from tableaudocumentapi.utils import _clean_aggregated_column_names

class Encoding(object):

"""A class representing one mark encoding on a worksheet pane.

Wraps a child element of <pane>/<encodings> (e.g. <color>, <text>,

<tooltip>, <size>, <lod>, <label>, <shape>, <detail>, <path>).

Channel name is pass-through from Tableau, so any tag emitted under

<encodings> is accepted.

"""

def __init__(self, encoding_xml):

self._xml = encoding_xml

self._channel = encoding_xml.tag

self._column = encoding_xml.get('column')

@property

def xml(self):

return self._xml

@property

def channel(self):

"""The visual channel tag name as emitted by Tableau."""

return self._channel

@property

def column(self):

"""The raw column reference (e.g. '[ds].[none:Country:nk]')."""

return self._column

@property

def datasource(self):

"""Datasource name extracted from the column reference, or None."""

if not self._column:

return None

ds, _ = _clean_aggregated_column_names(self._column)

return ds

@property

def field(self):

"""Field name extracted from the column reference, or None."""

if not self._column:

return None

_, field = _clean_aggregated_column_names(self._column)

return field