NAME

xpptut - Apache::XPP tutorial

I. HOW TO USE IT

Apache::XPP lets you embed perl code into html tags. Just like Mason, Perl::ASP, and embperl. Syntax:

 <?xpp my $variable = "bleh"; ?>

Tough, eh? There's also a "print" shortcut, which is useful if you don't need to do any funky variable manipulation

 <FONT SIZE=3>My variable = <?= $variable ?> </FONT><BR>

Even tougher, right?

It's also possible to split perl blocks between <?xpp ?> tags. This is insanely useful when checking for errors:

 <TABLE><TR>
 <?xpp if ($object->haserrors()) { ?>
 <TD BGCOLOR="#FF0000"><= $object->name() ?> has errors</TD>
 <?xpp } else { ?>
 <TD BGCOLOR="#000000"?><= $object->name() ?> has no errors</TD>
 <?xpp } ?>
 </TR></TABLE>

Basically, anything that's legal in perl is legal in XPP. However, it's usually a good idea to keep all your database connections and object creation to modules. The <A HREF="bingoxtut.xpml">BingoX.pm</A> module was specifically designed to create display objects that can be easily used in this environment.

There are also two methods that let you inlcude other files:

include ($file)

Includes the $file. Does not parse or buffer the file in any way. It's faster than xinclude(), and well suited for navs, or any other static components that get reused often. It is recursive, so it's possible to call include() from another included file.

xinclude ($file,[$object])

Identical to include only this will actually parse XPP tags from within the includes. Since most perl calls will be against a method, it helps to pass $objects as well, but this is not required.

In both cases, the location of $file is relative to the XPPIncludeDir specified in your httpd.conf file.

Custom Tags

Custom tags allow html integrators to use perl in there documents without having to know perl syntax. For a tutorial on custom tag creation see xpptut. The following tags are already in Apache::XPP::PreParse:

parser_xppcomment

Used to comment out blocks of xpml code.

Ex: <XPPCOMMENT> <title><?= $obj->title() ?></title> </XPPCOMMENT>

parser_xppcache

Cache a block of code using a specific expire/store module. Pass the caches name, group, expire, and store. See xppcache for more information.

Ex: <XPPCACHE name="mycache" group="cachegroup" store="File" expire="Duration, 10s"> .... </XPPCACHE>

parser_appmethod

Assign or print an object method. Ref checks the object before using it. Assigns the result to the value of the as tag parameter. If this param isn't present the result is printed.

Ex: <XPP app app="$obj" attr="bleh" as="$var"> <XPP app app="$obj" attr="bleh">

parser_print

Prints the result of an object method.

Ex: <XPP print obj="$obj" attr="bleh">

parser_xppxinclude

Calls xinclude with the passed filename and options.

Ex: <XPP xinclude filename="include.xmi" options="$obj1, $obj2">

parser_xppforeach

Places the included block within a foreach loop. Assigning each element of the array to 'as.' If 'as' is not present it uses $_.

Ex: <XPPFOREACH array="@ary" as="$val"> <XPPFOREACH array="@ary">

See Also

Apache::XPP Apache::XPP::PreParse