How to query Map values from the Daml through JSonApi? - daml

Question

I have tried to query Daml template text-Map it throwing me empty set instead of giving that particular data-
for Example:
"Data": [
{ "information":"XYZ",
{
"textMap": {
"Type": {
"_1": "A",
"_2": "B"
},
"Date": {
"_1": "2019-11-29",
"_2": "AMD"
},
}
}
}}
]
here,in the above sample i tried to query only using type key but it is not throwing any data related to that particular key,but when i sending both key values of Map i can able to get that particular data.but i want to send only one key value inside of that Map for querying it.how can achieve this in daml.

Answer 1

TextMap behaves similar to lists in the query API. A map is a value, which you can match on as a whole only. You can see the behaviour for lists here.
Suppose you have a simple TextMap in a template:
daml 1.2
module Main where
import DA.TextMap as Map
template T
with
p : Party
m : TextMap Int
where
signatory p
setup = scenario do
p <- getParty "p"
submit p do
create T with
p
m = Map.fromList [
("one", 1),
("two", 2)
]
The call to contracts/search with the below payload will match.
{
"%templates": [
{
"moduleName": "Main",
"entityName": "T"
}
],
"m" : {
"two": "2",
"one": "1"
}
}
Even though the order of the map items is switched around, the argument for m represents the same map, so the values are equal.
However, changing to simply "m" : { "one" : "1" } will not match. We are querying for a contract of type T with a map with only one entry "one".
There are currently no query options for "containsKey" or "contains".