Metadata Helper
(Custom Operators)
Synopsis
This operator can be used to manipulate the metadata of a Custom Operator.Description
The subprocess of this operator defines the metadata of its output port using the input metadata of the md ports. The data is not affected by the subprocess and just passed from the first input port to the output port. Use this for Custom Operators where the defining process does not correctly supply the metadata.
If the parameter only if metadata missing is selected the metadata of the subprocess is only used when there is no metadata at the input port, otherwise the existing metadata is just passed through to the output port.
Input
input (IOObject)The input data.
- md (IOObject)
It is not compulsory to connect any object with this port. Any metadata of a object connected at this port is delivered without any modifications to the subprocess. This operator can have multiple md inputs. When one input is connected, another md input port becomes available which is ready to accept another input (if any). The order of inputs remains the same. The object supplied at the first md input port of the operator is available at the first md output port in the subprocess.
Output
- output (IOObject)
The object that was given as input is passed without changing to the output through this port.
Parameters
- only if metadata missingIf this is selected the metadata of the subprocess is only used when there is no metadata at the input port, otherwise that is just passed through to the output port.
Tutorial Processes
Introduction to the Metadata Helper operator
This is a very basic process that demonstrates the use of the Metadata Helper operator. In the process, the Execute Script operator has no metadata until it has been executed. The metadata helper can be used to simulate the resulting metadata with existing operators.
Inside the Metadata Helper the Select Attributes and Filter Example Range operators do something similar to what the script does in order to simulate metadata for the Execute Script operator.
This approach of using the Metadata Helper operator together with scripting operators is mainly useful for custom operators. This allows them to have metadata like regular operators even if scripting operators are used in the defining process.
