converting img link to hyperlink?

[kwalan]

i want to convert a string containing image links to regular hyperlinks.

$string = "blah blah blah, an image! <img src="http://blah.com/image.jpg" alt="the image"> more blah";

//output:

blah blah blah, an image! <a href="http://blah.com/image.jpg">the image</a> more blah

basically, it takes the src link and makes it a regular hyperlink, and takes the value of alt and makes that into the title of the hyperlink.

been reading through some examples and string expression pages but i'm really confused on constructing such an expression (or series of expressions) to actually accomplish this task.

i wrote something that would be able to convert just a single image link in a string to what i wanted (probably really inefficient too, i'm still learning), but this really isn't applicable when given surrounding text.

$text3="<img src=\"http://blah.com/image.jpg\" alt=\"the title\">";

if (eregi("(<img src=\"http[^>]*>)", $text3))
{
	if (eregi("alt", $text3))
	{
		$alt = strstr($text3, "alt=\"");
		$alt = str_replace("alt=\"","",$alt);
		$alt = str_replace("\">","",$alt);
	}
	else
		$alt = "image";
	$imgarray = explode(" ", $text3);
	$url = str_replace("src=\"","",$imgarray[1]);
	$url = str_replace("\"","",$url);

$link = "<a href=\"".$url."\">".$alt."</a>";
echo $link;
}

any advice or related example code would be greatly appreciated...

i have a damn good feeling it involves using preg_replace but i'm still clueless..

[MrAlaska]

I wouldn't jump through hoops trying to modify the string. I would just parse out the elements I need then rebuild it:

<?php
$string="<img src=\"http://blah.com/image.jpg\" alt=\"the title\">";
//parse out the URL
if (eregi ("<img src=\"(.*)\" alt=", $string, $out)) {
	$url = $out[1];
}
//parse out the ALT
if (eregi ("alt=\"(.*)\">", $string, $out)) {
	$alt = $out[1];
}
//echo them back for the hell of it
echo "<p>URL : ".$url;
echo "<p>ALT : ".$alt;
//build a new string
$string="<a href='$url'>$alt</a>";
echo "<p>$string<p>";
?>

Edit: I didn't notice at first the image was cantained inside the original string, but it is still the approach I would take. Break the string up, rebuild the image link, then put the string back together.

[kwalan]

thanks, i'm not sure how to adapt it into an actual function, where it'd be like:

function img2link($text)
{
  ...

 return $text;
}

$string = 'a lot of surrounding text, then somewhere inside there is an <img src="http://blah.com/blah.jpg" alt="the blah of blah"> image....';

$newstring = img2link($string);

echo $newstring;
//output would be: a lot of surrounding text, then somewhere inside there is an <a href="http://blah.com/blah.jpg">the blah of blah</a> image....

thank you for your response.

[MrAlaska]

It's all the same idea. Grab what ya need and do what ya want with it:

<?php
$string="blah blah
	blah <img src=\"http://blah.com/image.jpg\" alt=\"the title\"> more
	blah blah blah";
//parse out the elements
if (eregi ("(.*)<img src=\"(.*)\" alt=\"(.*)\">(.*)", $string, $out)) {
	$string1 = $out[1];
	$url=$out[2];
	$alt=$out[3];
	$string2= $out[4];
	//put it all back together
	$string=$string1."<a href='$url'>$alt</a>".$string2;
}
//check out the parts and admire our butchering
echo "<p>String1= $string1
	<p>URL= $url
	<p>ALT= $alt
	<p>String2= $string2";

echo "<p>THE STRING= $string<p>";
?>

[kwalan]

thanks, and if the amount of image links in the string were variable... say, rather than just one, it could be five, or ten? i think an eregi_replace would be needed, though it's difficult with the conditionals.

[MrAlaska]

I never said I was showing you the BEST way, I was just showing
you how I would go about it l

With multiple images, you could still make that expression work
by putting it in a 'while' loop:

while(eregi ("<img", $string)){
if(eregi("(.*)<img .........
// all the string stuff
}

However, an eregi_replace might be a better option in that
case, being more efficient for one and also a while loop could turn
itself into an infinite loop. I am not exactly sure how I would go about
building an eregi_replace for that statement. First I would hafta
pour over the manual and learn how to do it, then I would hafta
coerce my brain into working on Sunday, which just ain't gonna
happen!

Another thing to keep in mind is how clean is your data? Is there
unexpected carriage returns? Are there double quotes neatly
wrapped around every URL and ALT statement? Or are there
sometimes single quotes or quotes missing altogether? All that
kind of stuff needs to be worked into your final model to make it
unbreakable.

[kwalan]

I didn't mean to sound ungrateful or demeaning, given more experience with PHP, that's how I would go about it too... i'm not experienced enough with regular expressions to create complex parse strings...

that said, i tried following a example from textism.com, which adds class="outclass" to hyperlinks if the link is external:

function outlinks($text,$outclass,$imgurl=""){

global $_SERVER;

$dr = $_SERVER[DOCUMENT_ROOT];

if (!empty($imgurl)) {
	$size = getimagesize($dr.$imgurl);
	$img = "<img src=\"$imgurl\" $size[3] alt=\"\" />"; 
}
$text = eregi_replace("(<a href=\"http[^>]*)>","$img \\1 class=\"$outclass\">",$text);
return $text;
}

the image part isn't what i'm interested in, but trying to understand the eregi_replace into adapting it for my use hasn't been fruitful.

i'm going to try it with the while loop, thanks again.