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

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Inherited
  1. Cursor
  2. CursorCompatAPI
  3. AnyRef
  4. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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  1. Public
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Abstract Value Members

  1. abstract def collect[M[_]](maxDocs: Int, err: ErrorHandler[M[T]])(implicit cbf: Factory[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: ErrorHandler[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: ErrorHandler[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: ErrorHandler[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: ErrorHandler[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: ErrorHandler[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: ErrorHandler[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: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. def +(other: String): String
    Implicit
    This member is added by an implicit conversion from Cursor[T] toany2stringadd[Cursor[T]] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (Cursor[T], B)
    Implicit
    This member is added by an implicit conversion from Cursor[T] toArrowAssoc[Cursor[T]] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()
  5. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  6. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  7. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @native() @HotSpotIntrinsicCandidate()
  8. def ensuring(cond: (Cursor[T]) => Boolean, msg: => Any): Cursor[T]
    Implicit
    This member is added by an implicit conversion from Cursor[T] toEnsuring[Cursor[T]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  9. def ensuring(cond: (Cursor[T]) => Boolean): Cursor[T]
    Implicit
    This member is added by an implicit conversion from Cursor[T] toEnsuring[Cursor[T]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  10. def ensuring(cond: Boolean, msg: => Any): Cursor[T]
    Implicit
    This member is added by an implicit conversion from Cursor[T] toEnsuring[Cursor[T]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  11. def ensuring(cond: Boolean): Cursor[T]
    Implicit
    This member is added by an implicit conversion from Cursor[T] toEnsuring[Cursor[T]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  12. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  13. def equals(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef → Any
  14. 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.

  15. def formatted(fmtstr: String): String
    Implicit
    This member is added by an implicit conversion from Cursor[T] toStringFormat[Cursor[T]] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @inline()
  16. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @native() @HotSpotIntrinsicCandidate()
  17. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native() @HotSpotIntrinsicCandidate()
  18. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  19. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  20. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @HotSpotIntrinsicCandidate()
  21. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @HotSpotIntrinsicCandidate()
  22. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  23. def toString(): String
    Definition Classes
    AnyRef → Any
  24. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  25. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  26. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()

Deprecated Value Members

  1. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.Throwable]) @Deprecated @deprecated
    Deprecated

    (Since version ) see corresponding Javadoc for more information.

  2. def [B](y: B): (Cursor[T], B)
    Implicit
    This member is added by an implicit conversion from Cursor[T] toArrowAssoc[Cursor[T]] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @deprecated
    Deprecated

    (Since version 2.13.0) Use -> instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.

Inherited from CursorCompatAPI[T]

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd fromCursor[T] to any2stringadd[Cursor[T]]

Inherited by implicit conversion StringFormat fromCursor[T] to StringFormat[Cursor[T]]

Inherited by implicit conversion Ensuring fromCursor[T] to Ensuring[Cursor[T]]

Inherited by implicit conversion ArrowAssoc fromCursor[T] to ArrowAssoc[Cursor[T]]

Ungrouped