Function: fnMemo()#

Call Signature#

function fnMemo<This, MethodArgs, Value>(target, context): FnMemoMethod<This, MethodArgs, Value>;

Defined in: decorators.ts:629

Decorator that memoizes a method return value on a ReactiveNode.

Type Parameters#

Parameters#

Returns#

FnMemoMethod<This, MethodArgs, Value>

Remarks#

Use @fnMemo or @fnMemo() for automatic dependency trapping. Pass a function only when you want finer cache-key control; the function receives the current instance and method arguments, so the values are read fresh each time the method is called. The method arguments are always shallow-compared.

Cache semantics:

• No argument: @fnMemo and @fnMemo() are interchangeable. Both run the method under automatic dependency trapping and recompute when the arguments or one of the trapped reads changes.
• Returns undefined: recompute when the arguments change, or on every reproxy of the ReactiveNode.
• Returns []: recompute only when the arguments change.
• Returns [a, b, ...]: recompute when the arguments or comparisons shallow-change.

Each decorated method stores one cache cell per instance, containing the last argument list and return value.

@fnMemo is a cache, not a subscription. It does not emit Retree events or trigger React renders by itself. Keep decorated methods deterministic for the same arguments and dependency values.

Do not apply @fnMemo to static methods or methods that intentionally perform side effects.

Example#

class ListFilter extends ReactiveNode {
   list: Card[] = [];
   searchText = "";

   @fnMemo
   filterBy(limit: number) {
       return this.list
           .filter((c) => c.text === this.searchText)
           .slice(0, limit);
   }

   get dependencies() { return [this.dependency(this.list)]; }
}

Pass explicit comparisons when the automatic trapper is broader than you want:

   @fnMemo((self: ListFilter, limit: number) => [
       self.list,
       self.searchText,
       limit,
   ])
   filterByWithExplicitComparisons(limit: number) {
       return this.list
           .filter((c) => c.text === this.searchText)
           .slice(0, limit);
   }

Call Signature#

function fnMemo<This, ComparisonArgs>(getComparisons?): <MethodArgs, Value>(target, context) => FnMemoMethod<This, MethodArgs, Value>;

Defined in: decorators.ts:641

Decorator that memoizes a method return value on a ReactiveNode.

Type Parameters#

Parameters#

Returns#

<MethodArgs, Value>(target, context) => FnMemoMethod<This, MethodArgs, Value>

Remarks#

Use @fnMemo or @fnMemo() for automatic dependency trapping. Pass a function only when you want finer cache-key control; the function receives the current instance and method arguments, so the values are read fresh each time the method is called. The method arguments are always shallow-compared.

Cache semantics:

• No argument: @fnMemo and @fnMemo() are interchangeable. Both run the method under automatic dependency trapping and recompute when the arguments or one of the trapped reads changes.
• Returns undefined: recompute when the arguments change, or on every reproxy of the ReactiveNode.
• Returns []: recompute only when the arguments change.
• Returns [a, b, ...]: recompute when the arguments or comparisons shallow-change.

Each decorated method stores one cache cell per instance, containing the last argument list and return value.

@fnMemo is a cache, not a subscription. It does not emit Retree events or trigger React renders by itself. Keep decorated methods deterministic for the same arguments and dependency values.

Do not apply @fnMemo to static methods or methods that intentionally perform side effects.

Example#

class ListFilter extends ReactiveNode {
   list: Card[] = [];
   searchText = "";

   @fnMemo
   filterBy(limit: number) {
       return this.list
           .filter((c) => c.text === this.searchText)
           .slice(0, limit);
   }

   get dependencies() { return [this.dependency(this.list)]; }
}

Pass explicit comparisons when the automatic trapper is broader than you want:

   @fnMemo((self: ListFilter, limit: number) => [
       self.list,
       self.searchText,
       limit,
   ])
   filterByWithExplicitComparisons(limit: number) {
       return this.list
           .filter((c) => c.text === this.searchText)
           .slice(0, limit);
   }