Named Group Flags

There are two sets of flags that control how named groups and members of named groups may be copied or propagated …

• NamedGroupFlags: The NamedGroupFlags structure holds settings for the NamedGroup as a whole. The members are public and can be manipulated directly
• NamedGroupMemberFlags: The Flags stored for each member of a NamedGroup. The members are public, so they can be manipulated directly.

Use NamedGroupFlags when you create a named group. NamedGroupFlags() instantiates a new NamedGroupFlags with default values of false for allowDuplicates, exclusiveMembers, allowFarReferences, closed, selectMembers, and anonymous …

flags = NamedGroupFlags()

Use NamedGroupMemberFlags when you add members to a named group. NamedGroupMemberFlags() instantiates a new NamedGroupMemberFlags with default values …

flags = NamedGroupMemberFlags()

Call AddMember() to add a new element to a named group. The new member is granted the default NamedGroupMemberFlags. GetFlags() and SetFlags() give you the option to change flags later.

Named Group Flags Documentation

The Python API documentation for the named group flags omits essential information: the flags themselves are not documented. As revealed on the MicroStation Programming Forum, you can ask Python to reveal the documentation in the source code. Thanks to Bentley Systems staffer YongAn Fu for helping with that missing information.

The flag names differ slightly from their source in the C++ MicroStationAPI …

# NamedGroupFlags
AllowDuplicates
AllowFarReferences
Anonymous
Closed
ExclusiveMembers
SelectMembers

# NamedGroupMemberFlags
BackwardPropagate
ForwardPropagate
GroupPropagate

Translate Named Group Flags for JSON

JSON doesn't understand custom classes such as NamedGroupFlags. We must translate an instance of NamedGroupFlags to something that JSON does understand, such as an int.

Two functions are provided that translate NamedGroupFlags to an int and translate an int to NamedGroupFlags. You'll find them in the Named Group Proxy module. Thanks to Bentley Systems staffer YongAn Fu for writing those functions …

def NamedGroupFlags_to_int(cls, flags: NamedGroupFlags) -> int:
	'''
	Class method interprets NamedGroupFlags as an integer.
	'''
	value = 0
	if flags.AllowDuplicates:
		value |= 1 << 0
	if flags.ExclusiveMembers:
		value |= 1 << 1
	if flags.AllowFarReferences:
		value |= 1 << 2
	if flags.Closed:
		value |= 1 << 3
	if flags.SelectMembers:
		value |= 1 << 4
	if flags.Anonymous:
		value |= 1 << 5
	return value

def int_to_NamedGroupFlags(cls, value: int) -> NamedGroupFlags:
	'''
	Class method interprets an integer as NamedGroupFlags.
	'''
	flags = NamedGroupFlags()
	flags.AllowDuplicates = bool(value & (1 << 0))
	flags.ExclusiveMembers = bool(value & (1 << 1))
	flags.AllowFarReferences = bool(value & (1 << 2))
	flags.Closed = bool(value & (1 << 3))
	flags.SelectMembers = bool(value & (1 << 4))
	flags.Anonymous = bool(value & (1 << 5))
	return flags

Questions

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