maxon.GraphNode¶

Description¶

A maxon.GraphNode represents a general node (g-node for short) in the hierarchy of a maxon.GraphModelInterface. There are five different kinds of such a node: It may be a true node, an input or output port or an input port list or output port list. A node may have attributes, and if it is a port, it may be connected to other ports. For a general overview, see maxon.GraphModelInterface.

Most functions of maxon.GraphNode can be used for all node kinds, some functions are specific for certain kinds (such as GraphNode.Connect() which is only supported for ports).

maxon.GraphNode holds a strong maxon.GraphModelRef reference on the graph, see GraphNode.GetGraph(). The node within the graph is referenced symbolically by a maxon.NodePath, see GraphNode.GetPath(). Therefore it is guaranteed for the referenced graph that it exists as long as the maxon.GraphNode, but not for the referenced node. Namely, a maxon.GraphNode can be in one of three states:

It may be a null value, then it doesn’t represent any node. GraphNode.IsNull() returns true in this state.
It may be a valid node in a graph (GraphNode.IsValid() returns true). GraphNode.GetGraph() returns the graph, GraphNode.GetPath() the path of the node, and all supported functions can be called.
It represents a node which doesn’t exist any longer. GraphNode.IsValid() returns false, but GraphNode.IsPopulated() still returns true. Also GraphNode.GetGraph() and GraphNode.GetPath() return valid values, but you can’t call any functions which would require access to the node. Such a state can be used to identify deleted nodes. A transition between the cases 2 and 3 can happen without this maxon.GraphNode being directly involved, namely when the graph is modified through another maxon.GraphNode and a node with the path of this maxon.GraphNode is added or removed.

Inheritance diagram¶

Inheritance

Parent Class:

Methods Signature¶

`AddPort`(name)	Adds a port to this node with the given id.
`AddPorts`(index, count)	Adds a number of variadic port instances to this variadic port.
`BeginTransactionImpl`([userData])
`ChangeValue`(attr, op, path, value)	Sets a part of the value of #attr to #value for this node.
`Connect`(target, args, *kwargs)	Connect this node with another node port.
`CopyConnectionsFrom`(source, direction, …)	Copies all connections of source to the port given by this `maxon.GraphNode`.
`CopyValuesFrom`(source, includeInner)	Copies all directly set attribute values of source to this node.
`FindChild`(idOrNodeKind)	Finds the child of this node whose kind matches the given mask.
`FindInnerNode`(relativePath)	Finds the inner child of this node with the given relative path.
`GetAncestor`(mask)	Returns the closest ancestor node of this node (possibly this node itself) whose kind matches the given mask.
`GetAttributeModificationsSince`(stamp, receiver)	Reports all attribute modifications which have been made for this node since the given stamp to the receiver.
`GetAttributeStamp`(attr)	Returns the modification stamp of the given attribute for this node.
`GetChildren`([callback, mask])	Gets all children of this node.
`GetConnectionStamp`(direction)	Returns the modification stamp of incoming/outgoing connections for this port.
`GetConnectionValue`(target, position, attr[, …])	Gets the value of the given attribute for the connection from this port to target.
`GetConnectionValues`(target, receiver)	Gets all attribute values of the connection from this port to target.
`GetConnections`(pDir[, conns, mask, mode])	Yields all connections of this port for the given direction dir.
`GetConstantValue`()	Returns the constant value of this port.
`GetDefaultValue`()	Returns the default value of this port.
`GetGraph`()	Returns the graph to which this node belongs.
`GetHashCode`()	Returns the hash code of `maxon.GraphNode`.
`GetId`()	Returns the identifier of this node.
`GetInnerNodes`(mask, includeThis[, receiver])	Yields all inner nodes of this node matching #mask in pre-order.
`GetInputs`()	Returns the input port list of this node.
`GetKind`()	Returns the kind of this node.
`GetMessageFlags`(attr)	Returns the message flags of the given attribute at this node.
`GetMessages`(attr, receiver)	Yields the error or warning messages (if any) of the given attribute at this node to receiver.
`GetOutputs`()	Returns the output port list of this node.
`GetParent`()	Returns the parent of this node.
`GetPath`()	Returns the path of this node.
`GetPortList`(dir)	Returns the input or output port list of this node, depending on dir.
`GetStoredValue`(attr[, expectedType])	Gets the current value of the given attribute for this node, REGARDLESS of whether it is valid or not.
`GetValue`(attr[, expectedType])	Gets the value of the given attribute attr for this node.
`GetValues`(mask, graphAttrMap)	Gets all attribute values of this node.
`GetWires`(target)	Returns the Wires from this node to #target.
`InheritValue`(attr)	Restores the inherited state of the value for attr.
`IsInner`()	Checks if this `maxon.GraphNode` belongs to an inner node of the graph.
`IsPopulated`()	Checks whether this `maxon.GraphNode` has graph and path references.
`IsValid`()	Checks whether this GraphNode points to a valid node.
`Remove`()	Removes this node from the graph.
`RemoveConnections`(pDir, mask)	Removes all connections of this port in the given direction which match the given mask.
`RemovePorts`(ports)	Removes a number of variadic port instances from this variadic port.
`RemoveValue`(attr)	Removes an attribute value from this node.
`Reset`()	Resets this `maxon.GraphNode` to the state it has right after default construction.
`SetConnectionValue`(target, position, attr, value)	Sets the value of attr to value for the connection from this port to target.
`SetDefaultValue`(value)	Sets the value of the attribute `maxon.DESCRIPTION.DATA.BASE.DEFAULTVALUE` (maxon.Id(“default”)) to value for this port.
`SetValue`(attr, value[, checkAndInvalidate])	Sets the value of attr to value for this node.
`TouchValue`(attr)	Marks the value of attr as modified without actually modifying it.
`__eq__`(other)	Checks if two nodes are representing the same node in a graph.
`__init__`([src])	Initializes a node from a graph.
`__ne__`(other)	Checks if two nodes are not representing the same node in a graph.

