FirebaseFirestore Framework Reference

Functions

The following functions are available globally.

• &&(_:_:)

  Combines two boolean expressions with a logical AND (&&).

  The resulting expression is true only if both the left-hand side (lhs) and the right-hand side (rhs) are true.

  // Find books in the "Fantasy" genre with a rating greater than 4.5
  firestore.pipeline()
    .collection("books")
    .where(
      Field("genre").equal("Fantasy") && Field("rating").greaterThan(4.5)
    )
  

  Declaration

  Swift

  public func && (lhs: BooleanExpression,
                  rhs: @autoclosure () throws -> BooleanExpression) rethrows -> BooleanExpression

  Parameters

  lhs	The left-hand boolean expression.
  rhs	The right-hand boolean expression.

  Return Value

  A new BooleanExpression representing the logical AND.

• ||(_:_:)

  Combines two boolean expressions with a logical OR (||).

  The resulting expression is true if either the left-hand side (lhs) or the right-hand side (rhs) is true.

  // Find books that are either in the "Romance" genre or were published before 1900
  firestore.pipeline()
    .collection("books")
    .where(
      Field("genre").equal("Romance") || Field("published").lessThan(1900)
    )
  

  Declaration

  Swift

  public func || (lhs: BooleanExpression,
                  rhs: @autoclosure () throws -> BooleanExpression) rethrows -> BooleanExpression

  Parameters

  lhs	The left-hand boolean expression.
  rhs	The right-hand boolean expression.

  Return Value

  A new BooleanExpression representing the logical OR.

• ^(_:_:)

  Combines two boolean expressions with a logical XOR (^).

  The resulting expression is true if the left-hand side (lhs) and the right-hand side (rhs) have different boolean values.

  // Find books that are in the "Dystopian" genre OR have a rating of 5.0, but not both.
  firestore.pipeline()
    .collection("books")
    .where(
      Field("genre").equal("Dystopian") ^ Field("rating").equal(5.0)
    )
  

  Declaration

  Swift

  public func ^ (lhs: BooleanExpression,
                 rhs: @autoclosure () throws -> BooleanExpression) rethrows -> BooleanExpression

  Parameters

  lhs	The left-hand boolean expression.
  rhs	The right-hand boolean expression.

  Return Value

  A new BooleanExpression representing the logical XOR.

• !(_:)

  Negates a boolean expression with a logical NOT (!).

  The resulting expression is true if the original expression is false, and vice versa.

  // Find books that are NOT in the "Science Fiction" genre
  firestore.pipeline()
    .collection("books")
    .where(!Field("genre").equal("Science Fiction"))
  

  Declaration

  Swift

  public prefix func ! (lhs: BooleanExpression) -> BooleanExpression

  Parameters

  lhs	The boolean expression to negate.

  Return Value

  A new BooleanExpression representing the logical NOT.

• nor(_:_:)

  Combines given boolean expressions with a logical NOR (nor).

  The resulting expression is true only if all of the provided expressions are false.

  // Find books that are neither "Fantasy" nor have a rating > 4.5
  firestore.pipeline()
    .collection("books")
    .where(nor(Field("genre").equal("Fantasy"), Field("rating").greaterThan(4.5)))
  

  Declaration

  Swift

  public func nor(_ condition: BooleanExpression,
                  _ conditions: BooleanExpression...) -> BooleanExpression

  Parameters

  condition	The first boolean expression.
  conditions	Additional boolean expressions.

  Return Value

  A new BooleanExpression representing the logical NOR.

• nor(_:)

  Combines given boolean expressions with a logical NOR (nor).

  The resulting expression is true only if all of the provided expressions are false.

  // Find books that are neither "Fantasy" nor have a rating > 4.5
  let conditions: [BooleanExpression] = [
    Field("genre").equal("Fantasy"),
    Field("rating").greaterThan(4.5)
  ]
  firestore.pipeline()
    .collection("books")
    .where(nor(conditions))
  

  Declaration

  Swift

  public func nor(_ conditions: [BooleanExpression]) -> BooleanExpression

  Parameters

  conditions

  An array of boolean expressions. Must contain at least 2 expressions.

  Return Value

  A new BooleanExpression representing the logical NOR.

• switchOn(_:_:_:)

  // Create a "sizeCategory" field based on the "amount" field.
  firestore.pipeline()
    .collection("items")
    .addFields([
      switchOn(
        Field("amount").lessThan(10), Constant("Small"),
        Field("amount").lessThan(100), Constant("Medium"),
        Constant("Large")
      ).as("sizeCategory")
    ])
  

  Declaration

  Swift

  public func switchOn(_ condition: BooleanExpression,
                       _ result: Expression,
                       _ others: Expression...) -> Expression

  Parameters

  condition	The first condition to evaluate.
  result	The expression to return if the first condition is true.
  others	Additional condition/result pairs, optionally followed by a default expression.

  Return Value

  A new Expression representing the switchOn logic.

• rand()

  Creates an expression that generates a random number between 0.0 and 1.0 but not including 1.0.

  // Generate a random number between 0.0 and 1.0.
  rand()
  

  Declaration

  Swift

  public func rand() -> RandomExpression

  Return Value

  A new RandomExpression representing the random number generator.