reactivemongo.api.bson.Macros.Placeholder
Handler
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package Placeholder
Prepares a BSONReader that returns the result of applying f
on the result of this reader.
Prepares a BSONReader that returns the result of applying f
on the result of this reader.
import scala.util.Try import reactivemongo.api.bson.{ BSONReader, BSONValue } // Try to return an integer + 1, // from any T that can be read from BSON // and is a numeric type def fromBSON[T](bson: BSONValue)( implicit r: BSONReader[T], n: Numeric[T]): Try[Int] = { val r2: BSONReader[Int] = r.afterRead { v => n.toInt(v) + 1 } r2.readTry(bson) }
the function to apply
Prepares a BSON writer that returns the result of applying f
on the BSON value from this writer.
Prepares a BSON writer that returns the result of applying f
on the BSON value from this writer.
If the f function is not defined for a BSONValue,
it will results in a Failure.
the partial function to apply
Prepares a BSONReader that transforms the input BSON value,
using the given f function, before passing the transformed BSON value
to the current reader.
Prepares a BSONReader that transforms the input BSON value,
using the given f function, before passing the transformed BSON value
to the current reader.
import reactivemongo.api.bson.{ BSONReader, BSONInteger, BSONNull, BSONString } val normalizingReader: BSONReader[Int] = implicitly[BSONReader[Int]].beforeRead { case BSONNull => BSONInteger(-1) case BSONString(s) => BSONInteger(s.size) // other values are unchanged } normalizingReader.readOpt(BSONNull) // Some(-1) normalizingReader.readTry(BSONString("foo")) // Success(3) normalizingReader.readOpt(BSONInteger(4)) // unchanged: Some(4)
Prepares a BSON writer that converts the input before calling the current writer.
Prepares a BSON writer that converts the input before calling the current writer.
the function apply the U input value to convert at T value used to the current writer
import reactivemongo.api.bson.BSONWriter val w: BSONWriter[String] = implicitly[BSONWriter[Int]].beforeWrite(_.size) w.writeTry("foo") // Success: BSONInteger(3)
Narrows this writer for a compatible type U.
Narrows this writer for a compatible type U.
import reactivemongo.api.bson.BSONWriter val listWriter: BSONWriter[Seq[String]] = implicitly[BSONWriter[Seq[String]]] val narrowAsListWriter: BSONWriter[List[String]] = listWriter.narrow[List[String]] // as List[String] <: Seq[String]
must be a sub-type of T
Tries to produce an instance of T from the document.
Tries to produce an instance of T from the document.
import scala.util.Try import reactivemongo.api.bson.{ BSONDocument, BSONDocumentReader } def fromBSON[T](document: BSONDocument)( implicit r: BSONDocumentReader[T]): Try[T] = r.readTry(document)
Tries to produce an instance of T from the bson value,
returns None if an error occurred.
Tries to produce an instance of T from the bson value,
returns None if an error occurred.
import reactivemongo.api.bson.{ BSONReader, BSONValue } def fromBSON[T](bson: BSONValue)(implicit r: BSONReader[T]): Option[T] = r.readOpt(bson)
Tries to produce an instance of T from the bson value,
returns the default value if an error occurred.
Tries to produce an instance of T from the bson value,
returns the default value if an error occurred.
import reactivemongo.api.bson.{ BSONReader, BSONValue } def fromBSON[T](bson: BSONValue, v: T)(implicit r: BSONReader[T]): T = r.readOrElse(bson, v)
Tries to produce an instance of T from the bson value.
Tries to produce an instance of T from the bson value.
import scala.util.Try import reactivemongo.api.bson.{ BSONReader, BSONValue } def fromBSON[T](bson: BSONValue)(implicit r: BSONReader[T]): Try[T] = r.readTry(bson)
Widens this reader for a compatible type U.
Widens this reader for a compatible type U.
import reactivemongo.api.bson.BSONReader val listReader: BSONReader[List[String]] = implicitly[BSONReader[List[String]]] val widenAsSeqReader: BSONReader[Seq[String]] = listReader.widen[Seq[String]] // as Seq[String] >: List[String]
must be a super-type of T
Tries to produce a BSON value from an instance of T,
returns None if an error occurred.
Tries to produce a BSON value from an instance of T,
returns None if an error occurred.
import reactivemongo.api.bson.{ BSONWriter, BSONValue } def maybeBSON[T](value: T)(implicit w: BSONWriter[T]): Option[BSONValue] = w.writeOpt(value)
Tries to produce a BSON value from an instance of T.
Tries to produce a BSON value from an instance of T.
import scala.util.Try import reactivemongo.api.bson.{ BSONWriter, BSONValue } def toBSON[T](value: T)(implicit w: BSONWriter[T]): Try[BSONValue] = w.writeTry(value)