Allow update JSON Object or array value

Question

Example

@startuml

!$data={

    "partlen": "2",

    "game": "GamePlantuml",

    "participants": [

        {

            "name": "XYZ",

            "as": "xyz",

            "team": "A"

        }

    ],

    "color": {

        "A": "red",

        "B": "blue",

        "rst": "fuck"

    },

    "asd": 1

}

!%set_json_val("$data.color.A", "black")

!$data.color.A = "black"

! %json_array_push($data.participants, {

    "name": "New"

})

@enduml

Comments

Yes please!  My use case:

I'm tracking in a sequence diagrams multiple queues which would greatly benefit from the ability to (a) start with an empty JSON array, and then (b) have the ability to add and remove entries.

My queues are:

• MQTT topic subscribers
• Messages in a MQTT topic

I've also commented in the above-linked discussions.

Answer 1

For the sake of completion:

- https://forum.plantuml.net/17474/modify-json-variables-in-preprocessor
- https://github.com/plantuml/plantuml/issues/328

Answer 2

Hello T., and all,

Available from last snapshot (~v1.2024.5beta1):

• https://github.com/plantuml/plantuml/releases/tag/snapshot

You can now use:

• %str2json
• %json_add
• %json_remove

Then:

• Could you test to confirm proper operation?
• or feel free to share your feedback...

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From:

• https://github.com/plantuml/plantuml/pull/1742

See also:

• https://github.com/plantuml/plantuml/discussions/1733
• https://forum.plantuml.net/15436/allow-update-json-object-or-array-value
• https://forum.plantuml.net/17474/modify-json-variables-in-preprocessor
• https://forum.plantuml.net/18418/request-%25set_json_keys-function-json-writing-capabilities

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Regards,
Th.