Output Schema Plugins

Overview

pycsw allows for extending the implementation of output schemas to the core standard. outputschemas allow for a client to request metadata in a specific format (ISO, Dublin Core, FGDC, NASA DIF and Atom are default).

All outputschemas must be placed in the pycsw/plugins/outputschemas directory.

Requirements

pycsw/
  plugins/
  __init__.py # empty
  outputschemas/
    __init__.py # __all__ is a list of all provided outputschemas
    atom.py # default
    dif.py # default
    fgdc.py # default

Implementing a new outputschema

Create a file in pycsw/plugins/outputschemas, which defines the following:

• NAMESPACE: the default namespace of the outputschema which will be advertised
• NAMESPACE: dict of all applicable namespaces to outputschema
• XPATH_MAPPINGS: dict of pycsw core queryables mapped to the equivalent XPath of the outputschema
• write_record: function which returns a record as an lxml.etree.Element object

Add the name of the file to __init__.py:__all__. The new outputschema is now supported in pycsw.

Testing

New outputschemas must add examples to the Tester interface, which must provide example requests specific to the profile.