output_buffering problem: PHP page cannot load fully. Help.

Kreshna · 11-22-2009, 06:18 AM

EDIT: changed the title on 2009-11-23, 7.30 pm.

I have a PHP application. The application runs flawlessly on Windows version of Apache 2.2.8 and PHP 5.2.5. (part of ms4w; MapServer for Windows). I'm also using Windows XP for development purposes.

Now I have compiled Apache 2.2.14 and PHP 5.2.11 on CentOS 4.2, x86, 32-bit. My directory is /usr/local/apache2/htdocs/. My PHP directory is /usr/local/apache2/php/.

I have a PHP application named kbn-gis.php. it is stored in /usr/local/apache2/htdocs/kbn-gis/ directory.

When I have copied the application to the CentOS box, the page just refuses to load. Firefox just give me a totally blank white page, while in Opera, it takes forever to load kbn-gis.php.

It is actually a PHP MapScript (MapServer) application, but I don't think the problem is MapServer-related, because I have written small PHP pages on the CentOS box, to test the functionalities of php_mapscript.so module. Everything works fine. The small PHP pages can display vector data, raster data, and vector data stored in PostgreSQL PostGIS.

Likewise, I don't really believe there is something wrong with the CentOS' PHP. I ran phpPgAdmin (a web-based administration console for PostgreSQL), and it goes flawlessly.

What's wrong? Here's the following codes of kbn-gis.php:

Code:

<?php


	$bahasa = $_GET["lang"];
	$kawasan = $_GET["scope"];
	
	include './include/panzoom.php';
	include './include/layers.php';
	include './include/queries.php';
	include './include/general.php';

	//loading extension
	if (!extension_loaded("MapScript"))
	dl ('php_mapscript.'.PHP_SHLIB_SUFFIX);
	
	//loading map	
	switch ($kawasan) {
		case 'cakung':
			$page_name="cakung";
			$map_scope="cakung";
			$file_name="cakung";
			$page_title="Cakung";
			$bound_minx=106.909733034;
			$bound_miny=-6.153840500;
			$bound_maxx=106.952991966;
			$bound_maxy=-6.129834500;
		break;
		case 'marunda':
			$page_name="marunda";
			$map_scope="marunda";
			$file_name="marunda";
			$page_title="Marunda";
			$bound_minx=106.900757632;
			$bound_miny=-6.135184500;
			$bound_maxx=107.008910368;
			$bound_maxy=-6.075166500;
		break;
		case 'priouk':
			$page_name="priouk";
			$map_scope="priouk";
			$file_name="priouk";
			$page_title="Tanjung Priouk";
			$bound_minx=106.859465860;
			$bound_miny=-6.115590500;
			$bound_maxx=106.889916140;
			$bound_maxy=-6.098692500;
		break;
		default:
			$page_name="cakung";
			$map_scope="cakung";
			$file_name="cakung";
			$page_title="Cakung";
			$bound_minx=106.909733034;
			$bound_miny=-6.153840500;
			$bound_maxx=106.974621432;
			$bound_maxy=-6.129834500;
	}
	switch ($bahasa) {
		case 'in':
			$lang='in';
			$lang_suffix='-in';
		break;
		case 'en':
			$lang='en';
			$lang_suffix='-en';
		break;
		default:
			$lang='en';
			$lang_suffix='-en';
	}
	
	$legend = legend_lang($lang);	

	$file_suffix="map";
	$file_path="./mapfiles/";	
	$map = ms_newMapObj($file_path.$file_name.$lang_suffix.".".$file_suffix);
	
	$box = ms_newrectObj();
	$box->setextent($bound_minx, $bound_miny, $bound_maxx, $bound_maxy);
	
	//From HTML (when submitted)
	$extent_from_html = explode(" ",$_POST["current_extent"]);
	$x_map_from_html = $_POST["current_x_map"];
	$y_map_from_html = $_POST["current_y_map"];
	
	$img_click_mode=img_click_mode();
		
	active_layers($map);	
	
	map_start($map,$extent_from_html[0],$extent_from_html[1],$extent_from_html[2],$extent_from_html[3]);
		
	map_north($map,$box);		
		
	map_south($map,$box);
				
	map_west($map,$box);
		
	map_east($map,$box);	
	
	map_zoomin($map);
	
	map_zoomout($map,$box);
	
