ATTRIBUTE_VJS_SOURCE_PORT_ID
constATTRIBUTE_VJS_SOURCE_PORT_ID:"data-vjs-source-port-id"="data-vjs-source-port-id"
Indicates the ID of the logical port that the element represents when it is acting as an edge source. In some situations you might want to use the same element as a source and target, but have the data model use different logical ports.
Advanced
Dom Attribute
Context
edge-dragging