Ruby SDK Reference

Getting started

1. Install ConfigCat SDK

gem install configcat

2. Import the package

require 'configcat'

3. Create the ConfigCat client with your SDK Key

configcat_client = ConfigCat.create_client("#YOUR-SDK-KEY#")

4. Get your setting value

isMyAwesomeFeatureEnabled = configcat_client.get_value("isMyAwesomeFeatureEnabled", false)
if isMyAwesomeFeatureEnabled
    do_the_new_thing()
else
    do_the_old_thing()
end

5. Stop ConfigCat client

You can safely shut down the client instance and release all associated resources on application exit.

configcat_client.stop()

Creating the ConfigCat Client

ConfigCat Client is responsible for:

managing the communication between your application and ConfigCat servers.
caching your setting values and feature flags.
serving values quickly in a failsafe way.

create_client() returns a client with default options.

Properties	Description
`sdk_key`	REQUIRED. SDK Key to access your feature flags and configurations. Get it from ConfigCat Dashboard.
`data_governance`	Optional, defaults to `DataGovernance::GLOBAL`. Describes the location of your feature flag and setting data within the ConfigCat CDN. This parameter needs to be in sync with your Data Governance preferences. More about Data Governance. Available options: `GLOBAL`, `EU_ONLY`.

create_client_with_auto_poll(), create_client_with_lazy_load(), create_client_with_manual_poll()
Creating the client is different for each polling mode. See below for details.

caution

We strongly recommend you to use the ConfigCat Client as a Singleton object in your application. If you want to use multiple SDK Keys in the same application, create only one ConfigCat Client per SDK Key.

Anatomy of `get_value()`

Parameters	Description
`key`	REQUIRED. Setting-specific key. Set on ConfigCat Dashboard for each setting.
`default_value`	REQUIRED. This value will be returned in case of an error.
`user`	Optional, User Object. Essential when using Targeting. Read more about Targeting.

value = configcat_client.get_value(
    "keyOfMySetting", # Setting Key
    false, # Default value
    ConfigCat::User.new("435170f4-8a8b-4b67-a723-505ac7cdea92") # Optional User Object
);

User Object

The User Object is essential if you'd like to use ConfigCat's Targeting feature.

user_object = ConfigCat::User.new("435170f4-8a8b-4b67-a723-505ac7cdea92")

user_object = ConfigCat::User.new("[email protected]")

Parameters	Description
`identifier`	REQUIRED. Unique identifier of a user in your application. Can be any value, even an email address.
`email`	Optional parameter for easier targeting rule definitions.
`country`	Optional parameter for easier targeting rule definitions.
`custom`	Optional dictionary for custom attributes of a user for advanced targeting rule definitions. e.g. User role, Subscription type.

user_object = ConfigCat::User.new("435170f4-8a8b-4b67-a723-505ac7cdea92", email: '[email protected]', country: 'United Kingdom',
                custom: {'SubscriptionType': 'Pro', 'UserRole': 'Admin'})

Polling Modes

The ConfigCat SDK supports 3 different polling mechanisms to acquire the setting values from ConfigCat. After latest setting values are downloaded, they are stored in the internal cache then all get_value() calls are served from there. With the following polling modes, you can customize the SDK to best fit to your application's lifecycle.
More about polling modes.

Auto polling (default)

The ConfigCat SDK downloads the latest values and stores them automatically every 60 seconds.

Use the poll_interval_seconds option parameter to change the polling interval.