	
	//Browse atau query?
	if (isset($_POST["map_img_x"]) && isset($_POST["map_img_y"]))  {
		$x_map = x_click_to_map($map, $_POST["map_img_x"]);
		$y_map = y_click_to_map($map, $_POST["map_img_y"]);

	}
	else {
	$x_map = $x_map_from_html;
	$y_map = $y_map_from_html;	
	}		
	
	what_to_do($img_click_mode,$map,$box);
	
	$map_img=what_to_draw($img_click_mode,$map);
	$scalebar_img=$map->drawScaleBar();
	$refmap_img=$map->drawreferencemap();
	
	$map_img_url=$map_img->saveWebImage(MS_JPG,1,1,0);
	$scalebar_url=$scalebar_img->saveWebImage();
	$refmap_url=$refmap_img->saveWebImage();
	
	//To HTML
	$extent_to_html = $map->extent->minx." ".$map->extent->miny." ".$map->extent->maxx." ".$map->extent->maxy;
	$x_map_to_html = $x_map;
	$y_map_to_html = $y_map;
?>

<html>
	<head>
		<title>KBN - <?php page_title_lang($lang); echo $page_title; ?></title>
		<meta name="keywords" content="<?php echo $page_title; ?>, Sinatrix, PT. Sinatrix Indonesia, KBN, Kawasan Berikat Nusantara, Kawasan, Berikat, Nusantara, Bonded, Zone, GIS, Geographic Information System"></meta>
		<meta name="description" content="<?php page_title_lang($lang); echo $page_title; ?>"></meta>		
		<link href="./styles/stylemain.css" rel="stylesheet" type="text/css" />
		<link href="./styles/layer-drop-down.css" rel="stylesheet" type="text/css" />
		<script src="./scripts/layer-drop-down.js">
		</script>
	</head>
	<body>
			
			<table id=header border="0" cellspacing="0" cellpadding="0" width="100%">
				<tr>
					<td id=logo>
					</td>
					<td>
						<h1><img src="./images/decors/header-text-version-01.png"></h1>
						<h2><?php page_title_lang($lang); echo $page_title; ?></h2>
					</td>
				</tr>
			</table>
			
		<form name=<?php echo $page_name; ?> id=<?php echo $page_name; ?> method=POST ACTION=<?php echo $PHP_SELF; ?>>
			
			<table id=toolbar border="0" cellspacing="0" cellpadding="0" width="100%">
				<tr>
					<td id=button-container><?php map_scope($map_scope,$lang); ?>
					</td>					
					<td id=button-container><?php mode_dropdown($img_click_mode, $lang); ?>
					</td>
					<td align=center id=button-container>
						<?php flags($map_scope); ?>
					</td>
					<td align=center id=button-container>
						<a href="#" style="border:none">
						<img name="go_home" value="go_home" src="./images/toolbars/logo-kbn-mini.gif" style="margin-left:14px;margin-right:14px;" alt="KBN" onmouseover="this.src='./images/toolbars/logo-kbn-mini_on_mouseover.gif';" onmouseout="this.src='./images/toolbars/logo-kbn-mini.gif';" onclick="this.src='./images/toolbars/logo-kbn-mini_on_click.gif';window.open('http://www.kbn.co.id')">
						</a>
					</td>
					<td align=center id=button-container>
						<input type=image name="back" value="back" src="./images/toolbars/icon_home.gif" alt="Back" onmouseover="this.src='./images/toolbars/icon_home_on_mouseover.gif';" onmouseout="this.src='./images/toolbars/icon_home.gif';" onclick="this.src='./images/toolbars/icon_home_on_click.gif';">
					</td>
					<td align=center id=button-container>
						<input type=image name="zoomin" value="zoomin" src="./images/toolbars/icon_zoomin.gif" alt="Zoom In" onmouseover="this.src='./images/toolbars/icon_zoomin_on_mouseover.gif';" onmouseout="this.src='./images/toolbars/icon_zoomin.gif';" onclick="this.src='./images/toolbars/icon_zoomin_on_click.gif';">
					</td>
					<td align=center id=button-container>
						<input type=image name="zoomout" value="zoomout" src="./images/toolbars/icon_zoomout.gif" alt="Zoom Out" onmouseover="this.src='./images/toolbars/icon_zoomout_on_mouseover.gif';" onmouseout="this.src='./images/toolbars/icon_zoomout.gif';" onclick="this.src='./images/toolbars/icon_zoomout_on_click.gif';">
					</td>
					<td id=button-container style="width:80px;vertical-align:top">
						<input type=image name="west" value= "west" src="./images/toolbars/west.jpg" alt="pan to West" style="position:relative; top:12px; left:9px;" onmouseover="this.src='./images/toolbars/west_on_mouseover.jpg';" onmouseout="this.src='./images/toolbars/west.jpg';" onclick="this.src='./images/toolbars/west_on_click.jpg';">
						<input type=image name="north" value="north" src="./images/toolbars/north.jpg" alt="pan to North" style="position:relative; top:2px; left:9px;" onmouseover="this.src='./images/toolbars/north_on_mouseover.jpg';" onmouseout="this.src='./images/toolbars/north.jpg';" onclick="this.src='./images/toolbars/north_on_click.jpg';">									
						<input type=image name="south" value="south" src="./images/toolbars/south.jpg" alt="pan to South" style="position:relative; top:22px; left:-12px;" onmouseover="this.src='./images/toolbars/south_on_mouseover.jpg';" onmouseout="this.src='./images/toolbars/south.jpg';" onclick="this.src='./images/toolbars/south_on_click.jpg';">
						<input type=image name="east" value="east" src="./images/toolbars/east.jpg" alt="pan to East" style="position:relative; top:12px; left:-11px;" onmouseover="this.src='./images/toolbars/east_on_mouseover.jpg';" onmouseout="this.src='./images/toolbars/east.jpg';" onclick="this.src='./images/toolbars/east_on_click.jpg';">
					</td>
					
