PHP Pulling content from a DIV using switch statement

Question

I've set up a section on my site, to switch out content, based on the DIV ID called, but the initial "value" results in an error, if the variable isn't in the url.

the error i get:Undefined index: item

item is my variable.

My PHP is this:

<?php
    $url = 'file.php';
    $content = file_get_contents( $url );


    $item = $_GET[ 'item' ];
    switch ( $item ) {
        case "content1":
            $start = explode( '<div id="content1">', $content );
            $end = explode( "</div>", $start[ 1 ] );
            echo $end[ 0 ];
            break;

        case "content2":
            $start = explode( '<div id="content2">', $content );
            $end = explode( "</div>", $start[ 1 ] );
            echo $end[ 0 ];
            break;

        case "content3":
            $start = explode( '<div id="content3">', $content );
            $end = explode( "</div>", $start[ 1 ] );
            echo $end[ 0 ];
            break;

        default:
            $start = explode( '<div id="content1">', $content );
            $end = explode( "</div>", $start[ 1 ] );
            echo $end[ 0 ];
    }?>

So the code works fine if I append ?item=content1 at the end of my url, however, on initial visit (without the ?item= at the end) i get the above error ( Undefined index: item)

What can I do so that if someone visits say index.php I won't get the error, and throw up the default called content?

That's how you test if they provided the parameter. The code that uses the parameter should be in that `if` statement. — Barmar, Feb 09 '18 at 23:20
Im not sure where in the code I'm supposed to include that or what I'm supposed to do with it. — Keoki, Feb 09 '18 at 23:23
Come on, this is trivial programming. You put it around all the code that depends on the variable. — Barmar, Feb 09 '18 at 23:29
@Keoki Have you learned about [if statements](http://php.net/manual/en/control-structures.if.php)? Use `isset($_GET['item'])` as the condition of the if statement and inside that if statement, put `$item = $_GET[ 'item' ];` — Chris Happy, Feb 09 '18 at 23:31
Chris, I did that and the content disappeared (nothing shows up) — Keoki, Feb 09 '18 at 23:40

score 1 · Accepted Answer · edited Feb 09 '18 at 23:35

1

Use an if statement to check if the variable is set. If not, set $item to a default value.

if (isset($_GET['item'])) {
    $item = $_GET['item'];
} else {
    $item = 'content1';
}

Also, there doesn't seem to be a need for the switch/case statement, since every case is identical except for what you're using as the explode delimiter.

$delimiter = '<div id="' . $item . '">';
$start = explode($delimiter, $content);
$end = explode("</div>", $start[ 1 ] );
echo $end[0];

It would probably be better to use DOMDocument and DOMXPath instead of string matching to parse your content.

You could also use the shorthand if statement for this if you want to get really fancy.

edited Feb 09 '18 at 23:35

Chris Happy

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answered Feb 09 '18 at 23:31

Barmar

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chris, thanks, but your if (isset) also produces the same error. – Keoki Feb 09 '18 at 23:44
It shouldn't. You replaced the assignment with this `if` statement, right? – Barmar Feb 09 '18 at 23:51

PHP Pulling content from a DIV using switch statement

1 Answers1