def convert(type, input, output, **kwargs):
"""
Convert data from one format to another.
:param type: The type specifier string of the input data.
:param input: A binding dict of the form
``{"format": format, "data", data}``, where ``format`` is the format
specifier string, and ``data`` is the raw data to convert.
The dict may also be of the form
``{"format": format, "uri", uri}``, where ``uri`` is the location of
the data (see :py:mod:`romanesco.uri` for URI formats).
:param output: A binding of the form
``{"format": format}``, where ``format`` is the format
specifier string to convert the data to.
The binding may also be in the form
``{"format": format, "uri", uri}``, where ``uri`` specifies
where to place the converted data.
:returns: The output binding
dict with an additional field ``"data"`` containing the converted data.
If ``"uri"`` is present in the output binding, instead saves the data
to the specified URI and
returns the output binding unchanged.
"""
if "data" not in input:
input["data"] = romanesco.io.fetch(input, **kwargs)
if input["format"] == output["format"]:
data = input["data"]
else:
data_descriptor = input
for c in converter_path(Validator(type, input['format']),
Validator(type, output['format'])):
result = romanesco.run(c, {"input": data_descriptor},
auto_convert=False, **kwargs)
data_descriptor = result["output"]
data = data_descriptor["data"]
if "mode" in output:
romanesco.io.push(data, output)
else:
output["data"] = data
return output
def test_converter_path(self):
# There is no path from validators that don't exist
with self.assertRaises(NetworkXNoPath):
converter_path(Validator('foo', 'bar'),
Validator('foo', 'baz'))
# There is no path for types which lie in different components
with self.assertRaises(NetworkXNoPath):
converter_path(self.stringTextValidator,
Validator('graph', 'networkx'))
self.assertEquals(converter_path(self.stringTextValidator,
self.stringTextValidator), [])
# There is a direct path from converting between these types
self.assertEquals(len(converter_path(self.stringTextValidator,
Validator('string', 'json'))), 1)
