Data Fetching Environment
Each resolver has access to a DataFetchingEnvironment
that provides additional information about the currently executed query including information about what data is requested
as well as details about current execution state. For more details on the DataFetchingEnvironment
please refer to graphql-java documentation
You can access this info by including the DataFetchingEnvironment
as one of the arguments to a Kotlin function. This argument will be automatically populated and injected
during the query execution but will not be included in the schema definition.
class Query {
fun printEnvironmentInfo(parentField: String): MyObject = MyObject()
}
class MyObject {
fun printParentField(childField: String, environment: DataFetchingEnvironment): String {
val parentField = environment.executionStepInfo.parent.getArgument("parentField")
return "The parentField was $parentField and the childField was $childField"
}
}
This will produce the following schema
type Query {
printEnvironmentInfo(parentField: String!): MyObject!
}
type MyObject {
printParentField(childField: String!): String!
}
Then the following query would return "The parentField was foo and the childField was bar"
{
printEnvironmentInfo(parentField: "foo") {
printParentField(childField: "bar")
}
}
You can also use this to retrieve arguments and query information from higher up the query chain. You can see a working
example in the graphql-kotlin-spring-example
module
[link].