feat(catalog): fetch options for partial variant selections

src/app/shared/components/variant-selector/variant-selector.component.ts

@@ -5,6 +5,7 @@ import {
   effect,
   input,
   model,
+  output,
   signal,
   untracked,
 } from '@angular/core';
@@ -23,6 +24,11 @@ export interface VariantSelectorVariant {
   values: Record<string, VariantAttributeValue>;
 }
 
+export interface VariantSelectorSelectionChange {
+  values: Record<string, VariantAttributeValue>;
+  selectedVariant: unknown;
+}
+
 interface VariantSelectorOption {
   key: string;
   label: string;
@@ -49,6 +55,7 @@ export class VariantSelectorComponent {
   readonly disabled = input(false);
   readonly compact = input(false);
   readonly autoSelectFirst = input(true);
+  readonly selectionValuesChange = output<VariantSelectorSelectionChange>();
 
   protected readonly selectedValues = signal<Record<string, VariantAttributeValue>>({});
   protected readonly compareValues = (
@@ -143,6 +150,10 @@ export class VariantSelectorComponent {
 
     this.selectedValues.set(values);
     this.selectedVariant.set(matchingVariant?.id ?? null);
+    this.selectionValuesChange.emit({
+      values: { ...values },
+      selectedVariant: matchingVariant?.id ?? null,
+    });
   }
 
   private optionsFor(variants: VariantSelectorVariant[], key: string): VariantSelectorOption[] {