ConfigCat.create_client_with_auto_poll(
    "#YOUR-SDK-KEY#", poll_interval_seconds: 95);

Adding a callback to on_configuration_changed_callback option parameter will get you notified about changes.

def configuration_changed_callback()
    # Configuration changed.
end

ConfigCat.create_client_with_auto_poll("#YOUR-SDK-KEY#", on_configuration_changed_callback: method(:configuration_changed_callback));

Available options:

Option Parameter	Description	Default
`poll_interval_seconds`	Polling interval.	60
`max_init_wait_time_seconds`	Maximum waiting time between the client initialization and the first config acquisition in secconds.	5
`on_configuration_changed_callback`	Callback to get notified about changes.	-
`config_cache_class`	Custom cache implementation.	nil
`base_url`	Obsolete Optional, sets the CDN base url from where the sdk will download the configurations.	nil
`open_timeout`	The number of seconds to wait for the server to make the initial connection.	10
`read_timeout`	The number of seconds to wait for the server to respond before giving up.	30
`flag_overrides`	Local feature flag & setting overrides. More about feature flag overrides	nil

Lazy loading

When calling get_value() the ConfigCat SDK downloads the latest setting values if they are not present or expired in the cache. In this case the get_value() will return the setting value after the cache is updated.

Use cache_time_to_live_seconds option parameter to set cache lifetime.

ConfigCat.create_client_with_lazy_load(
    "#YOUR-SDK-KEY#", cache_time_to_live_seconds: 600);

Use a custom config_cache_class option parameter.

class InMemoryConfigCache < ConfigCat::ConfigCache
    def initialize()
        @_value = {}
    end

    def get(key)
       return @_value.fetch(key, nil)
    end

    def set(key, value)
       @_value[key] = value
    end
end

ConfigCat.create_client_with_lazy_load("#YOUR-SDK-KEY#", config_cache_class: InMemoryConfigCache);

Available options:

Option Parameter	Description	Default
`cache_time_to_live_seconds`	Cache TTL.	60
`config_cache_class`	Custom cache implementation.	nil
`base_url`	Obsolete Optional, sets the CDN base url from where the sdk will download the configurations.	nil
`open_timeout`	The number of seconds to wait for the server to make the initial connection.	10
`read_timeout`	The number of seconds to wait for the server to respond before giving up.	30
`flag_overrides`	Local feature flag & setting overrides. More about feature flag overrides	nil

Manual polling

Manual polling gives you full control over when the config.json (with the setting values) is downloaded. ConfigCat SDK will not update them automatically. Calling force_refresh() is your application's responsibility.

configcat_client = ConfigCat.create_client_with_manual_poll("#YOUR-SDK-KEY#");
configcat_client.force_refresh();

Available options:

Option Parameter	Description	Default
`config_cache_class`	Custom cache implementation.	nil
`base_url`	Obsolete Optional, sets the CDN base url from where the sdk will download the configurations.	nil
`open_timeout`	The number of seconds to wait for the server to make the initial connection.	10
`read_timeout`	The number of seconds to wait for the server to respond before giving up.	30
`flag_overrides`	Local feature flag & setting overrides. More about feature flag overrides	nil

get_value() returns default_value if the cache is empty. Call force_refresh() to update the cache.

configcat_client = ConfigCat.create_client_with_manual_poll("#YOUR-SDK-KEY#");
value = configcat_client.get_value("key", "my default value") # Returns "my default value"
configcat_client.force_refresh();
value = configcat_client.get_value("key", "my default value") # Returns "value from server"

Flag Overrides

With flag overrides you can overwrite the feature flags & settings downloaded from the ConfigCat CDN with local values. Moreover, you can specify how the overrides should apply over the downloaded values. The following 3 behaviours are supported:

Local/Offline mode (ConfigCat::OverrideBehaviour::LOCAL_ONLY): When evaluating values, the SDK will not use feature flags & settings from the ConfigCat CDN, but it will use all feature flags & settings that are loaded from local-override sources.
Local over remote (ConfigCat::OverrideBehaviour::LOCAL_OVER_REMOTE): When evaluating values, the SDK will use all feature flags & settings that are downloaded from the ConfigCat CDN, plus all feature flags & settings that are loaded from local-override sources. If a feature flag or a setting is defined both in the downloaded and the local-override source then the local-override version will take precedence.
Remote over local (ConfigCat::OverrideBehaviour::REMOTE_OVER_LOCAL): When evaluating values, the SDK will use all feature flags & settings that are downloaded from the ConfigCat CDN, plus all feature flags & settings that are loaded from local-override sources. If a feature flag or a setting is defined both in the downloaded and the local-override source then the downloaded version will take precedence.

