apache_mod_perl-101~38::mod_perperl-101~38:mod:dapi::ModPerl::RegistryCooker(3)
NAME
ModPerl::RegistryCooker - Cook mod_perl 2.0 Registry Modules
Synopsis
# shouldn't be used as-is but sub-classed first
# see ModPerl::Registry for an example
Description
"ModPerl::RegistryCooker" is used to create flexible and overridable registry modules which emulate
mod_cgi for Perl scripts. The concepts are discussed in the manpage of the following modules:
"ModPerl::Registry", "ModPerl::Registry" and "ModPerl::RegistryBB".
"ModPerl::RegistryCooker" has two purposes:
Provide ingredients that can be used by registry sub-classes
Provide a default behavior, which can be overriden in sub-classed
META: in the future this functionality may move into a separate class.
Here are the current overridable methods:
META: these are all documented in RegistryCooker.pm, though not using pod. please help to port these
to pod and move the descriptions here.
new()
create the class's object, bless it and return it
my $obj = $class->new($r);
$class -- the registry class, usually "__PACKAGE__" can be used.
$r -- "Apache2::Request" object.
default: new()
init()
initializes the data object's fields: "REQ", "FILENAME", "URI". Called from the new().
default: init()
default_handler()
default: default_handler()
run()
default: run()
can_compile()
default: can_compile()
make_namespace()
default: make_namespace()
namespace_root()
default: namespace_root()
namespace_from()
If "namespace_from_uri" is used and the script is called from the virtual host, by default the
virtual host name is prepended to the uri when package name for the compiled script is created.
Sometimes this behavior is undesirable, e.g., when the same (physical) script is accessed using
the same path_info but different virtual hosts. In that case you can make the script compiled
only once for all vhosts, by specifying:
$ModPerl::RegistryCooker::NameWithVirtualHost = 0;
The drawback is that it affects the global environment and all other scripts will be compiled
ignoring virtual hosts.
default: namespace_from()
is_cached()
default: is_cached()
should_compile()
default: should_compile()
flush_namespace()
default: flush_namespace()
cache_table()
default: cache_table()
cache_it()
default: cache_it()
read_script()
default: read_script()
shebang_to_perl()
default: shebang_to_perl()
get_script_name()
default: get_script_name()
chdir_file()
default: chdir_file()
get_mark_line()
default: get_mark_line()
compile()
default: compile()
error_check()
default: error_check()
strip_end_data_segment()
default: strip_end_data_segment()
convert_script_to_compiled_handler()
default: convert_script_to_compiled_handler()
Special Predefined Functions
The following functions are implemented as constants.
NOP()
Use when the function shouldn't do anything.
TRUE()
Use when a function should always return a true value.
FALSE()
Use when a function should always return a false value.
Sub-classing Techniques
To override the default "ModPerl::RegistryCooker" methods, first, sub-class "ModPerl::RegistryCooker"
or one of its existing sub-classes, using "use base". Second, override the methods.
Those methods that weren't overridden will be resolved at run time when used for the first time and
cached for the future requests. One way to to shortcut this first run resolution is to use the symbol
aliasing feature. For example to alias "ModPerl::MyRegistry::flush_namespace" as
"ModPerl::RegistryCooker::flush_namespace", you can do:
package ModPerl::MyRegistry;
use base qw(ModPerl::RegistryCooker);
*ModPerl::MyRegistry::flush_namespace =
\&ModPerl::RegistryCooker::flush_namespace;
1;
In fact, it's a good idea to explicitly alias all the methods so you know exactly what functions are
used, rather then relying on the defaults. For that purpose "ModPerl::RegistryCooker" class method
install_aliases() can be used. Simply prepare a hash with method names in the current package as keys
and corresponding fully qualified methods to be aliased for as values and pass it to
install_aliases(). Continuing our example we could do:
package ModPerl::MyRegistry;
use base qw(ModPerl::RegistryCooker);
my %aliases = (
flush_namespace => 'ModPerl::RegistryCooker::flush_namespace',
);
__PACKAGE__->install_aliases(\%aliases);
1;
The values use fully qualified packages so you can mix methods from different classes.
Examples
The best examples are existing core registry modules: "ModPerl::Registry", "ModPerl::Registry" and
"ModPerl::RegistryBB". Look at the source code and their manpages to see how they subclass
"ModPerl::RegistryCooker".
For example by default "ModPerl::Registry" uses the script's path when creating a package's
namespace. If for example you want to use a uri instead you can override it with:
*ModPerl::MyRegistry::namespace_from =
\&ModPerl::RegistryCooker::namespace_from_uri;
1;
Since the "namespace_from_uri" component already exists in "ModPerl::RegistryCooker". If you want to
write your own method, e.g., that creates a namespace based on the inode, you can do:
sub namespace_from_inode {
my $self = shift;
return (stat $self->[FILENAME])[1];
}
META: when $r->finfo will be ported it'll be more effecient. (stat $r->finfo)[1]
Authors
Doug MacEachern
Stas Bekman
See Also
"ModPerl::Registry", "ModPerl::RegistryBB" and "ModPerl::PerlRun".
perl v5.8.8 apache_mod_perl-100perl-2.0.2::docs::api::ModPerl::RegistryCooker(3)
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