Extension Point: Setting Value Retrieval

Basics

Parameter	Value
Extension Point Key	SETTING_VALUE_RETRIEVAL
Extension Point Name	Retrieve setting values
Extension Interface	SettingValueRetrievalStrategy
Supports Multiple Extensions?	Yes
Selector Type	None
Available Since	1.0.0

Use Cases

Extensions implementing this Extension Point can retrieve setting values from a source outside the Elastic Path database. For example, sensitive values could be retrieved from a secrets management service, or environment-specific values could be retrieved from a configuration vault.

Methods

getSettingValue

The getSettingValue method is invoked whenever Elastic Path Commerce code requests a setting value through SettingValueProvider. Each SettingValueRetrievalStrategy is invoked in priority order. The first strategy method that returns a present XPFSettingValue "wins" and the value is used. If the strategy method returns a non-present result, then the next SettingValueRetrievalStrategy is executed. If no SettingValueRetrievalStrategy extensions return a result, then an exception is thrown.

There is an embedded extension named DBSettingValueRetrievalStrategy with priority 50 that will attempt to read the setting value from the database using the SettingsService.

note

Settings retrieved through SettingsReader or SettingsService read directly from the database and do not invoke this Extension Point.

Extension Sample

@Extension
@XPFAssignment(extensionPoint = XPFExtensionPointEnum.SETTING_VALUE_RETRIEVAL, priority = 100)
public class PropertyFileSettingValueRetrievalStrategy extends XPFExtensionPointImpl implements SettingValueRetrievalStrategy {
    private static final String COMMA_DELIMITER = ",";
    private static final String PROPERTY_FILE_SETTING_NAME = "PROPERTIES_FILE_LOCATION";
    private static final String DEFAULT_PROPERTIES_FILE = "/ep/settings.properties";
    private static final int ARRAY_INDEX_VALUE = 0;
    private static final int ARRAY_INDEX_DATA_TYPE = 1;

    private String propertiesFilePath;

    @Override
    public void initialize(final XPFExtensionInitializationContext context) {
        Optional<XPFPluginSetting> settingOptional =
            Optional.ofNullable(context.getSettings().get(PROPERTY_FILE_SETTING_NAME));

        propertiesFilePath = settingOptional
            .map(XPFPluginSetting::getSettingValues)
            .map(xpfPluginSettingValues -> xpfPluginSettingValues.get(0))
            .map(XPFPluginSettingValue::getShortTextValue)
            .orElse(DEFAULT_PROPERTIES_FILE);
    }

    @Override
    public Optional<XPFSettingValue> getSettingValue(final XPFSettingValueRetrievalContext context) {
        Properties settings = new Properties();
        try (FileInputStream fis = new FileInputStream(System.getProperty("user.home") + propertiesFilePath)) {
            settings.load(fis);
        } catch (IOException e) {
            throw new XPFPluginRuntimeException("Could not load setting properties file ", e);
        }
        String settingValueTuple = settings.getProperty(context.getSettingPath());

        if (settingValueTuple == null) {
            return Optional.notPresent();
        }

        String[] propertyValues = StringUtils.split(settingValueTuple, COMMA_DELIMITER);
        return Optional.of(new XPFSettingValue(propertyValues[ARRAY_INDEX_VALUE],
            XPFSettingValueTypeEnum.valueForTypeKey(propertyValues[ARRAY_INDEX_DATA_TYPE])));
    }
}