Change Nested Array value

[gednz]

Hi Benoit

Love your work!

I currently declare the following globally so that I can add data from various functions to dataa:

const char*  DEVICEID = "DevGW";
StaticJsonDocument<300> doca;
JsonArray devicea = doca.createNestedArray(DEVICEID); 
JsonObject dataa = devicea.createNestedObject();

My problem is that I want to store the DEVICEID value in an eeprom which I can't access before setup()
Is it possible to change the DEVICEID value after declaring the NestedArray?

Regards
Gerald

[bblanchon]

Hi @gednz,

No, it's currently not possible to change a key or rename a member (requested in issue #979)
It wouldn't be too hard to implement, but I doubt the usefulness of this feature.

Are you sure there isn't a more straightforward solution to your problem?
Why (and how) do you need to create the JsonDocument before setup()?
It looks like you're using a global JsonDocument, are you aware of the problems with a global document?
Why don't you delay the creation of the document until you get all the data?

Best regards,
Benoit

[gednz]

Hi Benoit

Thanks for clearing that up.

My routine was to directly collect data in various functions using dataa["R"] = rssi; and then when ready to transmit serializeJson(doc, output);. I always did a doc.clear() when done and never had any issues.
I can change to declaring the jsondocuments in a "sampling" function and call sub functions with return values from there. Once that completes I can then serialize to a global char before exiting.

Regards
Gerald