NAME
    CGI::Application::Plugin::Config::General - Add Config::General Support
    to CGI::Application

VERSION
    Version 0.08

NOTE
    This module is obsolete and has now been superceded by
    CGI::Application::Plugin::Config::Context.

SYNOPSIS
  Simple Access to Configuration
    In your CGI::Application-based module:

        use base 'CGI::Application';
        use CGI::Application::Plugin::Config::General;

        sub cgiapp_init {
            my $self = shift;

            # Set config file and other options
            $self->conf->init(
                -ConfigFile => 'app.conf',
            );
        }

        sub my_run_mode {
            my $self = shift;

            # get entire configuration
            my %conf = $self->conf->getall;

            # get entire configuration (as a reference)
            my $conf = $self->conf->getall;

            # get single config parameter
            my $value = $self->conf->param('some_value');

            # get underlying Config::General::Match object
            my $obj = $self->conf->obj;
        }

  Configuration Based on URL or Module
    You can match a configuration section to the request URL, or to the
    module name. For instance, given the following configuration file:

        admin_area    = 0

        <AppMatch ^MyApp::Admin>
            admin_area = 1
            title      = Admin Area
        </AppMatch>

        <Location /cgi-bin/feedback.cgi>
            title      = Feedback Form
        </Location>

    The configuration will depend on how the script is called:

        # URL:      /cgi-bin/feedback.cgi?rm=add
        # Module:   MyApp::Feedback

        print $self->conf->param('admin_area');  # 0
        print $self->conf->param('title');       # 'Feedback Form'

        # URL:      /cgi-bin/admin/users.cgi
        # Module:   MyApp::Admin::Users

        print $self->conf->param('admin_area');  # 1
        print $self->conf->param('title');       # 'Admin Area'

  Matching Configuration based on a Virtual Host
    This module can also pick a configuration section based on the current
    virtual-host:

        # httpd.conf
        <VirtualHost _default_:8080>
            SetEnv SITE_NAME REDSITE
        </VirtualHost>

        # in app.conf
        <Site BLUESITE>
            background = blue
            foreground = white
        </Site>

        <Site REDSITE>
            background = red
            foreground = pink
        </Site>

        <Site GREENSITE>
            background = darkgreen
            foreground = lightgreen
        </Site>

DESCRIPTION
    This module allows you to easily access configuration data stored in
    Config::General (i.e. Apache-style) config files.

    You can also automatically match configuration sections to the request
    URL, or to the module name. This is similar to how Apache dynamically
    selects a configuration by matching the request URL to e.g. "<Location>"
    and "<LocationMatch>" sections.

    You can also select configuration sections based on Virtual Host or by a
    variable you set in an ".htaccess" file. This allows you to share a
    single application between many virtual hosts, each with its own unique
    configuration. This could be useful, for instance, in providing multiple
    themes for a single application.

  Simple access to Configuration
    This module provides a "conf" method to your CGI::Application object.
    First, you initialize the configuration system (typically in your
    "cgiapp_init" method):

        $self->conf->init(
            -ConfigFile => 'app.conf',
        );

    The configuration file is parsed at this point and is available from
    this point on.

    Then, within your run-modes you can retrieve configuration data:

        # get entire configuration
        my %conf = $self->conf->getall;
        my $value = $conf{'some_value'};

        # get entire configuration (as a reference)
        my $conf = $self->conf->getall;
        my $value = $conf->{'some_value'};

        # get single config parameter
        my $value = $self->conf->param('some_value');

  Multiple named Configurations
    You can use more than one configuration by providing a name to the
    "conf" method:

        $self->conf('database')->init(
            -ConfigFile => 'app.conf',
        );
        $self->conf('application')->init(
            -ConfigFile => 'app.conf',
        );

        ...

        my %db_config  = $self->conf('database')->getall;
        my %app_config = $self->conf('application')->getall;

  Configuration based on URL or Module
    Within your configuration file, you can provide different configurations
    depending on the current URL, or on the package name of your
    application.

    <Site>
        Matches against the "SITE_NAME" environment variable, using an
        *exact* match.

            # httpd.conf
            <VirtualHost _default_:8080>
                SetEnv SITE_NAME REDSITE
            </VirtualHost>

            # in app.conf
            <Site BLUESITE>
                background = blue
                foreground = white
            </Site>

            <Site REDSITE>
                background = red
                foreground = pink
            </Site>

            <Site GREENSITE>
                background = darkgreen
                foreground = lightgreen
            </Site>

        You can use name your sections something other than "<Site>", and
        you can use a different environment variable than "SITE_NAME". See
        "Notes on Site Matching", below.

