Echoing a variable which isn't set until later in the file?

[hatrickpatrick]

I could have sworn this was possible somehow, but it isn't working for me... Let's say I have a line at the top of my file, which is echo "$links". Then, the variable $links is set further down in the file, depending on some SQL results and GET variables. For me, even though I'm setting $links in the file, it will only echo if it's set before it's echoed. It make sense, but I have a definete memory that I once had a way around that problem - anyone know how to do it?

 

echo "$links"
if (isset($board))
{
$links="Return to <A HREF=boards.php>Board list</a>";
}
if (isset($thread))
{
$links="Return to <A HREF=threads.php>Thread list</a>";
}

 

^ That isn't my code, but an example of what I'm trying to do...

[Psycho]

Why would you want to echo something before it is set. Good code will always be in control of what is happening. Just bad programming practice in my opioning.

 

The problem might be due to a server setting. I'm not real familiar with them, but I'm sure there is one that will cause an error in such a situation. The one I am familar with is "Option Explicit" in VBScript. With it turned off you can use a variable you have not yet set, but not with it on. This is to ensure your code is properly written.

[lemmin]

if (isset($links))
{
echo "$links";
}
if (isset($board))
{
$links="Return to <A HREF=boards.php>Board list</a>";
}
if (isset($thread))
{
$links="Return to <A HREF=threads.php>Thread list</a>";
}

[hatrickpatrick]

Didn't work, just tried it

 

And the reason I want to do this is because my links() function is called at the top of every page, and I want to be able to change which links are displayed depending on whether certain variables are set later or not...

 

Is there any other way to do this?

[lemmin]

There must be a problem with your code, then. What I added to your code will make it echo the $links variable if it isn't null and do nothnig if it is. If it isn't echoing, then your $links variable is null.

[hatrickpatrick]

It must be the server, then, because I just tested that code by putting it into a new PHP file and trying it with board=1, and still nothing...

 

My server allows me to change the php.ini settings myself, but have you any idea which setting I need to change?

[d22552000]

put script buffering to ON then it will process the entire file BEFORE handing out the variables.

 

IE... it will read your ffile... set the variable... then read the file again to output the variables.

[Daniel0]

put script buffering to ON then it will process the entire file BEFORE handing out the variables.

 

IE... it will read your ffile... set the variable... then read the file again to output the variables.

I never heard of a such thing... were would you do that? I don't see it in php.ini

 

Don't attempt to do so though, it would be bad programming practice.

[hatrickpatrick]

^ How would I turn on this "script buffering"?

And if I can't, how can I actually get this to work?

[Daniel0]

Don't do so (if it's even possible). Initialize the variables BEFORE using them.

[dbo]

What exactly are you trying to accomplish here? Outing a variable that's not defined will obviously generate an error and output nothing. At best you get rid of the error message and it still outputs nothing b/c there variable has no contents.

 

I'm sure there is an alternative solution for what you're trying to accomplish. Can you explain what it is you want to do?

[hatrickpatrick]

I can't, though

 

The if ($board=whatever) statement also displays the entire board list, and I want it to send the links header before anything else

 

If I echo it after setting it, it means I have to echo it inside every single if() statment, and there are a lot of them in this file... Is there any other way to do this?

[dbo]

Can you show us some of the real code?

[hatrickpatrick]

echo "<div id=bar class=lite>Return to: <A HREF=cpanel.php class=menu>Control Panel</a> $exlink</div>";
if ($editpro)
{
$exlink="| <A HREF=editbrands.php>Brand Editor</a>";
$sqledp="SELECT * FROM processors WHERE pro_id=$editpro";
$resultedp=mysql_query($sqledp);
$rowedp=mysql_fetch_assoc($resultedp);
?>
<form action="editbrands.php?brand=<?=$brand ?>&pro=<?=$editpro ?>" METHOD=post>
Product Name: <input type=text name=edpname><br>
Product Type: <input type=text name=edptype><br>
<input type=submit name=edprosub value="Add New Product"></form></td></tr>
<?
}

 

I know the code is messy, but this is only a first draft of the file... but basically, I need that bar at the top, I want the links displayed in it to depend on the variables below it, and I don't want to have to echo the bar in every if() statement, and the bar has to be echoed before any of the other elements are...

[dbo]

So why can't you move your if statement and stuff above that so it's set before you use it?

[hatrickpatrick]

Because, take the example I just gave you, I want the links bar to be ABOVE all that, not below it... It's supposed to be the first thing in the file, the links bar...

[dbo]

echo "<div id=bar class=lite>Return to: <A HREF=cpanel.php class=menu>Control Panel</a> $exlink</div>";
if ($editpro)
{
$exlink="| <A HREF=editbrands.php>Brand Editor</a>";
$sqledp="SELECT * FROM processors WHERE pro_id=$editpro";
$resultedp=mysql_query($sqledp);
$rowedp=mysql_fetch_assoc($resultedp);
?>
<form action="editbrands.php?brand=<?=$brand ?>&pro=<?=$editpro ?>" METHOD=post>
Product Name: <input type=text name=edpname><br>
Product Type: <input type=text name=edptype><br>
<input type=submit name=edprosub value="Add New Product"></form></td></tr>
<?
}

 

I know the code is messy, but this is only a first draft of the file... but basically, I need that bar at the top, I want the links displayed in it to depend on the variables below it, and I don't want to have to echo the bar in every if() statement, and the bar has to be echoed before any of the other elements are...

 

I guess I'm blind but I don't see why this won't work.

 

if ($editpro)
{
$exlink="| <A HREF=editbrands.php>Brand Editor</a>";
echo "<div id=bar class=lite>Return to: <A HREF=cpanel.php class=menu>Control Panel</a> $exlink</div>";
$sqledp="SELECT * FROM processors WHERE pro_id=$editpro";
$resultedp=mysql_query($sqledp);
$rowedp=mysql_fetch_assoc($resultedp);
?>
<form action="editbrands.php?brand=<?=$brand ?>&pro=<?=$editpro ?>" METHOD=post>
Product Name: <input type=text name=edpname><br>
Product Type: <input type=text name=edptype><br>
<input type=submit name=edprosub value="Add New Product"></form></td></tr>
<?
}

[dbo]

It will output in the exact same position as it was before (given the if condition is met) the only difference is the variable now has data....

[hatrickpatrick]

Yeah I know I could do that, but the problem is I have about 6 if statements and I wanted to output the links bar before them all...

[lemmin]

echo "<div id=bar class=lite>Return to: <A HREF=cpanel.php class=menu>Control Panel</a>";
if (isset($exlink))
    echo $exlink;
echo "</div>";

 

That should work, whatever the case is.

[Psycho]

What does the position of content on your page have to do with the order in which code is processed in your script? You should be able to separate the two completely. I think your approach to the problem just needs to be modified. This is not a PHP problem per se.

 

Have all of your condition statments at the top of the page to set any variables and to grab any data. Then at the bottom of the page acutally build the HTML content.

[dbo]

I concur.

[lemmin]

It is because he is using if statements for the content to be in its specified locations. It is definately not the best way to output the data, but there is no reason that it shouldn't be possible.