Indexing
========

``p4a.ploneaudio`` provides various extensible indexes so that catalog searches
are more fine tuned.

SearchableText
--------------

We need to provide our own SearchableText index for getting in the audio
enhanced content for searching.

Begin by checking on a regular ATFile instance which cannot be adapted
to IAudio.  In this case the standard ``SearchableText`` behaviour should be
returned.

    >>> from p4a.ploneaudio import atct, indexing
    >>> from Products.ATContentTypes.content import file
    >>> from Products.MimetypesRegistry.MimeTypesRegistry \
    ...     import MimeTypesRegistry

    >>> basicfile = file.ATFile('basicfile')
    >>> basicfile.mimetypes_registry = MimeTypesRegistry()
    >>> indexing.SearchableText(basicfile, None)
    'basicfile '

First try a file that has had no genre set.  The resulting value will
be a unicode string that only contains the regular ``SearchableText`` content.

    >>> from zope import interface
    >>> from p4a.audio import interfaces

    >>> audiofile = file.ATFile('audiofile')
    >>> interface.alsoProvides(audiofile, interfaces.IAudio)
    >>> audiofile.obj = audiofile
    >>> audiofile.genre = None
    >>> audiofile.artist = u''
    >>> audiofile.SearchableText = lambda: 'hello world'
    >>> indexing.SearchableText(audiofile, None)
    u'hello world'

When a genre is set to it's numeric code, the indexed content will contain
the english-looking title of that genre.

    >>> audiofile.genre = 4
    >>> indexing.SearchableText(audiofile, None)
    u'hello world Disco'

Audio-specific Indexes
----------------------

There are various indexes for directly querying audio information.

The ``audio_genre_id`` function returns the numeric genre code.

    >>> indexing.audio_genre_id(audiofile, None)
    4

Of course that function will yield an AttributeError when used on an object
with no ``IAudio`` adapter.

    >>> indexing.audio_genre_id(basicfile, None)
    Traceback (most recent call last):
      ...
    AttributeError

The ``audio_artist`` function is used for retrieving artist info.

    >>> audiofile.artist = u'Rocky Burt'
    >>> indexing.audio_artist(audiofile, None)
    u'Rocky Burt'

Again, the ``audio_artist`` function will yield an AttributeError when used on
an object with no ``IAudio`` adapter.

    >>> indexing.audio_artist(basicfile, None)
    Traceback (most recent call last):
      ...
    AttributeError
