/ 
App-Config-Chronicle-0.07
River stage zero No dependents
/ App::Config::Chronicle

NAME

App::Config::Chronicle - An OO configuration module which can be changed and stored into chronicle database.

SYNOPSIS

my $app_config = App::Config::Chronicle->new;

DESCRIPTION

This module parses configuration files and provides interface to access configuration information.

FILE FORMAT

The configuration file is a YAML file. Here is an example:

system:
  description: "Various parameters determining core application functionality"
  isa: section
  contains:
    email:
      description: "Dummy email address"
      isa: Str
      default: "dummy@mail.com"
      global: 1
    refresh:
      description: "System refresh rate"
      isa: Num
      default: 10
      global: 1
    admins:
      description: "Are we on Production?"
      isa: ArrayRef
      default: []

Every attribute is very intuitive. If an item is global, you can change its value and the value will be stored into chronicle database by calling the method save_dynamic.

SUBROUTINES/METHODS (LEGACY)

REDIS_HISTORY_TTL

The maximum length of time (in seconds) that a cached history entry will stay in Redis.

definition_yml

The YAML file that store the configuration

chronicle_reader

The chronicle store that configurations can be fetch from it. It should be an instance of Data::Chronicle::Reader. But user is free to implement any storage backend he wants if it is implemented with a 'get' method.

chronicle_writer

The chronicle store that updated configurations can be stored into it. It should be an instance of Data::Chronicle::Writer. But user is free to implement any storage backend he wants if it is implemented with a 'set' method.

chronicle_subscriber

The chronicle connection that can notify via callbacks when particular configuration items have a new value set. It should be an instance of Data::Chronicle::Subscriber.

refresh_interval

How much time (in seconds) should pass between check_for_update invocations until it actually will do (a bit heavy) lookup for settings in redis.

Default value is 10 seconds

check_for_update

check and load updated settings from chronicle db

Checks at most every refresh_interval unless forced with a truthy first argument

save_dynamic

Save dynamic settings into chronicle db

current_revision

Loads setting from chronicle reader and returns the last revision

It is more likely that you want "loaded_revision" in regular use

loaded_revision

Returns the revision loaded and served by this instance

This may not reflect the latest stored version in the Chronicle persistence. However, it is the revision of the data which will be returned when querying this instance

SUBROUTINES/METHODS ###################################################### ###### Start new API ######################################################

local_caching

If local_caching is set to the true then key-value pairs stored in Redis will be cached locally.

Calling update_cache will update the local cache with any changes from Redis. refresh_interval defines (in seconds) the minimum time between seqequent updates.

Calls to get on this object will only ever access the cache. Calls to set on this object will immediately update the values in the local cache and Redis.

update_cache

Loads latest values from data chronicle into local cache. Calls to this method are rate-limited by refresh_interval.

global_revision

Returns the global revision version of the config chronicle. This will correspond to the last time any of values were changed.

set

Takes a hashref of key->value pairs and atomically sets them in config chronicle

Example: set({key1 => 'value1', key2 => 'value2', key3 => 'value3',...});

get

Takes either - an arrayref of keys, gets them atomically, and returns a hashref of key->values, including the global_revision under the key '_global_rev'. - a single key (as a string), gets the value, and returns it directly. If a key has an empty value, it will return with undef.

For convenience a get with just a key string will return the value only.

Example: get(['key1','key2','key3',...]); Returns: {'key1' => 'value1', 'key2' => 'value2', 'key3' => 'value3',..., '_global_rev' => '<number>'}

Example: get(['key1']); Returns: {'key1' => 'value1', '_global_rev' => '<number>'}

Example: get('key1'); Returns: 'value1'

get_history

Retreives a past revision of an app config entry, where $rev is the number of revisions in the past requested. If the optional third argument is true then result of the query will be cached in Redis. This is useful if a certain revision will be needed repeatedly, to avoid excessive database access. By default this argument is 0. All cached revisions will become stale if the key is set with a new value.

Example: get_history('system.email', 0); Retrieves current version get_history('system.email', 1); Retreives previous revision get_history('system.email', 2); Retreives version before previous

subscribe

Subscribes to changes for the specified $key with the sub $subref called when a new value is set. The chronicle_writer must have publish_on_set enabled.

unsubscribe

Stops the sub $subref from being called when $key is set with a new value. The chronicle_writer must have publish_on_set enabled.

all_keys

Returns a list containing all keys in the config chronicle schema

dynamic_keys

Returns a list containing only the dynamic keys in the config chronicle schema

static_keys

Returns a list containing only the static keys in the config chronicle schema

get_data_type

Returns the data type associated with a particular key

get_default

Returns the default value associated with a particular key

get_description

Returns the default value associated with a particular key

get_key_type

Returns the key type associated with a particular key

BUILD

AUTHOR

Binary.com, <binary at cpan.org>

BUGS

Please report any bugs or feature requests to bug-app-config at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=App-Config. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

perldoc App::Config::Chronicle

You can also look for information at:

ACKNOWLEDGEMENTS

INHERITED METHODS

Moose::Object

BUILDALL, BUILDARGS, DEMOLISHALL, DOES, does, dump