Nested array in a nested array

[gibix]

Hello,
I need to encode a json that has a value that is an array of arrays, like this:
{"value1": "x", "value2": [["Yes","No"],["Maybe"]}
is there a way to create a nested array as a value of a nested array in a json object?

I also tried to pass all the string "[[\"Yes\",\"No\"],[\"Maybe\"]" as a value, but the json library encodes the value also with the backslash!

Thanks for the support

[bblanchon]

Hi Gilberto,

The canonical way to do this is:

JsonObject& root = jsonBuffer.createObject();

root["value1"] = "x";
JsonArray& value2 = root.createNestedArray("value2");

JsonArray& yesno = value2.createNestedArray();
yesno.add("Yes");
yesno.add("No");

JsonArray& maybe = value2.createNestedArray();
maybe.add("Maybe");

It's also possible to create the arrays and then put them in the object:

JsonObject& root = jsonBuffer.createObject();
JsonObject& value2 = jsonBuffer.createArray();
JsonObject& yesno = jsonBuffer.createArray();
JsonObject& maybe = jsonBuffer.createArray();

root["value1"] = "x";
root["value2"] = value2;
value2.add(yesno);
yesno.add("Yes");
yesno.add("No");
value2.add(maybe);
maybe.add("Maybe");

But it's a little less efficient in term of CPU and memory.

Lastly, it was possible to use the workaround with an undocumented feature:

JsonObject& root = jsonBuffer.createObject();
root["value1"] = "x";
root["value2"] = ArduinoJson::Internals::Unparsed("[[\"Yes\",\"No\"],[\"Maybe\"]");

BTW, I see that you are in the Arduino organisation.
Can you help me have this pull request merged?
This is very important for me, because it'd allow to fix #170 without increasing the code size.
Thanks.

Regards,

[heman4t]

It should be added to documentation as it seems a common problem.

[bblanchon]

@hemantsangwan It's now in the wiki Bag of tricks: nested array in nested array

[gibix]

Thanks for the fast support!
@bblanchon your PR will be tested later today and merged as soon as possible.

[bblanchon]

@gibix Did you have an opportunity to look at my pull request ?