Feature: Nested Tags (#10833)

---------

Co-authored-by: Trenton H <797416+stumpylog@users.noreply.github.com>

src-ui/src/app/components/common/edit-dialog/tag-edit-dialog/tag-edit-dialog.component.html

@@ -12,6 +12,8 @@
 
     <pngx-input-color i18n-title title="Color" formControlName="color" [error]="error?.color"></pngx-input-color>
 
+    <pngx-input-select i18n-title title="Parent" formControlName="parent" [items]="tags" [allowNull]="true" [error]="error?.parent"></pngx-input-select>
+
     <pngx-input-check i18n-title title="Inbox tag" formControlName="is_inbox_tag" i18n-hint hint="Inbox tags are automatically assigned to all consumed documents."></pngx-input-check>
     <pngx-input-select i18n-title title="Matching algorithm" [items]="getMatchingAlgorithms()" formControlName="matching_algorithm"></pngx-input-select>
     @if (patternRequired) {

src-ui/src/app/components/common/edit-dialog/tag-edit-dialog/tag-edit-dialog.component.ts

@@ -35,11 +35,16 @@ import { TextComponent } from '../../input/text/text.component'
   ],
 })
 export class TagEditDialogComponent extends EditDialogComponent<Tag> {
+  tags: Tag[]
+
   constructor() {
     super()
     this.service = inject(TagService)
     this.userService = inject(UserService)
     this.settingsService = inject(SettingsService)
+    this.service.listAll().subscribe((result) => {
+      this.tags = result.results
+    })
   }
 
   getCreateTitle() {
@@ -55,6 +60,7 @@ export class TagEditDialogComponent extends EditDialogComponent<Tag> {
       name: new FormControl(''),
       color: new FormControl(randomColor()),
       is_inbox_tag: new FormControl(false),
+      parent: new FormControl(null),
       matching_algorithm: new FormControl(DEFAULT_MATCHING_ALGORITHM),
       match: new FormControl(''),
       is_insensitive: new FormControl(true),

src-ui/src/app/components/common/filterable-dropdown/filterable-dropdown.component.ts

@@ -114,6 +114,13 @@ export class FilterableDropdownSelectionModel {
           b.id == NEGATIVE_NULL_FILTER_VALUE)
       ) {
         return 1
+      }
+
+      // Preserve hierarchical order when provided (e.g., Tags)
+      const ao = (a as any)['orderIndex']
+      const bo = (b as any)['orderIndex']
+      if (ao !== undefined && bo !== undefined) {
+        return ao - bo
       } else if (
         this.getNonTemporary(a.id) == ToggleableItemState.NotSelected &&
         this.getNonTemporary(b.id) != ToggleableItemState.NotSelected

src-ui/src/app/components/common/filterable-dropdown/toggleable-dropdown-button/toggleable-dropdown-button.component.html

@@ -15,12 +15,17 @@
       <i-bs width="1em" height="1em" name="x"></i-bs>
     }
   </div>
-  <div class="me-1">
-    @if (isTag) {
-      <pngx-tag [tag]="item" [clickable]="false"></pngx-tag>
-    } @else {
-      <small>{{item.name}}</small>
+  <div class="me-1 name-cell" [style.--depth]="isTag ? getDepth() + 1 : 1">
+    @if (isTag && getDepth() > 0) {
+      <div class="indicator"></div>
     }
+    <div>
+      @if (isTag) {
+        <pngx-tag [tag]="item" [clickable]="false"></pngx-tag>
+      } @else {
+        <small>{{item.name}}</small>
+      }
+    </div>
   </div>
   @if (!hideCount) {
     <div class="badge bg-light text-dark rounded-pill ms-auto me-1">{{currentCount}}</div>

src-ui/src/app/components/common/filterable-dropdown/toggleable-dropdown-button/toggleable-dropdown-button.component.scss

