Finding nodes

Flows provide a number of ways for locating an existing node. These methods are summarized in the following table.

Table 1. Methods for locating an existing node
Method	Return type	Description
`s.findAll(type, label)`	Collection	Returns a list of all nodes with the specified type and label. Either the type or label can be `None`, in which case the other parameter is used.
`s.findAll(filter, recursive)`	Collection	Returns a collection of all nodes that are accepted by the specified filter. If the recursive flag is `True`, any SuperNodes within the specified flow are also searched.
`s.findByID(id)`	Node	Returns the node with the supplied ID or `None` if no such node exists. The search is limited to the current stream.
`s.findByType(type, label)`	Node	Returns the node with the supplied type, label, or both. Either the type or name can be `None`, in which case the other parameter is used. If multiple nodes result in a match, then an arbitrary one is chosen and returned. If no nodes result in a match, then the return value is `None`.
`s.findDownstream(fromNodes)`	Collection	Searches from the supplied list of nodes and returns the set of nodes downstream of the supplied nodes. The returned list includes the originally supplied nodes.
`s.findUpstream(fromNodes)`	Collection	Searches from the supplied list of nodes and returns the set of nodes upstream of the supplied nodes. The returned list includes the originally supplied nodes.
`s.findProcessorForID(String id, boolean recursive)`	Node	Returns the node with the supplied ID or `None` if no such node exists. If the recursive flag is `true`, then any composite nodes within this diagram are also searched.

As an example, if a flow contains a single Filter node that the script needs to access, the Filter node can be found by using the following script:

stream = modeler.script.stream()
node = stream.findByType("filter", None)
...

Alternatively, you can use the ID of a node. For example:

stream = modeler.script.stream()
node = stream.findByID("id49CVL4GHVV8")  # the Derive node ID
node.setPropertyValue("mode", "Multiple")
node.setPropertyValue("name_extension", "new_derive")

To obtain the ID for any node in a flow, click the Scripting icon on the toolbar, then select the desired node in your flow and click Insert selected node ID.