					<td  id=button-container>				
						<span id="layer-drop-down">
							<?php
								$div_id = 'd1';
								$hid_id = 'h1';
								$div_status = 'div_status';
								if ( $_POST[$div_status] == 'show' ) {
									$div_status_to_html = 'show';
									$div_style='style="visibility:visible"';
								}
								elseif ( $_POST[$div_status] == 'hidden' ) {
									$div_status_to_html = 'hidden';
									$div_style='style="visibility:hidden"';
								}
								else {
									$div_status_to_html = 'hidden';
									$div_style='style="visibility:hidden"';
								}							
							?>
							<span>
							<a href="#" onclick="mcheck('<?php echo $div_id; ?>','<?php echo $hid_id; ?>')">Layer</a><br>
								<div id="<?php echo $div_id; ?>" <?php echo $div_style; ?> >
									<b><?php									
										layer_checkboxes('cakung', $map_scope, $page_name, $lang);
										echo "<input type=hidden id=".$hid_id." name=".$div_status." value=".$div_status_to_html." >";
									?></b>
								</div>
							</span>				
							
						</span>
					</td>
					
					<td style="color:#f0f0f0">filler
					</td>
				</tr>
			</table>

			<table width="100%">
				<tr valign=top>
					<td id=mapframe>
						<input id="mapimg" name="map_img" type=IMAGE src="<?php echo $map_img_url?>" ><br>
						<input type=HIDDEN name="current_extent" value="<?php echo $extent_to_html ?>">
						<input type=HIDDEN name="current_x_map" value="<?php echo $x_map_to_html ?>">
						<input type=HIDDEN name="current_y_map" value="<?php echo $y_map_to_html ?>">
						<?php show_query_result($img_click_mode, (y_map_to_click($map, $y_map)+80), (x_map_to_click($map, $x_map)),$lang); ?>
					</td>
					<td rowspan=2>
						
						<table border=0 height=400px width=100% align=center>
							<tr>
								<td valign=top height=10px align=center>						
									<img src="<?php echo $refmap_url; ?>" >
								</td>
							</tr>
							<tr>
								<td height=100% valign=top align=center style="border-top-width:1px;border-top-color:#80A080;border-top-style:solid">
									<table style="font:12px arial" width=270px valign=top align=center border=0><tr valign=top><td valign=top>
											<?php
												echo "<b>"; echo $legend; echo "</b>"; echo "<br>"; ;
												$jml_layer = $map->numlayers;
												for ($i=0; $i<$jml_layer; $i++) {
													$layer = $map->getLayer($i);
													if ( $layer->status != MS_OFF ) {
														if ( $layer->name != 'jkt_raster' ) {
															$layer_class = $layer->getclass(0);
															$layer_name = $layer->name ;
															$layer_icon_img = $layer_class->createLegendIcon(25, 15);
															$layer_icon_url = $layer_icon_img->saveWebImage();
															echo "<img src=".$layer_icon_url." > "; echo str_replace("_"," ",$layer_name); echo "<br>";
														}
													}
												}
											?>
									</td><tr></table>
								</td>
							</tr>
							<tr>
								<td valign=bottom align=center style="border-top-width:1px;border-top-color:#80A080;border-top-style:solid">
									<?php copyright($lang);?>
								</td>
							</tr>
						</table>
					</td>
				</tr>
				<tr valign=bottom align=center>
					<td colspan=1>
						<img src="<?php echo $scalebar_url; ?>" >
					</td>
				</tr>
			</table>

