[ 2607593 ] [Jsonp][Question] Is it possible to combine multiple lists into a list?

[thanhbnq]

Dear team,

I would like to consult your advice for my following usecase.

Example: there is a jsonp file

{
    "nodeA" : {
        "propA1": {
            "channels": ["A1_01", "A1_02", "A1_03"]
        },
        "propA2": {
            "channels": ["A2_01", "A2_02"]
        },
        "propA3": {
            "channels": ["A3_01"]
        }
    },
    "nodeB" : {
        "measure": [${nodeA.propA1.channels}, ${nodeA.propA2.channels}, ${nodeA.propA3.channels}]
    }
}

I would like to know that whether it is possible to have ${nodeB.measure} as "a list" instead of "a list of list".

[test-fullautomation]

Hi @tanhbnq,

A $-reference need to keep the data-type or the referenced data except of used as a part of a string.
This is same behavior you have and expect from python.

If you need ${nodeB.measure} a flat list, then you need to do this on pyhton level.
e.g. like this:

from itertools import chain
flat_list = list(chain(nodeB["measure"]))

On json-preprocessor level we won't do this. I hope this helps.

Thank you,
Thomas

[namsonx]

Hello @test-fullautomation ,

For this case, if we implement a feature that allowing $-references do some basic mathematical operators such as +, -, x, :, then we can use + to merge 2 or more lists.

JPP will raise an exception in case the data-type of the $-references are different.

Thank you,
Son

[test-fullautomation]

Hi @namsonx ,

this is not a good idea. It opens a door for masses of new issues, and it deviates from python.

What could be interesting is to allow python functions with jpp files. In TML I could to this with backticks

`list(chain([${nodeA.propA1.channels}, ${nodeA.propA2.channels}, ${nodeA.propA3.channels}]))` 

But this is also complex to stabilize and test.

Can you check what effort it would be to allow this as generic solution?

When good implemented it should effect only few places in the code.

Thank you,
Thomas

[thanhbnq]

Hi @ThPoll and @namsonx ,

Thank you very much for suggestion and consideration.
To be honest, I also think that it is better and cleaner if I handle it inside python code.
Just in case this is still interesting to you, I just think that maybe we can have something like

"nodeB" : {
     "measure": flattern[${nodeA.propA1.channels}, ${nodeA.propA2.channels}, ${nodeA.propA3.channels}]
}

Thanh

[test-fullautomation]

Hi @thanhbnq ,

thank you four your idea.
For me it's not a good idea to provide special functions as part of the jpp syntax.
Better is my proposal above which enables all python builtin functions.

Thank you,
Thoma

[thanhbnq]

Hi @test-fullautomation ,

Yeah, totally agree with you. From my side, I have no more concern.
Please close the this issue if it should be.

Thank you,
Thanh

[test-fullautomation]

Hi @thanhbnq ,
I let it in the backlog, we will work on this.
To provide access to python builtins is meaningful and powerful.
Thank you,
Thomas