Methods Definition¶

GraphNode.AddPort(name)¶

Adds a port to this node with the given id.

This node has to be a port list or a port itself.

Parameters: name (Union[str, maxon.String, maxon.Id]) – The identifier for the new port.
Returns: The added port.
Return type: maxon.GraphNode

GraphNode.AddPorts(index, count)¶

Adds a number of variadic port instances to this variadic port.

This is more efficient than a repeated call to GraphNode.AddPort().

Warning

It is an error if this GraphNode is no variadic port.

Parameters

index (int) – The index within the current list of variadic port instances where the new instances shall be added.
count (int) – The number of instances to add.

Returns

The newly added port instances as an array.

Return type

maxon.GraphNode

GraphNode.BeginTransactionImpl(userData=None)¶

GraphNode.ChangeValue(attr, op, path, value)¶

Sets a part of the value of #attr to #value for this node.

Parameters

attr (Union[str, maxon.String, maxon.Id, maxon.InternedId]) – The attribute whose value shall be set.
op (maxon.SubDataOperation) – The SubDataOperation to use.
path (maxon.SubDataPathBlock) – The path to the part of the attribute value which shall be changed.
value (maxon.Data) – The new value for the part.

GraphNode.Connect(target, *args, **kwargs)¶

Connect this node with another node port.

Only one of this calls is allowed: - Connect(target, modes=WIRE_MODE.NORMAL, reverse=False) - Connect(target, portId)

Parameters

target (maxon.GraphNode) – The node to connect to
modes (Union[maxon.Wires, maxon.WIRE_MODE]) – The type to use for the connection.
reverse (bool) – If true the direction is reversed (from target to this port).
portId (Union[maxon.InternedId, maxon.Id]) – The port’s id to be found.

GraphNode.CopyConnectionsFrom(source, direction, includeInner)¶

Copies all connections of source to the port given by this maxon.GraphNode.

For each connection of source to a port in the given direction, a corresponding port in this graph is searched (based on the relative path) and, if it exists, a connection to that port is created.

Parameters

source (maxon.GraphNode) – Another maxon.GraphNode port, may stem from a different graph.
direction (maxon.PORT_DIR) – The direction of connections to copy.
includeInner (bool) – If True, copies connections for all inner nodes, too.

GraphNode.CopyValuesFrom(source, includeInner)¶

Copies all directly set attribute values of source to this node.

This excludes derived attribute values as well as attribute values which are inherited from a base.