    <App>
        Matches the Package name of your application module, for instance:

            <App ABC_Books::Admin>
                ...
            </App>

        The match is performed hierachically, like a filesystem path, except
        using "::" as a delimiter, instead of "/". The match is tied to the
        beginning of the package name, just like absolute paths. For
        instance, given the section:

            <App Site::Admin>
                ...
            </App>

        the packages "Site::Admin" and "Site::Admin::Users" would match, but
        the packages "My::Site::Admin" and "Site::Administrative" would not.

    <AppMatch>
        Matches the package name of your application module, using a regular
        expression. The expression is not tied to the start of the string.
        For instance, given the section:

            <AppMatch Site::Admin>
                ...
            </AppMatch>

        The following packages would all match: "Site::Admin",
        "Site::Admin::Users", "My::Site::Admin", "MySite::Admin",
        "Site::Administrative".

    <Location>
        Matches hierarchically against the request URI, including the path
        and the "PATH_INFO" components, but *excluding* the scheme, host,
        port and query string.

        So, for instance with the following URL:

            http://bookstore.example.com/cgi-bin/category.cgi/fiction/?rm=list

        The Location would be:

            /cgi-bin/category.cgi/fiction/

        Internally, the location is obtained by calling the "url" method of
        the query object (which is usually either a CGI or CGI::Simple
        object):

            $path = $webapp->query->url('-absolute' => 1, '-path_info' => 1);

    <LocationMatch>
        Matches against the request URI, using a regular expression.

  Section Merge Order
    The sections are matched in the following order:

        Site:         <Site>
        Package Name: <App>      and <AppMatch>
        URL:          <Location> and <LocationMatch>

    When there is more than one matching section at the same level of
    priority (e.g. two "<Location>" sections, or both an "<App>" and an
    "<AppMatch>" section), then the sections are merged in the order of
    shortest match first.

    Values in sections matched later override the values in sections matched
    earlier.

    The idea is that the longer matches are more specific and should have
    priority, and that URIs are more specific than Module names.

  Section Nesting
    The sections can be nested inside each other. For instance:

        <Site BOOKSHOP>
            <Location /admin>
                admin_books = 1
            </Location>
        </Site>

        <Location /admin>
            <Site RECORDSHOP>
                admin_records = 1
            </Site>
        </Location>

        <App Bookshop::>
            <App Admin::>
            </App>
        </App>

    By default, the sections can be nested up to two levels deep. You can
    change this by setting the -NestingDepth parameter to init.

  Merging Configuration Values into your Template
    You can easily pass values from your configuration files directly to
    your templates. This allows you to associate HTML titles with URLs, or
    keep text like copyright notices in your config file instead of your
    templates:

        copyright_notice    =  Copyright (C) 1492 Christopher Columbus

        <Location /about>
            title = "Manifest Destiny, Inc. -  About Us"
        </Location>

        <Location /contact>
            title = "Manifest Destiny, Inc. - Contact Us"
        </Location>

    If you use HTML::Template, you use the associate method when you load
    the template:

        $self->load_template(
            'template.tmpl',
            'associate' => $self->conf,
        );

    If you use Template::Toolkit (via the CGI::Application::Plugin::TT
    module), you can accomplish the same thing by providing a custom
    tt_pre_process method:

        sub tt_pre_process {
            my $self            = shift;
            my $template        = shift;
            my $template_params = shift;

            my $config = $self->conf->getall
            foreach (keys %$config) {
                unless (exists $template_params->{$_}) {
                    $template_params->{$_} = $config->{$_};
                }
            }
        }

    *NOTE: If you plan to merge data directly from your config files to
    your* *templates, you should consider keeping your database passwords
    and other* *sensitive data in a separate configuration file, in order to
    avoid* *accidentally leaking these data into your web pages.*

METHODS
  init
    Initializes the plugin. The only required parameter is a config file:

        $self->conf->init(
            -ConfigFile => 'app.conf',
        );

    The other paramters are described below:

    -ConfigFile
        The path to the configuration file to be parsed.

    -Options
        Any additional Config::General::Match options. See the documentation
        to Config::General and Config::General::Match for more details.

    -CacheConfigFiles
        Whether or not to cache configuration files. Enabled, by default.
        This option is only really useful in a persistent environment such
        as "mod_perl". See "Config File Caching" under "ADVANCED USAGE",
        below.

    -StatConfig
        If config file caching is enabled, this option controls how often
        the config files are checked to see if they have changed. The
        default is 60 seconds. This option is only really useful in a
        persistent environment such as "mod_perl". See "Config File Caching"
        under "ADVANCED USAGE", below.

    -SiteSectionName
        Change the name of the "<Site>" section to something else. For
        instance, to use sections named "<VirtualHost>", use:

            -SiteSectionName => 'VirtualHost'

    -SiteVar
        Change the name of the "SITE_NAME" environment variable used to
        match against "<Site>" sections. For instance To change this name to
        "HTTP_HOST", use:

            -SiteVar => 'HTTP_HOST',

    -NestingDepth
        The number of levels deep that sections can be nested. The default
        is two levels deep.