@@ -2,3 +2,19 @@
   min-width: 1em;
   min-height: 1em;
 }
+
+.name-cell {
+  padding-left: calc(calc(var(--depth) - 2) * 1rem);
+  display: flex;
+  align-items: center;
+
+  .indicator {
+    display: inline-block;
+    width: .8rem;
+    height: .8rem;
+    border-left: 1px solid var(--bs-secondary);
+    border-bottom: 1px solid var(--bs-secondary);
+    margin-right: .25rem;
+    margin-left: .5rem;
+  }
+}

src-ui/src/app/components/common/filterable-dropdown/toggleable-dropdown-button/toggleable-dropdown-button.component.ts

@@ -1,6 +1,7 @@
 import { Component, EventEmitter, Input, Output } from '@angular/core'
 import { NgxBootstrapIconsModule } from 'ngx-bootstrap-icons'
 import { MatchingModel } from 'src/app/data/matching-model'
+import { Tag } from 'src/app/data/tag'
 import { TagComponent } from '../../tag/tag.component'
 
 export enum ToggleableItemState {
@@ -45,6 +46,10 @@ export class ToggleableDropdownButtonComponent {
     return 'is_inbox_tag' in this.item
   }
 
+  getDepth(): number {
+    return (this.item as Tag).depth ?? 0
+  }
+
   get currentCount(): number {
     return this.count ?? this.item.document_count
   }

src-ui/src/app/components/common/input/tags/tags.component.html

@@ -7,13 +7,14 @@
       <div class="input-group flex-nowrap">
         <ng-select #tagSelect name="tags" [items]="tags" bindLabel="name" bindValue="id" [(ngModel)]="value"
           [disabled]="disabled"
-          [multiple]="true"
+          [multiple]="multiple"
           [closeOnSelect]="false"
           [clearSearchOnAdd]="true"
           [hideSelected]="tags.length > 0"
           [addTag]="allowCreate ? createTagRef : false"
           addTagText="Add tag"
           i18n-addTagText
+          (add)="onAdd($event)"
           (change)="onChange(value)">
 
           <ng-template ng-label-tmp let-item="item">
@@ -25,9 +26,20 @@
             </button>
           </ng-template>
           <ng-template ng-option-tmp let-item="item" let-index="index" let-search="searchTerm">
-            <div class="tag-wrap">
+            <div class="tag-option-row d-flex align-items-center">
               @if (item.id && tags) {
-                <pngx-tag class="me-2" [tag]="getTag(item.id)"></pngx-tag>
+                @if (getTag(item.id)?.parent) {
+                  <i-bs name="list-nested" class="me-1"></i-bs>
+                  <span class="hierarchy-reveal d-flex align-items-center">
+                    <span class="parents d-flex align-items-center">
+                      @for (p of getParentChain(item.id); track p.id) {
+                        <span class="badge me-1" [style.background]="p.color" [style.color]="p.text_color">{{p.name}}</span>
+                        <i-bs name="chevron-right" width=".8em" height=".8em" class="me-1"></i-bs>
+                      }
+                    </span>
+                  </span>
+                }
+                <pngx-tag class="current-tag d-flex" [tag]="getTag(item.id)"></pngx-tag>
               }
             </div>
           </ng-template>

src-ui/src/app/components/common/input/tags/tags.component.scss

@@ -20,3 +20,33 @@
       }
   }
 }
+
+// Dropdown hierarchy reveal for ng-select options
+::ng-deep .ng-dropdown-panel .ng-option {
+  overflow-x: scroll;
+
+  .tag-option-row {
+    font-size: 1rem;
+    width: max-content;
+  }
+
+  .hierarchy-reveal {
+    overflow: hidden;
+    max-width: 0;
+    transition: max-width 200ms ease;
+  }
+
+  .parents .badge {
+    white-space: nowrap;
+  }
+}
+
+::ng-deep .ng-dropdown-panel .ng-option:hover .hierarchy-reveal,
+::ng-deep .ng-dropdown-panel .ng-option.ng-option-marked .hierarchy-reveal {
+  max-width: 1000px;
+}
+
+::ng-deep .ng-dropdown-panel .ng-option:hover .hierarchy-indicator,
+::ng-deep .ng-dropdown-panel .ng-option.ng-option-marked .hierarchy-indicator {
+  background: transparent;
+}

