Chris Winters > OpenInteract-1.99_05 > OpenInteract2::Context

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Module Version: 1.78   Source   Latest Release: OpenInteract-1.99_06

NAME ^

OpenInteract2::Context - Provides the environment for a server

SYNOPSIS ^

 use OpenInteract2::Context qw( CTX );
 
 # You can create a variable for the context as well, but normal way
 # is to import it
 my $ctx = OpenInteract2::Context->instance;
 
 # Get the context but don't throw an exception if it 
 # doesn't exist yet, just return undef
 my $ctx = OpenInteract2::Context->instance( 1 ); 

 # Get the information (\%) for the 'TT' content generator
 my $generator_info = CTX->lookup_content_generator_config( 'TT' );

 # Get the 'TT' content generator object
 my $generator = CTX->content_generator( 'TT' );
 
 # Grab the server configuration
 my $conf = CTX->server_config;
 
 # Grab the 'main' datasource -- this could be DBI/LDAP/...
 my $db = CTX->datasource( 'main' );
 
 # Get the 'accounting' datasource
 my $db = CTX->datasource( 'accounting' );
 
 # Get the default system datasource
 my $db = CTX->datasource;
 
 # Find an object class
 my $news_class = CTX->lookup_object( 'news' );
 my $news = $news_class->fetch( 42 );
 
 # All in one step
 my $news = CTX->lookup_object( 'news' )->fetch( 42 );
 
 # Lookup an action
 my $action = CTX->lookup_action( 'news' );
 $action->params({ security_level => 8, news => $news });
 $action->task( 'show' );
 return $action->execute;
 
 # XXX: Add a cleanup handler (NOT DONE)
 #CTX->add_handler( 'cleanup', \&my_cleanup );

DESCRIPTION ^

This class supports a singleton object that contains your server configuration plus pointers to other OpenInteract services. Much of the information it holds is similar to what was in the OpenInteract::Request ($R) object in OpenInteract 1.x. However, the OpenInteract2::Context object does not include any information about the current request.

The information is holds and services it provides access to include:

configuration

The data in the server configuration is always available. (See server_config property.)

datasource

All datasources are retrieved through the context, including DBI, LDAP and any others. (See datasource())

object aliases

SPOPS object classes are stored based on the name so you do not need to know the class of the object you are working with, just the name. (See lookup_object())

actions

The context contains the action table and can lookup action information as well as create a OpenInteract2::Action object from it. (See lookup_action(), lookup_action_info(), lookup_action_none(), lookup_action_not_found())

controllers

The context provides a shortcut to lookup controller information from the server configuration.

security checking

You can check the security for any object or class from one place. (See check_security()

caching

If it is configured, you can get the cache object for storing or looking up data. (See cache property)

packages

The package repository and packages in your site are available from the context. (See properties repository and packages)

METHODS ^

Class Methods

instance( [ $no_exception ] )

This is the method you will see many times when the object is not being imported, since it returns the current context. There is only one context object available at any one time. If the context has not yet been created (with create()) then we either throw an exception if $no_exception is false or return undef if $no_exception is true. (Subclasses of OpenInteract2::Exception should set $no_exception to avoid an infinite loop...)

Returns: OpenInteract2::Context object

create( $base_config|\%config_params, [ \%setup_params ] )

Creates a new context. If you pass in a OpenInteract2::Config::Base object or specify 'website_dir' in \%setup_params, it will run the server initialization routines in setup(). (If you pass in an invalid directory for the parameter an exception is thrown.)

If you do not know these items when the context is created, you can do something like:

 my $ctx = OpenInteract2::Context->create();
 
 ... some time later ...
 
 my $base_config = OpenInteract2::Config::Base->new({ website_dir => $dir } );
 ... or ...
 my $base_config = OpenInteract2::Config::Base->new({ filename => $file } );
 $ctx->base_config( $base_config );
 $ctx->setup();

You may also initialize the Log::Log4perl logger when creating the context by passing a true value for the 'initialize_log' parameter in \%setup_params. This is typically only done for standalone scripts and as a convenience. For example:

 my $ctx = OpenInteract2::Context->create( { website_dir => $dir },
                                           { initialize_log => 1 });

Finally, create() stores the context for later retrieval by instance().

If the context has already been created then it is returned just as if you had called instance().

See setup() for the parameters possible in \%setup_params.

Returns: the new OpenInteract2::Context object.

setup( \%params )

Runs a series of routines, mostly from OpenInteract2::Setup, to initialize the singleton context object. If the base_config property has not been set with a valid OpenInteract2::Config::Base object, an exception is thrown.

If you pass to create() a base_config object or a valid website directory, setup() will be called automatically.