Parameters

source (maxon.GraphNode) – Another maxon.GraphNode, may stem from a different graph.
includeInner (bool) – If True, copies attribute values for all inner nodes, too.

GraphNode.FindChild(idOrNodeKind)¶

Finds the child of this node whose kind matches the given mask.
If no such child can be found, a null node is returned.
If there is more than one matching child, an error is returned.

Parameters: idOrNodeKind (Union[str, maxon.String, maxon.InternedId, maxon.Id]) – A particual Id of a node or mask kind to look for.
Returns: A direct child of this node which matches the given mask, or a null node if no such child exists.
Return type: maxon.GraphNode

GraphNode.FindInnerNode(relativePath)¶

Finds the inner child of this node with the given relative path.

Note

If no such child can be found, a null node is returned.

Parameters: relativePath (Union[maxon.NodePath, str]) – The relative path of the child to find, starting at this node.
Returns: The inner child of this node with the given relativePath, or a null node if no such child exists.
Return type: maxon.GraphNode

GraphNode.GetAncestor(mask)¶

Returns the closest ancestor node of this node (possibly this node itself) whose kind matches the given mask.

i.e., the function goes upwards in the hierarchy until it finds a matching node.

Parameters: mask (maxon.NODE_KIND) – Mask for the kind of node to look for.
Returns: Closest ancestor of this node matching the given mask, may be this node itself or a null node.
Return type: maxon.GraphNode

GraphNode.GetAttributeModificationsSince(stamp, receiver)¶

Reports all attribute modifications which have been made for this node since the given stamp to the receiver.

Only stored attributes will be reported, so to also check for new values of computed attributes you should use GraphAttributeInterface.IsComputedFrom().

See also

GraphModelInterface.GetModificationsSince()

Parameters

stamp (maxon.TimeStamp) – A reference time stamp. Only modifications newer than this stamp are reported.
receiver (Callable[[maxon.InternedId, maxon.Data], bool]) – Modifications are reported to this receiver as a pair of the attribute identifier and the current value.

Returns

False if the receiver cancelled further evaluation, True otherwise.

Return type

bool

GraphNode.GetAttributeStamp(attr)¶

Returns the modification stamp of the given attribute for this node.

This is the value of the graph’s time stamp (see GraphModelInterface.GetModificationStamp()) at the time when the attribute value has been set last for this node, or a null value if it hasn’t been set at all.

Parameters: attr (Union[str, maxon.String, maxon.InternedId]) – An attribute.
Returns: The modification stamp of the last change of the attribute value.
Return type: maxon.TimeStamp

GraphNode.GetChildren(callback=None, mask=31)¶

Gets all children of this node.
For a true node this will be its child nodes as well as a single input port list and a single output port list.
Otherwise, the children are ports.

Parameters

callback (Union[None, list, Callable[[maxon.GraphNode], bool]]) – This callback will receive all children.
mask (maxon.NODE_KIND) – Mask to filter the kind of node to look for.

Returns

If callback is None or a list then a list of maxon.GraphNode otherwise False if callback cancelled further evaluation, True otherwise.

Return type

Union[list[maxon.GraphNode], bool]

GraphNode.GetConnectionStamp(direction)¶

Returns the modification stamp of incoming/outgoing connections for this port.

This is the value of the graph’s time stamp (see GraphModelInterface.GetModificationStamp()) at the time when connections in the given direction have been modified last for this port.

Parameters: direction (maxon.PORT_DIR) – The connection direction.
Returns: The modification stamp of the last connection change of the port.
Return type: maxon.TimeStamp

GraphNode.GetConnectionValue(target, position, attr, expectedType=None, reverse=False)¶

Gets the value of the given attribute for the connection from this port to target.

If there is no such connection, the connection has no value for the attribute or the value doesn’t have the expected type, an empty maxon.Data is returned.

Parameters

target (maxon.GraphNode) – The other end of the connection.
position (maxon.CONNECTION_POSITION) – The connection position at which the attribute’s value shall be obtained.
attr (maxon.InternedId) – The attribute whose value shall be obtained.
expectedType (maxon.DataType) – The expected type of the attribute value, may be nullptr if no check shall be done.
reverse (bool) – True if the connection shall be from target to this port (also position is reversed in this case), False otherwise (the default).

