Modules | |
| Data Model Default Parameter Action Implementations | |
| Data Model Default Object Action Implementations | |
Detailed Description
Data model actions are the functions that make the data model work.
For each action a default implementation is provided. It is however possible to provide your own implementation, but in most cases the default one will be sufficient.
When overriding the default implementations, most of the time something extra needs to be done (extra check, pushing to system configuration, ...), so the default implementation could be called from within your own implementation.
There are two groups of actions available:
- object actions: read, write, validate, list, describe, add instance, delete instance, destroy
- parameter actions: read, write, validate, describe, destroy
Object actions are invoked on an object and will have a valid object pointer, while parameter actions are invoked on a specific parameter, the object and parameter pointer will be valid.
Instance objects and their parameters inherit the actions from the multi-instance object (aka the template object) and its parameters. When an instance has been created it is possible to set specific action implementation(s) for that instance.
Invoking actions recursivly (that is invoking actions from within an action) is subject to some restrictions. As a general rule it is not possible to invoke actions recursively with the following exceptions:
- Object actions can invoke parameter actions
- Read actions (read, list, describe) and validate actions can always be invoked recursively.
- Object destroy and delete instance actions can be called recursively on child objects (deeper in the hierarchical object tree).
Multiple action implementations can be set for a single action.
