MongoDB $addField and $indexOfArray in Spring Data - mongodb

Question

I am trying to implement a custom sort with MongoDB and Spring Data according to Asya Kamsky's post:
List<AggregationOperation> operations = new ArrayList<>();
operations.add(Aggregation.addFields().addField("scorrrz")
.withValueOfExpression("{ \"$indexOfArray\" : [ [\"John\", \"Bill\"], \"$name\" ] }").build());
When I try to execute this, I get:
ERROR a.insurance.misc.ErrorAttributes - /api/v1/insurance/opportunity/all
org.springframework.expression.spel.SpelParseException: Expression [{ "$indexOfArray" : [ ["John", "Bill"], "$name" ] }] #29: EL1043E: Unexpected token. Expected 'rsquare(])' but was 'comma(,)'
Is this not the right syntaxt? How can this be done with Spring Data?

Answer 1

Collection<String> nameList = Arrays.asList("John", "Bill");
Aggregation agg = newAggregation(
addFields()
.addField("scorrrz").withValue(arrayOf(nameList).indexOf("$name"))
.build()
);
The aggregation's projection is an $addFields stage with a $indexOfArray aggregation array operation. This will return a field scorrrz, and it will have index value or -1 when there is no match. This ran okay with Spring Boot v2.3.10 and MongoDB v4.2.8.
The run this aggregation pass the pipeline agg to the MongoTemplate#aggregate method.

Answer 2

If you want to calculate $indexOfArray using the array from the DB document itself, you need the aggregate pipeline to perform the calculation instead of the Java code.
Here is my solution
Aggregation.addFields()
.addField("scorrrz")
.withValueOf(MongoExpression.create(" $indexOfArray : [ [ 'John', 'Bill' ], '$name' ]"))
.build()
This creates the following pipeline stage
{
"$addFields": {
"scorrrz": {
"$indexOfArray": [
[
"John",
"Bill"
],
"$name"
]
}
}
}