Filter example - read collection configuration options

The FilterContext includes a number of methods for accessing the data source configuration.

Set<String> getConfigKeys()

Gets the set of all configuration keys for data source the filter is running under.

Map<String, List<String>> getConfigKeysMatchingPattern(String pattern)

Provides config settings which match the given key pattern.

Set<String> getConfigKeysWithPrefix(String prefix)

Provides a list of config setting keys which have some prefix.

Optional<String> getConfigValue(String key):

Gets the value of the configuration setting for the data source the filter is running under.

public FilterResult filterAsStringDocument(StringDocument document, FilterContext context) {
    String color = context.getConfigValue(PluginUtils.KEY_PREFIX+".color").get(); (1)
    String library = Optional.ofNullable(this.setup.getConfigSetting(PluginUtils.KEY_PREFIX+".library")).orElse("British Library"); (2)"Color: "+color);"Library: "+library);
    return FilterResult.of(document);
1 Read the color variable from a configuration key.
2 Read the library variable from a configuration key, setting it to British Library if the configuration key is not set.