<?php
///////////////////////////////////////////////////////////////////////////
// menus.php - A program to build an imint menu from a mysql database
// copyright (c) KM Newnham 2001
// 
//The best way to debug this code is to run it straight from the browser
//and check the stream of data that is returned. If you call it from within
//the applet and there is an error, the applet will simply fail to load. 
//You will not receive any useful PHP debugging info.
//
// Note that we do not use any HTML formatting, we are simply streaming data
// into the applet
/////////////////////////////////////////////////////////////////////////// 

///////////////////////////////////////////////////////////////////////////
// Open a mySQL session, I'll assume a database named test on the local
// machine, change as required
///////////////////////////////////////////////////////////////////////////

$conn=mysql_connect("localhost","","") or die( "no connection");
mysql_select_db("test") or die ("no select");

///////////////////////////////////////////////////////////////////////////
// Define the functions that we will recurse down to build the menu
///////////////////////////////////////////////////////////////////////////


/////////////////////////////////////////////////////////////////////////
// This function provides the stream of data into the menufile param of
// the applet. Each of the items passed to the function matches an item
// required by the applet. I am not using the stylesheet parameter
// in this example, but it is passed ready to be used.
/////////////////////////////////////////////////////////////////////////
function writeItem($text,$level,$style,$link,$mouseover) {
 
	////////////////////////////////////////////
	// I'll predefine a couple of strings first
	// to make the program more understandable
	////////////////////////////////////////////

    $sm = "\""; // An escaped quote
    $smc = "\","; // An escaped quote followed by a comma

	/////////////////////////////////////////////////
	// Write the passed data to the standard output
	////////////////////////////////////////////////
	
	print $sm . $text . $smc;	// The applet text
    print $sm . $level . $smc; // The menu level
    print $sm . $style . $smc; // Any icon required
    print $sm . $link . $smc; // The url to be called
    print $sm . $mouseover . $smc; // The mouse parameter
    print "\n"; // Send a newline - very important
 
 
}
//////////////////////////////////////////////////////////////////////
// This function recurses the database, creating the menu items
//////////////////////////////////////////////////////////////////////

function buildMenus ($parent,$level) {
 
	global $conn; // The database connection
	
	$newlevel=$level+1;	//This will be the value we pass to the next
						//recursion of this function if required
	
	$SQL="SELECT * FROM imint_menus where parent=" . $parent;

	////////////////////////////////////////////////////
	// Each time we execute a new query in the function,
	// we do not destroy the previous result set , 
	// that is the one in the recursive parent, so that
	// when this one dies, the parent can continue on 
	// where it left off. This is simply a side effect of 
	// using a function, which isolates the query. This means
	// we can have multiple queries running at the same time.
	/////////////////////////////////////////////////////

	$result=mysql_query($SQL) or die ("query failed");
	
	////////////////////////////////////////////////////////
	// Loop through the menu items with the correct parent
	// until we hit EOF
	/////////////////////////////////////////////////////////
	while ($row = mysql_fetch_object ($result)) {

		$imint_index = $row->imint_index;
		$description = "text:" . $row->description;
		$url = $row->url;
		$mouseover = $row->mouseover;

		////////////////////////////////////////////////
		// If the URL is not blank, create a link entry
		// we could just as easily embed some javascript
		// using the SCRIPT syntax.
		////////////////////////////////////////////////
		if ($url != '') $url="link:".$url;
		
		////////////////////////////////////////////////
		// Whether we have a link, or a pointer to a new
		// sub-menu, we always need to create an entry in
		// the imint menu
		////////////////////////////////////////////////

		WriteItem($description,$level,"",$url,$mouseover);
 
		if ($url==""){  
			///////////////////////////////////////////////////
			// if the url is blank, we will assume that is a
			// link to a new menu or sub-menu,so we recurse, passing 
			// the function the current index number, which
			// will become the parent in our SQL statement,
			// and the next imint layer number
			//////////////////////////////////////////////////
			buildMenus($imint_index,$newlevel);
			///////////////////////////////////////////////////////
			// Once we return from the called function, we continue
			// on at the same menu level where we left off.
			///////////////////////////////////////////////////////
		}
	}
	//////////////////////////////////////////////
	// At the end of the loop the function dies
	//////////////////////////////////////////////
}
////////////////////////////////////////////////////////////
// End of functions
////////////////////////////////////////////////////////////
// To Start, we can statically create a couple of menu/
// sub menu items
////////////////////////////////////////////////////////////
writeItem ("TEXT:Useful Resources","1","","","");
writeItem ("TEXT:PHP","2","","link:http://www.php.net,_new","PHP");
writeItem ("TEXT:mySQL","2","","link:http://www.mysql.com,_new","mySQL DBMS");
writeItem ("TEXT:Apache","2","","link:http://www.apache.org,_new","Apache Web Servers");

////////////////////////////////////////////////////////////////////
// Create a start point for our dynamic menu
///////////////////////////////////////////////////////////////////

writeItem ("TEXT:Dynamic Menu","1","","","This is where it starts");

///////////////////////////////////////////////////////////////////
// Start recursion, the first parameter is the value of the parent
// field in the database, the second is the imint level
///////////////////////////////////////////////////////////////////
buildMenus(0,2);

/////////////////////////////////////////////////////////////////////
// Finish off with a final static menu perhaps
/////////////////////////////////////////////////////////////////////
writeItem ("TEXT:IMINT","1","","link:http://www.imint.com","Java Applets");
?>