ZCU-PUB/feat(community): show "Články" collection 3rd, after "Kapitoly v knihách" (#953)

Hardcode the display order for the ZCU publications community so that the
"Články" collection appears in 3rd position, immediately after "Kapitoly v
knihách", while all other collections keep their existing alphabetical order.

Approach: the base sub-collection-list component gains a no-op
`applyCustomCollectionOrder` seam applied to each fetched page, keeping
behavior identical for every other theme/customer. The custom theme overrides
it to pin the two named collections via a small, unit-tested pure
`reorderCollections` helper.

Assumption: only the "Články -> 3rd" constraint is encoded here; a full
configurable custom ordering would be the separate Option B feature.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: Matus Kasak

src/app/community-page/sub-collection-list/community-page-sub-collection-list.component.ts

@@ -88,10 +88,24 @@ export class CommunityPageSubCollectionListComponent implements OnInit, OnDestro
         });
       })
     ).subscribe((results) => {
-      this.subCollectionsRDObs.next(results);
+      this.subCollectionsRDObs.next(this.applyCustomCollectionOrder(results));
     }));
   }
 
+  /**
+   * Extension point for theme/customer-specific ordering of the current page of collections.
+   *
+   * The default implementation is a no-op that returns the RemoteData unchanged, so behavior
+   * stays identical for every theme and customer. Themes that need a bespoke display order
+   * (e.g. a hardcoded pinned position for a specific collection) override this method.
+   *
+   * @param rd the RemoteData holding the current page of collections
+   * @returns the RemoteData to emit, potentially with a reordered page
+   */
+  protected applyCustomCollectionOrder(rd: RemoteData<PaginatedList<Collection>>): RemoteData<PaginatedList<Collection>> {
+    return rd;
+  }
+
   ngOnDestroy(): void {
     this.paginationService.clearPagination(this.config?.id);
     this.subscriptions.map((subscription: Subscription) => subscription.unsubscribe());

src/themes/custom/app/community-page/sub-collection-list/community-page-sub-collection-list.component.spec.ts

@@ -0,0 +1,97 @@
+import { Collection } from '../../../../../app/core/shared/collection.model';
+import { CommunityPageSubCollectionListComponent } from './community-page-sub-collection-list.component';
+
+/**
+ * Builds a minimal Collection-like stub that only exposes the `name` getter used by the
+ * reordering logic under test.
+ *
+ * @param name the collection name (dc.title) to expose
+ * @returns an object typed as Collection for the purposes of these tests
+ */
+function fakeCollection(name: string): Collection {
+  return { get name(): string { return name; } } as Collection;
+}
+
+/**
+ * Maps a list of collections to their names for concise assertions.
+ *
+ * @param collections the collections to map
+ * @returns the ordered list of collection names
+ */
+function names(collections: Collection[]): string[] {
+  return collections.map((collection: Collection) => collection.name);
+}
+
+const SECOND_COLLECTION_NAME = 'Kapitoly v knihách';
+const THIRD_COLLECTION_NAME = 'Články';
+
+describe('CommunityPageSubCollectionListComponent (custom theme) reorderCollections', () => {
+  let component: CommunityPageSubCollectionListComponent;
+
+  const reorder = (collections: Collection[]): Collection[] =>
+    (component as any).reorderCollections(collections);
+
+  beforeEach(() => {
+    component = new CommunityPageSubCollectionListComponent(null, null, null);
+  });
+
+  it('pins "Články" to the 3rd position, directly after "Kapitoly v knihách"', () => {
+    const input = [
+      fakeCollection('Alfa'),
+      fakeCollection(SECOND_COLLECTION_NAME),
+      fakeCollection(THIRD_COLLECTION_NAME),
+      fakeCollection('Zeta'),
+    ];
+
+    const result = reorder(input);
+
+    expect(names(result)).toEqual(['Alfa', SECOND_COLLECTION_NAME, THIRD_COLLECTION_NAME, 'Zeta']);
+    expect(result[2].name).toBe(THIRD_COLLECTION_NAME);
+    expect(result[1].name).toBe(SECOND_COLLECTION_NAME);
+    expect(names(result).indexOf(THIRD_COLLECTION_NAME))
+      .toBe(names(result).indexOf(SECOND_COLLECTION_NAME) + 1);
+  });
+
+  it('leaves the list unchanged when "Kapitoly v knihách" is missing', () => {
+    const input = [
+      fakeCollection('Alfa'),
+      fakeCollection(THIRD_COLLECTION_NAME),
+      fakeCollection('Zeta'),
+    ];
+
+    expect(names(reorder(input))).toEqual(['Alfa', THIRD_COLLECTION_NAME, 'Zeta']);
+  });
+
+  it('leaves the list unchanged when "Články" is missing', () => {
+    const input = [
+      fakeCollection('Alfa'),
+      fakeCollection(SECOND_COLLECTION_NAME),
+      fakeCollection('Zeta'),
+    ];
+
+    expect(names(reorder(input))).toEqual(['Alfa', SECOND_COLLECTION_NAME, 'Zeta']);
+  });
+
+  it('leaves the list unchanged when there are no other collections', () => {
+    const input = [
+      fakeCollection(SECOND_COLLECTION_NAME),
+      fakeCollection(THIRD_COLLECTION_NAME),
+    ];
+
+    expect(names(reorder(input))).toEqual([SECOND_COLLECTION_NAME, THIRD_COLLECTION_NAME]);
+  });
+
+  it('uses the exact diacritic collection names', () => {
+    expect(SECOND_COLLECTION_NAME).toBe('Kapitoly v knihách');
+    expect(THIRD_COLLECTION_NAME).toBe('Články');
+
+    const input = [
+      fakeCollection('Alfa'),
+      fakeCollection('Kapitoly v knihach'),
+      fakeCollection('Clanky'),
+      fakeCollection('Zeta'),
+    ];
+
+    expect(names(reorder(input))).toEqual(['Alfa', 'Kapitoly v knihach', 'Clanky', 'Zeta']);
+  });
+});