	</form>
	</body>
</html>

Kreshna · 11-22-2009, 06:26 AM

Ah yes, when I do ls from PuTTy, the PHP file I unable to load (kbn-gis.php) is colored green. The PHP files I written using vi (directly on the server), which is run flawlessly on the CentOS box, is colored white. Does it matter? However, I already did "chmod 777", "chown root", and "chgrp root" on the kbn-gis.php.

The white-colored PHP files is also owned by root.

Kreshna · 11-22-2009, 08:58 AM

I have run php from cli, and apparently I got a lot of undefined indexes:

Code:

[root@kbnweb kbn-gis]# /usr/local/apache2/php/bin/php kbn-gis.php
PHP Notice:  Undefined index:  lang in /usr/local/apache2/htdocs/kbn-gis/kbn-gis.php on line 4
PHP Notice:  Undefined index:  scope in /usr/local/apache2/htdocs/kbn-gis/kbn-gis.php on line 5
PHP Warning:  Module 'MapScript' already loaded in Unknown on line 0
PHP Notice:  Undefined index:  current_extent in /usr/local/apache2/htdocs/kbn-gis/kbn-gis.php on line 81
PHP Notice:  Undefined index:  current_x_map in /usr/local/apache2/htdocs/kbn-gis/kbn-gis.php on line 82
PHP Notice:  Undefined index:  current_y_map in /usr/local/apache2/htdocs/kbn-gis/kbn-gis.php on line 83
PHP Notice:  Undefined index:  click_mode in /usr/local/apache2/htdocs/kbn-gis/include/general.php on line 54
PHP Notice:  Undefined index:  click_mode in /usr/local/apache2/htdocs/kbn-gis/include/general.php on line 54
PHP Notice:  Undefined index:  click_mode in /usr/local/apache2/htdocs/kbn-gis/include/general.php on line 57
PHP Notice:  Undefined index:  click_mode in /usr/local/apache2/htdocs/kbn-gis/include/general.php on line 57
PHP Notice:  Undefined index:  click_mode in /usr/local/apache2/htdocs/kbn-gis/include/general.php on line 60
PHP Notice:  Undefined index:  click_mode in /usr/local/apache2/htdocs/kbn-gis/include/general.php on line 60
PHP Notice:  Undefined variable: img_click_mode in /usr/local/apache2/htdocs/kbn-gis/include/general.php on line 63
PHP Notice:  Undefined index:  warehouses_and_factories in /usr/local/apache2/htdocs/kbn-gis/include/layers.php on line 11
PHP Notice:  Undefined index:  available_for_rent in /usr/local/apache2/htdocs/kbn-gis/include/layers.php on line 11
PHP Notice:  Undefined index:  facilities in /usr/local/apache2/htdocs/kbn-gis/include/layers.php on line 11
PHP Notice:  Undefined offset:  1 in /usr/local/apache2/htdocs/kbn-gis/kbn-gis.php on line 89
PHP Notice:  Undefined offset:  2 in /usr/local/apache2/htdocs/kbn-gis/kbn-gis.php on line 89
PHP Notice:  Undefined offset:  3 in /usr/local/apache2/htdocs/kbn-gis/kbn-gis.php on line 89

However, I also ran php cli on a small PHP page that I coded directly on the Linux (using vi), and I got undefined indexes as well. The difference is; this one runs without problem, while the former cannot be load at all by the browser.

Code:

[root@kbnweb kbn-gis]# /usr/local/apache2/php/bin/php test-cakung-in.php
PHP Notice:  Undefined index:  lang in /usr/local/apache2/htdocs/kbn-gis/test-cakung-in.php on line 2
PHP Notice:  Undefined index:  scope in /usr/local/apache2/htdocs/kbn-gis/test-cakung-in.php on line 3

<html>
<body bgcolor="#CCCCCC">
<center>

<H1>Test GIS Page</H1>
<P>

PHP Warning:  Module 'MapScript' already loaded in Unknown on line 0
<img src=temp/4b094c42_1fbd_0.jpeg >temp/4b094c42_1fbd_0.jpeg
</body>
</html>

Both have undefined indexes, but kbn-gis.php cannot even be loaded by the browser, while test-cakung.php runs flawlessly.