You can skip steps of the process by passing the step name in an arrayref 'skip' in \%params. (You normally pass these to create().) This is most useful when you are creating a website for the first time.

For instance, if you do not wish to activate the SPOPS objects:

 OpenInteract2::Context->create({ skip => 'activate spops' });

If you do not wish to read in the action table or SPOPS configuration:

 OpenInteract2::Context->create({ skip => [ 'initialize action',
                                            'initialize spops' ] });

The steps we take to setup the site are listed below. Steps performed by OpenInteract2::Setup are marked with the method called.

Returns: the context object

Object Methods: Date/Time

timezone()

Returns the string from the server configuration key 'Global.timezone'.

timezone_object()

Returns a DateTime::TimeZone object corresponding to the server configuration key 'Global.timezone'.

create_date( \%params )

A factory for creating DateTime objects using the timezone() from the context. Any parameters in \%params will be passed along to the DateTime constructor (with one exception, see below) but if you do not specify a year then we assume you want the current time and call the DateTime now() method.

The exception: when you specify 'epoch' in \%params we call the from_epoch() method instead of the constructor.

This is just a shortcut method and you instead may want to get the timezone from the context to create your own DateTime objects. Up to you.

Object Methods: Actions

lookup_action( $action_name [, \%values )

Looks up the information for $action_name in the action table and returns a OpenInteract2::Action object created from it. We also pass along \%values as the second argument to new() -- any properties found there will override what is in the action table configuration, and any properties there will be set into the resulting object.

If $action_name is not found, an exception is thrown.

Returns: OpenInteract2::Action object

lookup_action_name( $url_chunk )

Given the URL piece $url_chunk, find the associated action name. Whenever we set the action table (using action_table()), we scan the actions to see if they have an associated URL, peeking into the 'url' key in the action configuration.

If so, we only create one entry in the URL-to-name mapping.

If not, we create three entries in the URL-to-name mapping: the lowercased name, the uppercased name, and the name with the first character uppercased.

Additionally, we check the action configuration key 'url_alt' to see if it may have one or more URLs that it responds to. Each of these go into the URL-to-name mapping as well.

For example, say we had the following action configuration:

 [news]
 class = OpenInteract2::Action::News
 task_default = list

This would give the action key 'news' to three separate URLs: 'news', 'NEWS', and 'News'.

Given:

 [news]
 class = OpenInteract2::Action::News
 task_default = list
 url_alt = NeWs
 url_alt = Newsy

It would respond to the three URLs listed above, plus 'NeWs' and 'Newsy'.

Given:

 [news]
 class = OpenInteract2::Action::News
 task_default = list
 url = WhatReallyMatters

It would only respond to a single URL: 'WhatReallyMatters'.

lookup_action_none()

Finds the action configured for no name -- this is used when the user does not specify an action to take, such as when the root of a deployed URL is queried. (e.g., 'http://www.mysite.com/')

If the configured item is not found or the action it refers to is not found, an exception is thrown.

Returns: OpenInteract2::Action object

lookup_action_not_found()

Finds the action configured for when an action is not found. This can be used when an action is requested but not found in the action table. Think of it as a 'catch-all' for requests you cannot foresee in advance, such as mapping requests to the filesystem to an OpenInteract action.

Currently, this is not called by default when you try to lookup an action that is not found. This is a change from 1.x behavior. Instead, you would probably do something like:

 my $action = eval { CTX->lookup_action( 'my_action' ) };
 if ( $@ ) {
     $action = eval { CTX->lookup_action_not_found() };
 }

This requires more on your part, but there is no peek-a-boo logic going on, which to us is a good trade-off.

If the configured item is not found or the action it refers to is not found, an exception is thrown.

Returns: OpenInteract2::Action object

lookup_action_info( $action_name )

Find the raw action information mapped to $action_name. This is used mostly for internal purposes.

This method follows 'redir' paths to their end. See OpenInteract2::Action for more information about these. If an action redirects to an action which is not found, we still return undef.

This method will never throw any exceptions or errors.

Returns: hashref of action information, or undef if the action is not defined.

action_table( [ \%action_table ] )

Retrieves the action table, and sets it if passed in. The action table is a hashref of hashrefs -- the keys are the names of the actions, the values the information for the actions themselves.

When it gets passed in we do some work to find all the URLs each action will respond to and save them elsewhere in the server configuration.

Application developers will probably never use this.

Returns: hashref of action information

Object Methods: SPOPS

lookup_object( $object_name )

Finds the SPOPS object class mapped to $object_name. An exception is thrown if $object_name is not specified or not defined as an SPOPS object.

