Context-based parameters are used to transmit data between ancestor and descendant nodes. This topic describes how to define and use context-based input and output parameters.

After you define an output parameter and its value for an ancestor node, you can configure a descendant node to reference this value in an input parameter.

Double-click a node to open it. Click Properties on the right of the page that appears. Then, configure the input and output parameters in the Parameters section.

Input parameters

An input parameter of a node defines the reference to the output of the ancestor node that it depends on. The reference can be used inside the node in the same way as other parameters.

  • Define an input parameter
    1. In the Dependencies section, configure Parent Nodes.Add the dependency
    2. In the Parameters section, add an input parameter and configure this parameter to reference the output parameter value of an ancestor node.
      Field Description Remarks
      No. The ID of the input parameter, which auto-increments. None.
      Parameter Name The name of the input parameter. None.
      Value Source The value source of the input parameter. The input parameter references the value of the corresponding output parameter of an ancestor node.
      Description The brief description of the input parameter. None.
      Parent Node ID The ID of the ancestor node. The system automatically parses the ancestor node ID.
      Add Method The source of the input parameter. The options are Added Automatically, Auto Parse, and Added Manually.
      Actions The actions allowed. The options are Save and Cancel. None.
  • Use the input parameter

    The defined input parameter is referenced on a node in the same way as other system variables. The parameter value is referenced in the ${input parameter name} format.

Output parameters

You can configure output parameters in the Parameters section. Two types of output parameter values are supported: Constant and Variable.

After you complete defining an output parameter and committing the current node, the output parameter value can be referenced on the descendant node as the input parameter value.
Note You cannot compile code on the current node to assign a value to the defined output parameter.
Field name Description Remarks
No. The ID of the output parameter, which auto-increments. None.
Parameter Name The name of the output parameter. None.
Type The type of the output parameter. The options are Constant and Variable.
Value The value of the output parameter.
  • If Type is Constant, the value is a fixed string.
  • System variables include global variables, built-in scheduling variables, and custom variables in the format of ${...} or $[...].
Description The brief description of the output parameter. None.
Add Method The source of the output parameter. The options are Added Automatically, Auto Parse, and Added Manually.
Actions The actions allowed. The options are Save and Cancel. The Save and Cancel actions are not supported if a descendant node depends on the current node. Before configuring the descendant node to reference the output parameter value of the current node, make sure that the output parameter is defined correctly on the current node.

Global variables supported by the system

  • System variables
    System variable Description
    ${projectId} The ID of the project.
    ${projectName} The name of the MaxCompute project.
    ${nodeId} The ID of the node.
    ${gmtdate} 00:00:00 on the date on which the node instance is run, in the yyyy-MM-dd 00:00:00 format.
    ${taskId} The ID of the node instance.
    ${seq} The sequence of the node instance, which indicates the ranking of this instance among all node instances on the same day.
    ${cyctime} The scheduled runtime of the node instance.
    ${status} The status of the node instance. Valid values: SUCCESS and FAILURE.
    ${bizdate} The data timestamp of the node instance.
    ${finishTime} The end time of the node instance.
    ${taskType} The running type of the node instance. Valid values: NORMAL, MANUAL, PAUSE, SKIP, UNCHOOSE, and SKIP_CYCLE.
    ${nodeName} The name of the node.
  • For more information about other parameters, see Scheduling parameters.