You can set up the SDK to load your feature flag & setting overrides from a file or a hash.

JSON File

The SDK can be configured to load your feature flag & setting overrides from a file.

File

configcat_client = ConfigCat::ConfigCatClient.new(
    "#YOUR-SDK-KEY#",
    flag_overrides: ConfigCat::LocalFileDataSource.new(
        "path/to/the/local_flags.json",  # path to the file
        ConfigCat::OverrideBehaviour::LOCAL_ONLY  # local/offline mode
    )
)

JSON File Structure

The SDK supports 2 types of JSON structures to describe feature flags & settings.

1. Simple (key-value) structure

{
  "flags": {
    "enabledFeature": true,
    "disabledFeature": false,
    "intSetting": 5,
    "doubleSetting": 3.14,
    "stringSetting": "test"
  }
}

2. Complex (full-featured) structure

This is the same format that the SDK downloads from the ConfigCat CDN. It allows the usage of all features you can do on the ConfigCat Dashboard.

You can download your current config.json from ConfigCat's CDN and use it as a baseline.

The URL to your current config.json is based on your Data Governance settings:

GLOBAL: https://cdn-global.configcat.com/configuration-files/{YOUR-SDK-KEY}/config_v5.json
EU: https://cdn-eu.configcat.com/configuration-files/{YOUR-SDK-KEY}/config_v5.json

{
    "f": { // list of feature flags & settings
        "isFeatureEnabled": { // key of a particular flag
            "v": false, // default value, served when no rules are defined
            "i": "430bded3", // variation id (for analytical purposes)
            "t": 0, // feature flag's type, possible values: 
                    // 0 -> BOOLEAN 
                    // 1 -> STRING
                    // 2 -> INT
                    // 3 -> DOUBLE
            "p": [ // list of percentage rules
                { 
                    "o": 0, // rule's order
                    "v": true, // value served when the rule is selected during evaluation
                    "p": 10, // % value
                    "i": "bcfb84a7" // variation id (for analytical purposes)
                },
                {
                    "o": 1, // rule's order
                    "v": false, // value served when the rule is selected during evaluation
                    "p": 90, // % value
                    "i": "bddac6ae" // variation id (for analytical purposes)
                }
            ],
            "r": [ // list of targeting rules
                {
                    "o": 0, // rule's order
                    "a": "Identifier", // comparison attribute
                    "t": 2, // comparator, possible values:
                        // 0  -> 'IS ONE OF',
                        // 1  -> 'IS NOT ONE OF',
                        // 2  -> 'CONTAINS',
                        // 3  -> 'DOES NOT CONTAIN',
                        // 4  -> 'IS ONE OF (SemVer)',
                        // 5  -> 'IS NOT ONE OF (SemVer)',
                        // 6  -> '< (SemVer)',
                        // 7  -> '<= (SemVer)',
                        // 8  -> '> (SemVer)',
                        // 9  -> '>= (SemVer)',
                        // 10 -> '= (Number)',
                        // 11 -> '<> (Number)',
                        // 12 -> '< (Number)',
                        // 13 -> '<= (Number)',
                        // 14 -> '> (Number)',
                        // 15 -> '>= (Number)',
                        // 16 -> 'IS ONE OF (Hashed)',
                        // 17 -> 'IS NOT ONE OF (Hashed)'
                    "c": "@example.com", // comparison value
                    "v": true, // value served when the rule is selected during evaluation
                    "i": "bcfb84a7" // variation id (for analytical purposes)
                }
            ]
        },
    }
}

