HTML::Mason::Params - Mason configuration parameters

- NAME
- DESCRIPTION
- PERL AND APACHE NAMES

- Where Apache Names Are Used
- Where Perl Names Are Used

- PARAMETERS

- allow_globals
- apache_status_title
- args_method
- auto_send_headers
- autoflush
- autohandler_name
- buffer_class
- code_cache_max_size
- comp_class
- comp_root
- compiler_class
- current_time
- data_cache_api
- data_cache_defaults
- data_dir
- decline_dirs
- default_escape_flags
- dhandler_name
- error_format
- error_mode
- escape_flags
- ignore_warnings_expr
- in_package
- interp_class
- lexer_class
- max_recurse
- out_method
- postamble
- postprocess_perl
- postprocess_text
- preamble
- preloads
- preprocess
- request_class
- resolver_class
- static_source
- subcomp_class
- use_object_files
- use_strict

# NAME

HTML::Mason::Params - Mason configuration parameters

# DESCRIPTION

This document lists all of the Mason configuration parameters that are intended to be used by end users.

# PERL AND APACHE NAMES

Each parameter has two names: a Perl version and an Apache version. The Perl version uses `lowercase_with_underscores`, while the Apache version uses `StudlyCaps` with a `Mason` prefix. The conversion from one version to the other is otherwise very predictable. For example,

`autohandler_name` `<-->` `MasonAutohandlerName`

`comp_root` `<-->` `MasonCompRoot`

`data_cache_defaults` `<-->` `MasonDataCacheDefaults`

## Where Apache Names Are Used

The Apache parameter names are used in the Apache configuration file in an httpd-based configuration. They are only effective if you have

       PerlHandler HTML::Mason::ApacheHandler

in your `httpd.conf`. They cannot be used in conjunction with a handler.pl-based configuration.

## Where Perl Names Are Used

The Perl parameter names are used from Perl code, i.e. anywhere other than the Apache configuration file. For example,

In an handler.pl-based configuration, you can pass most of these parameters to the ApacheHandler constructor.

In a standalone Mason script, you can pass most of these parameters to the Interp constructor.

When launching a subrequest, you can pass any of the `HTML::Mason::Request` parameters to make_subrequest.

# PARAMETERS

## allow_globals

Perl name: |  | allow_globals
Apache name: |  | MasonAllowGlobals
Type: |  | list
Default: |  | []
Belongs to: |  | HTML::Mason::Compiler

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.

## apache_status_title

Perl name: |  | apache_status_title
Apache name: |  | MasonApacheStatusTitle
Type: |  | string
Default: |  | HTML::Mason status
Belongs to: |  | HTML::Mason::ApacheHandler

Title that you want this ApacheHandler to appear as under Apache::Status. Default is ``HTML::Mason status''. This is useful if you create more than one ApacheHandler object and want them all visible via Apache::Status.

## args_method

Perl name: |  | args_method
Apache name: |  | MasonArgsMethod
Type: |  | string
Default: |  | mod_perl
Belongs to: |  | HTML::Mason::ApacheHandler

Method to use for unpacking GET and POST arguments. The valid options are 'CGI' and 'mod_perl'; these indicate that a `CGI.pm` or `Apache::Request` object (respectively) will be created for the purposes of argument handling.

'mod_perl' is the default and requires that you have installed the `Apache::Request` package.

If the args_method is 'CGI', the Mason request object (`$m`) will have a method called `cgi_object` available. This method returns the CGI object used for argument processing.

If args_method is 'mod_perl', the `$r` global is upgraded to an Apache::Request object. This object inherits all Apache methods and adds a few of its own, dealing with parameters and file uploads. See Apache::Request for more information.

While Mason will load `Apache::Request` or `CGI` as needed at runtime, it is recommended that you preload the relevant module either in your httpd.conf or handler.pl file, as this will save some memory.

## auto_send_headers

Perl name: |  | auto_send_headers
Apache name: |  | MasonAutoSendHeaders
Type: |  | boolean
Default: |  | 1
Belongs to: |  | `HTML::Mason::Request::ApacheHandler`

True or false, default is true. Indicates whether Mason should automatically send HTTP headers before sending content back to the client. If you set to false, you should call `$r->send_http_header` manually.

See the sending HTTP headers section of the developer's manual for more details about the automatic header feature.

## autoflush

Perl name: |  | autoflush
Apache name: |  | MasonAutoflush
Type: |  | boolean
Default: |  | 0
Belongs to: |  | HTML::Mason::Request

True or false, default is false. Indicates whether to flush the output buffer after every string is output. Turn on autoflush if you need to send partial output to the client, for example in a progress meter.