Here are two different examples. The first uses a temporary variable to hold the class name, the second does not.

 my $news_class = CTX->lookup_object( 'news' );
 my $newest_items = $news_class->fetch_group({ where => 'posted_on = ?',
                                               value => [ $now ] });
 
 my $older_items = CTX->lookup_object( 'news' )
                      ->fetch_group({ where => 'posted_on = ?',
                                      value => [ $then ] });

Returns: SPOPS class name; throws an exception if $object_name is not found.

spops_config( [ $name ] )

Returns the raw SPOPS configuration for $name. If $name not provided returns the full SPOPS configuration hashref.

Object Methods: Datasource

datasource( [ $name ] )

Returns the datasource mapped to $name. If $name is not provided, the method looks up the default datasource in the server configuration (under datasource_info.default_connection) and uses that.

Returns: the result of looking up the datasource using OpenInteract2::DatasourceManager

lookup_datasource_config( [ $name ] )

Returns the datasource configuration hashref for $name. If $name not provided returns the full datasource configuration hashref.

lookup_datasource_type_config( [ $type ] )

Returns the datasource type configuration hashref for $type. If $type not provided returns the full datasource type configuration hashref.

lookup_system_datasource_name()

Returns the datasource name in 'datasource_config.system'.

lookup_default_datasource_name()

Returns the datasource name in 'datasource_config.spops'.

lookup_default_ldap_datasource_name()

Returns the datasource name in 'datasource_config.ldap'.

Object Methods: Observers

lookup_observer( [ $observer_name ] )

Returns observer mapped to $observer_name, or returns hashref of all name-to-observer pairs

set_observer_registry( \%registry )

Assigns a full observer registry to the context. The registry is a hashref of name-to-observer pairs.

add_observer( $observer_name, \%info )

Shortcut to register_observer() method of OpenInteract2::Observer that passes the context observer registry as the last argument.

map_observer( $observer_name, $action_name )

Shortcut to add_observer_to_action() method of OpenInteract2::Observer.

Object Methods: Controller

lookup_controller_config( [ $controller_name ] )

Returns a hashref of information about $controller_name. If $controller_name not given returns a hashref with the controller names as keys and the associated info as values. This is typically just a class and content generator type, but we may add more...

Object Methods: Content Generator

lookup_content_generator_config( [ $generator_name ] )

Returns the data (a hashref) associated with $generator_name. If you want the object associated with $generator_name use content_generator(), below. If you do not provide $generator_name returns a hashref of all content generator information, keys as the generator names and values as the data associated with them.

content_generator( $name )

Returns information necessary to call the content generator named by $name. A 'content generator' is simply a class which can marry some sort of template with some sort of data to produce content. The generator that is used most prominently in OpenInteract is built around the Template Toolkit, but it also includes implementations for other templating systems (HTML::Template and Text::Template), and there is no reason you cannot use an entirely different technology, like SOAP.

Returns: an object with a parent of OpenInteract2::ContentGenerator. Generally you would only call generate() on it with the appropriate parameters to get the generated content -- these are initialized in setup().

Object Methods: Full-text Indexer

lookup_fulltext_config( [ $indexer_name ] )

Returns the data (a hashref) associated with $indexer_name. If you want the object associated with $indexer_name use fulltext_indexer(), below. If you do not provide $indexer_name returns a hashref of all fulltext indexer information, keys as the indexer names and values as the data associated with them. There is also the additional key 'default' which holds the name of the default fulltext indexer.

fulltext_indexer( [ $indexer_name ] )

Return the OpenInteract2::FullTextSearch object associated with $indexer_name. If $indexer_name not provided it uses the value of the server configuration key 'fulltext.default'.

Return: an object with the parent of OpenInteract2::FullTextSearch.

Object Methods: Deployment Context

There are three separate deployment contexts used in OpenInteract2: the application context, image context and static context. These control how OI2 parses incoming requests and the URLs it generates in OpenInteract2::URL.

All deployment contexts are set from the server configuration file at startup. You'll find the relevant configuration keys under context_info.

assign_deploy_url( $path )

This is the primary application context, and the one you should be most interested in. OI2 uses this value to define a URL-space which it controls. Since OI2 controls the space it's free to parse incoming URLs and assign resources to them, and to generate URLs and have them map to known resources.

The default deployment context is '', or the root context. So the following request:

 http://foo.com/User/show/

OI2 will try to find an action mapping to 'User' and assign the 'show' task to it. Similarly when OI2 generates a URL it will not prepend any URL-space to it.

However, if we set the context to /OI2, like:

 CTX->assign_deploy_url( '/OI2' )

then the following request:

 http://foo.com/User/show/

will not be properly parsed by OI2. In fact OI2 won't be able to find an action for the request and will map it to the 'none' action, which is not what you want. Instead it will look for the following:

 http://foo.com/OI2/User/show/

And when it generates a URL, such as with:

 my $url = OpenInteract2::URL->create( '/User/show/', { user_id => 55 } );

It will create:

 /OI2/User/show/?user_id=55

Use the server configuration key context_info.deployed_under to set this.

