Atlas API : Create Trait Type

Traits are Atlas types that act like decorators to provide a mechanism for classification. Traits can be applied to any Atlas entities (instances of classes). An entity can have any number of traits.

For example, a SECURITY_CLEARANCE trait could be defined with an attribute ‘security_level’. An Atlas entity (e.g. an instance of Person class) could be tagged with the SECURITY_CLEARANCE trait by providing a value for the trait’s ‘security_level’ attribute.

In order to use a trait, you first need to define the trait type. You can do that by posting to the Types resource of the Atlas REST APIs.

Types Resource

A type is the description of any representable item. In this case we are creating a trait type but the same resource is used to represent enums, structs and classes as well.

/types

POST

Submits a types definition containing a type definition representing a trait.

Request Body

Types Definition application/json

Response Body

Types Response application/json

Types Definition

Properties

enumTypes : Array of Type Definition for ENUM types

structTypes : Array of Type Definition for STRUCT types

traitTypes : Array of Type Definition for TRAIT types

classTypes : Array of Type Definition for CLASS types

Type Definition

Properties

superTypes : Array of super type names.

hierarchicalMetaTypeName : String : The trait class name.

typeName : String : The type name.

attributeDefinitions : Array of Attribute Definition.

Attribute Definition

Properties

name : String : The attribute name.

dataTypeName : String : The owning data type name.

multiplicity : String : OPTIONAL, REQUIRED, COLLECTION, SET

isComposite : Boolean : True if the attribute’s lifecycle is dependent on the enclosing type and is not just a reference.

isUnique : Boolean : True if the attribute must be unique.

isIndexable : Boolean : True if the attribute can be indexed.

reverseAttributeName : String : If this is a reference attribute, then the name of the attribute on the Class that this refers to.

Types Response

Properties

requestId : String : The unique id for the request.

types : Array of Type Name Definition.

Type Name Definition

Properties

name : String : The type name.

Example

The following example creates an Atlas trait type called EXPIRES_ON that has a single attribute called ‘expiry_date’.

POST

http://c6401.ambari.apache.org:21000/api/atlas/types

Body

{
"enumTypes": [],
"structTypes": [],
"traitTypes": [
{
"superTypes":[],
"hierarchicalMetaTypeName":
"org.apache.atlas.typesystem.types.TraitType",
"typeName": "EXPIRES_ON",
"attributeDefinitions": [
{
"name": "expiry_date",
"dataTypeName": "date",
"multiplicity": "required",
"isComposite": false,
"isUnique": false,
"isIndexable": true,
"reverseAttributeName": null
}
]
}
],
"classTypes": []
}

Response

{
requestId:"qtp1796488937-14 - 1a194816-1c6f-451a-b706-6dc2f53139e5"
types:{
name:"EXPIRES_ON"
}
}