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Overview

invirt-mongodb is a thin Kotlin layer on top of the MongoDB Kotlin driver. It provides:

  • A small Mongo wrapper for managing the client lifecycle and running transactions.
  • Document interfaces (VersionedDocument, TimestampedDocument) with optimistic locking and managed timestamps.
  • Strongly-typed filters, sorts and indexes via KProperty extensions.
  • A bridge from Invirt's DataFilter / Sort / Page abstractions to native MongoDB constructs.
  • A cursor-based pagination helper for aggregation pipelines.
  • Helpers for Atlas Search.

Dependency​

implementation(platform("dev.invirt:invirt-bom:${invirtVersion}"))
implementation("dev.invirt:invirt-mongodb")

Connecting​

The Mongo class wraps a MongoClient and is the entry point for the rest of the API. The database name is extracted from the connection string — an explicit database name is required.

val mongo = Mongo("mongodb://localhost:27017/myapp")

mongo.database // com.mongodb.kotlin.client.MongoDatabase
mongo.databaseName // "myapp"

mongo.runInTransaction { session ->
    // ...
}

mongo.close()

runInTransaction starts a session with WriteConcern.MAJORITY and either commits or aborts based on the block outcome.

Documents​

VersionedDocument and TimestampedDocument are interfaces your domain documents can implement to opt into optimistic locking and managed createdAt / updatedAt timestamps.

data class Product(
    override val id: String = uuid7(),
    val name: String,
    val priceMinor: Long,
    override var version: Long = 0,
    override var createdAt: Instant = mongoNow(),
    override var updatedAt: Instant = mongoNow()
) : TimestampedDocument

MongoCollection.insert(document) and MongoCollection.update(document) (and their transactional txInsert / txUpdate counterparts) handle version increment and timestamp maintenance automatically. See Collection operations for the full surface.

Indexes​

Indexes are built with the MongoDB driver's own Indexes and IndexOptions:

collection.createIndexes(
    listOf(
        IndexModel(Indexes.ascending(Product::name.name), IndexOptions().collation(caseInsensitive())),
        IndexModel(Indexes.descending(Product::priceMinor.name)),
        *TimestampedDocument.allIndices()
    )
)

TimestampedDocument.allIndices() returns the version + createdAt + updatedAt indices used by the framework's optimistic locking and timestamp handling.

Querying​

For ad-hoc queries the standard Kotlin driver API works as-is. For composing filters, sort and pagination together, use MongoQuery:

val results: RecordsPage<Product> = collection.query()
    .andFilter(Product::priceMinor.mongoGte(1000_00), Product::name.mongoIn("Apple", "Pear"))
    .sort(Product::createdAt.mongoSortDesc())
    .page(request.page())
    .find()

MongoCollection.pagedQuery(...) exposes the same operation as a single call when you already have the filter/sort/page constructed elsewhere. To translate Invirt's request-derived DataFilter into a MongoDB filter, use .mongoFilter():

"/products" GET { request ->
    val filter = productFilter(request)?.mongoFilter() ?: Filters.empty()
    val results = collection.pagedQuery(filter, request.page(), request.sort()?.mongoSort()?.let { listOf(it) } ?: emptyList())
    // ...
}

What's next​

See the API reference for the complete surface: