Trait justconfig::source::Source

source · [−]
pub trait Source {
    fn get(&self, key: ConfPath) -> Option<StringItem>;
}
Expand description

Trait that must be implemented by configuration sources.

Required Methods

Get a configuration option.

This method is called by the configuration framework to retrieve the value for a configuration option. The configuration source must return Some(StringItem) with the StringItem containing the configuration value or None to signal that the item is not known to this configuration provider.

There is a special distinction between returning None and returning Some(StringItem) with an empty values vector.

  • Returning None lets the configuration system continue the search for an other configuration provider that may know about this value.
  • Returning Some(StringItem) will stop the search for other configuration providers and let the empty value travel down the pipeline.

Eventually returning None and Some(StringItem) with an empty values vector yields the same results.

See item for more Information.

Implementors