## autohandler_name

Perl name: |  | autohandler_name
Apache name: |  | MasonAutohandlerName
Type: |  | string
Default: |  | autohandler
Belongs to: |  | HTML::Mason::Interp

File name used for autohandlers. Default is ``autohandler''.

## buffer_class

Perl name: |  | buffer_class
Apache name: |  | MasonBufferClass
Type: |  | string
Default: |  | HTML::Mason::Buffer
Belongs to: |  | HTML::Mason::Request

The class to use when creating buffers. Defaults to HTML::Mason::Buffer.

## code_cache_max_size

Perl name: |  | code_cache_max_size
Apache name: |  | MasonCodeCacheMaxSize
Type: |  | string
Default: |  | 10485760
Belongs to: |  | HTML::Mason::Interp

Specifies the maximum size, in bytes, of the in-memory code cache where components are stored. Default is 10 MB. See the ADMIN<code cache> section of the administrator's manual for further details.

## comp_class

Perl name: |  | comp_class
Apache name: |  | MasonCompClass
Type: |  | string
Default: |  | HTML::Mason::Component
Belongs to: |  | HTML::Mason::Compiler::ToObject

The class into which component objects are blessed. This defaults to HTML::Mason::Component.

## comp_root

Perl name: |  | comp_root
Apache name: |  | MasonCompRoot
Type: |  | list
Default: |  | Varies
Belongs to: |  | HTML::Mason::Resolver::File

The component root marks the top of your component hierarchy and defines how component paths are translated into real file paths. For example, if your component root is /usr/local/httpd/docs, a component path of /products/index.html translates to the file /usr/local/httpd/docs/products/index.html.

Under Apache and CGI, comp_root defaults to the server's document root. In standalone mode comp_root defaults to the current working directory.

This parameter may be either a scalar or an array reference. If it is a scalar, it should be a filesystem path indicating the component root. If it is an array reference, it should be of the following form:

     [ [ key1 => '/path/to/root' ],
       [ key2 => '/path/to/other/root' ] ]

The ``keys'' for each path must be unique names and their ``values'' must be filesystem paths. These paths will be searched in the provided order whenever a component path must be resolved to a filesystem path.

## compiler_class

Perl name: |  | compiler_class
Apache name: |  | MasonCompilerClass
Type: |  | string
Default: |  | HTML::Mason::Compiler::ToObject
Belongs to: |  | HTML::Mason::Interp

The class to use when creating a compiler. Defaults to HTML::Mason::Compiler.

## current_time

Perl name: |  | current_time
Apache name: |  | MasonCurrentTime
Type: |  | string
Default: |  | real
Belongs to: |  | HTML::Mason::Interp

Interpreter's notion of the current time (deprecated).

## data_cache_api

Perl name: |  | data_cache_api
Apache name: |  | MasonDataCacheApi
Type: |  | string
Default: |  | 1.1
Belongs to: |  | HTML::Mason::Request

The `$m->cache` API to use. '1.1', the default, indicates the newer API documented in this manual. '1.0' indicates the old API documented in 1.0x and earlier. This compatibility layer is provided as a convenience for users upgrading from older versions of Mason, but will not be supported indefinitely.

## data_cache_defaults

Perl name: |  | data_cache_defaults
Apache name: |  | MasonDataCacheDefaults
Type: |  | hash
Default: |  | None
Belongs to: |  | HTML::Mason::Request

A hash reference of default options to use for the `$m->cache` command. For example, to use the `MemoryCache` implementation by default,

        data_cache_defaults => {cache_class => 'MemoryCache'}

These settings are overriden by options given to particular `$m->cache` calls.

## data_dir

Perl name: |  | data_dir
Apache name: |  | MasonDataDir
Type: |  | string
Default: |  | None
Belongs to: |  | HTML::Mason::Interp

The data directory is a writable directory that Mason uses for various features and optimizations: for example, component object files and data cache files. Mason will create the directory on startup, if necessary, and set its permissions according to the web server User/Group.

Under Apache, data_dir defaults to a directory called ``mason'' under the Apache server root. You will need to change this on certain systems that assign a high-level server root such as /usr!

In non-Apache environments, data_dir has no default. If it is left unspecified, Mason will not use the object files section of the administrator's manual, and the default data cache class will be `MemoryCache` instead of `FileCache`.

