MetaData

MetaData is a special schema part that is always available to a graph. The MetaData is always shown at the top of the Data Schema panel on the right of the application:

Normally, the MetaData only contains:

• Graph name: Always the name of the top-level graph deployed
• Project name: Name of the project
• Environment name: Name of the environment
• Transaction id: Transaction ids are generated with UUID
• Transaction start timestamp: Time when the transaction occurred

Therefore, the simple graph below will return corresponding simple MetaData.

In the event of an error, the MetaData will be populated entirely with the following information: 

• Error
  • Message - the error message created by the node that errored
  • Node
    • Name - the name of the node that caused the error
    • Type - the type of the node that caused the error 
  • Time - the timestamp when the error occurred
• TransactionState
  • PublicVariables - an object with all of the public variables in at the time the error occurred
  • Schema - an object containing the schema at the time the error occurred

This information can be used by your graph to record the error or to make a decision about whether the error is recoverable or not.

For Example:

In this graph, which deliberately attempts to get a value from a non-existent schema location, the fully populated MetaData object can be seen: