Function: memo()#

Call Signature#

function memo<This, Value>(target, context): (this) => Value;

Defined in: decorators.ts:176

Decorator that memoizes a getter on a ReactiveNode.

Type Parameters#

Parameters#

Returns#

(this) => Value

Remarks#

Use @memo or @memo() for automatic dependency trapping. Pass a function only when you want finer cache-key control; the function captures this lazily, so the values are read fresh each time the getter is accessed.

Cache semantics (matches ReactiveNode.memo):

• No argument: @memo and @memo() are interchangeable. Both run the getter under automatic dependency trapping and recompute when one of the trapped reads changes.
• Returns undefined: recompute on every reproxy of the ReactiveNode.
• Returns []: compute once, cache forever for this instance.
• Returns [a, b, ...]: recompute on shallow-change.

The cache key is the getter's property name, so each @memo-decorated getter has its own cell automatically.

@memo is a cache, not a subscription. It does not emit Retree events or trigger React renders by itself. Use ReactiveNode.dependencies, Retree.select, or useSelect when you also need notification behavior.

Do not use @memo on methods; use fnMemo. Do not use it for values with side effects.

Example#

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

   @memo
   get filteredList() {
       return this.list.filter((c) => c.text === this.searchText);
   }

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

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

   @memo((self: ListFilter) => [self.list, self.searchText])
   get filteredListWithExplicitComparisons() {
       return this.list.filter((c) => c.text === this.searchText);
   }

Call Signature#

function memo<This>(getComparisons?): <Value>(target, context) => (this) => Value;

Defined in: decorators.ts:181

Decorator that memoizes a getter on a ReactiveNode.

Type Parameters#

Parameters#

Returns#

<Value>(target, context) => (this) => Value

Remarks#

Use @memo or @memo() for automatic dependency trapping. Pass a function only when you want finer cache-key control; the function captures this lazily, so the values are read fresh each time the getter is accessed.

Cache semantics (matches ReactiveNode.memo):

• No argument: @memo and @memo() are interchangeable. Both run the getter under automatic dependency trapping and recompute when one of the trapped reads changes.
• Returns undefined: recompute on every reproxy of the ReactiveNode.
• Returns []: compute once, cache forever for this instance.
• Returns [a, b, ...]: recompute on shallow-change.

The cache key is the getter's property name, so each @memo-decorated getter has its own cell automatically.

@memo is a cache, not a subscription. It does not emit Retree events or trigger React renders by itself. Use ReactiveNode.dependencies, Retree.select, or useSelect when you also need notification behavior.

Do not use @memo on methods; use fnMemo. Do not use it for values with side effects.

Example#

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

   @memo
   get filteredList() {
       return this.list.filter((c) => c.text === this.searchText);
   }

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

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

   @memo((self: ListFilter) => [self.list, self.searchText])
   get filteredListWithExplicitComparisons() {
       return this.list.filter((c) => c.text === this.searchText);
   }