KtMongo: MongoDB request DSL/opensavvy.ktmongo.dsl.path

Package-level declarations

Syntax to refer to specific fields in MongoDB documents.

When creating a query, we need to refer to specific fields in a MongoDB document, which may be in a nested document or in an array. Traditionally, this is done with the string representation of the path, but that leads to brittle code that is hard to navigate and refactor. Instead, KtMongo provides a DSL to refer to fields with type-safety:

User::_id                          // _id
User::profile / Profile::name      // profile.name
User::friends[1] / Friend::name    // friends.1.name

The operators are implemented in the interface FieldDsl which is already brought into scope by all KtMongo methods, and return instances of Field, the type-safe representation of a MongoDB path.

Operators

Types

interface Field<in Root, out Type>

High-level, typesafe pointer to a specific field in a document.

interface FieldDsl

Operators to construct MongoDB field references from Kotlin code.

data class Path(val segment: PathSegment, val parent: Path?)

Low-level, type-unsafe pointer to a specific field in a document.

sealed class PathSegment

Single segment in a Path.

PropertyNameStrategy

interface PropertyNameStrategy

Allows configuring how the DSL generates MongoDB paths from KProperty1 instances.

Functions

infix inline fun <T> Bson.at(field: Field<*, T>): T

Finds the first value that matches path in a given BSON document.

@DangerousMongoApi

operator fun Path.div(path: Path): Path

Returns a new Path instance that is the concatenation of the current path and a child path.

operator fun Path.div(segment: PathSegment): Path

Returns a new Path instance that is the concatenation of the current path and a segment.

fun FieldDsl(nameStrategy: PropertyNameStrategy): FieldDsl

Creates an instance of FieldDsl.

fun Path(root: String): Path

Creates a root path from the provided root field name.

inline fun <T> Bson.select(field: Field<*, T>): Sequence<T>

Finds all values that match field in a given BSON document.

inline fun <T> Bson.selectFirst(field: Field<*, T>): T

Finds the first value that matches field in a given BSON document.

fun Field<*, *>.toBsonPath(): BsonPath

Converts this MongoDB Field to a BsonPath.

fun Path.toBsonPath(): BsonPath

Converts this MongoDB Path to a BsonPath.