wayward / blueprint Goto Github PK

Methods are currently mapped to paths in the configuration in a fixed manner (by method name). Allow both:

– Overriding individual method's path, e.g. with an annotation: @Named("timeout") int getTimeout().
This poses a specific problem: paths with more than one component will need to be given either as arrays or as a string with delimiters. If using delimited strings, the delimiter must be appropriate for the configuration source, but this is a run-time concern and should not leak into the API. E.g. @Named("foo.bar.baz") is syntactically a 3-component path in Properties, but in XML it is a single tag name. Slashes ("/") would be appropriate for XML, but not necessarily for all other source types.

– Specifying the mapping strategy at creation time (one could be: build paths by stripping JavaBeans-style getter prefixes).

Methods inherited from child interfaces aren't mapped onto configuration keys. They should be.

Have a configuration source provider that parses command line arguments in some canonical form (e.g. -n|--name[=value]).

Sub-interface methods are instantiated even if the corresponding configuration key is missing. Find a way to signal to the user that there is nothing interesting under them (return null?) Make sure it doesn't play foul with validations and default values.

JSON, YAML, JDBC, … (most likely depends on #11)

Let the programmer specify custom deserializers for types not supported out-of-the-box.

Blueprint talks about "validation" in three different contexts:

• whether the configuration is syntactically correct;
• whether all the method calls from the blueprint interface will complete successfully;
• asserting that the validation constraints are met.

These three levels of validation need to be disentangled and offered as a choice to the user (with reasonable defaults).

Rework Source to expose a tree-like structure (node: { name, value, children }).
This will help write new Source impl's more easily.

Each proxy object is associated with a node in the configuration tree, but it can only access subnodes by name.
Provide proxy objects with an interface to:
– obtain the value associated with the current node ("here" value);
– collect all unclaimed keys in the current node ("&rest" map).

Updating and saving configuration objects for supported sources (e.g. readable files; not available for system properties, environment variables, etc.)

Allow attaching default values to methods. Specify the behavior when both default value and validation constraint(s) are given.