reactivemongo.api

Cursor

trait Cursor[T] extends CursorCompatAPI[T]

Cursor over results from MongoDB.

import scala.concurrent.{ ExecutionContext, Future }

import reactivemongo.api.Cursor
import reactivemongo.api.bson.{ BSONDocument, Macros }
import reactivemongo.api.bson.collection.BSONCollection

case class User(name: String, pass: String)

implicit val handler = Macros.reader[User]

def findUsers(coll: BSONCollection)(
  implicit ec: ExecutionContext): Future[List[User]] =
  coll.find(BSONDocument("enabled" -> true)).
    cursor[User](). // obtain cursor for User results
    collect[List](
      maxDocs = 10,
      err = Cursor.FailOnError[List[User]]())
T

the type parsed from each result document

Linear Supertypes
CursorCompatAPI[T], AnyRef, Any
Known Subclasses
FlattenedCursor, WrappedCursor
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Inherited
  1. Cursor
  2. CursorCompatAPI
  3. AnyRef
  4. Any
Implicitly
  1. by any2stringadd
  2. by any2stringfmt
  3. by any2ArrowAssoc
  4. by any2Ensuring
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Abstract Value Members

  1. abstract def collect[M[_]](maxDocs: Int, err: (M[T], Throwable) ⇒ State[M[T]])(implicit cbf: CanBuildFrom[M[_], T, M[T]], ec: ExecutionContext): Future[M[T]]

    Collects all the documents into a collection of type M[T].

    Collects all the documents into a collection of type M[T].

    maxDocs

    the maximum number of documents to be retrieved (-1 for unlimited).

    err

    The binary operator to be applied when failing to get the next response. Exception or Fail raised within the suc function cannot be recovered by this error handler.

    import scala.concurrent.ExecutionContext

import reactivemongo.api.Cursor
import reactivemongo.api.bson.BSONDocument
import reactivemongo.api.bson.collection.BSONCollection

def foo(collection: BSONCollection, query: BSONDocument)(
  implicit ec: ExecutionContext) = {
  val cursor = collection.find(query).cursor[BSONDocument]()
  // return the 3 first documents in a Vector[BSONDocument].
  cursor.collect[Vector](3, Cursor.FailOnError[Vector[BSONDocument]]())
}
    Definition Classes
    CursorCompatAPI

  2. abstract def foldBulks[A](z: ⇒ A, maxDocs: Int = 1)(suc: (A, Iterator[T]) ⇒ State[A], err: (A, Throwable) ⇒ State[A] = FailOnError[A]())(implicit ec: ExecutionContext): Future[A]

    Applies a binary operator to a start value and all bulks of documents retrieved by this cursor, going first to last.

    Applies a binary operator to a start value and all bulks of documents retrieved by this cursor, going first to last.

    A

    the result type of the binary operator

    import reactivemongo.api.Cursor
import scala.concurrent.ExecutionContext

case class Person(name: String, age: Int)

def foo(cursor: Cursor[Person])(implicit ec: ExecutionContext) =
  cursor.foldBulks(Nil: Seq[Person])(
    (s, bulk: Iterator[Person]) => Cursor.Cont(s ++ bulk),
    { (l, e) => println("last valid value: " + l); Cursor.Fail(e) })
    z

    the initial value

    maxDocs

    the maximum number of documents to be retrieved (-1 for unlimited). The actual document count can exceed this, when this maximum devided by the batch size given a non-zero remainder.

    suc

    The binary operator to be applied when the next response is successfully read.

    err

    The binary operator to be applied when failing to get the next response. Exception or Fail raised within the suc function cannot be recovered by this error handler.

  3. abstract def foldBulksM[A](z: ⇒ A, maxDocs: Int = 1)(suc: (A, Iterator[T]) ⇒ Future[State[A]], err: (A, Throwable) ⇒ State[A] = FailOnError[A]())(implicit ec: ExecutionContext): Future[A]

    Applies a binary operator to a start value and all bulks of documents retrieved by this cursor, going first to last.

    Applies a binary operator to a start value and all bulks of documents retrieved by this cursor, going first to last.