Hash

You can set up the SDK to load your feature flag & setting overrides from a hash.

dictionary = {
    "enabledFeature" => true,
    "disabledFeature" => false,
    "intSetting" => 5,
    "doubleSetting" => 3.14,
    "stringSetting" => "test"
}

configcat_client = ConfigCat::ConfigCatClient.new(
    "#YOUR-SDK-KEY#",
    flag_overrides: ConfigCat::LocalDictionaryDataSource.new(dictionary, ConfigCat::OverrideBehaviour::LOCAL_ONLY)
)

Logging

In the ConfigCat SDK there is a default logger writes logs to the standard output. The following example shows how to configure the Log Level of the default logger.

ConfigCat.logger.level = Logger::INFO

Available log levels:

Level	Description
ERROR	Only error level events are logged.
WARN	Default. Errors and Warnings are logged.
INFO	Errors, Warnings and feature flag evaluation is logged.
DEBUG	All of the above plus debug info is logged. Debug logs can be different for other SDKs.

Info level logging helps to inspect the feature flag evaluation process:

INFO -- : Evaluating get_value('isPOCFeatureEnabled').
User object:
{
    "Identifier" : "435170f4-8a8b-4b67-a723-505ac7cdea92",
    "Email" : "[email protected]"
}
Evaluating rule: [Email] [CONTAINS] [@something.com] => no match
Evaluating rule: [Email] [CONTAINS] [@example.com] => match, returning: true

You can easily replace the default logger with your own one. The following example shows how to set a logger writes logs into a text file.

ConfigCat.logger = Logger.new('log.txt')

`get_all_keys()`

You can query the keys from your configuration in the SDK with the get_all_keys() method.

configcat_client = ConfigCat.create_client("#YOUR-SDK-KEY#")
keys = configcat_client.get_all_keys()

`get_all_values()`

Evaluates and returns the values of all feature flags and settings. Passing a User Object is optional.

Parameters	Description
`user`	Optional, User Object. Essential when using Targeting. Read more about Targeting.

configcat_client = ConfigCat.create_client("#YOUR-SDK-KEY#")
setting_values = configcat_client.get_all_values(ConfigCat::User.new("435170f4-8a8b-4b67-a723-505ac7cdea92"))  # Optional User Object

Using ConfigCat behind a proxy

Provide your own network credentials (username/password), and proxy server settings (proxy server/port) by passing the proxy details to the creator method.

configcat_client = ConfigCat::create_client_with_auto_poll("#YOUR-SDK-KEY#",
                                                           proxy_address: "127.0.0.1",
                                                           proxy_port: 8080,
                                                           proxy_user: "user",
                                                           proxy_pass: "password")

Sample Applications

Sample Console App

Getting started​

1. Install ConfigCat SDK​

2. Import the package​

3. Create the ConfigCat client with your SDK Key​

4. Get your setting value​

5. Stop ConfigCat client​

Creating the ConfigCat Client​

Anatomy of get_value()​

User Object​

Polling Modes​

Auto polling (default)​

Lazy loading​

Manual polling​

Flag Overrides​

JSON File​

File​

JSON File Structure​

1. Simple (key-value) structure​

2. Complex (full-featured) structure​

Hash​

Logging​

get_all_keys()​

get_all_values()​

Using ConfigCat behind a proxy​

Sample Applications​

Look under the hood​

Getting started

1. Install ConfigCat SDK

2. Import the package

3. Create the ConfigCat client with your SDK Key

4. Get your setting value

5. Stop ConfigCat client

Creating the ConfigCat Client

Anatomy of `get_value()`

User Object

Polling Modes

Auto polling (default)

Lazy loading

Manual polling

Flag Overrides

JSON File

File

JSON File Structure

1. Simple (key-value) structure

2. Complex (full-featured) structure

Hash

Logging

`get_all_keys()`

`get_all_values()`

Using ConfigCat behind a proxy

Sample Applications

Look under the hood