DMOs

The DMOs are the well known Data Mapper Object and into the Torpedo ecosystem DMOs are the chosen objects to use as output.

Each defined output adapter will have their own DMO instance. Sometimes could be the same one or sometimes not.

A DMO instance has the responsibility to map the entity data to the specific adapter. For instance, an adapter of type mongodb will have a DMO with the capability to encode (map) the entity data to bson format.

Let's illustrate this with the Author's Blog Entity sample.

Having the previous defined author entity schema as:

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version: torpedo.darksub.io/v1.0
kind: entity
spec:
  name: "author"
  plural: "authors"
  description: "The blog post author"

  schema:
    reserved:
      # By default, an ID is assigned as ULID format (string).
      # the field name id is reserved, but you can configure it from this section
      id:
        type: ulid

    fields:
      - name: name
        type: string
        description: "The author full name"
        doc: "The author full name"

      - name: email
        type: string
        description: "The author contact email"
        doc: "The author contact email"

  adapters:
    output:
      - type: mongodb
        metadata:
          collection: "authors"

And the output adapter as mongodb the generated DMO will be an object with the capability to be stored in MongoDB implementing the generated interface.

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// IEntityDMO interface to defines the Data Mapper Object implementation
type IEntityDMO interface {
    ToEntity() (*AuthorEntity, error)
    HydrateFromEntity(entity *AuthorEntity) error
    Id() string
    Created() int64
    Updated() int64
    Name() string
    Email() string
}

Following the golang implementation, the generated DMO will be:

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// EntityDMOMongoDB Data Mapper Object (DMO) to store entity into MongoDB
type EntityDMOMongoDB struct {
    *author.EntityDMO `bson:"-"`

    Id_      string `bson:"_id"`
    Created_ int64  `bson:"created"`
    Updated_ int64  `bson:"updated"`

    Name_      string `bson:"name"`
    Email_     string `bson:"email"`
}