    A

    the result type of the binary operator

    import scala.concurrent.{ ExecutionContext, Future }
import reactivemongo.api.Cursor

case class Person(name: String, age: Int)

def foo(cursor: Cursor[Person])(implicit ec: ExecutionContext) =
  cursor.foldBulksM(Nil: Seq[Person])(
    { (s, bulk: Iterator[Person]) =>
     Future.successful(Cursor.Cont(s ++ bulk))
   },
    { (l, e) =>
      println("last valid value: " + l)
      Cursor.Fail[Seq[Person]](e)
    })
    z

    the initial value

    maxDocs

    the maximum number of documents to be retrieved (-1 for unlimited). The actual document count can exceed this, when this maximum devided by the batch size given a non-zero remainder.

    suc

    The binary operator to be applied when the next response is successfully read. This must be safe, and any error must be returned as Future.failed[State[A]].

    err

    The binary operator to be applied when failing to get the next response. Exception or Fail raised within the suc function cannot be recovered by this error handler.

  4. abstract def foldWhile[A](z: ⇒ A, maxDocs: Int = 1)(suc: (A, T) ⇒ State[A], err: (A, Throwable) ⇒ State[A] = FailOnError[A]())(implicit ec: ExecutionContext): Future[A]

    Applies a binary operator to a start value and all elements retrieved by this cursor, going first to last.

    Applies a binary operator to a start value and all elements retrieved by this cursor, going first to last.

    A

    the result type of the binary operator

    import reactivemongo.api.Cursor
import scala.concurrent.ExecutionContext

case class Person(name: String, age: Int)

def foo(cursor: Cursor[Person])(implicit ec: ExecutionContext) =
  cursor.foldWhile(Nil: Seq[Person])((s, p) => Cursor.Cont(s :+ p),
    { (l, e) => println("last valid value: " + l); Cursor.Fail(e) })
    z

    the initial value

    maxDocs

    the maximum number of documents to be retrieved (-1 for unlimited).

    suc

    The binary operator to be applied when the next document is successfully read.

    err

    The binary operator to be applied when failing to get the next response. Exception or Fail raised within the suc function cannot be recovered by this error handler.

  5. abstract def foldWhileM[A](z: ⇒ A, maxDocs: Int = 1)(suc: (A, T) ⇒ Future[State[A]], err: (A, Throwable) ⇒ State[A] = FailOnError[A]())(implicit ec: ExecutionContext): Future[A]

    Applies a binary operator to a start value and all elements retrieved by this cursor, going first to last.

    Applies a binary operator to a start value and all elements retrieved by this cursor, going first to last.

    A

    the result type of the binary operator

    import scala.concurrent.{ ExecutionContext, Future }
import reactivemongo.api.Cursor

case class Person(name: String, age: Int)

def foo(cursor: Cursor[Person])(implicit ec: ExecutionContext) =
  cursor.foldWhileM(Nil: Seq[Person])(
    (s, p) => Future.successful(Cursor.Cont(s :+ p)),
    { (l, e) =>
      println("last valid value: " + l)
      Cursor.Fail[Seq[Person]](e)
    })
    z

    the initial value

    maxDocs

    the maximum number of documents to be retrieved (-1 for unlimited).

    suc

    The binary operator to be applied when the next document is successfully read. This must be safe, and any error must be returned as Future.failed[State[A]].

    err

    The binary operator to be applied when failing to get the next response. Exception or Fail raised within the suc function cannot be recovered by this error handler.

  6. abstract def head(implicit ec: ExecutionContext): Future[T]

    Returns the first document matching the query, or fails with Cursor.NoSuchResultException if none.

    Returns the first document matching the query, or fails with Cursor.NoSuchResultException if none.

    import scala.concurrent.{ ExecutionContext, Future }

import reactivemongo.bson.BSONDocument
import reactivemongo.api.collections.bson.BSONCollection

def first(query: BSONDocument)(collection: BSONCollection)(
  implicit ec: ExecutionContext): Future[BSONDocument] = {
  val cursor = collection.find(query).cursor[BSONDocument]()
  // return option of the first element.
  cursor.head
}

  7. abstract def headOption(implicit ec: ExecutionContext): Future[Option[T]]

    Returns the first document matching the query, if any.

