Package org.apache.tapestry5.ioc.services

## Interface SymbolProvider

- All Known Implementing Classes:
    `ClasspathResourceSymbolProvider`, `ContextResourceSymbolProvider`, `DelegatingSymbolProvider`, `MapSymbolProvider`, `ResourceSymbolProvider`, `ServletContextSymbolProvider`, `SingleKeySymbolProvider`, `SystemEnvSymbolProvider`, `SystemPropertiesSymbolProvider`

      @UsesMappedConfiguration(java.lang.String.class)
      public interface SymbolProvider

  A provider of values for symbols, used by the `SymbolSource` service. This is the service interface for the FactoryDefaults and ApplicationDefaults services; each of these takes a configuration mapping symbols to their values.
  See Also:
    `FactoryDefaults`, `ApplicationDefaults`

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `String` | `valueForSymbol​(String symbolName)` | Returns the value for the symbol, or null if this provider can not provide a value.

- - ### Method Detail

    - #### valueForSymbol

          String valueForSymbol​(String symbolName)

      Returns the value for the symbol, or null if this provider can not provide a value. The value itself may contain symbols that will be recursively expanded.
      Parameters:
        `symbolName` -
      Returns:
        the value or null