SaveDropDownSelectedItem

[QilongTang]

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Purpose

REVIT-141868
DynamoRevit 2.x Categories Dropdown Produces Inconsistent Results Between Revit versions.
Also fixes DynamoDS/DynamoRevit#2281

I believe this is a more complete version of what you're trying to achieve. @ZiyunShang Let me know how you want to cooperate this task

TODOs:

• Add Json Unit tests
• Add XML Unit tests
• Testing undo redo

"Nodes": [
    {
      "ConcreteType": "DSRevitNodesUI.Categories, DSRevitNodesUI",
      "SelectedIndex": 6,
      "SelectedString": "OST_DuctTerminal",
      "NodeType": "ExtensionNode",
      "Id": "e16b9ac4ad604e7eb4d29a7975335d7c",
      "Inputs": [],
      "Outputs": [
        {
          "Id": "ac2e1b04ef994a4fb5dbe4b2855d1097",
          "Name": "Category",
          "Description": "The selected Category.",
          "UsingDefaultValue": false,
          "Level": 2,
          "UseLevels": false,
          "KeepListStructure": false
        }
      ],
      "Replication": "Disabled",
      "Description": "All built-in categories."
    }
  ]

I have did my manual testing in three basic cases:

• Using master build, place a categories node into canvas and save
• Using master build, opening a DYN saved in Dynamo 2.1.0 w/ R2020 worked
• Using master build, opening a DYN saved in Dynamo 1.3.3 w/ R2019 worked
  

Declarations

Check these if you believe they are true

• The code base is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning, and are documented in the API Changes document.

Reviewers

@mjkkirschner @ZiyunShang

FYIs

[ZiyunShang]

Hi @QilongTang , it seems like all the subclass of DSDropDownBase would set their SelectedString and save to .dyn files, right? It looks good to me. I would close my PR.

[mjkkirschner]

@QilongTang in your manual testing did you also switch the version of revit or only the version of dynamo on which you opened and saved the graphs? To replicate this the number of items or order of them must be changed between saving and loading, which would be accomplished by adding new types (family types) or switching revit version. Seems a unit test could also replicate this issue with some mocked data.

[QilongTang]

@mjkkirschner See picture I attached, I tested a valid use by opening a DYN saved w/ Dynamo 1.3.3 Revit 2019 in Dynamo 2.2.0 R2020. The selection is differen index between two version. I will make unit tests.

[mjkkirschner]

LGTM

[mjkkirschner]

@QilongTang this is to cherry pick right?

[QilongTang]

@mjkkirschner This is for master branch

[mjkkirschner]

@QilongTang you don't intend to get this to 2.1 as well?

[QilongTang]

@mjkkirschner For some reason, the self CI job has been hanging so I can't cherry-pick before that comes out