Trait former::protected::FormerMutator
source · pub trait FormerMutator: FormerDefinitionTypes {
// Provided method
fn form_mutation(
_storage: &mut Self::Storage,
_context: &mut Option<Self::Context>
) { ... }
}Expand description
Provides a mechanism for mutating the context and storage just before the forming process is completed.
The FormerMutator trait allows for the implementation of custom mutation logic on the internal state
of an entity (context and storage) just before the final forming operation is completed. This mutation
occurs immediately before the FormingEnd callback is invoked.
§Differences from FormingEnd
Unlike FormingEnd, which is responsible for integrating and finalizing the formation process of a field within
a parent former, form_mutation directly pertains to the entity itself. This method is designed to be independent
of whether the forming process is occurring within the context of a superformer or if the structure is a standalone
or nested field. This makes form_mutation suitable for entity-specific transformations that should not interfere
with the hierarchical forming logic managed by FormingEnd.
§Use Cases
- Applying last-minute changes to the data being formed.
- Setting or modifying properties that depend on the final state of the storage or context.
- Storage-specific fields which are not present in formed structure.
Look example former_custom_mutator.rs
Provided Methods§
sourcefn form_mutation(
_storage: &mut Self::Storage,
_context: &mut Option<Self::Context>
)
fn form_mutation( _storage: &mut Self::Storage, _context: &mut Option<Self::Context> )
Mutates the context and storage of the entity just before the formation process completes.
This function is invoked immediately prior to the FormingEnd callback during the forming process.
It provides a hook for implementing custom logic that modifies the internal state (storage and context)
of the entity. form_mutation is particularly useful for adjustments or updates that need to reflect
in the entity just before it is finalized and returned.