Returns

The attribute value of the connection, or a null maxon.Data.

Return type

maxon.Data

GraphNode.GetConnectionValues(target, receiver)¶

Gets all attribute values of the connection from this port to target.

Parameters

target – The other end of the connection.
receiver (Callable[[maxon.CONNECTION_POSITION, maxon.InternedId, maxon.Data], bool]) – All attribute values of the connection will be reported to the receiver.

Returns

False if receiver cancelled further evaluation, True otherwise.

Return type

bool

GraphNode.GetConnections(pDir, conns=None, mask=Wires - Value:63, Event:63, Dependency:63, Context:63, Hidden:63, Inhibit:63, Slink:63, Tlink:63, mode=1)¶

Yields all connections of this port for the given direction dir.
Depending on the graph model implementation, this may include implicit wires due to connections between enclosing ports.
The latter are marked with maxon.WIRE_MODE.IMPLICIT.

Parameters

pDir (maxon.PORT_DIR) – Whether to yield incoming or outgoing connections.
conns (Union[None, list, Callable[[maxon.GraphNode, maxon.Wires], bool]]) – The receiver for the found connections.
mask (maxon.Wires) – Only yield connections whose wires match this mask.
mode (maxon.WIRE_MODE) – Mode for GetConnections.

Returns

A list if conns is None or a list otherwise False if conns cancelled further evaluation, True otherwise.

Return type

Union[list[tuple[maxon.GraphNode, maxon.Wires]], bool]

GraphNode.GetConstantValue()¶

Returns the constant value of this port.

The constant value is set whenever the graph implementation is able to determine a constant value for the port, either because the default value has been set directly at the port, or because it is possible to compute the value from connected ports and nodes.

Returns: The default value of this port.
Returns: maxon.Data

GraphNode.GetDefaultValue()¶

Returns the default value of this port.
This is the value of the DefaultValue attribute,which in turn is synthesized from maxon.DESCRIPTION.DATA.BASE.DEFAULTVALUE:
(maxon.Id(“default”))
Default values are derived from right to left along connections.

Returns: The default value of this port.
Returns: maxon.Data

GraphNode.GetGraph()¶

Returns the graph to which this node belongs.

Returns: Owning graph of this node.
Return type: maxon.GraphModelRef

GraphNode.GetHashCode()¶

Returns the hash code of maxon.GraphNode.

Returns: Hash code.
Return type: int

GraphNode.GetId()¶

Returns the identifier of this node.

This is the last part of the GraphNode.GetPath() “path”, so it’s unique within the siblings of this node, but not within the whole graph.

Returns: Identifier of this node.
Return type: maxon.InternedId

GraphNode.GetInnerNodes(mask, includeThis, receiver=None)¶

Yields all inner nodes of this node matching #mask in pre-order. The recursive traversal stops at nodes which don’t match mask.

Parameters

mask (maxon.NODE_KIND) –

Mask to filter the tree traversal.

Only nodes matching this mask are considered.

The node on which GetInnerNodes is called isn’t checked for mask.
includeThis (bool) – If True, the node on which GetInnerNodes is called is yielded to receiver too.
receiver (Union[Callable[[maxon.GraphNode], bool], list, None]) – Inner nodes are reported to this value receiver.

Returns

If None or a list, a list with all the inner maxon.GraphNode

False* if receiver cancelled further evaluation, True otherwise.

Return type

Union[list[maxon.GraphNode], bool]

GraphNode.GetInputs()¶

Returns the input port list of this node.

All top-level input ports of a node can be found as children of its input port list.

Returns: Input port list of this node.
Return type: maxon.GraphNode

GraphNode.GetKind()¶

Returns the kind of this node.

This can be used to check whether this node is a true node, a port or a port list, see maxon.NODE_KIND and maxon.GraphModelInterface.

Returns: maxon.NODE_KIND

GraphNode.GetMessageFlags(attr)¶

Returns the message flags of the given attribute at this node.

You have to call this method if you want to check if an attribute has a message (an error or a warning) for this node.

