How To Fix FDT_WD_EXPRESSION018 - Cannot add the node as child node to itself

SAP Error Message - Details

• Message type: E = Error

• Message class: FDT_WD_EXPRESSION -

• Message number: 018

• Message text: Cannot add the node as child node to itself

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message FDT_WD_EXPRESSION018 - Cannot add the node as child node to itself ?

  The SAP error message FDT_WD_EXPRESSION018 ("Cannot add the node as child node to itself") typically occurs in the context of SAP's Floorplan Manager (FPM) or Web Dynpro applications when there is an attempt to create a recursive relationship in the UI component tree. This means that a node is trying to reference itself as a child, which is not allowed.
  Cause:
  
  Recursive Node Reference: The most common cause of this error is that the application logic is attempting to add a node to itself, either directly or indirectly. This can happen due to incorrect configuration or coding in the Web Dynpro component or FPM application.
  Incorrect Data Binding: If the data model or binding is set up incorrectly, it may lead to a situation where the application tries to treat a node as its own child.
  Dynamic UI Changes: If the UI is being modified dynamically (e.g., adding/removing nodes based on user actions), there may be a logic flaw that leads to this error.
  
  Solution:
  
  Check Node Configuration: Review the configuration of the nodes in your Web Dynpro or FPM application. Ensure that no node is set to reference itself as a child.
  Review Data Binding: Ensure that the data binding for the nodes is correctly set up. Check the data model to ensure that it does not create circular references.
  Debugging: Use the debugging tools available in the SAP environment to trace the execution flow and identify where the recursive call is being made. Look for any loops or conditions that might lead to this situation.
  Code Review: If you have custom code, review it for any logic that might inadvertently cause a node to be added as a child to itself.
  Consult Documentation: Refer to SAP documentation or community forums for any known issues or patches related to this error.
  
  Related Information:
  
  SAP Notes: Check SAP Notes for any specific fixes or updates related to this error message. Sometimes, SAP releases patches that address specific issues.
  SAP Community: Engage with the SAP Community forums to see if other users have encountered similar issues and what solutions they found effective.
  Testing: After making changes, thoroughly test the application to ensure that the error does not recur and that the application behaves as expected.
  
  By following these steps, you should be able to identify the root cause of the error and implement a solution to resolve it.