55 

    56 

    57 def find_objects_matching(root, condition, ignore_root=False):

    58     """Find all objects in root that match the condition

    59 

    60     The condition is a Python callable object that takes an object as

    61     argument and must return a boolean result.

    62 

    63     All sub-objects of the root will also be searched recursively.

    64     """

    65     if (not ignore_root) and condition(root):

    66         yield root

    67     locations = ISublocations(root, None)

    68     if locations is not None:

    69         for location in locations.sublocations():

    70             if condition(location):

    71                 yield location

    72             for sublocation in find_objects_matching(location, condition, ignore_root=True):

    73                 yield sublocation

    74 

    75 

    76 def find_objects_providing(root, interface):

    77     """Find all objects in root that provide the specified interface

    78 

    79     All sub-objects of the root will also be searched recursively.

    80     """

    81     for match in find_objects_matching(root, interface.providedBy):

    82         yield match