Help needed with writing a header image rotation script

[princesspepper]

I want to include a small script to rotate the image in the header so that it displays an alternative image on certain special days which I can specify. A bit like Google does. :)

I am running VB4.2 PL2

Here is the script, which is kept in a file called 'headerrotate.php' in my plugins/headerrotate/ folder :


<?php


// example random image based on time


// fetch date unit that we will be using. d:m will give the day and month in numeric form with leading 0

// You can find other date units aside from 'd:m' on http://www.php.net/date

// You could also combine these, for example 'H:i" will give you hours:minutes


$HeaderDateUnit = date('d:m');



// the switch statement compares the variable $HeaderDateUnit to every "case"

// if it matches, whatever command after the colon is performed.

// the break; statement tells the switch statement to stop attempting comparisons

// Before we break;, we assign an image filename to $image variable.

// The default : is what happens if the switch statement doesn't match anything to $HeaderDateUnit.


switch($HeaderDateUnit)

{
// New Year
case "01:01" : $image = "images/misc/headers/newyear.png";
break;

// King's Day
case "06:01" : $image = "images/misc/headers/kingsday.png";
break;

// Valentine's Day
case "14:02" : $image = "images/misc/headers/valentines.png";
break;

// Default image
default : $image = "images/misc/vbulletin4-logo.png";
break;

}


// "echo" prints the variable $image onto the screen (in this case, our filename).

echo $image;


?>


I have read the manual here : http://www.vbulletin.com/docs/html/main/templates_externalfiles

And it says I first need to create a plugin, which I have done... however when I make the plugin active (all image files that are referenced are uploaded, as is the php file) all that happens is a blank page, so I am assuming that something is wrong because what 'should' happen is that it returns the image variable, and as this is not used at present until I change the header template to include it in the code, it would do nothing...

This is my plugin code :

Hook Location : global_start
Execution Order : 5
Plugin PHP Code :
ob_start();
include('plugins/headerrotate/headerrotate.php');
$headerrotate = ob_get_contents();
ob_end_clean();

Also, I understand from the tutorial that I will need to change the {vb:stylevar titleimage} to {vb:raw headerrotate} in the header template. Is this correct?

Finally, it also mentions in the tutorial that in vBulletin 4+, you need to register variables for them to be available in specific templates and usable. You would do this with code like this:

vB_Template::preRegister('FORUMHOME',array('includ edphp ' => $includedphp));

What does this mean, and where would I do this? Is this why I'm getting my blank page?

Any help would be greatly appreciated :)

[kh99]

... however when I make the plugin active (all image files that are referenced are uploaded, as is the php file) all that happens is a blank page, so I am assuming that something is wrong because what 'should' happen is that it returns the image variable, and as this is not used at present until I change the header template to include it in the code, it would do nothing...

You are right, a blank page means there's an error somewhere. But I tried the code you posted and it seems to work (at least it doesn't cause any errors), so I'm not sure what to suggest.

Also, I understand from the tutorial that I will need to change the {vb:stylevar titleimage} to {vb:raw headerrotate} in the header template. Is this correct?

I'm not sure but that does sound like it should work. But you'd have to register a 'headerrotate' variable to the header template.


Finally, it also mentions in the tutorial that [B]in vBulletin 4+, you need to register variables for them to be available in specific templates and usable. You would do this with code like this:

vB_Template::preRegister('FORUMHOME',array('includ edphp ' => $includedphp));

What does this mean, and where would I do this? Is this why I'm getting my blank page?


To use a variable in a template, you need to preRegister it. In your case you'd do this in your plugin after the ob_end_clean(); line. Based on what you've posted above, I think what you'd want is:

vB_Template::preRegister('header',array('headerrot ate' => $includedphp));


I should also mention that unless you *want* your code to be in an external file, you could put it all in the plugin. If you did that, your plugin code would look like this:

// example random image based on time


// fetch date unit that we will be using. d:m will give the day and month in numeric form with leading 0

// You can find other date units aside from 'd:m' on http://www.php.net/date

// You could also combine these, for example 'H:i" will give you hours:minutes


$HeaderDateUnit = date('d:m');



// the switch statement compares the variable $HeaderDateUnit to every "case"

// if it matches, whatever command after the colon is performed.

// the break; statement tells the switch statement to stop attempting comparisons

// Before we break;, we assign an image filename to $image variable.

// The default : is what happens if the switch statement doesn't match anything to $HeaderDateUnit.


switch($HeaderDateUnit)

{
// New Year
case "01:01" : $image = "images/misc/headers/newyear.png";
break;

// King's Day
case "06:01" : $image = "images/misc/headers/kingsday.png";
break;

// Valentine's Day
case "14:02" : $image = "images/misc/headers/valentines.png";
break;

// Default image
default : $image = "images/misc/vbulletin4-logo.png";
break;

}

vB_Template::preRegister('header',array('headerrot ate' => $image));

and of course you wouldn't need the file any more.

Also I would recommend using hook location parse_templates. global_start would probably work most of the time, but there's a chance that it would be too late to add something to the header template in the case where another plugin did something with templates.