Simplify this IF?

homer09001

is there anyway i can simplify this IF statement:

$page = $_REQUEST['page'];

if($page == "aircraft")
{
include "Admin_list_aircraft.php";
}
elseif($page == "members")
{
include "Admin_list_members.php";
}
elseif($page == "pireps")
{
include "Admin_get_Pirep1.php";
}
elseif($page == "newacset")
{
include "Admin_set_newac.php";
}
elseif($page == "getpirep")
{
include "Admin_get_Pirep1.php";
}
elseif($page == "getaircraft")
{
include "Admin_get_aircraft.php";
}
elseif($page == "delete")
{
include "Admin_delete.php";
}
elseif($page == "newac")
{
include "Admin_new_aircraft.php";
}
elseif($page == "setac")
{
include "Admin_set_aircraft.php";
}
elseif($page == "setpirep")
{
include "Admin_set_Pirep.php";
}
elseif($page == "setpilot")
{
include "Admin_set_member.php";
}
elseif($page == "listflts")
{
include "Admin_list_flights.php";
}
elseif($page == "getflight")
{
include "Admin_get_flight.php";
}

its making the page load a lot slower than i want it to?

Paul_Ferrie

You code try switch()
not sure if it will give better performance but it is worth a try.

//else if statement
if ($i == 0) {
    echo "i equals 0";
} elseif ($i == 1) {
    echo "i equals 1";
} elseif ($i == 2) {
    echo "i equals 2";
}
//Same statement using switch
switch ($i) {
case 0:
    echo "i equals 0";
    break;
case 1:
    echo "i equals 1";
    break;
case 2:
    echo "i equals 2";
    break;
}

hope it helps

Installer

I doubt that code will slow down the page loading by much.

At any rate, you could simplify it greatly if you change the possible request strings to match the actual include file name, and use an array:

$choices = array('list_aircraft', 'list_members', 'get_Pirep1', 'set_newac');  // etc.
$page = $_REQUEST['page'];
if (in_array($page, $choices)) {
    include 'Admin_' . $page . '.php';
} else {
    echo 'Request not recognized.';
}

Roger_Ramjet

You should use a SWITCH for this for several reasons. Not only is it much faster than loads of IFs, it is more legible, more easily modified and extended and all together more flexible.

At the moment you are just using it to determine the php include, but down the track you may want to also set CSS or JS files for particular includes: eg

<?php
// blah blah

$inc = '';
$css = '';
$js = '';
$page = $_REQUEST['page'];
switch $page {
  case "aircraft":
     $inc = "Admin_list_aircraft.php";
     $css = "aircraft.css";
     break;
  case "members":
     $inc = "Admin_list_members.php";
     $js = "members.js";
     break;
// etc

?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
blah blah
<?php
if ($css != '') {
  echo '<link rel="stylesheet" type="text/css" href="' . $css . ' " />';
}
if ($js !='') {
  echo '<script src="' . $js . '"></script>';
}
?>
blah blah
</head>
<body>
<?php
include ($inc);
?>

As you can see, the switch option allows for great felxibility when working with a page generator like this.

If you want to go with Installer's option then why not go all the way and just use the whole file name in the first place. You could also use that method for css and js includes, but it is not as generalised or flexible because all pages are tightly coupled to the file naming used.

laserlight

You do not necessarily have to "change the possible request strings to match the actual include file name", as you can adapt Installer's suggestion to use an associative array. For example:

$choices = array('aircraft' => 'list_aircraft',
                 'members' => 'list_members',
                 'pireps', => 'get_Pirep1');

$page = $_REQUEST['page'];
if (array_key_exists($page, $choices)) {
    include 'Admin_' . $choices[$page] . '.php';
} else {
    echo 'Request not recognized.';
}

Roger_Ramjet

Whatever!!

Thing is, the switch construct is at least as processor efficient as an array function whilst being more legible, flexible and maintainable. It makes for a truly general purpose page generator which the other methods cannot match except through further conditional constructs.

Installer

OP's file naming is descriptive; the input naming nearly matches it. I see no reason not to remove one level of complexity by melding them to make them exactly match. Further, the array method, to me, is more legible and maintainable than using "switch". The input names and file names are all there in one array definition. The including code is simple and straightforward.

As for flexibility: The including file should remain as generic as possible. Coding specific to an included file (css, js, etc. or the loading of same) belongs in the file that it is specific to. Putting it in the main file only decreases flexibility.

bradgrafelman

Roger Ramjet wrote:
Not only is it much faster than loads of IFs

Really? Do you have some benchmarks to support this? The benchmarks I've seen prove the inverse is true (though only slightly).

I think it comes down to personal preference. Personally, I like the array method. :p

laserlight

Really? Do you have some benchmarks to support this? The benchmarks I've seen prove the inverse is true (though only slightly).

That is true for some implementations in languages typically interpreted at compile time, but in any case either a switch or an array would be easier to understand at a glance.

Weedpacket

But a switch is a bit harder to modify programmatically than an array (to reflect different user access permissions, for instance)....

NogDog

Let's not forget the database option. 🙂

$sql = "SELECT filename FROM includes WHERE pagename = '" .
       mysql_real_escape_string($_REQUEST['page']) . "'";
$result = mysql_query($sql) or die(mysql_error());
if(mysql_num_rows($result))
{
   include mysql_result($result, 0, 'filename');
}
else
{
   include 'default_page.php';
}