Store PHP code in db.

Anon

I'd like to store html code (with php mixed in) in a db. Eval isn't any good for executing that. Is there anyway that I can achieve the same functionality as include or require with this code?

Anon

Use eval()

Yes I know you said eval was no good for that, but I can't figure out why.

try this example

define a string

$j="hello";

pretend to get PHP code from the database and placing it in $a

$a="function p($a){echo $j.'\n';};";

Eval the code

eval ($a);

execute the function declared in the eval'ed code

p();

Anon

Note that eval expects the code passed to it to be in PHP mode, not HTML. If your code starts off in HTML, you can do something like this:

$code = "<body>Hello <? echo $name; ?></body>";
eval("?> $code <?");

With this, the code should start and end in HTML mode...

That's probably why it wasn't working.

---John Holmes...

Anon

Ahh, that is good John. Curious, would something like this be useful ? :

function evalCode($code)
{
$code = trim($code);

if ( strpos($code,0,2) != '<?' ) {

    $code = '?> ' . $code;
}

if ( strpos($code,-2) != '?>' ) {

   $code = $code . ' <?php';
}

eval ($code);

}

I've not used eval() much outside of evaluating known php code ... so if not known then perhaps the above would be useful and work? The logic behind the second part of function may not be properly done, discuss. ASP style tags wouldn't work for this but who cares :-)

Anon

Hmm...not sure. eval() starts off in PHP mode, so if code started with another <?, it seems like that would cause an error. you'd be opening a PHP tag while already in PHP mode.

I'm thinking that you should either start right off in PHP mode, or with a closing PHP bracket

Like for the following:

$code = "echo \"<p>Hello World.</p>\";"
$code = "<p>Hello World.</p>";
$code = "Hello World.";

How would you know the mode that $code starts off in? Unless you programmed $code yourself and know what mode you always start off in, then there's really no way to tell.

Most people are going to design code to start off a certain way all the time, then you can tailor eval() to match that, so there are no errors.

Good discussion.

---John Holmes...

Anon

Ack! Meant to use substr rather then strpos, doh! Will teach me to write blind code :-)

Blah. It's all wrong anyway as I was assuming one to add surrounding tags for the code but that is of course not correct! Not sure where that came from, need to do more eval()ating I guess :-)

In honor of finishing the job :

function evalCode ($code,$type='php')
{
if ($type == 'php') {
eval($code);
}
elseif ($type == 'html') {
eval("?>$code");
}
else {
eval($code);
}
} // EOF;

$a = '<h3>foo</h3>bar';
$b = 'print "<h3>foo</h3>bar";';

evalCode($a,'html');
evalCode($b,'php');

Nothing special or all that useful but had to clear up the other VERY useless code. There must be a way for eval to know how to evaluate ... although this may be one of those "yo php user, don't be lazy, don't rely on php reading your mind, it is inefficient to do so." I am lazy. At somepoint playing with ob_* functions will prove fruitful for this venture.

Bottom line : As stated, prepending ?> works for html :-)

Anon

Check out the midgard project (http://www.midgard-project.org/) which already does this.

Tom