By the way, I coded kbn-gis.php on Windows, using Notepad++, while test-cakung.php was coded directly on the CentOS box, using vi. Does it matter?

Help....

Kreshna · 11-22-2009, 09:40 AM

Ah, I know that! It is a WHITE SPACE PROBLEM!!!!

I don't have a good white space remover, so I take the "dirty way" of removing white space; namely, copy paste from Notepad++ to the vi on my PuTTy window.

It solves the problem... partially. See, the page runs now, but it is only loaded partially. When I do "view source" from either Firefox or Opera, the page stops at this point:

Code:

<input type="HIDDEN" name="

instead of:

Code:

</html>

The rest of lines after <input type="HIDDEN" name=" is never processed, never displayed by any browser I tried.

It is because the whitespace, isn't it? What is the best whitespace remover, then? Thanks.

chrism01 · 11-22-2009, 10:58 PM

Normally, if you insist on editing on MS, then uploading to linux, you'd use dos2unix, which converts the line endings.
Personally, I'd recommend finding a Linux editor you can live with and using that exclusively.

Kreshna · 11-23-2009, 06:28 AM

Thanks for the reply.

But, I just found out that copy-pasting to VI does convert the text to Linux. Thus, the problem about partially-load PHP page above is not cause by incompatible line feed.

Like I said above, the production server's never loads the page fully, ie, when showing the codes in a browser, it never reaches the closing </html> part. And it has nothing to do with bandwitdh either, I have tried browsing locally from the server itself.

I have to admit that my php page is quite large, about 9 kilobytes. It also has a lot of "echo" commands. The page also contains a lot of tab.

Recently I found out that it has something to do with output_buffering parameter in php.ini. Starting from zero, if I increase the output_buffering value, the loaded portion of my PHP page also increases. So I think if I max the output_buffering value, my PHP page will be fully loaded by the server.

Alas, that's not the case.

See, when I reach certain value, the loaded portion of the PHP page decreases again. The page reaches its biggest portion in output_buffering=1024. Increasing it to 1025, for example, doesn't change anything. But when I set it to 1210, the

Here's what happen when I set output_buffering=0. The page does not load fully, it only shows the HTML header and the toolbar.
http://i3.photobucket.com/albums/y71...ng_off_wip.jpg
output_buffering=0

At output_buffering=512, more portions of the PHP page starts to show up, evident by the code lines below the toolbar.
http://i3.photobucket.com/albums/y71...ng_512_wip.jpg
output_buffering=512

Apparently, output_buffering=1024 is the "optimum" setting, although it still fails to load the PHP page fully. The page you see below is not the full PHP page, by the way.
http://i3.photobucket.com/albums/y71...g_1024_wip.jpg
output_buffering=1024

I don't know if it is relevant, but originally, the php.ini has extension_dir = './' Problem is, I don't know what does it mean by './' (is it /usr/local/apache2/php ? is it /usr/local/apache2/lib ?). On the other hand, I need to dl php_mapscript.so into my PHP page, which I put in PHP installation prefix (/usr/local/apache2/php). So I hardcoded the extension_dir into '/usr/local/apache2/php'.

In short, what's wrong? Why the production server cannot load my PHP page fully? What should I do? Please help.

Kreshna · 11-23-2009, 07:11 AM

By the way, I forgot to mention, but I also tried using implicit_flush = On. When I use implicit_flush = On with output_buffer = 0, it works just exactly like using implicit_flush = Off with output_buffer = 1024.

However, increasing output_buffer with implicit_flush = On does not improve the situation. For example, using implicit_flush = On with output_buffer = 1024 does not fully load the PHP page either. Seems like nothing can fully load my PHP page.

What's wrong? What happens?

Kreshna · 11-24-2009, 03:59 AM

Ah, I've just found something new: the same output_buffering value does not always give consistent result.

For example, I just set output_buffering value to 3650, which showed most (alas, not the entire) of my PHP page. But about five minutes later, the same 3650 value just gave me a totally blank page (just like when I'm using output_buffering=On)

By the way, and I don't know if it's relevant, but it is a production server, which is also used by the "primary" website and a web mail server.