CAF tests: type property (barGenericStructure, barPath)

Attribute holding type of the feature delineated by given path. For example it can be like gray matter, white matter, single cell, ventricle, and other... This property tries to mimic INCF DAI feature attribute would be extended after establishing the INCF DAI common metadata set.

Tests

>>> import bar

Let’s create simple path:

>>> path = bar.barPath("structure_test00_test", "M 100 100 L 100 200 L 200 200 Z", "#00ff00")

By default, path has no type assigned:

>>> print path.type
None

We can assingn any consistent string as feature type:

>>> path.type="white-matter"

But inconsistent string will not work:

>>> path.type="invalid:  hite-mat ter"
Traceback (most recent call last):
AssertionError: Invalid feature type name provided: invalid:  hite-mat ter

Also, any non-string value (except None) will raise an exception:

>>> path.type= []
Traceback (most recent call last):
AssertionError: String or 'None' value expected
>>> path.type = None

Similarly as for single path, you can define the type attribute for the whole structure Let’s create exemplary structure and assign a type:

>>> structure = bar.barGenericStructure("test", "#00ff00")

By default, structure type property is also None:

>>> print structure.type
None

You can assign any reasonable string or None value:

>>> structure.type = "test-type"
>>> structure.type = None

But you cannot assign any other type than string or None:

>>> structure.type = ['dsf']
Traceback (most recent call last):
AssertionError: String or 'None' value expected

>>> structure.type = True
Traceback (most recent call last):
AssertionError: String or 'None' value expected

You can assign a path to a structure:

>>> structure.addPaths(path)

After that, their types match. Type from structure is copied to the all paths belonging to this structure.

>>> path.type, structure.type
(None, None)
>>> path.type == structure.type
True

After altering type of the structure, the type of its path is also altered:

>>> structure.type="test-type"

>>> path.type, structure.type
('test-type', 'test-type')
>>> path.type == structure.type
True

But it doesn’t work at the opposite direction:

>>> path.type = "other-type"

>>> path.type, structure.type
('other-type', 'test-type')
>>> path.type == structure.type
False

Thus after adding given path to the structure it is recommended to define type of the path indirectly - thought the structure. Type property is stored with CAF slide and can be loaded from XML.