src-ui/src/app/components/common/input/tags/tags.component.spec.ts

@@ -177,4 +177,59 @@ describe('TagsComponent', () => {
     component.onFilterDocuments()
     expect(emitSpy).toHaveBeenCalledWith([tags[2]])
   })
+
+  it('should remove all descendants from selection', () => {
+    const c: Tag = { id: 4, name: 'c' }
+    const b: Tag = { id: 3, name: 'b', children: [c] }
+    const a: Tag = { id: 2, name: 'a' }
+    const root: Tag = { id: 1, name: 'root', children: [a, b] }
+
+    const inputIDs = [2, 3, 4, 99]
+    const result = (component as any).removeChildren(inputIDs, root)
+    expect(result).toEqual([99])
+  })
+
+  it('should append all parents recursively', () => {
+    const root: Tag = { id: 1, name: 'root' }
+    const mid: Tag = { id: 2, name: 'mid', parent: 1 }
+    const leaf: Tag = { id: 3, name: 'leaf', parent: 2 }
+    component.tags = [root, mid, leaf]
+
+    component.value = []
+    component.onAdd(leaf)
+    expect(component.value).toEqual([2, 1])
+
+    // Calling onAdd on a root should not change value
+    component.onAdd(root)
+    expect(component.value).toEqual([2, 1])
+  })
+
+  it('should return ancestors from root to parent using getParentChain', () => {
+    const root: Tag = { id: 1, name: 'root' }
+    const mid: Tag = { id: 2, name: 'mid', parent: 1 }
+    const leaf: Tag = { id: 3, name: 'leaf', parent: 2 }
+    component.tags = [root, mid, leaf]
+
+    expect(component.getParentChain(3).map((t) => t.id)).toEqual([1, 2])
+    expect(component.getParentChain(2).map((t) => t.id)).toEqual([1])
+    expect(component.getParentChain(1).map((t) => t.id)).toEqual([])
+    // Non-existent id
+    expect(component.getParentChain(999).map((t) => t.id)).toEqual([])
+  })
+
+  it('should handle cyclic parents via guard in getParentChain', () => {
+    const one: Tag = { id: 1, name: 'one', parent: 2 }
+    const two: Tag = { id: 2, name: 'two', parent: 1 }
+    component.tags = [one, two]
+
+    const chain = component.getParentChain(1)
+    // Guard avoids infinite loop; chain contains both nodes once
+    expect(chain.map((t) => t.id)).toEqual([1, 2])
+  })
+
+  it('should stop when parent does not exist in getParentChain', () => {
+    const lone: Tag = { id: 5, name: 'lone', parent: 999 }
+    component.tags = [lone]
+    expect(component.getParentChain(5)).toEqual([])
+  })
 })

src-ui/src/app/components/common/input/tags/tags.component.ts

@@ -100,6 +100,9 @@ export class TagsComponent implements OnInit, ControlValueAccessor {
   @Input()
   horizontal: boolean = false
 
+  @Input()
+  multiple: boolean = true
+
   @Output()
   filterDocuments = new EventEmitter<Tag[]>()
 
@@ -124,13 +127,40 @@ export class TagsComponent implements OnInit, ControlValueAccessor {
 
     let index = this.value.indexOf(tagID)
     if (index > -1) {
+      const tag = this.getTag(tagID)
+
+      // remove tag
       let oldValue = this.value
       oldValue.splice(index, 1)
+
+      // remove children
+      oldValue = this.removeChildren(oldValue, tag)
+
       this.value = [...oldValue]
       this.onChange(this.value)
     }
   }
 