    Returns the first document matching the query, if any.

    import scala.concurrent.{ ExecutionContext, Future }

import reactivemongo.api.bson.BSONDocument

import reactivemongo.api.bson.collection.BSONCollection

def maybeFirst(query: BSONDocument)(collection: BSONCollection)(
  implicit ec: ExecutionContext): Future[Option[BSONDocument]] = {
  val cursor = collection.find(query).cursor[BSONDocument]()
  // return option of the first element.
  cursor.headOption
}

  8. abstract def foldResponses[A](z: ⇒ A, maxDocs: Int = 1)(suc: (A, Response) ⇒ State[A], err: (A, Throwable) ⇒ State[A] = FailOnError[A]())(implicit ec: ExecutionContext): Future[A]

    Applies a binary operator to a start value and all responses handled by this cursor, going first to last.

    Applies a binary operator to a start value and all responses handled by this cursor, going first to last.

    A

    the result type of the binary operator

    z

    the initial value

    maxDocs

    the maximum number of documents to be retrieved (-1 for unlimited). The actual document count can exceed this, when this maximum devided by the batch size given a non-zero remainder.

    suc

    The binary operator to be applied when the next response is successfully read.

    err

    The binary operator to be applied when failing to get the next response. Exception or Fail raised within the suc function cannot be recovered by this error handler.

    Annotations
    @deprecated
    Deprecated

    (Since version 0.19.4) Internal: will be made private

  9. abstract def foldResponsesM[A](z: ⇒ A, maxDocs: Int = 1)(suc: (A, Response) ⇒ Future[State[A]], err: (A, Throwable) ⇒ State[A] = FailOnError[A]())(implicit ec: ExecutionContext): Future[A]

    Applies a binary operator to a start value and all responses handled by this cursor, going first to last.

    Applies a binary operator to a start value and all responses handled by this cursor, going first to last.

    A

    the result type of the binary operator

    z

    the initial value

    maxDocs

    the maximum number of documents to be retrieved (-1 for unlimited). The actual document count can exceed this, when this maximum devided by the batch size given a non-zero remainder.

    suc

    The binary operator to be applied when the next response is successfully read. This must be safe, and any error must be returned as Future.failed[State[A]].

    err

    The binary operator to be applied when failing to get the next response. Exception or Fail raised within the suc function cannot be recovered by this error handler.

    Annotations
    @deprecated
    Deprecated

    (Since version 0.19.4) Internal: will be made private

Concrete Value Members

  1. final def !=(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef

  2. final def !=(arg0: Any): Boolean

    Definition Classes
    Any

  3. final def ##(): Int

    Definition Classes
    AnyRef → Any

  4. def +(other: String): String

    Implicit information
    This member is added by an implicit conversion from Cursor[T] to StringAdd performed by method any2stringadd in scala.Predef.
    Definition Classes
    StringAdd

  5. def ->[B](y: B): (Cursor[T], B)

    Implicit information
    This member is added by an implicit conversion from Cursor[T] to ArrowAssoc[Cursor[T]] performed by method any2ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()

  6. final def ==(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef

  7. final def ==(arg0: Any): Boolean

    Definition Classes
    Any

  8. final def asInstanceOf[T0]: T0

    Definition Classes
    Any

  9. def clone(): AnyRef

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  10. def ensuring(cond: (Cursor[T]) ⇒ Boolean, msg: ⇒ Any): Cursor[T]

    Implicit information
    This member is added by an implicit conversion from Cursor[T] to Ensuring[Cursor[T]] performed by method any2Ensuring in scala.Predef.
    Definition Classes
    Ensuring

  11. def ensuring(cond: (Cursor[T]) ⇒ Boolean): Cursor[T]

    Implicit information
    This member is added by an implicit conversion from Cursor[T] to Ensuring[Cursor[T]] performed by method any2Ensuring in scala.Predef.
    Definition Classes
    Ensuring

  12. def ensuring(cond: Boolean, msg: ⇒ Any): Cursor[T]

    Implicit information
    This member is added by an implicit conversion from Cursor[T] to Ensuring[Cursor[T]] performed by method any2Ensuring in scala.Predef.
    Definition Classes
    Ensuring

  13. def ensuring(cond: Boolean): Cursor[T]

    Implicit information
    This member is added by an implicit conversion from Cursor[T] to Ensuring[Cursor[T]] performed by method any2Ensuring in scala.Predef.
    Definition Classes
    Ensuring

  14. final def eq(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef

  15. def equals(arg0: Any): Boolean

    Definition Classes
    AnyRef → Any

  16. def finalize(): Unit

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )

  17. def fold[A](z: ⇒ A, maxDocs: Int = 1)(suc: (A, T) ⇒ A)(implicit ec: ExecutionContext): Future[A]

    Applies a binary operator to a start value and all elements retrieved by this cursor, going first to last.

