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Namespace

Namespaces help organise model artefacts into logical groups. Think of a namespace as a container that groups related components so the model is easier to understand, navigate and maintain. 1

Namespaces also:

  • Make the model structure clearer for users
  • Allow teams to adopt only the parts they need
  • Reduce disruption when parts of the model are restructured
  • Map directly to the namespaces’ Group and Artefact directory structure (a.k.a. ‘GAV coordinates’), which is visible in the model editor 2

Namespaces are arranged in a hierarchy, from inner layers to outer layers. Key points about this hierarchy:

  • Each layer can access (import) the layer outside it
  • Outer layers can be used independently of inner layers
  • A layer may contain multiple sibling namespaces, which can reference each other

Namespace syntax​

A namespace is defined using the namespace keyword followed by its directory path: namespace cdm.product.common Naming rules:

  • All component names must be unique within the same namespace.
  • Components inside the same namespace can refer to each other by name only.

To reference components in another namespace, you must either:

  • Use the fully qualified name, e.g. cdm.base.datetime.AdjustableDate, or
  • Import the namespace.

Importing namespaces​

To access components from another namespace, use the import keyword: import cdm.product.asset.* This imports all components in the cdm.product.asset namespace. Important details:

  • Only the components in the specific layer you import are included.
  • If you need components from deeper nested namespaces, you must import each one individually.

Example: importing multiple namespaces. This brings in all components from the various layers under cdm.base:

import cdm.base.math.*
import cdm.base.datetime.*
import cdm.base.staticdata.party.*
import cdm.base.staticdata.asset.common.*
import cdm.base.staticdata.asset.rates.*
import cdm.base.staticdata.asset.credit.*

You can also reference a namespace is by using an import ... as ... alias.

Using namespace aliases​

You can assign an alias to an imported namespace to make references shorter and clearer:

import cdm.base.staticdata.party.* as cdmParty

Now you can reference types from that namespace using the alias:

type MyContainer:
  party cdmParty.Party (1..1)

Rules for aliases​

  • You can only alias imports that use the * wildcard (i.e. full namespace imports).
  • When using an alias, you must prefix all referenced types with that alias.

Footnotes​

  1. Do we need to explain how to create namespaces? ↩

  2. What does this last bullet point mean? Can we explain it better ↩