Data Trigger#
Data Trigger Overview#
Although data contracts provide much needed constraints on the structure of the data being stored on Dash Platform, there are limits to what they can do. Certain system data contracts may require server-side validation logic to operate effectively. For example, DPNS must enforce some rules to ensure names remain DNS compatible. Dash Platform Protocol (DPP) supports this application-specific custom logic using Data Triggers.
Details#
Since all application data is submitted in the form of documents, data triggers are defined in the context of documents. To provide even more granularity, they also incorporate the document transition action so separate triggers can be created for the CREATE, REPLACE, or DELETE actions.
When document state transitions are received, DPP checks if there is a trigger associated with the document transition type and action. If there is, it then executes the trigger logic.
Note: Successful execution of the trigger logic is necessary for the document to be accepted and applied to the platform state.
Example#
As an example, DPP contains several data triggers for DPNS as defined in the data triggers factory. The domain
document has added constraints for creation. All DPNS document types have constraints on replacing or deleting:
Data Contract |
Document |
Action(s) |
Trigger Description |
---|---|---|---|
DPNS |
|
Enforces DNS compatibility, validates provided hashes, and restricts top-level domain (TLD) registration |
|
—- |
—- |
—- |
—- |
DPNS |
All Document Types |
Prevents updates to existing documents |
|
DPNS |
All Document Types |
Prevents deletion of existing documents |
DPNS Trigger Constraints
The following table details the DPNS constraints applied via data triggers. These constraints are in addition to the ones applied directly by the DPNS data contract.
Document |
Action |
Constraint |
---|---|---|
|
|
Full domain length <= 253 characters |
|
|
|
|
|
|
|
|
Only creating a top-level domain with an authorized identity |
|
|
Referenced |
|
|
Subdomain registration for non top level domains prevented if |
|
|
Subdomain registration only allowed by the parent domain owner if |
|
|
Referenced |
|
|
Action not allowed |
|
|
Action not allowed |
|
|
Action not allowed |
|
|
Action not allowed |