def iter_request_header_errors(self, request_headers):
"""
Validates individual request headers against the schema, yielding
a :class:`~spectastic.errors.FieldError` for each failure.
"""
header_schemas = self.header_schemas()
if len(header_schemas) == 0:
return
request_headers = Headers(request_headers)
for header, value in request_headers.iteritems():
if header in header_schemas:
schema = self.header_schema(header)
for error in self.validator.iter_errors(value, schema):
yield FieldError(error.message, 'header', header)
for name, schema in header_schemas.iteritems():
if schema.get('required') and name.lower() \
not in request_headers:
yield FieldError(
'Required header is missing',
'header',
schema.get('name')
)