    Applies a binary operator to a start value and all elements retrieved by this cursor, going first to last.

    A

    the result type of the binary operator

    import scala.concurrent.ExecutionContext
import reactivemongo.api.Cursor

case class Person(name: String, age: Int)

def foo(cursor: Cursor[Person])(implicit ec: ExecutionContext) =
  cursor.foldWhile(Nil: Seq[Person])((s, p) => Cursor.Cont(s :+ p),
    { (l, e) => println("last valid value: " + l); Cursor.Fail(e) })
    z

    the initial value

    maxDocs

    the maximum number of documents to be retrieved (-1 for unlimited).

    suc

    The binary operator to be applied when the next document is successfully read.

  18. def formatted(fmtstr: String): String

    Implicit information
    This member is added by an implicit conversion from Cursor[T] to StringFormat performed by method any2stringfmt in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @inline()

  19. final def getClass(): Class[_]

    Definition Classes
    AnyRef → Any

  20. def hashCode(): Int

    Definition Classes
    AnyRef → Any

  21. final def isInstanceOf[T0]: Boolean

    Definition Classes
    Any

  22. final def ne(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef

  23. final def notify(): Unit

    Definition Classes
    AnyRef

  24. final def notifyAll(): Unit

    Definition Classes
    AnyRef

  25. final def synchronized[T0](arg0: ⇒ T0): T0

    Definition Classes
    AnyRef

  26. def toString(): String

    Definition Classes
    AnyRef → Any

  27. final def wait(): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  28. final def wait(arg0: Long, arg1: Int): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  29. final def wait(arg0: Long): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  30. def →[B](y: B): (Cursor[T], B)

    Implicit information
    This member is added by an implicit conversion from Cursor[T] to ArrowAssoc[Cursor[T]] performed by method any2ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc

Shadowed Implicit Value Members

  1. val self: Any

    Implicit information
    This member is added by an implicit conversion from Cursor[T] to StringAdd performed by method any2stringadd in scala.Predef.
    Shadowing
    This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
    To access this member you can use a type ascription:
    (cursor: StringAdd).self
    Definition Classes
    StringAdd

  2. val self: Any

    Implicit information
    This member is added by an implicit conversion from Cursor[T] to StringFormat performed by method any2stringfmt in scala.Predef.
    Shadowing
    This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
    To access this member you can use a type ascription:
    (cursor: StringFormat).self
    Definition Classes
    StringFormat

Deprecated Value Members

  1. def x: Cursor[T]

    Implicit information
    This member is added by an implicit conversion from Cursor[T] to ArrowAssoc[Cursor[T]] performed by method any2ArrowAssoc in scala.Predef.
    Shadowing
    This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
    To access this member you can use a type ascription:
    (cursor: ArrowAssoc[Cursor[T]]).x
    Definition Classes
    ArrowAssoc
    Annotations
    @deprecated
    Deprecated

    (Since version 2.10.0) Use leftOfArrow instead

  2. def x: Cursor[T]

    Implicit information
    This member is added by an implicit conversion from Cursor[T] to Ensuring[Cursor[T]] performed by method any2Ensuring in scala.Predef.
    Shadowing
    This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
    To access this member you can use a type ascription:
    (cursor: Ensuring[Cursor[T]]).x
    Definition Classes
    Ensuring
    Annotations
    @deprecated
    Deprecated

    (Since version 2.10.0) Use resultOfEnsuring instead

Inherited from CursorCompatAPI[T]

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd from Cursor[T] to StringAdd

Inherited by implicit conversion any2stringfmt from Cursor[T] to StringFormat

Inherited by implicit conversion any2ArrowAssoc from Cursor[T] to ArrowAssoc[Cursor[T]]

Inherited by implicit conversion any2Ensuring from Cursor[T] to Ensuring[Cursor[T]]

Ungrouped