        See "Section Nesting", above.

    You can initialize the plugin from within your instance CGI script:

        my $app = WebApp->new();
        $app->conf->init(-ConfigFile => '../../config/app.conf');
        $app->run();

    Or you can do so from within your "cgiapp_init" method within the
    application:

        sub cgiapp_init {
            my $self = shift;
            $self->conf->init(
                -ConfigFile => "$ENV{DOCUMENT_ROOT}/../config/app.conf"
            );
        }

  getall
    Gets the entire configuration as a hash or hashref:

        my %config = $self->conf->getall;  # as hash
        my $config = $self->conf->getall;  # as hashref

    Note that the following two method calls will return different results:

        my %config = $self->conf->getall;       # parsed config
        my %config = $self->conf->obj->getall;  # raw config

    In the first case, the matching based on URI, Module, etc. has already
    been performed. In the second case, you get the raw config with all of
    the "<Location>", "<App>", etc. sections intact.

  param
    Allows you to retrieve individual values from the configuration.

    It behvaves like the "param" method in other classes, such as CGI,
    CGI::Application and HTML::Template:

        $value      = $self->conf->param('some_key');
        @all_keys   = $self->conf->param();

  obj
    Provides access to the underlying Config::General::Match object.

    You can access the raw unparsed configuration data by calling

        my $config = $self->conf->obj->getall;  # raw config

    See the note under getall, above.

    In future versions of this module, certain caching strategies may
    prevent you from accessing the underlying Config::General::Match object
    in certain situations.

  get_current_config ($name)
    This is a class method which returns the current configuration object.

        my $conf = CGI::Application::Plugin::Config::General->get_current_config;
        print $conf->{'title'};

        my %db_conf = CGI::Application::Plugin::Config::General->get_current_config('db');
        print $db_conf{'username'};

    This method is most useful in situations where you don't have access to
    the CGI::Application object, such within a Class::DBI class. See "Access
    to Configuration information from another Class" for an example.

    Note that get_current_config returns the configuration hash (or hashref)
    directly, and does not give you access to the object itself. It is the
    equivalent of calling "$self->conf->getall".

ADVANCED USAGE
  Usage in a Persistent Environment such as mod_perl
    The following sections describe some notes about running this module
    under mod_perl:

   Config File Caching
    By default each config file is read only once when the conf object is
    first initialized. Thereafter, on each init, the cached config is used.

    This means that in a persistent environment like mod_perl, the config
    file is parsed on the first request, but not on subsequent requests.

    If enough time has passed (sixty seconds by default) the config file is
    checked to see if it has changed. If it has changed, then the file is
    reread.

    If you are using Config::General version 2.28 or greater, then you can
    safely use the "include" feature of Config::General and all included
    files will be checked for changes along with the main file.

    To disable caching of config files pass a false value to the
    -CacheConfigFiles parameter to init, e.g:

        $self->conf->init(
            -ConfigFile           => 'app.conf',
            -CacheConfigFiles     => 0,
        );

    To change how often config files are checked for changes, change the
    value of the -StatConfig paramter to init, e.g.:

        $self->conf->init(
            -ConfigFile => 'app.conf',
            -StatConfig => 1, # check the config file every second
        );

    Internally the configuration cache is implemented by a hash, keyed by
    the absolute path of the configuration file. This means that if you have
    two web applications that use the same configuration file, they will use
    the same cache.

    This would only matter if you wanted to use different "Config::General"
    or "Config::General::Match" options for different applications running
    in the same process that use the same config file.

   PerlSetVar instead of SetEnv
    For a (slight) performance improvement, you can use "PerlSetVar" instead
    of "SetEnv" within a "<VirtualHost>":

        # httpd.conf
        <VirtualHost _default_:8080>
            PerlSetVar SITE_NAME REDSITE
        </VirtualHost>

  Notes on Site Matching
   Renaming "<Site>" or "SITE_NAME"
    Normally, the environment variable "SITE_NAME" is matched to "<Site>"
    section.

    You can change these with the -SiteSectionName and -SiteVar parameters
    to init:

        $self->conf->init(
            -ConfigFile           => 'app.conf',
            -SiteSectionName      => 'Host',
            -SiteVar              => 'MY_HOST',
        );

    This will match the environment variable "MY_HOST" to the "<Host>"
    section.

