maxon.GraphAttributeInterface¶

Description¶

A graph attribute provides extra information about an attribute of nodes and ports.
Attributes are identified and accessed only by an InternedId which carries no extra information about the attribute.
If a GraphModelInterface wants to provide additional information for an attribute, its GraphModelInterface.GetGraphAttribute() returns
a graph attribute to get that information (such as the attribute :maxon.GraphAttributeInterface.FLAGS).

Inheritance diagram¶

Inheritance

Parent Class:

maxon.ObjectInterface

Child Class:

maxon.GraphAttribute

Methods Signature¶

`GetFlags`()	Returns the flags of this attribute.
`GetId`()	Returns the id of this attribute.
`GetMessageFlags`(node)	Returns the message flags of the attribute value at node.
`GetMessages`(node, receiver)	Yields the messages of this attribute at node to receiver.
`IsComputedFrom`(other)	Checks for a FLAGS.DERIVED “derived” attribute if its value is computed

Methods Definition¶

GraphAttributeInterface.GetFlags()¶

Returns the flags of this attribute.

Note

If FLAGS.ERROR or FLAGS.WARNING is set, this means that the attribute can contain an error or warning, however a check for a concrete node using GraphAttributeInterface.GetMessageFlags() has to be done to test if the value of the attribute at that node really contains an error or warning.

Note

Usually you shouldn’t call this method directly, but use GraphNode.GetGraphAttributeFlags().

Return type: maxon.GraphAttributeInterface.FLAGS
Returns: Flags of this attribute.

GraphAttributeInterface.GetId()¶

Returns the id of this attribute.

Return type: maxon.InternedId
Returns: Id of this attribute.

GraphAttributeInterface.GetMessageFlags(node)¶

Returns the message flags of the attribute value at node.

An attribute which may contain an error or warning according to GraphAttributeInterface.GetFlags() doesn’t necessarily have to do so, you have to test for a concrete node if the value of the attribute at that node really contains an error or warning.

Note

Usually you shouldn’t call this method directly, but use GraphNode.GetGraphAttributeFlags().

Parameters: node (maxon.GraphNode) – A node or port where the message flags of this attribute shall be checked.
Returns: Message flags (maxon.GraphAttributeInterface.FLAGS.WARNING, maxon.GraphAttributeInterface.FLAGS.ERROR) of this attribute at node.
Return type: maxon.GraphAttributeInterface.FLAGS

GraphAttributeInterface.GetMessages(node, receiver)¶

Yields the messages of this attribute at node to receiver.

Note

Usually you shouldn’t call this method directly, but use GraphNode.GetMessages().

Parameters

node (maxon.GraphNode) – A node or port at which the messages shall be obtained.
receiver (Callable[[maxon.GraphMessage], bool]) – All messages are reported to this receiver.

Returns

False if the receiver cancelled further evaluation, True otherwise.

GraphAttributeInterface.IsComputedFrom(other)¶

Checks for a FLAGS.DERIVED “derived” attribute if its value is computed
on-the-fly and needs the value of #other for that computation.
A derived attribute may store its value in the graph, or it may compute it on-the-fly.
In the latter case you can check the required attributes with this method.

Note

This is important e.g. when you check for attribute modifications using GraphNodeFunctions.GetAttributeModificationsSince()

You only get notified about changes of stored attribute values.

Parameters: other (maxon.InternedId) – Another attribute.
Returns: True if other is the same as #this, or if this is a computed attribute which needs #other to compute its value.