_set( "America/New_York" );
function logit($msg){
  $fp = fopen("log.txt","a+");
  $msg = date("Y-m-d h:i:s a") . ": " . $msg;
  fwrite($fp, $msg."\r\n");
  fclose($fp);
}

//-----------------------------------------------------
//-----------------------------------------------------
function connectToMySql( ) {
  include 'accessinfo.php';
  $database = "220a_hw6";

  //--- connect to mysql server ---
  $link = mysql_connect( $hostName, $userName, $password );
  if ( ! $link ) 
    die( "Could not connect to server: " . $mysql_error() );
  
  //--- select database ---
  $database = "220a_hw6";
  $db = mysql_select_db( $database, $link );
  if ( ! $db ) 
    die( "Could not connect to database " . $database . ": "
	 . mysql_error() );
  return $link;
}

//-----------------------------------------------------
// getKml: get Kml file with Index $Id from database
//-----------------------------------------------------
function getKml(  $link, $Id ) {

  $query = sprintf( "SELECT `data` from `kmldata` WHERE `Id`='%s'", $Id );
  $result = mysql_query( $query, $link );
  if ( ! $result ) 
    die( "Invalid query (" . $query . "): " . mysql_error() );
  
  if  ( $row = mysql_fetch_array( $result, MYSQL_NUM ) ) 
    return $row[0];
  
  return "";
}

$Id = $_REQUEST[ 'Id' ];
if ( ! isset( $Id ) ) {
?>

<body>
<FORM ACTION="showMap3.php" METHOD="POST">
   KML File Id: <INPUT TYPE="text" NAME="Id" VALUE="" SIZE="5"><br />
   <INPUT TYPE="SUBMIT" VALUE="Show Map!">
</FORM>
</body>
</html>



<?php
}
else {

  logit( "Requested Id =  $Id" );

  //--- get kml data ---
  $link = connectToMySql();
  $kmlData = getKml( $link, $Id );
  mysql_close( $link );

  
  //--- store it to file ---
  $fileName = sprintf( "dft_%d.kml", rand() );
  $_SESSION[ 'kmlFile' ] = $fileName;
  file_put_contents( "uploads/" . $fileName, $kmlData );
  
  //--- open a body that loads up the map ---
?>

<body onload="initialize()"> 
  <div id="map_canvas" style="width: 640px; height: 480px; float:left; border: 1px solid black;"></div> 
    </div> 
    <br clear="all"/> 
    <br/> 
    <FORM ACTION="showMap3.php" METHOD="POST">
          KML File Id: <INPUT TYPE="text" NAME="Id" VALUE="" SIZE="5"><br />
         <INPUT TYPE="SUBMIT" VALUE="Show Map!">
    </FORM>
    <br />
    <input type="button" value="Toggle KML" onClick="toggleMyKml();" /> 
  </body> 
</html>

<?php
}
?>










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