Returns: new deployment URL.

assign_deploy_image_url( $path|$url )

This serves the same purpose as the application deployment context in generating URLs but has no effect on URL/request parsing. It's useful if you have your images on a separate host, so you can do:

 CTX->assign_image_url( 'http://images.foo.com' );
 ...
 my $url = OpenInteract2::URL->create_image( '/images/photos/happy_baby.jpg' );

and generate the URL:

 http://images.foo.com/images/photos/happy_baby.jpg

Unlike assign_deploy_url you can use a fully-qualified URL here.

Returns: new deployment URL for images.

assign_deploy_static_url( $path|$url )

Exactly like assign_deploy_image_url, except it's used for static resources other than images.

Returns: new deployment URL for static resources.

Object Methods: Other Resources

lookup_class( $name )

The server configuration key system_class holds a number of name-to-class mappings for some system resources. This is a way to lookup a class based on the name. For example, if you want to manipulate the page template objects you'd use:

 # Server configuration
 [system_class]
 template_class = OpenInteract2::SiteTemplate
 
 # Usage
 my $template_class = CTX->lookup_class( 'template' );
 my $template = $template_class->fetch( ... );

NOTE: This replaces the aliasing feature found in early betas of OI2 and in all versions of OI 1.x. The aliasing feature would create methods for each name found in the server configuration key server_alias so you'd previously have:

 # Server configuration
 [system_alias]
 template_class = OpenInteract2::SiteTemplate
 
 # Usage
 my $template_class = CTX->template_class;
 my $template = $template_class->fetch( ... );

This will fail with a message that the template_class subroutine is not found in OpenInteract2::Context.

lookup_directory( $dir_tag )

Finds fully-qualified directory matching dir.$dir_tag in the server configuration. For example:

 my $full_html_dir = CTX->lookup_directory( 'html' );

This is preferred to poking about in the server configuration data structure yourself.

Returns: fully-qualified directory

lookup_temp_lib_directory()

Creates the fully-qualified name for the temporary library directory. This can be specified in the base configuration (conf/base.conf) or a default (tmplib/) is provided. Both are relative to the website directory.

This method does not care of the directory exists or not, it just creates the name.

Returns: fully-qualified directory

lookup_temp_lib_refresh_filename()

Relative name of file in the temporary library directory that is used (by OpenInteract2::Setup) to identify whether the directory needs refreshed. Normally this is 'refresh.txt'.

Returns: relative filename

lookup_override_action_filename()

Returns name of action global override file ('action_override.ini').

lookup_override_spops_filename()

Returns name of SPOPS global override file ('spops_override.ini').

lookup_session_config()

Returns 'session_info' section of server configuration (hashref).

lookup_login_config()

Returns 'login' section of server configuration (hashref).

lookup_mail_config()

Returns 'email' section of server configuration (hashref).

lookup_default_object_id( [ $name ] )

Returns the default object ID mapped to $name. If $name not given returns a hashref of all default object IDs.

lookup_id_config( [ $definition ] )

Returns the ID configuration to report what types of IDs basic OI objects are using. Normally we only care about 'user' and 'group', and we want to find out the 'type' or 'size'. So $definition will be one of 'user_type', 'user_size', 'group_type' and 'group_size'. If $definition is not given returns a hashref of all definitions.

lookup_config_watcher_config()

Looks up the configuration watcher configuration.

lookup_redirect_config()

Looks up the redirect configuration.

lookup_box_config()

Looks up the configuration for boxes, found in the 'box' section.

PROPERTIES ^

The following are simple get/set properties of the context object.

base_config: Holds the OpenInteract2::Config::Base object. This must be defined for the context to be initialized.

server_config: Holds the OpenInteract2::Config::IniFile object with the server configuration. This will be defined after the context is initialized via setup().

repository: Holds the OpenInteract2::Repository object with methods for retrieving packages. This will be defined after the context is initialized via setup().

packages: Holds an arrayref of OpenInteract2::Package objects. These will be defined after the context is initialized via setup().

cache: Holds an object whose parent is OpenInteract2::Cache. This allows you to store and retrieve data rapidly. This will be defined (if configured) after the context is initialized via setup().

SEE ALSO ^

OpenInteract2::Action

OpenInteract2::Config::Base

OpenInteract2::Setup

OpenInteract2::URL

COPYRIGHT ^

Copyright (c) 2002-2004 Chris Winters. All rights reserved.

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

AUTHORS ^

Chris Winters <chris@cwinters.com>

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