Not to able to skip iteration in loop.

[mdevale]

I want to transform Json that contains array. In one scenario, i want to skip iteration in loop. Is it possible to skip iteration on condition. As of now i want to skip first and last iteration

[Courela]

If you know array's length shorthand you can build a proper JsonPath expression that will filter the wanted positions, then apply it with #loop function:

Input:

{ "test": [ { "id": 1, "dummy": "Item1", "ignored": "bla" }, { "id": 2, "dummy": "Item2", "ignored": "bla" }, { "id": 3, "dummy": "Item3", "ignored": "bla" }, { "id": 4, "dummy": "Item4", "ignored": "bla" } ]}

Transformer:

{ "iteration": { "#loop($.test[1:3:1])": { "id": "#currentvalueatpath($.id)", "dummy": "#currentvalueatpath($.dummy)" } } }

Result:

{ "iteration": [ { "id": 2, "dummy": "Item2" }, { "id": 3, "dummy": "Item3" } ] }

[mdevale]

Normally array's length is not fixed. It can be any number. Can i apply any condition with #currentIndex() or #lastIndex() in loop.

[Courela]

Those functions are only available inside a #loop function, so you will end up with something generated for first and last element of the array, which as I understand is what you don't want.

Besides what I mentioned, I don't see any other way of doing it as it stands.
One change that can be done to accommodate this it to allow having functions as argument for #loop function, so you can create the JsonPath expression dynamically. One will need a function to give the array's size, as described in #56.

[mdevale]

$.test[1:3:1] what it indicates. How it will skip first and last iteration.

[Courela]

JsonPath Expressions

The first number is the start index (zero based), the second is the end index, the third is the step (optional)

[mdevale]

Facing issue with the following scenario

Input:
{ "test": [ { "id": 1, "dummy": "Item1", "ignored": "bla" }, { "id": 2, "dummy": "Item2", "ignored": "bla" }, { "id": 3, "dummy": "Item3", "ignored": "bla" }, { "id": 4, "dummy": "Item4", "ignored": "bla" } ]}

Transformer:
{ "iteration": { "values": "#valueof($.test[*].dummy)" } }

Please see attached screenshot

I want following result:
{ "iteration" : { "values": ["Item1", "Item2", "Item3", "Item4"] } }

This is not able to achieve using #currentvalueatpath() also.

[Courela]

Currently #valueof function does not support multiple tokens as result, in other words, selecting multiple values and return the result as an array.

Pull request #48 was an attempt to solve similar problems (#46 ) by allowing #valueof function to handle multiple results, but it was reverted back by #50.