Parameters: attr (Union[str, maxon.String, maxon.Id, maxon.InternedId]) – The attribute which shall be asked.
Returns: Message flags (GraphAttribute.FLAGS.WARNING, GraphAttribute.FLAGS.ERROR) of attr at this node.
Return type: maxon.GraphAttribute.FLAGS

GraphNode.GetMessages(attr, receiver)¶

Yields the error or warning messages (if any) of the given attribute at this node to receiver.

Parameters

attr (Union[str, maxon.String, maxon.Id, maxon.InternedId]) – The attribute which shall be asked.
receiver (Callable[[maxon.GraphMessage], bool]) – All messages are reported to this receiver.

Returns

False if the receiver cancelled further evaluation, True otherwise.

Return type

bool

GraphNode.GetOutputs()¶

Returns the output port list of this node.

All top-level output ports of a node can be found as children of its output port list.

Returns: Output port list of this node.
Return type: maxon.GraphNode

GraphNode.GetParent()¶

Returns the parent of this node.

Returns: Parent node of this node, or a null node if this node is the root node.
Return type: maxon.GraphNode

GraphNode.GetPath()¶

Returns the path of this node.

Note

It is not guaranteed that a node with that path still exists in the graph, to check this use NodePath.IsValid().

Returns: Path of this node.
Return type: maxon.NodePath

GraphNode.GetPortList(dir)¶

Returns the input or output port list of this node, depending on dir.

Parameters: dir (maxon.PORT_DIR.INPUT or maxon.PORT_DIR.OUTPUT.) – PORT_DIR.INPUT to return the input port list, PORT_DIR.OUTPUT to return the output port list.
Returns: Port list of this node.
Return type: maxon.GraphNode

GraphNode.GetStoredValue(attr, expectedType=None)¶

Gets the current value of the given attribute for this node, REGARDLESS of whether it is valid or not.

If using lazy updates then this may be out of date.
If NOT using lazy updates then this should always match GetValue().
If this node doesn’t have a value for the attribute of the correct type, an empty Opt is returned.

Parameters

attr (Union[str, maxon.String, maxon.Id, maxon.InternedId]) – The attribute whose value shall be obtained.
expectedType (maxon.DataType) – The expected type of the attribute value, may be None if no check shall be done.

Returns

The attribute value of this node.

Return type

maxon.Data

GraphNode.GetValue(attr, expectedType=None)¶

Gets the value of the given attribute attr for this node.

If this node doesn’t have a value for the attribute of the correct type, an empty maxon.Data is returned.

Parameters

attr (Union[str, maxon.String, maxon.Id, maxon.InternedId]) – The attribute whose value shall be obtained.
expectedType (maxon.DataType) – The expected type of the attribute value, may be None if no check shall be done.

Returns

The attribute value of this node

Return type

maxon.Data

GraphNode.GetValues(mask, graphAttrMap)¶

Gets all attribute values of this node.

Parameters

mask (maxon.GraphAttributeInterface.FLAGS) – All attribute values of this node will be added to map.
graphAttrMap (maxon.HashMap [maxon.InternedId, maxon.Data]) –

GraphNode.GetWires(target)¶

Returns the Wires from this node to #target.
Depending on the graph model implementation, this may include implicit wires due to connections between enclosing nodes.
The latter are marked with maxon.WIRE_MODE.IMPLICIT.

Parameters: target (maxon.GraphNode) – Another graph node.
Returns: Wires between from this node to target.
Return type: maxon.Wires

GraphNode.InheritValue(attr)¶

Restores the inherited state of the value for attr.

This removes any value which has been set directly in this graph.

Parameters: attr (Union[str, maxon.String, maxon.Id, maxon.InternedId]) – The attribute whose value shall be removed from this node.
Returns: True if the value has been inherited.
Return type: bool

GraphNode.IsInner()¶

Checks if this maxon.GraphNode belongs to an inner node of the graph.

The root node and its port lists and ports aren’t inner nodes, all other nodes are.

Returns: True if this maxon.GraphNode is an inner node of the graph.
Return type: bool

GraphNode.IsPopulated()¶

Checks whether this maxon.GraphNode has graph and path references.
This is not the same as GraphNode.IsValid(), because GraphNode.IsPopulated() just checks if graph and path are set,
but not if the graph really contains a node with the path, see GraphNode.IsValid().
Therefore we also don’t have an GraphNode.IsEmpty() counterpart, because it would hide
that there are two different functions to check the content of a maxon.GraphNode.

