Source for MIME type interfaces

Some sample interfaces have been created in the zope.mimetype.tests module for use in this test. Let’s import them:

>>> from zope.mimetype.tests import (
...     ISampleContentTypeOne, ISampleContentTypeTwo)

The source should only include IContentTypeInterface interfaces that have been registered. Let’s register one of these two interfaces so we can test this:

>>> import zope.component
>>> from zope.mimetype.interfaces import IContentTypeInterface

>>> zope.component.provideUtility(
...     ISampleContentTypeOne, IContentTypeInterface, name="type/one")

>>> zope.component.provideUtility(
...     ISampleContentTypeOne, IContentTypeInterface, name="type/two")

We should see that these interfaces are included in the source:

>>> from zope.mimetype import source

>>> s = source.ContentTypeSource()

>>> ISampleContentTypeOne in s
>>> ISampleContentTypeTwo in s

Interfaces that do not implement the IContentTypeInterface are not included in the source:

>>> import zope.interface
>>> class ISomethingElse(zope.interface.Interface):
...    """This isn't a content type interface."""

>>> ISomethingElse in s

The source is iterable, so we can get a list of the values:

>>> values = list(s)

>>> len(values)
>>> values[0] is ISampleContentTypeOne

We can get terms for the allowed values:

>>> terms = source.ContentTypeTerms(s, None)
>>> t = terms.getTerm(ISampleContentTypeOne)
>>> terms.getValue(t.token) is ISampleContentTypeOne

Interfaces that are not in the source cause an error when a term is requested:

>>> terms.getTerm(ISomethingElse)
Traceback (most recent call last):
LookupError: value is not an element in the source

The term provides a token based on the module name of the interface:

>>> t.token

The term also provides the title based on the “title” tagged value from the interface:

>>> t.title
'Type One'

Each interface provides a list of MIME types with which the interface is associated. The term object provides access to this list:

>>> t.mimeTypes
['type/one', 'type/foo']

A list of common extensions for files of this type is also available, though it may be empty:

>>> t.extensions

The term’s value, of course, is the interface passed in:

>>> t.value is ISampleContentTypeOne

This extended term API is defined by the IContentTypeTerm interface:

>>> from zope.mimetype.interfaces import IContentTypeTerm
>>> IContentTypeTerm.providedBy(t)

The value can also be retrieved using the getValue() method:

>>> iface = terms.getValue('zope.mimetype.tests.ISampleContentTypeOne')
>>> iface is ISampleContentTypeOne

Attempting to retrieve an interface that isn’t in the source using the terms object generates a LookupError:

>>> terms.getValue('zope.mimetype.tests.ISampleContentTypeTwo')
Traceback (most recent call last):
LookupError: token does not represent an element in the source

Attempting to look up a junk token also generates an error:

>>> terms.getValue('')
Traceback (most recent call last):
LookupError: could not import module for token