xpptut - Apache::XPP tutorial
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
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
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 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">
Apache::XPP Apache::XPP::PreParse
To install Apache::XPP, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Apache::XPP
CPAN shell
perl -MCPAN -e shell install Apache::XPP
For more information on module installation, please visit the detailed CPAN module installation guide.