def make_select_fields(self, product, field_names, custom_offsets):
"""
Parse and generate the list of select fields to be passed to the database API.
"""
assert product and field_names
dataset_fields = product.metadata_type.dataset_fields
dataset_section = product.metadata_type.definition['dataset']
select_fields = []
for field_name in field_names:
if dataset_fields.get(field_name):
select_fields.append(dataset_fields[field_name])
else:
# try to construct the field
if field_name in {'transform', 'extent', 'crs', 'bounds'}:
grid_spatial = dataset_section.get('grid_spatial')
if grid_spatial:
select_fields.append(SimpleDocField(
'grid_spatial', 'grid_spatial', DATASET.c.metadata,
False,
offset=grid_spatial
))
elif custom_offsets and field_name in custom_offsets:
select_fields.append(SimpleDocField(
field_name, field_name, DATASET.c.metadata,
False,
offset=custom_offsets[field_name]
))
elif field_name == 'uris':
select_fields.append(Field('uris', 'uris'))
return select_fields
def as_expression(field: Field, value) -> Expression:
"""
Convert a single field/value to expression, following the "simple" conventions.
"""
if isinstance(value, Range):
return field.between(value.begin, value.end)
elif isinstance(value, list):
return OrExpression(*(as_expression(field, val) for val in value))
# Treat a date (day) as a time range.
elif isinstance(value, date) and not isinstance(value, datetime):
return as_expression(
field,
Range(datetime.combine(value, time.min.replace(tzinfo=tz.tzutc())),
datetime.combine(value,
time.max.replace(tzinfo=tz.tzutc()))))
return field == value