from xml.sax.saxutils import XMLGenerator
from io import StringIO
from .exceptions import SerializationException
class XMLSerializer:
"""Serializes data to XML"""
def __init__(self):
self.generator = None
def serialize(self, data):
"""
Serializes data to XML so that it can be
sent to backend, if data is not a dictionary
raises a SerializationException
Params:
`data`: A dictionary containing the data to serialize
Return:
`xml`: Returns a string containing data serialized to XML
"""
if not isinstance(data, dict):
raise SerializationException("Can't serialize data, must be a dictionary.")
stream = StringIO()
self.generator = XMLGenerator(stream, "utf-8")
self.generator.startDocument()
self.generator.startElement("request", {})
self._parse(data)
self.generator.endElement("request")
self.generator.endDocument()
return stream.getvalue()
def _parse(self, data, previous_element_tag=None):
"""
Parses data and creates the relative elements
Params:
`data`: Data to parse
`previous_element_tag`: When parsing a list we pass the previous element tag
"""
if isinstance(data, dict):
for key in data:
value = data[key]
self._parse(value, key)
elif isinstance(data, (list, tuple)):
for item in data:
self.generator.startElement(previous_element_tag, {})
self._parse(item, previous_element_tag)
self.generator.endElement(previous_element_tag)
else:
self.generator.startElement(previous_element_tag, {})
self.generator.characters("%s" % data)
self.generator.endElement(previous_element_tag)