## decline_dirs

Perl name: |  | decline_dirs
Apache name: |  | MasonDeclineDirs
Type: |  | boolean
Default: |  | 1
Belongs to: |  | HTML::Mason::ApacheHandler

True or false, default is true. Indicates whether Mason should decline directory requests, leaving Apache to serve up a directory index or a `FORBIDDEN` error as appropriate. See the allowing directory requests section of the administrator's manual for more information about handling directories with Mason.

## default_escape_flags

Perl name: |  | default_escape_flags
Apache name: |  | MasonDefaultEscapeFlags
Type: |  | string
Default: |  | []
Belongs to: |  | HTML::Mason::Compiler

Escape flags to apply to all <% %> expressions by default. The current valid flags are

        h - escape for HTML ('<' => '&lt;', 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.

## dhandler_name

Perl name: |  | dhandler_name
Apache name: |  | MasonDhandlerName
Type: |  | string
Default: |  | dhandler
Belongs to: |  | HTML::Mason::Request

File name used for dhandlers. Default is ``dhandler''.

## error_format

Perl name: |  | error_format
Apache name: |  | MasonErrorFormat
Type: |  | string
Default: |  | Varies
Belongs to: |  | HTML::Mason::Request

Indicates how errors are formatted. The built-in choices are

brief - just the error message with no trace information

text - a multi-line text format

line - a single-line text format, with different pieces of information separated by tabs (useful for log files)

html - a fancy html format

The default format under Apache and CGI is either line or html depending on whether the error mode is fatal or output, respectively. The default for standalone mode is text.

The formats correspond to `HTML::Mason::Exception` methods named as_format. You can define your own format by creating an appropriately named method; for example, to define an ``xml'' format, create a method `HTML::Mason::Exception::as_xml` patterned after one of the built-in methods.

## error_mode

Perl name: |  | error_mode
Apache name: |  | MasonErrorMode
Type: |  | string
Default: |  | Varies
Belongs to: |  | HTML::Mason::Request

Indicates how errors are returned to the caller. The choices are fatal, meaning die with the error, and output, meaning output the error just like regular output.

The default under Apache and CGI is output, causing the error to be displayed in the browser. The default for standalone mode is fatal.

## escape_flags

Perl name: |  | escape_flags
Apache name: |  | MasonEscapeFlags
Type: |  | list
Default: |  | None
Belongs to: |  | HTML::Mason::Interp

A hash reference of escape flags to set for this object. See the section on the `set_escape()` method for more details.

## ignore_warnings_expr

Perl name: |  | ignore_warnings_expr
Apache name: |  | MasonIgnoreWarningsExpr
Type: |  | regex
Default: |  | qr/Subroutine .* redefined/i
Belongs to: |  | HTML::Mason::Interp

Regular expression indicating which warnings to ignore when loading components. Any warning that is not ignored will prevent the component from being loaded and executed. For example:

        ignore_warnings_expr =>
            'Global symbol.*requires explicit package'

If undef, all warnings are heeded; if '.', all warnings are ignored.

By default, this is set to 'Subroutine .* redefined'. This allows you to declare global subroutines inside <%once> sections and not receive an error when the component is reloaded.

## in_package

Perl name: |  | in_package
Apache name: |  | MasonInPackage
Type: |  | string
Default: |  | HTML::Mason::Commands
Belongs to: |  | HTML::Mason::Compiler::ToObject

This is the package in which a component's code is executed. For historical reasons, this defaults to `HTML::Mason::Commands`.

## interp_class

Perl name: |  | interp_class
Apache name: |  | MasonInterpClass
Type: |  | string
Default: |  | HTML::Mason::Interp
Belongs to: |  | HTML::Mason::ApacheHandler

The class to use when creating a interpreter. Defaults to HTML::Mason::Interp.

## lexer_class

Perl name: |  | lexer_class
Apache name: |  | MasonLexerClass
Type: |  | string
Default: |  | HTML::Mason::Lexer
Belongs to: |  | HTML::Mason::Compiler

The class to use when creating a lexer. Defaults to HTML::Mason::Lexer.

## max_recurse

Perl name: |  | max_recurse
Apache name: |  | MasonMaxRecurse
Type: |  | string
Default: |  | 32
Belongs to: |  | HTML::Mason::Request

The maximum recursion depth for the component stack, for the request stack, and for the inheritance stack. An error is signalled if the maximum is exceeded. Default is 32.

