HTML::Mason::Compiler(User Contributed Perl DocumentatHTML::Mason::Compiler(3)NAMEHTML::Mason::Compiler - Compile Mason component source
VERSION
version 1.54
SYNOPSIS
package My::Funky::Compiler;
use base qw(HTML::Mason::Compiler);
DESCRIPTION
The compiler starts the compilation process by calling its lexer's
"lex" method and passing itself as the "compiler" parameter. The lexer
then calls various methods in the compiler as it parses the component
source.
PARAMETERS TO THE new() CONSTRUCTOR
allow_globals
List of variable names, complete with prefix ("$@%"), that you
intend to use as globals in components. Normally global variables
are forbidden by "strict", but any variable mentioned in this list
is granted a reprieve via a "use vars" statement. For example:
allow_globals => [qw($DBH %session)]
In a mod_perl environment, $r (the request object) is automatically
added to this list.
default_escape_flags
Escape flags to apply to all <% %> expressions by default. The
current valid flags are
h - escape for HTML ('<' => '<', etc.)
u - escape for URL (':' => '%3A', etc.)
The developer can override default escape flags on a per-expression
basis; see the escaping expressions section of the developer's
manual.
If you want to set multiple flags as the default, this should be
given as a reference to an array of flags.
enable_autoflush
True or false, default is true. Indicates whether components are
compiled with support for autoflush. The component can be compiled
to a more efficient form if it does not have to check for autoflush
mode, so you should set this to 0 if you can.
lexer
The Lexer object to associate with this Compiler. By default a new
object of class lexer_class will be created.
lexer_class
The class to use when creating a lexer. Defaults to
HTML::Mason::Lexer.
preprocess
Sub reference that is called to preprocess each component before
the compiler does it's magic. The sub is called with a single
parameter, a scalar reference to the script. The sub is expected
to process the script in-place. This is one way to extend the
HTML::Mason syntax with new tags, etc., although a much more
flexible way is to subclass the Lexer or Compiler class. See also
postprocess_text and postprocess_perl.
postprocess_text
Sub reference that is called to postprocess the text portion of a
compiled component, just before it is assembled into its final
subroutine form. The sub is called with a single parameter, a
scalar reference to the text portion of the component. The sub is
expected to process the string in-place. See also preprocess and
postprocess_perl.
postprocess_perl
Sub reference that is called to postprocess the Perl portion of a
compiled component, just before it is assembled into its final
subroutine form. The sub is called with a single parameter, a
scalar reference to the Perl portion of the component. The sub is
expected to process the string in-place. See also preprocess and
postprocess_text.
use_source_line_numbers
True or false, default is true. Indicates whether component line
numbers that appear in error messages, stack traces, etc. are in
terms of the source file instead of the object file. Mason does
this by inserting '#line' directives into compiled components.
While source line numbers are more immediately helpful, object file
line numbers may be more appropriate for in-depth debugging
sessions.
ACCESSOR METHODS
All of the above properties have read-only accessor methods of the same
name.
You cannot change any property of a compiler after it has been created
- among other things, this would potentially invalidate any existing
cached component objects or object files. Your best bet is to create
different compiler objects and load them into different interpreters.
METHODS
There are several methods besides the compilation callbacks below that
a Compiler subclass needs to implement.
compile(...)
This method has several parameters:
· comp_source (required)
Either a scalar or reference to a scalar containing the
component source.
· name (required)
The name of the component. This should be the filename of
the component if it is file-based, or some other clear
identifier of the component source.
· comp_path (required)
This should be the component's path.
· fh (optional)
If this is given then the output of the compiler will be
sent directly to this handle, rather than being buffered in
memory. This is an optimization to avoid memory usage.
object_id
This method should return a unique id for the given compiler
object. This is used by the interpreter when determining the
object directory, for example.
Compilation Callbacks
These are methods called by the Lexer while processing a component
source. You may wish to override some of these methods if you're
implementing your own custom Compiler class.
start_component()
This method is called by the Lexer when it starts processing a
component.
end_component()
This method is called by the Lexer when it finishes processing a
component.
start_block(block_type => <string>)
This method is called by the Lexer when it encounters an opening
Mason block tag like "<%perl>" or "<%args>". Its main purpose is
to keep track of the nesting of different kinds of blocks within
each other. The type of block ("init", "once", etc.) is passed via
the "block_type" parameter.
end_block(block_type => <string>)
This method is called by the Lexer when it encounters a closing
Mason block tag like "</%perl>" or "</%args>". Like
"start_block()", its main purpose is to help maintain syntactic
integrity.
*_block(block => <string>, [ block_type => <string> ])
Several compiler methods like "doc_block()", "text_block()", and
"raw_block()" are called by the Lexer after "start_block()" when it
encounters blocks of certain types. These methods actually do the
work of putting the body of a block into the compiled data
structure.
The methods that follow this pattern are "init_block()",
"perl_block()", "doc_block()", "text_block()", and "raw_block()".
The last method is called for all "<%once>", "<%cleanup>",
"<%filter>", "<%init>", "<%perl>", and "<%shared>" blocks.
text(text => <string>)
Inserts the text contained in a "text" parameter into the component
for verbatim output.
This is called when the lexer finds plain text in a component.
variable_declaration( type => <string>, name => <string>, default =>
<string> )
Inserts a variable declaration from the "<%args>" section into the
component.
The type will be either "$", "@", or "%", indicating a scalar,
array, or hash. The name is the variable name without the leading
sigil. The default is everything found after the first "=>" on an
"<%args>" block line, and may include a comment.
key_value_pair(block_type => <string>, key => <string>, value =>
<string>)
Inserts a key-value pair from a "<%flags>" or "<%attr>" section
into the component.
The "block_type" parameter will be either "flags" or "attr".
start_named_block(block_type => <string>, name => <name>)
Analogous to item_start_block, but starts a "named" block
("<%method>" or "<%def>").
end_named_block()
Called by the Lexer to end a "named" block.
substitution(substitution => <string>, escape => <string>)
Called by the Lexer when it encounters a substitution tag ("<% ...
%>").
The value of the "escape" parameter will be everything found after
the pipe (|) in the substitution tag, and may be more than one
character such as "nh".
component_call(call => <string>)
Called by the Lexer when it encounters a component call tag without
embedded content ("<& ... &>").
The "call" parameter contains the entire contents of the tag.
component_content_call(call => <string>)
Called by the Lexer when it encounters a component call tag with
embedded content ("<&| ... &>").
component_content_call_end()
Called by the Lexer when it encounters an ending tag for a
component call with content ("</&>"). Note that there is no
corresponding "component_call_end()" method for component calls
without content, because these calls don't have ending tags.
perl_line(line => <string>)
Called by the Lexer when it encounters a "%"-line.
SUBCLASSING
We recommend that any parameters you add to Compiler be read-only,
because the compiler object_id is only computed once on creation and
would not reflect any changes to Lexer parameters.
SEE ALSO
Mason
AUTHORS
· Jonathan Swartz <swartz@pobox.com>
· Dave Rolsky <autarch@urth.org>
· Ken Williams <ken@mathforum.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2012 by Jonathan Swartz.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
perl v5.18.2 2014-01-19 HTML::Mason::Compiler(3)
