PHP Function 'return' not returning

Question

This is a bit of an oddity for me. PHP is my forte, and I can normally figure out any issue I encounter.

I have a custom framework that I have been using for years. I have taken it upon myself to rewrite it, and I'm doing everything essentially the same that I was before. The problem lies in the following construct:

function ModPages_GetPage() {
    $page = ModPages_GetPageByName($_GET['page_name']);
    if($page != false) {
        include(TPL_DIR.'pages/pages.view.php');
    } else {
        ErrorMessage('Invalid Page', 'The selected page could not be found.');
    }
}


function ModPages_GetPageByName($page_name = null) {
    $db = new Database;
    $query = '
        SELECT *
        FROM pages
        WHERE page_name = "'.CleanStr($page_name).'"
            AND page_enabled = "yes"
        LIMIT 1
        ';
    $page = $db->GetRow($query);

    return $page;
}

This code is being called with 'home' for the value of $_GET['page_name']. The call to ModPages_GetPageByName() is working fine, but the value of $page in ModPages_GetPage() isn't getting set. Matter of fact, any debugging statements thrown in after that call are failing to display anything.

I have display_errors set to on, and error_reporting set to E_ALL. I get a couple notices from my Database class, but that's it.

Running the script at a shell fails to produce any errors. When using strace, I do see the process spits out an 'exit_group(255)'.

This one has me quite baffled. I could sure use some direction on this.

Answer 1

ok before we get to a solution can we first make sure that before setting the $page variable, first just echo $_GET['page_name'] to see if there is a value being received.

PK

Answer 2

I would think it's your query, shouldn't you just return the page name instead of star? as star (*) would return an array which is probably being passed back as the value? just my guess.

$query = '
        SELECT *
        FROM pages
        WHERE page_name = "'.CleanStr($page_name).'"
            AND page_enabled = "yes"
        LIMIT 1
        ';

if you do a print_r on the $page return I would think it should be an array

$page = $db->GetRow($query);
echo "Page:<pre>".print_r($page,true)."</pre><br />\n";

Then maybe return something like this

return $page['page_name_field'];

Answer 3

Does your script stop right after your database call, or just doesn't display any output?

If the first is true, then it looks like a fatal error. With E_ALL, it should be displayed, are you sure both display_errors and error_reporting are as you say at that point, and that the GetRow function doesn't alter them in any way? If so, maybe there's something in the Apache error log (PHP errors are sometimes logged there).

If the latter is true I'm thinking about an exception being thrown in a method that is being called, and caught in a higher level function. To check this you can put the database call (ie: the point where things go wrong) inside a try/catch block and see if you reach the catch block.

Answer 4

I would try following:

• replace $_GET with $_REQUEST (maybe your form is using POST?)
• do a print_r to check contents of your variables.
• use mysql_error to view any errors, or print your mysql query in your browser, copy/paste it in phpmyadmin, is it returning anything? error.. data?
• something similar happend to me once, my framework was encoded in ANSI and my calling php file was UTF8+BOM... I changed everything to UTF8+BOM and it worked.
• try also different browser, I know it might not be a browser problem, but it might be that your script is cached somewhere.
• are you using some caching? like eaccelerator?

Answer 5

Are those functions in a class? If so, you will need $page = $this->ModPages_GetPageByName().

Also I would echo out the argument and the sql statment in ModPages_GetPageByName(). This way you can verify that it isn't a SQL error.

Answer 6

I can't say for sure why your code isn't working, but I can make some suggestions that might help in locating the error.

The first thing I notice is you don't check that $db actually contains a valid database. I don't know the details of your Database object but I'm assuming there's some mechanism in there for checking if it's actually connected to the database. You should use that to determine if the database is connected before running queries on it.

$db = new Database ();
if ($db -> isConnected ())
{
    $query = 'SELECT * (etc etc etc)';
    // ...
}
else
{
    // Put some kind of DB connection error notification or throw an exception here
}

Just on a stylistic note, you don't need to store the results of your DB lookup before returning it, unless you're planning on doing some processing on the result before returning it. You can just return the lookup directly. Of course that's just a stylistic choice, but it saves a line or two :)

return ($db->GetRow($query));

After you run your getpage function, I'd strongly recommend var_dump()ing the result. Even if your function returned NULL, you'll still see this in the var_dump. If in doubt, dump it out :). I'd also recommend installing xdebug to make the var_dump output more readable.

$page = ModPages_GetPageByName($_GET['page_name']);
var_dump ($page);

I would also strongly recommending var_dumping your query before you execute just to make absolutely sure that you're running the query you think you're running. Copy and paste the outputted query into sqlyog or phpmyadmin or whatever you use for interactive access to your database and make sure it returns what you think it should return.

Other things to check, is the page you're trying to return actually set page_enabled='yes'? Does the page_enabled column actually store the value as 'yes', or is it a bool or an integer or something else? Is magic quotes enabled or disabled? If they're in one state when you think they're in the other they can cause confusion. Are errors actually being reported to the browser? Add a line at the top of your script that's guaranteed to fail just to make sure, like an attempted foreach on an integer. If you don't see an error, then maybe error reporting isn't configured properly. I know those are obvious questions but I also know how easy it is to overlook the obvious if you're not getting what you expect out of a query.

Answer 7

Are you sure $page is not set, or is it just that your debug instructions don't print anything? Try logging to a file or a database instead; maybe your code triggered output buffering or something like that.

Also, you are calling ModPages_GetPageByName before declaring it. That is usually okay, but might not be in special circumstances (e.g. when the code is wrapped in an if block). Try swapping the two.

Also, check your environment and disable opcode caching and other possible error sources. APC for example can call the old version of the script long after you changed the PHP file.