I need to transform array to array with some extra logic:
name in array if it exists in the mapping object, if not process it as it is in the sourcefor example here is the source json:
{
"additive": [
{
"name": "field-1",
"volume": "10"
},
{
"name": "field-2",
"volume": "10"
},
{
"name": "field-3",
"volume": "0"
},
{
"name": "field-4",
"volume": "5"
}
]
}
object with mapping config(field-1 and field-2 is mapped to the same value):
{
"field-1": "field-1-mapped",
"field-2": "field-1-mapped",
"field-3": "field-3-mapped"
}
and this is the result that I need to have
{
"chemicals": [
{
"name": "field-1-mapped",
"value": 20
},
{
"name": "field-4",
"value": 5
}
]
}
as you can see field-1 and field-2 is mapped to field-1-mapped so the values are summed up, field-3 has 0 value so it is removed and field-4 is passed as it is because it's missing in the mapping.
so my question is: is it possible to make it with JSONata?
I have tried to make it work but I stuck with this lookup function that doesn't return default value when name is missing in mapping:
{
"chemicals": additive @ $additive #$.{
"name": $res := $lookup({
"field-1": "field-1-mapped",
"field-2": "field-1-mapped",
"field-3": "field-3-mapped"
}, $additive.name)[ $res ? $res : $additive.name],
"amount": $number($additive.volume),
} [amount>0]
}
Probably easiest to break it down into steps as follows:
(
/* define lookup table */
$table := {
"field-1": "field-1-mapped",
"field-2": "field-1-mapped",
"field-3": "field-3-mapped"
};
/* substitute the name; if it's not in the table, just use the name */
$mapped := additive.{
"name": [$lookup($table, name), name][0],
"volume": $number(volume)
};
/* group by name, and aggregate the volumes */
$grouped := $mapped[volume > 0]{name: $sum(volume)};
/* convert back to array */
{
"chemicals": $each($grouped, function($v, $n) {{
"name": $n,
"volume": $v
}})
}
)