Change content-type

[Mr.Clean]

I need to write a function to return an image that
has been base64 encoded into a string.
This is how it is done in PHP and I need to know
how I can do the same in javascript:

function img_65()
{
header("Content-type: image/png");
header("Content-length: 174");
echo base64_decode(
"iVBORw0KGgoAAAANSUhEUgAAABAAAAAWCAMAAAD+dOxOAAAAB 3".
"RJTUUH0gkQEysKRu4rNAAAAAlwSFlzAAALEgAACxIB0t1 +/AAA".
"AARnQU1BAACxjwv8YQUAAAAJUExURQAAAP//AAAzM+Z4gaYAAA".
"AoSURBVHjaY2DAAExMDIyMUARkYxHAABAJCAKysQgMnBZkhEV g".
"QBwGAJlmANH7wbaHAAAAAElFTkSuQmCC".
"");
}

Here is how I call it in my PHP code:

<?
$img = $_GET["img"];
switch($img)
{
case "65":
img_65();
break;
}
?>
In my HTML, I do this:

<img src="digits.php?img=65" />
I have javascript base64 decode functions so I just
need to know how to change the content-type like
in img_65 function above above in javascript.

Also, how would I call this javascript function
in the img tag?

[Martin Honnen]

Mr.Clean wrote:

I need to write a function to return an image that
has been base64 encoded into a string. Here is how I call it in my PHP code:

<?
$img = $_GET["img"];
switch($img)
{
case "65":
img_65();
break;
}
?>
In my HTML, I do this:

<img src="digits.php?img=65" />
I have javascript base64 decode functions so I just
need to know how to change the content-type like
in img_65 function above above in javascript.
Where do you want to use Javascript, on the server instead of PHP? Then
it depends on the environment, in ASP you would need to set
Response.ContentType = 'image/png';
With client-side JavaScript you can't change a HTTP response header
obviously but you are dealing with specialized host objects like an
HTMLImageElement which expects image data.
Also, how would I call this javascript function
in the img tag?

Some browsers support
<img src="javascript:functionToReturnImageData()" alt="">
but don't rely on that, see
<http://www.elf.org/pnglets/>
<http://www.elf.org/essay/inline-image.html>
Browser support for such stuff has not improved.
--

Martin Honnen
http://JavaScript.FAQTs.com/