[PN/NH] Configuration schema

Niclas Hedhman niclas at hedhman.org
Mon Nov 1 02:28:13 EST 2004


Gang,

Peter initiated the concept of Configuration schema, validation of it and 
exposure of Conf schemas in blocks.

Upon further discussions, that led to;

*** Configuration schema is an API concern.  ***

Blocks can be seen as black boxes of functionality that one needs in a larger 
scope. But it is highly inefficient to look into the implementation of the 
components inside such a block to find the configuration required.
And that also will prevent the implementation in the blocks to change 
effectively, since that would then constitute an incompatible change, which 
we would like to avoid at almost all cost.

The solution we came to was that the Configuration schema should be declared 
together with the Service/API/semantic contract and be included in the API 
artifact. This could either be done by embedding the schema in the .xservice 
file or by naming convention such as <classfile>.xsd

Implementation specific configuration is independent of this, and treated in a 
separate mail.

Comments?


Cheers
Niclas

P.S.  "Configuration" above is not necessarily equivalent to the Configuration 
interface/instance passed over the Configurable interface, but more 
generically what information/data is required to be provided to the service 
for its proper functionality, incl. default values and explicit declaration 
requirements.

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