Returns: True if this GraphNode has graph and path set, False otherwise.
Return type: bool

GraphNode.IsValid()¶

Checks whether this GraphNode points to a valid node.

This is not the same as GraphNode.IsPopulated():

GraphNode.IsValid() return true if the node is a valid, existing node in the graph.
GraphNode.IsPopulated() also returns true for graph nodes which point to non-existing (deleted) nodes.

They have a valid graph and path to identify the node, but you can’t call any function

which would require access to the node.

Returns

True if this maxon.GraphNode points to a valid node,

False if it is a null node or a reference to a deleted node.

Return type

bool

GraphNode.Remove()¶: Removes this node from the graph.

This will also remove all nested nodes as well as connections of this node and its nested ports.

GraphNode.RemoveConnections(pDir, mask)¶

Removes all connections of this port in the given direction which match the given mask.

Parameters

pDir (maxon.PORT_DIR) – Connection direction.
mask (maxon.Wires) – Mask for the connections to remove.

GraphNode.RemovePorts(ports)¶

Removes a number of variadic port instances from this variadic port.

This is more efficient than a repeated call to GraphNode.Remove() on each of the instances.

Warning

It is an error if this GraphNode is no variadic port.

Parameters: ports (Union[list[str, maxon.InternedId]]) – The identifiers of the port instances which shall be removed.
Returns

GraphNode.RemoveValue(attr)¶

Removes an attribute value from this node.

Nothing happens if this node doesn’t have a value for the given attribute.

Parameters: attr (Union[str, maxon.String, maxon.Id, maxon.InternedId]) – The attribute whose value shall be removed from this node.
Returns: True if the value has been changed.
Return type: bool

GraphNode.Reset()¶: Resets this maxon.GraphNode to the state it has right after default construction.

This includes freeing all resources held by this maxon.GraphNode.

GraphNode.SetConnectionValue(target, position, attr, value)¶

Sets the value of attr to value for the connection from this port to target.

This will override any previously existing value.

Parameters

target (maxon.GraphNode) – The other end of the connection.
position (maxon.CONNECTION_POSITION) – The connection position at which the attribute’s value shall be set.
attr (maxon.InternedId) – The attribute whose value shall be set.
value (maxon.Data) – The value for the attribute.

Returns

True if the value has been changed.

Return type

bool

GraphNode.SetDefaultValue(value)¶

Sets the value of the attribute maxon.DESCRIPTION.DATA.BASE.DEFAULTVALUE (maxon.Id(“default”)) to value for this port.

This will override any values which would otherwise be inherited from a base port.

Parameters: value (maxon.Data) – The value for the DefaultValue attribute.
Returns: True if the value has been changed.
Return type: bool

GraphNode.SetValue(attr, value, checkAndInvalidate=True)¶

Sets the value of attr to value for this node.

Note

This will override any previously existing value.

Parameters

attr (Union[str, maxon.String, maxon.Id, maxon.InternedId]) – The attribute whose value shall be set.
value (maxon.Data) – The value for the attribute.
checkAndInvalidate (bool) – Validate the node once the value is set.

Returns

True if the value has been changed.

Return type

bool

GraphNode.TouchValue(attr)¶

Marks the value of attr as modified without actually modifying it.
Use this if the value points to some external data which has changed without knowledge of the graph
(for example a maxon.Url for a file which has been modified).
If there is no value yet for attr, an IllegalStateError is returned.

Parameters: attr (Union[str, maxon.String, maxon.Id, maxon.InternedId]) – The attribute whose value shall be set.

GraphNode.__eq__(other)¶

Checks if two nodes are representing the same node in a graph.

Parameters: other (maxon.GraphNode) – The other node.
Return type: bool
Returns: True if both node are equal.

GraphNode.__init__(src=None)¶

Initializes a node from a graph.

Parameters: src (Optional[maxon.GraphNode]) – Another node to re-use.

GraphNode.__ne__(other)¶

Checks if two nodes are not representing the same node in a graph.

Parameters: other (maxon.GraphNode) – The other node.
Return type: bool
Returns: True if both node are not equal.