execute_request {gqlr}

Execute GraphQL server response

Description

Executes a GraphQL server request with the provided request.

Usage

execute_request(
  request,
  schema,
  operation_name = NULL,
  variables = list(),
  initial_value = NULL
)

Arguments

request

a valid GraphQL string

schema

a character string (to be used along side initial_value) or a schema object created from gqlr_schema

operation_name

name of request operation to execute. If not value is provided it will use the operation in the request string. If more than one operations exist, an error will be produced. See https://graphql.github.io/graphql-spec/October2016/#GetOperation()

variables

a named list containing variable values. https://graphql.github.io/graphql-spec/October2016/#sec-Language.Variables

initial_value

default value for executing requests. This value can either be provided and/or combined with the resolve method of the query root type or mutation root type. The value provided should be a named list of the field name (key) and a value matching that field name type. The value may be a function that returns a value of the field name type.

References

https://graphql.github.io/graphql-spec/October2016/#sec-Execution

Examples

# bare bones
schema <- gqlr_schema("
  type Person {
    name: String
    friends: [Person]
  }
  schema {
    query: Person
  }
")

data <- list(
  name = "Barret",
  friends = list(
    list(name = "Ryan", friends = list(list(name = "Bill"), list(name = "Barret"))),
    list(name = "Bill", friends = list(list(name = "Ryan")))
  )
)

ans <- execute_request("{ name }", schema, initial_value = data)
ans$as_json()

execute_request("
  {
    name
    friends {
      name
      friends {
        name
        friends {
          name
        }
      }
    }
  }",
  schema,
  initial_value = data
)$as_json()






# Using resolve method to help with recursion
people <- list(
  "id_Barret" = list(name = "Barret", friends = list("id_Ryan", "id_Bill")),
  "id_Ryan" = list(name = "Ryan", friends = list("id_Barret", "id_Bill")),
  "id_Bill" = list(name = "Bill", friends = list("id_Ryan"))
)
schema <- gqlr_schema("
    type Person {
      name: String
      friends: [Person]
    }
    schema {
      query: Person
    }
  ",
  Person = list(
    resolve = function(name, schema, ...) {
      if (name %in% names(people)) {
        people[[name]]
      } else {
        NULL
      }
    }
  )
)

ans <- execute_request("{ name }", schema, initial_value = "id_Barret")
ans$as_json()

execute_request("
  {
    name
    friends {
      name
      friends {
        name
        friends {
          name
        }
      }
    }
  }",
  schema,
  initial_value = "id_Barret"
)$as_json()