src/themes/custom/app/community-page/sub-collection-list/community-page-sub-collection-list.component.ts

@@ -1,6 +1,19 @@
 import { Component } from '@angular/core';
 import { CommunityPageSubCollectionListComponent as BaseComponent }
   from '../../../../../app/community-page/sub-collection-list/community-page-sub-collection-list.component';
+import { RemoteData } from '../../../../../app/core/data/remote-data';
+import { PaginatedList } from '../../../../../app/core/data/paginated-list.model';
+import { Collection } from '../../../../../app/core/shared/collection.model';
+
+/**
+ * Name of the collection pinned to the 2nd position for the ZCU publications community.
+ */
+const SECOND_COLLECTION_NAME = 'Kapitoly v knihách';
+
+/**
+ * Name of the collection pinned to the 3rd position for the ZCU publications community.
+ */
+const THIRD_COLLECTION_NAME = 'Články';
 
 @Component({
   selector: 'ds-community-page-sub-collection-list',
@@ -9,4 +22,43 @@ import { CommunityPageSubCollectionListComponent as BaseComponent }
   // templateUrl: './community-page-sub-collection-list.component.html',
   templateUrl: '../../../../../app/community-page/sub-collection-list/community-page-sub-collection-list.component.html'
 })
-export class CommunityPageSubCollectionListComponent extends BaseComponent {}
+export class CommunityPageSubCollectionListComponent extends BaseComponent {
+
+  /**
+   * Reorders the current page of collections so that "Kapitoly v knihách" is shown 2nd and
+   * "Články" 3rd, while all other collections keep their existing alphabetical order.
+   *
+   * @param rd the RemoteData holding the current page of collections
+   * @returns the RemoteData with a reordered page, or unchanged when the page is empty
+   */
+  protected applyCustomCollectionOrder(rd: RemoteData<PaginatedList<Collection>>): RemoteData<PaginatedList<Collection>> {
+    const page = rd?.payload?.page;
+    if (Array.isArray(page) && page.length > 0) {
+      rd.payload.page = this.reorderCollections(page);
+    }
+    return rd;
+  }
+
+  /**
+   * Pure helper that reorders a list of collections to pin "Kapitoly v knihách" to the 2nd
+   * position and "Články" to the 3rd, keeping every other collection in its original order.
+   *
+   * The rule only applies when both pinned collections are present and there is at least one
+   * other collection; otherwise the list is returned unchanged. The result is
+   * `[others[0], second, third, ...others.slice(1)]`.
+   *
+   * @param collections the collections of the current page (alphabetical by dc.title)
+   * @returns a new, reordered array, or the original array when the rule does not apply
+   */
+  protected reorderCollections(collections: Collection[]): Collection[] {
+    const second = collections.find((collection: Collection) => collection.name === SECOND_COLLECTION_NAME);
+    const third = collections.find((collection: Collection) => collection.name === THIRD_COLLECTION_NAME);
+    const others = collections.filter((collection: Collection) => collection !== second && collection !== third);
+
+    if (second && third && others.length >= 1) {
+      return [others[0], second, third, ...others.slice(1)];
+    }
+    return collections;
+  }
+
+}