php, GD library, Content-type

Hello,
I've managed to get as far as using some of the GD2 drawing functions
included in the php_gd2.dll. I can't figure out how to put HTML and
PHP output on the same browser page, no doubt this has something to
do with the header; any help would be greatly appreciated.
Thank you,
Gerard

header ("Content-type: image/png");

$t = imagecreate(400,150); // create a blank canvas
$c = imagecolorallocate($t,0,255,0); // set color for the first
thing
imagefilledrectangle($t,10,10,50,50,$c); // draw a rectange
$c = imagecolorallocate($t,215,20,20); // set color for the next
imagefilledellipse($t,50,50,75,75,$c); // draw an ellipse
$w = "it's not easy to learn this stuff!";
$c = imagecolorallocate($t,50,50,150);
imagestring($t,4,100,70,$w,$c);
imagepng($t); // output the image
imagedestroy($t); // clear memory, but not the browser

/* NOTHING FOLLOWING OUTPUTS */

echo "

";

var_dump(gd_info());

echo "

Re: php, GD library, Content-type

gerrymcc@indigo.ie wrote:
> Hello,
> I've managed to get as far as using some of the GD2 drawing functions
> included in the php_gd2.dll. I can't figure out how to put HTML and
> PHP output on the same browser page, no doubt this has something to
> do with the header; any help would be greatly appreciated.
> Thank you,
> Gerard
>
> > header ("Content-type: image/png");
>
> $t = imagecreate(400,150); // create a blank canvas
> $c = imagecolorallocate($t,0,255,0); // set color for the first
> thing
> imagefilledrectangle($t,10,10,50,50,$c); // draw a rectange
> $c = imagecolorallocate($t,215,20,20); // set color for the next
> imagefilledellipse($t,50,50,75,75,$c); // draw an ellipse
> $w = "it's not easy to learn this stuff!";
> $c = imagecolorallocate($t,50,50,150);
> imagestring($t,4,100,70,$w,$c);
> imagepng($t); // output the image
> imagedestroy($t); // clear memory, but not the browser
>
> /* NOTHING FOLLOWING OUTPUTS */
>
> echo "

";

> var_dump(gd_info());

> echo "

Re: php, GD library, Content-type

First save the image, then call it, or call this script thruoogh another
(wich contains the html/php)


On 06-08-2007 14:56, in article yREti.21321$j7.381704@news.indigo.ie,
"gerrymcc@indigo.ie" wrote:

> Hello,
> I've managed to get as far as using some of the GD2 drawing functions
> included in the php_gd2.dll. I can't figure out how to put HTML and
> PHP output on the same browser page, no doubt this has something to
> do with the header; any help would be greatly appreciated.
> Thank you,
> Gerard
>
> > header ("Content-type: image/png");
>
> $t = imagecreate(400,150); // create a blank canvas
> $c = imagecolorallocate($t,0,255,0); // set color for the first
> thing
> imagefilledrectangle($t,10,10,50,50,$c); // draw a rectange
> $c = imagecolorallocate($t,215,20,20); // set color for the next
> imagefilledellipse($t,50,50,75,75,$c); // draw an ellipse
> $w = "it's not easy to learn this stuff!";
> $c = imagecolorallocate($t,50,50,150);
> imagestring($t,4,100,70,$w,$c);
> imagepng($t); // output the image
> imagedestroy($t); // clear memory, but not the browser
>
> /* NOTHING FOLLOWING OUTPUTS */
>
> echo "

";

> var_dump(gd_info());

> echo "

Re: php, GD library, Content-type

On 06.08.2007 14:56 gerrymcc@indigo.ie wrote:
> Hello,
> I've managed to get as far as using some of the GD2 drawing functions
> included in the php_gd2.dll. I can't figure out how to put HTML and
> PHP output on the same browser page, no doubt this has something to
> do with the header; any help would be greatly appreciated.
> Thank you,
> Gerard
>

hi there

just a few lines:


>
if(key($_GET) == 'img') {

> header ("Content-type: image/png");
>
> $t = imagecreate(400,150); // create a blank canvas
> $c = imagecolorallocate($t,0,255,0); // set color for the first
> thing
> imagefilledrectangle($t,10,10,50,50,$c); // draw a rectange
> $c = imagecolorallocate($t,215,20,20); // set color for the next
> imagefilledellipse($t,50,50,75,75,$c); // draw an ellipse
> $w = "it's not easy to learn this stuff!";
> $c = imagecolorallocate($t,50,50,150);
> imagestring($t,4,100,70,$w,$c);
> imagepng($t); // output the image
> imagedestroy($t); // clear memory, but not the browser
>

die(); }

> /* NOTHING FOLLOWING OUTPUTS */
>
> echo "

";

> var_dump(gd_info());

> echo "

Re: php, GD library, Content-type

gosha bine wrote:

>hi there

>just a few lines:

>>
>if(key($_GET) == 'img') {

>> header ("Content-type: image/png");
>>
>> $t = imagecreate(400,150); // create a blank canvas
>> $c = imagecolorallocate($t,0,255,0); // set color for the first
>> thing
>> imagefilledrectangle($t,10,10,50,50,$c); // draw a rectange
>> $c = imagecolorallocate($t,215,20,20); // set color for the next
>> imagefilledellipse($t,50,50,75,75,$c); // draw an ellipse
>> $w = "it's not easy to learn this stuff!";
>> $c = imagecolorallocate($t,50,50,150);
>> imagestring($t,4,100,70,$w,$c);
>> imagepng($t); // output the image
>> imagedestroy($t); // clear memory, but not the browser
>>

>die(); }

>> /* NOTHING FOLLOWING OUTPUTS */
>>
>> echo "

";

>> var_dump(gd_info());

>> echo "

Re: php, GD library, Content-type

On 07.08.2007 12:05 gerrymcc@indigo.ie wrote:

> Thanks very much, that works beautifully; I have only a vague idea
> why, so I hope you don't mind a question or two about it.

That's what we are here for. ;)

> 1) I presume that sends a GET request to the server,
> something like thisFile.php?keyName. The server then looks at the
> file again, sees an 'img' key in $_GET and processes the script?

Correct, you got it: acquiring html file and image are two distinct and
absolutely independent requests in http.

> 2) I know key() returns the key currently pointed to in the $_GET
> array, but there's no way I can see the content of that array, is
> there? I did a var_dump($_GET) but that shows an empty array.

When you script is called with a single parameter name, without a value,
the $_GET array looks like:

array('param_name' => '') <-- empty string

> As you said, I have a LOT of reading to do :-) I spent a few
> hours last night searching; a Google on "http and web browsers"
> got many hits on specific browsers and the RFC on HTTP, but little
> of the information was useful in the context of understanding scripts
> like the above. If you could suggest any resources, that would be
> much appreciated too.

I'd start here http://en.wikipedia.org/wiki/HTTP

Also, "http sniffer" tools (that show the traffic from and to your
browser) are very useful to understand what's going on. FireBug (firefox
extension) includes such a tool.


--
gosha bine

makrell ~ http://www.tagarga.com/blok/makrell
php done right ;) http://code.google.com/p/pihipi