JSON updates with $ - Expected an identifier by Dart

[tiofabby]

Hi,
I am trying to update a JSON entry with the following command:
await Command.send_object((["JSON.SET", "myKey", "$.myfield", newValue]));
Issue is that "$.myfield" is not accepted by dart, it says "Expected an Identifier" and so it does not compile.
I tried to put $ alone like: "$", "json format.." but Dart still complains.. it does not like having a $.

Would someone know how to do a JSON UPDATE then using command.send_object ?

Thank you
Fabrice

[ra1u]

I think that it is string in dart that has an issue. Can you try with raw strings and report if that heps.

await Command.send_object((["JSON.SET", "myKey", r"$.myfield", newValue]));

String reference

[tiofabby]

Hi @ra1u , Thank you for your quick feedback.
I tried what you suggested, it compiles correctly now but it gives an exception when executed:
I/flutter ( 8131): The following exception was thrown Error in ...:
I/flutter ( 8131): RedisError(expected value at line 1 column 1)

[ra1u]

I suspect that newValue is not json in form expected by redis. Can you provide example that can be reproduced and would be clear what newValue is?

[tiofabby]

Sure, here is full line with your "r" suggestion (my keys are "player:uid" and I am trying to update the avatar string field (image name) of the user):

await newCommand.send_object(([
          "JSON.SET",
          "player:${user.userId}",
          r"$.avatar",
          "${user.avatar}"
        ]));

It works just fine if I do

await newCommand.send_object(([
          "JSON.SET",
          "player:${user.userId}",
          ".",
          '{ "avatar": "${user.avatar}"}'
        ]));

but the issue is that it does not do an update it replaces the whole JSON entry with this new one. In my case, I am looking for a way of just updating one field and keep other ones.
Thanks

[ra1u]

I see. It think that you not using redis set as it should be. Take a look into example as documeted by redis in JSON.SET . Can you check that what you are trying to do complies with command that can be executed over terminal as shown in example.

[tiofabby]

Trying to make it work manually with RedisInsight it fails too and I ended finding this link which kind of say that we cannot update just one field in one JSON entry... I feel this is a pity but I would have to deal with such bad behavior I guess...

[craiglabenz]

@tiofabby, try this:

await newCommand.send_object(([
          "JSON.SET",
          "player:${user.userId}",
          r"$.avatar",
          '"${user.avatar}"'
        ]));

The difference changing "${user.avatar}" into '"${user.avatar}"'. You need quotes INSIDE the string you pass to Redis.