## out_method

Perl name: |  | out_method
Apache name: |  | MasonOutMethod
Type: |  | code
Default: |  | Print to STDOUT
Belongs to: |  | HTML::Mason::Request

Indicates where to send output. If out_method is a reference to a scalar, output is appended to the scalar. If out_method is a reference to a subroutine, the subroutine is called with each output string. For example, to send output to a file called ``mason.out'':

        my $fh = new IO::File ">mason.out";
        ...
        out_method => sub { $fh->print($_[0]) }

By default, out_method prints to standard output. Under Apache, standard output is redirected to `$r->print`.

## postamble

Perl name: |  | postamble
Apache name: |  | MasonPostamble
Type: |  | string
Default: |  | None
Belongs to: |  | HTML::Mason::Compiler::ToObject

Text given for this parameter is placed at the end of each component. See also preamble.

## postprocess_perl

Perl name: |  | postprocess_perl
Apache name: |  | MasonPostprocessPerl
Type: |  | code
Default: |  | None
Belongs to: |  | HTML::Mason::Compiler

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.

## postprocess_text

Perl name: |  | postprocess_text
Apache name: |  | MasonPostprocessText
Type: |  | code
Default: |  | None
Belongs to: |  | HTML::Mason::Compiler

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.

## preamble

Perl name: |  | preamble
Apache name: |  | MasonPreamble
Type: |  | string
Default: |  | None
Belongs to: |  | HTML::Mason::Compiler::ToObject

Text given for this parameter is placed at the beginning of each component. See also postamble.

## preloads

Perl name: |  | preloads
Apache name: |  | MasonPreloads
Type: |  | list
Default: |  | None
Belongs to: |  | HTML::Mason::Interp

A list of component paths, optionally with glob wildcards, to load when the interpreter initializes. e.g.

        preloads => ['/foo/index.html','/bar/*.pl']

Default is the empty list. For maximum performance, this should only be used for components that are frequently viewed and rarely updated. See the the preloading section of the administrator's manual section of the administrator's manual for further details.

As mentioned in the developer's manual, a component's `<%once>` section is executed when it is loaded. For preloaded components, this means that this section will be executed before a Mason or Apache request exist, so preloading a component that uses `$m` or `$r` in a `<%once>` section will fail.

## preprocess

Perl name: |  | preprocess
Apache name: |  | MasonPreprocess
Type: |  | code
Default: |  | None
Belongs to: |  | HTML::Mason::Compiler

Sub reference that is called to preprocess each component before Parser 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.

## request_class

Perl name: |  | request_class
Apache name: |  | MasonRequestClass
Type: |  | string
Default: |  | HTML::Mason::Request
Belongs to: |  | HTML::Mason::Interp

The class to use when creating requests. Defaults to HTML::Mason::Request.

## resolver_class

Perl name: |  | resolver_class
Apache name: |  | MasonResolverClass
Type: |  | string
Default: |  | HTML::Mason::Resolver::File
Belongs to: |  | HTML::Mason::Interp

The class to use when creating a resolver. Defaults to HTML::Mason::Resolver::File.

## static_source

Perl name: |  | static_source
Apache name: |  | MasonStaticSource
Type: |  | boolean
Default: |  | 0
Belongs to: |  | HTML::Mason::Interp

True or false, default is false. When false, Mason checks the timestamp of the component source file each time the component is used to see if it has changed. This provides the instant feedback for source changes that is expected for development. However it does entail a file stat for each component executed.

When true, Mason assumes that the component source tree is unchanging: it will not check component source files to determine if the memory cache or object file has expired. This can save many file stats per request. However, in order to get Mason to recognize a component source change, you must remove object files and restart the server (so as to clear the memory cache).

Use this feature for live sites where performance is crucial and where updates are infrequent and well-controlled.

## subcomp_class

Perl name: |  | subcomp_class
Apache name: |  | MasonSubcompClass
Type: |  | string
Default: |  | HTML::Mason::Component::Subcomponent
Belongs to: |  | HTML::Mason::Compiler::ToObject

The class into which subcomponent objects are blessed. This defaults to HTML::Mason::Component::Subcomponent.

## use_object_files

Perl name: |  | use_object_files
Apache name: |  | MasonUseObjectFiles
Type: |  | boolean
Default: |  | 1
Belongs to: |  | HTML::Mason::Interp

True or false, default is true. Specifies whether Mason creates object files to save the results of component parsing. You may want to turn off object files for disk space reasons, but otherwise this should be left alone.

## use_strict

Perl name: |  | use_strict
Apache name: |  | MasonUseStrict
Type: |  | boolean
Default: |  | 1
Belongs to: |  | HTML::Mason::Compiler::ToObject

True or false, default is true. Indicates whether or not a given component should `use strict`.