Namespaces

Namespace inheritance

The default namespace of any element is an empty namespace. Functions paxb.field(), paxb.model(), paxb.wrapper() and paxb.nested() have a ns argument which alters the default (empty) namespace by a passed one. Compare two examples:

>>> import paxb as pb
>>>
>>> @pb.model
... class User:
...     name = pb.field()
...     surname = pb.field()
...
>>> user = User(name='Alex', surname='Ivanov')
>>>
>>> pb.to_xml(user)
b'<User><name>Alex</name><surname>Ivanov</surname></User>'

>>> import paxb as pb
>>>
>>> @pb.model(ns='test1')
... class User:
...     name = pb.field(ns='test2')
...     surname = pb.field(ns='test3')
...
>>> user = User(name='Alex', surname='Ivanov')
>>>
>>> pb.to_xml(user, ns_map={
...     'test1': 'http://test1.org',
...     'test2': 'http://test2.org',
...     'test3': 'http://test3.org',
... })
b'<test1:User xmlns:test1="http://test1.org" xmlns:test2="http://test2.org" xmlns:test3="http://test3.org"><test2:name>Alex</test2:name><test3:surname>Ivanov</test3:surname></test1:User>'

The ns_map argument describes a mapping from a namespace prefix to a full name that will be used during serialization and deserializaion.

The namespace of paxb.field(), paxb.wrapper() and paxb.nested() is inherited from the containing model if it is not declared explicitly. Look at the example:

from xml.dom.minidom import parseString
import paxb as pb

@pb.model
class Passport:                     # implicit namespace, will be inherited from a containing model
    series = pb.field()             # implicit namespace, the same as of Passport model
    number = pb.field(ns='test3')   # explicit namespace 'test3'

@pb.model(ns='test2')               # namespace 'test2' explicitly set for DrivingLicence and implicitly set for all contained elements
class DrivingLicence:               # explicit namespace 'test2'
    number = pb.field()             # implicit namespace 'test2'

@pb.model(ns='test1')               # namespace 'test1' explicitly set for User and implicitly set for all contained elements
class User:                         # explicit namespace 'test1'
    name = pb.field()               # implicit namespace 'test1'
    surname = pb.field(ns='test2')  # explicit namespace 'test2'

    passport = pb.nested(Passport)                 # default namespace for the contained model Passport will be set to 'test1'
    driving_licence = pb.nested(DrivingLicence)    # default namespace for the contained model DrivingLicence will be set to 'test1'

passport = Passport(series="5425", number="541125")
licence = DrivingLicence(number="673457")
user = User(name='Alex', surname='Ivanov', passport=passport, driving_licence=licence)

xml = pb.to_xml(user, ns_map={
    'test1': 'http://test1.org',
    'test2': 'http://test2.org',
    'test3': 'http://test3.org',
}, encoding='unicode')
print(parseString(xml).toprettyxml(indent=' ' * 4), end='')

Output:

<?xml version="1.0" ?>
<test1:User xmlns:test1="http://test1.org" xmlns:test2="http://test2.org" xmlns:test3="http://test3.org">
    <test1:name>Alex</test1:name>
    <test2:surname>Ivanov</test2:surname>
    <test1:Passport>
        <test1:series>5425</test1:series>
        <test3:number>541125</test3:number>
    </test1:Passport>
    <test2:DrivingLicence>
        <test2:number>673457</test2:number>
    </test2:DrivingLicence>
</test1:User>