HTML::Mason::Component - Mason Component Class
my $comp1 = $m->current_comp; my $comp2 = $m->callers(1); my $comp3 = $m->fetch_comp('foo/bar'); foreach ($comp1,$comp2,$comp3) { print "My name is ".$_->title.".\n"; }
Mason uses the Component class to store components loaded into memory. Components come from three distinct sources:
File-based: loaded from a source or object file.
Subcomponents: embedded components defined with the <%def> tag.
<%def>
Anonymous: created on-the-fly with the make_component Parser method.
make_component
Some of the methods below return different values (or nothing at all) depending on the component type.
The component API is primarily useful for introspection, e.g. "what component called me" or "does the next component take a certain argument". You can build complex Mason sites without ever dealing directly with a component object.
Common ways to get handles on existing component objects include the "current_comp" in Request, "callers" in Request, and "fetch_comp" in Request Request methods.
There is no published new method, because creating a component requires a parser. Use the "make_component" in Parser Parser method to create a new component dynamically.
new
Similarly, there is no execute or call method, because calling a component requires a request. All of the interfaces for calling a component (<& &>, $m-comp>, $interp->exec which normally take a component path, will also take a component object.
execute
call
$m-
$interp->exec
Returns the data cache filename for this component.
Returns the time (in Perl time() format) when this component object was created.
Returns a reference to a hash of hashes representing the arguments declared in the <%args> section. The keys of the main hash are the variable names including prefix (e.g. $foo, @lst). Each secondary hash contains:
<%args>
$foo
@lst
'default': the string specified for default value (e.g. 'fido') or undef if none specified. Note that in general this is not the default value itself but rather an expression that gets evaluated every time the component runs.
For example:
# does $comp have an argument called $fido? if (exists($comp->declared_args->{'$fido'})) { ... } # does $fido have a default value? if (defined($comp->declared_args->{'$fido'}->{default})) { ... }
Returns the component's notion of a current directory, relative to the component root; this is used to resolve relative component paths. For file-based components this is the full component path minus the final piece. For subcomponents this is the same as its parent component. Undefined for anonymous components.
Returns true if this is the first time the component has executed, false otherwise. Useful for initializing persistent component lexicals:
if ($m->current_comp->first_time) { $dbh = DBI->connect(...);
Note that in a web-based environment, this "first time" will come once for each child and every time the component is reloaded.
Returns true if this is a subcomponent of another component.
Returns true if this component was loaded from a source or object file.
Returns a short name of the component. For file-based components this is the filename without the path. For subcomponents this is the name specified in <%def>. Undefined for anonymous components.
Returns the object filename for this component.
Defined only for subcomponents; returns the parent component that this subcomponent was defined in.
Returns the absolute path of this component.
Returns the number of times this component has been invoked. In a web-based environment, this value is separate for each child and resets every time the component is reloaded.
With no arguments, returns a hashref containing the subcomponents defined in this component, with names as keys and component objects as values. With one argument, returns the subcomponent of that name or undef if no such subcomponent exists. e.g.
if (my $subcomp = $comp->subcomps('.link')) { ... }
Returns a printable string denoting this component. It is intended to uniquely identify a component within a given interpreter although this is not 100% guaranteed. Mason uses this string in error messages, the previewer component trace, and $m-comp_stack>.
For file-based components this is the component path. For subcomponents this is "parent_component_path:subcomponent_name". For anonymous components this is a unique label like "[anon 17]".
The following methods apply only to file-based components (those loaded from source or object files). They return undef for other component types.
Returns the source filename for this component.
Returns the directory of the source filename for this component.
Jonathan Swartz, swartz@transbay.net
HTML::Mason::Request
To install HTML::Mason, copy and paste the appropriate command in to your terminal.
cpanm
cpanm HTML::Mason
CPAN shell
perl -MCPAN -e shell install HTML::Mason
For more information on module installation, please visit the detailed CPAN module installation guide.