   Setting "SITE_NAME" from an ".htaccess" file or the CGI script
    Since "SITE_NAME" is just an environment variable, you can set it
    anywhere you can set environment variables. For instance in an
    ".htaccess" file:

        # .htaccess
        SetEnv SITE_NAME bookshop

    Or even the calling CGI script:

        #!/usr/bin/perl

        use MySite::WebApp;

        $ENV{'SITE_NAME'} = 'recordshop';
        my $app = MySite::WebApp->new();
        $app->run();

  Access to Configuration information from another Class
    You can also get at the current configuration settings from a completely
    unrelated Perl module. This can be useful for instance if you need to
    configure a set of Class::DBI classes, and you want them to be able to
    pick up their configuration on their own. For instance:

        # app.conf

        <database>
            connect_string = dbi:Pg:dbname=example
            username       = test
            password       = test

            <options>
                RaiseError = 1
                AutoCommit = 1
            </options>
        </database>


        # In your Class::DBI subclass
        package My::Class::DBI::Base;
        use base 'Class::DBI';

        sub db_Main {

            my $conf = CGI::Application::Plugin::Config::General->get_current_config;

            my $dsn  = $conf->{'database'}{'connect_string'};
            my $user = $conf->{'database'}{'username'};
            my $pass = $conf->{'database'}{'password'};
            my $opts = $conf->{'database'}{'options'};

            return DBI->connect_cached($dsn, $user, $pass, $opts);
        }

    For this example to work, you need to make sure you call
    "$self->conf->init" before you access the database through any of your
    Class::DBI objects.

    Note that get_current_config returns the configuration hash (or hashref)
    directly, and does not give you access to the object itself. It is the
    equivalent of calling "$self->conf->getall".

  Changing Parsing Behaviour Using Custom -MatchSections
    Internally, this module uses Config::General and Config::General::Match
    to parse its config files. If you want to change the parsing behaviour,
    you can pass your own -MatchSections list to init. For instance, if you
    want to allow only sections named "<URL>", with no nesting, and have
    these matched exactly to the complete request path, you could do the
    following:

        # app.conf

        admin_area = 0
        user_area  = 0

        <URL /cgi-bin/admin.cgi>
            admin_area = 1
        </URL>

        <URL /cgi-bin/user.cgi>
            user_area = 1
        </URL>


        # in your cgiapp_init:
        $self->conf->init(
            -ConfigFile        => 'app.conf',
            -NestingDepth      => 1,
            -Options           => {
                -MatchSections => [
                    {
                        -Name          => 'URL',
                        -MatchType     => 'exact',
                        -MergePriority => 0,
                        -SectionType   => 'path',
                    },
                ]
            }
        );

    For reference, here is the default -MatchSections:

        -MatchSections => [
            {
                -Name          => 'Site', # overridden by -SiteSectionName
                -MatchType     => 'exact',
                -MergePriority => 0,
                -SectionType   => 'env',
            },
            {
                -Name          => 'AppMatch',
                -MatchType     => 'regex',
                -SectionType   => 'module',
                -MergePriority => 1,
            },
            {
                -Name              => 'App',
                -MatchType         => 'path',
                -PathPathSeparator => '::',
                -SectionType       => 'module',
                -MergePriority     => 1,
            },
            {
                -Name          => 'LocationMatch',
                -MatchType     => 'regex',
                -SectionType   => 'path',
                -MergePriority => 3,
            },
            {
                -Name          => 'Location',
                -MatchType     => 'path',
                -SectionType   => 'path',
                -MergePriority => 3,
            },
        ],

    For each section, the -SectionType param indicates what runtime variable
    the section will be matched against. Here are the allowed values

        env:     matched to the environment variable SITE_NAME (overridden by -SiteNameVar)
        module:  name of the Perl Module handling this request (e.g. MyApp::Users)
        path:    path of the request, including path_info (e.g. /cgi-bin/myapp/users.cgi/some/path)

    You can use the above -SectionType values in your own custom
    -MatchSections.

    For more information on the syntax of -MatchSections, see the docs for
    Config::General::Match.

AUTHOR
    Michael Graham, "<[email protected]>"

BUGS
    Please report any bugs or feature requests to
    "[email protected]", or through the
    web interface at <http://rt.cpan.org>. I will be notified, and then
    you'll automatically be notified of progress on your bug as I make
    changes.

ACKNOWLEDGEMENTS
    This module would not be possible without Thomas Linden's excellent
    Config::General module.

    Thanks to the excellent examples provided by the other CGI::Application
    plugin authors: Mark Stosberg, Michael Peters, Cees Hek and others.

SOURCE
    The source code repository for this module can be found at
    http://github.com/mgraham/CGI-Application-Plugin-Config-General

SEE ALSO
        CGI::Application
        Config::General
        Config::General::Match
        CGI::Application::Plugin::Config::Simple
        CGI::Application::Plugin::ConfigAuto

        CGI::Application::Plugin::TT
        Template::Toolkit
        HTML::Template

COPYRIGHT & LICENSE
    Copyright 2005 Michael Graham, All Rights Reserved.

    This program is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.