Adding alt="" to img tags : PCRE

bubblenut

I can return an image tag fine but returning just image tags which do not have ' alt="' seems beyond me. Surely it can't be very difficult.
This may sound silly but if it really isn't very hard can you not tell me how to do it, just give me nudge in the right direction. 🙂
Thanks
Bubble

AstroTeg

Huh?

With alt:
<imt src="img.gif" alt="alt text goes here">

without alt:
<img src="img.gif">

What are you looking to do?

bubblenut

If an img tag does not have an alt tag
eg

<img src="1234.jpg" id="name" />

Then it is returned, otherwise
eg

<img src="1234.jpg" id="name" alt="" />

I know where the problem with this ('/<img\s[^{>(\salt)]+>/i')} one is now. The (alt) is still being seen as individual letters rather than the literal string '\salt'
Thanks Bubble

AstroTeg

Its still not clear what you're ultimate goal is. Are you having a problem retrieving (using regular expressions) the image source file name from HTML code when the alt tag is included? Also, have you thought about what happens if the image's dimensions (width and height) are included?

bubblenut

I'm really not sure how better to explain it. I am trying to return the whole img tag (that means from the opening < to the closing >) if said tag has has no alt tag in it. So here is some code to explain.

<?php

$text='Here is some <img src="an_image.jpg" width="100" alt="none really" height="20" /> text and <img src="another_image.jpg" width="30" height="10" /> some images';
$regex1='regex goes here';
echo(preg_replace($regex1,"\${1} alt="" />",$text);
?>

And what would be echoed would be

Here is some <img src="an_image.jpg" width="100" alt="none really" height="20" /> text and <img src="another_image.jpg" width="30" height="10" alt="" /> some images

See?
I'm trying to make the site more XHTML compliant and one of the requirements is that all img tags have alt text.
Thanks
Bubble

Shrike

Now that wasn't too hard to explain was it 😉 It's a pretty easy regexp really, you could do it with one big expression I should think, but my regexp isn't very good so...

if(!preg_match("/alt=[\"]?.*?[\"]?/si", $imgstring)){
  $imgstring = preg_replace("/<img[^>](.*?)>/si", "<img alt=\"\" $1">, $imgstring;
}

Or something like that. If you have lots of image tags (which I guess you would) then you could capture each one into an array first. Making one big expression is sounding like the better solution 🙂