Enum Relation 

pub enum Relation {
    BelongsTo {
        local_type: &'static str,
        foreign_type: &'static str,
        fk_field_json: &'static str,
        extract_fk: FkExtractor,
        exclude_from_tree: bool,
    },
    OwnsMany {
        local_type: &'static str,
        foreign_type: &'static str,
        extract_ids: ArrayExtractor,
        remove_id: ArrayRemover,
        exclude_from_tree: bool,
    },
    EnsureFor {
        local_type: &'static str,
        dependencies: &'static [EnsureForDependency],
        make_entity: EntityFactory,
        exclude_from_tree: bool,
    },
}

Represents the different types of entity relationships

Variants

BelongsTo

Child entity has a foreign key pointing to parent. When parent is DEL’d -> cascade delete all children with matching FK.

Example: Binding.scope_id belongs to Scene.id When Scene is deleted, all Bindings with that scope_id are deleted.

Fields

local_type: &'static str

Entity type that has the foreign key (child)

foreign_type: &'static str

Entity type being referenced (parent)

fk_field_json: &'static str

The camelCase JSON field name of the FK (e.g., “scopeId”, “projectId”)

extract_fk: FkExtractor

Function to extract the FK value from a child entity

exclude_from_tree: bool

If true, this child type is excluded from entity tree exports. The relationship still cascades on delete — only tree traversal is affected.

OwnsMany

Parent entity owns an array of child IDs. When parent DEL’d -> cascade delete all referenced children. When child DEL’d -> remove child ID from parent’s array, recalculate hash.

Example: Scene.node_ids owns BindingNode entities When Scene is deleted, all BindingNodes in node_ids are deleted. When a BindingNode is deleted, it’s removed from the owning Scene’s node_ids.

Fields

local_type: &'static str

Entity type that owns the array (parent)

foreign_type: &'static str

Entity type being owned (child)

extract_ids: ArrayExtractor

Function to extract owned IDs from a parent entity

remove_id: ArrayRemover

Function to remove an ID from parent and return updated entity as Value

exclude_from_tree: bool

If true, exclude this child type from entity tree exports.

EnsureFor

Auto-create entity for each combination of dependencies. When any dependency is SET -> ensure local entity exists for all combinations.

Example: BundleStatus ensure-for (Session, Bundle) Creates one BundleStatus per Session×Bundle combination.

Fields

local_type: &'static str

Entity type to auto-create

dependencies: &'static [EnsureForDependency]

Dependencies to create Cartesian product from

make_entity: EntityFactory

Factory function to create entity with dependency IDs populated. Takes slice of dependency IDs in same order as dependencies array. Returns complete entity with id, hash, FK fields, and default values.

exclude_from_tree: bool

If true, exclude this entity type from entity tree exports.

Trait Implementations

impl Clone for Relation

fn clone(&self) -> Relation

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Relation

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.