https://github.com/sbabcoc/settings

The SettingsCore class extends CompositeConfiguration, using the facilities provided by this class to produce an aggregated configuration.
https://github.com/sbabcoc/settings

apache-configuration configuration configuration-file default-value settings system-properties

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The SettingsCore class extends CompositeConfiguration, using the facilities provided by this class to produce an aggregated configuration.

• Host: GitHub
• URL: https://github.com/sbabcoc/settings
• Owner: sbabcoc
• License: apache-2.0
• Created: 2017-11-17T23:46:27.000Z (about 7 years ago)
• Default Branch: master
• Last Pushed: 2023-02-05T04:10:41.000Z (about 2 years ago)
• Last Synced: 2023-09-22T06:45:05.081Z (over 1 year ago)
• Topics: apache-configuration, configuration, configuration-file, default-value, settings, system-properties
• Language: Java
• Homepage:
• Size: 130 KB
• Stars: 2
• Watchers: 5
• Forks: 1
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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# SettingsCore

### Composition of configurations

The **SettingsCore** class extends [CompositeConfiguration](https://commons.apache.org/proper/commons-configuration/apidocs/org/apache/commons/configuration2/CompositeConfiguration.html), using the facilities provided by this class to produce an aggregated configuration from three sources in the following order of precedence: 

1. System properties

2. (optional) Stored properties, typically from a properties file

3. (optional) Default values, typically specified in the enumeration

### Declaring stored properties

To specify stored properties for your configuration, override one of following methods:

* **`getStoredConfig`** - Your implementation returns a populated [Configuration](https://commons.apache.org/proper/commons-configuration/apidocs/org/apache/commons/configuration2/Configuration.html) object.

* **`getInputStream`** - Your implementation returns an input stream supplying key/value pairs.

* **`getSettingsUrl`** - Your implementation returns the URL from which to load your settings.

* **`getSettingsPath`** - Your implementation returns the path from which to load your settings.

> **NOTE**: These methods are listed in order of evaluation, which stops at the first non-null response.  

> **NOTE**: Typical implementations override **`getSettingsPath`**, which will support most scenarios.  

> **NOTE**: Stored properties are declared in Apache's extended syntax. See [PropertiesConfiguration](https://commons.apache.org/proper/commons-configuration/apidocs/org/apache/commons/configuration2/PropertiesConfiguration.html) for details.  

> **NOTE**: By overriding the **`getStoredConfig`** method, you're able to incorporate any arbitrary [Configuration](https://commons.apache.org/proper/commons-configuration/apidocs/org/apache/commons/configuration2/Configuration.html) object you need into your settings - including another [CompositeConfiguration](https://commons.apache.org/proper/commons-configuration/apidocs/org/apache/commons/configuration2/CompositeConfiguration.html) object.

### Specifying default values

Two methods have been provided for you to supply default values for your configuration:

* Specify default values as arguments of the constant declarations in your settings enumeration and override the **`SettingsAPI.val`** method. Specifying _'null'_ for a setting's default value indicates that no default exists.

* Alternatively, you can override the **`getDefaults`** method with your own implementation.

> **NOTE**: For settings collections with no default values, you can eliminate unnecessary processing in the core API by overriding **`getDefaults`** with a method that simply returns _'null'_.

It can be advantageous to create a hybrid of these two approaches - default values declared in the settings enumeration augmented by scenario-specific values produced by an override of the **`getDefaults`** method. You can see an example of this strategy in the [Selenium Foundation](https://github.com/sbabcoc/Selenium-Foundation) project. The settings defined in this project include default values that are specific to the target **Selenium** API version:

* [Core Configuration](https://github.com/sbabcoc/Selenium-Foundation/blob/master/src/main/java/com/nordstrom/automation/selenium/AbstractSeleniumConfig.java#L498)

* [Selenium 3 Specific](https://github.com/sbabcoc/Selenium-Foundation/blob/master/src/selenium3/java/com/nordstrom/automation/selenium/SeleniumConfig.java#L219)

### Declaring configuration settings

Implementations of **SettingsCore** supply a context-specific enumeration (which extends **Enum<T>**) to provide the collection of settings needed in this context. This enumeration must implement the **SettingsAPI** interface to provide clients with a common method for retrieving configuration keys and to give the core settings implementation access to the constants and default values of the enumeration.

### Configuration examples

For example implementations of **SettingsCore**, check out this project's units tests. These demonstrate all of the major features of the API, including:

* Declaration of settings and default values

* Declaration and formatting of backing files

* Extraction of typed data

* Declaration of lists of values

* Overrides of stored and default values

* Configurable inclusion of sub-configurations