def process_url_params(params, columns):
"""
Converts a dictionary of parameters from the user to sql filters.
If a parameter is of the form <field name>-<suffix>, where suffix is
defined in `sql_directives`, the corresponding function is used to
produce a filter.
"""
# support passing `format` instead of `$format` so we don't break people's
# existing URLs. Let's remove this once we can.
format_ = params.get('$format', params.get('format', Format.UNZIPPED_CSV))
keyword_filters = {}
sql_filters = []
for key, value in params.items():
if key in ('$format', 'format'):
continue
for suffix, fn in sql_directives:
if key.endswith(suffix):
field = key[:-len(suffix)]
if field not in columns:
raise UserQueryError(_('No field named {}').format(field))
sql_filters.append(fn(columns[field], value))
break
else:
if key in columns:
keyword_filters[key] = value
else:
raise UserQueryError(
_('Invalid filter parameter: {}').format(key))
return ExportParameters(format_, keyword_filters, sql_filters)
def _range_filter(column, value):
try:
start, end = value.split('..')
except ValueError:
raise UserQueryError(_('Ranges must have the format "start..end"'))
return column.between(start, end)
def _last_n_days(column, value):
if not isinstance(column.type, (types.Date, types.DateTime)):
raise UserQueryError(_("You can only use 'lastndays' on date columns"))
end = datetime.date.today()
start = end - datetime.timedelta(days=int(value))
return column.between(start, end)