[service] enforce that Service argument and return are json-serialisable
The call_service API need to be able to run through RPC. So we ensure front
start that it is possible serialise both input and output.
Schema of the data
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First take a look at the data schema_ then try to remember that you are browsing
through a heap of data by applying stylesheets to the results of queries. This
site is not a content management system with items placed in folders. It is an
interface to a database which applies a view to retreived data.
.. _schema: schema