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Imports

In order for one namespace to reference types defined in another namespace, the types must be imported from a versioned namespace. Via imports you can decompose your modles into discrete files (and namespaces), version them and build a graph of dependencies between your models.

Single Import​

// imports PostalAddress from version 1.0.0 of the org.accordproject.address namespace
import org.accordproject.address@1.0.0.PostalAddress

Multiple Imports​

To import multiple types from the same namespace, use the {} syntax:

// imports PostalAddress and Country from version 1.0.0 of the org.accordproject.address namespace
import org.accordproject.address@1.0.0.{PostalAddress,Country}

Importing from model published to a public URL​

Import also can use the optional from declaration to import a model file that has been deployed to a URL.

// imports a type from a publicly addressable URL
import org.accordproject.address@1.0.0.PostalAddress from https://models.accordproject.org/address.cto

Imports using a from declaration can be downloaded into the model manager by calling modelManager.updateExternalModels or the concerto get CLI command.

The Model Manager will resolve all imports to ensure that the set of declarations that have been loaded are globally consistent.

Aliasing imported types​

Imported types can also be aliased to local names. Aliasing is only allowed using the {} syntax. Aliased and non-aliased types can be mixed within the same import statement, as demonstrated in the example below


import org.accordproject.address@1.0.0.{PostalAddress as pa, Country}

concept Person{
    o String name
    o pa address optional
    o Country country
}

Note: Aliasing is disabled by default in concerto. To enable this feature in Concerto, set environment variable IMPORT_ALIASING='true' or provide importAliasing as an option to the Concerto ModelManager constructor.

Strict:false mode​

For backwards compatability, and when running with strict:false imports may import types from unversioned namespaces, or may import all types in a namespace.

Please migrate models to use versioned namespaces and imports as this capability will be deprecated and removed in a future major release.

Imports can be either qualified or can use wildcards.

// import a type from an unversioned namespace (only if strict=false)
import org.accordproject.address.PostalAddress
// import all types from an unversioned namespace (only if strict=false)
import org.accordproject.address.*