+  private removeChildren(tagIDs: number[], tag: Tag) {
+    if (tag.children?.length) {
+      const childIDs = tag.children.map((child) => child.id)
+      tagIDs = tagIDs.filter((id) => !childIDs.includes(id))
+      for (const child of tag.children) {
+        tagIDs = this.removeChildren(tagIDs, child)
+      }
+    }
+    return tagIDs
+  }
+
+  public onAdd(tag: Tag) {
+    if (tag.parent) {
+      // add all parents recursively
+      const parent = this.getTag(tag.parent)
+      this.value = [...this.value, parent.id]
+      this.onAdd(parent)
+    }
+  }
+
   createTag(name: string = null, add: boolean = false) {
     var modal = this.modalService.open(TagEditDialogComponent, {
       backdrop: 'static',
@@ -166,6 +196,7 @@ export class TagsComponent implements OnInit, ControlValueAccessor {
 
   addTag(id) {
     this.value = [...this.value, id]
+    this.onAdd(this.getTag(id))
     this.onChange(this.value)
   }
 
@@ -180,4 +211,20 @@ export class TagsComponent implements OnInit, ControlValueAccessor {
       this.tags.filter((t) => this.value.includes(t.id))
     )
   }
+
+  getParentChain(id: number): Tag[] {
+    // Returns ancestors from root → immediate parent for a tag id
+    const chain: Tag[] = []
+    let current = this.getTag(id)
+    const guard = new Set<number>()
+    while (current?.parent) {
+      if (guard.has(current.parent)) break
+      guard.add(current.parent)
+      const parent = this.getTag(current.parent)
+      if (!parent) break
+      chain.unshift(parent)
+      current = parent
+    }
+    return chain
+  }
 }

src-ui/src/app/components/common/tag/tag.component.html

@@ -1,4 +1,8 @@
 @if (tag) {
+  @if (showParents && tag.parent) {
+    <pngx-tag [tagID]="tag.parent" [clickable]="clickable" [linkTitle]="linkTitle"></pngx-tag>
+      &nbsp;&gt;&nbsp;
+  }
   @if (!clickable) {
     <span class="badge" [style.background]="tag.color" [style.color]="tag.text_color">{{tag.name}}</span>
   }

src-ui/src/app/components/common/tag/tag.component.ts

@@ -50,4 +50,7 @@ export class TagComponent {
 
   @Input()
   clickable: boolean = false
+
+  @Input()
+  showParents: boolean = false
 }

src-ui/src/app/components/document-list/bulk-editor/bulk-editor.component.spec.ts

@@ -1204,7 +1204,7 @@ describe('BulkEditorComponent', () => {
     expect(tagListAllSpy).toHaveBeenCalled()
 
     expect(tagSelectionModelToggleSpy).toHaveBeenCalledWith(newTag.id)
-    expect(component.tagSelectionModel.items).toEqual(
+    expect(component.tagSelectionModel.items).toMatchObject(
       [{ id: null, name: 'Not assigned' }].concat(tags.results as any)
     )
   })

src-ui/src/app/components/document-list/bulk-editor/bulk-editor.component.ts

@@ -37,6 +37,7 @@ import { StoragePathService } from 'src/app/services/rest/storage-path.service'
 import { TagService } from 'src/app/services/rest/tag.service'
 import { SettingsService } from 'src/app/services/settings.service'
 import { ToastService } from 'src/app/services/toast.service'
+import { flattenTags } from 'src/app/utils/flatten-tags'
 import { MergeConfirmDialogComponent } from '../../common/confirm-dialog/merge-confirm-dialog/merge-confirm-dialog.component'
 import { RotateConfirmDialogComponent } from '../../common/confirm-dialog/rotate-confirm-dialog/rotate-confirm-dialog.component'
 import { CorrespondentEditDialogComponent } from '../../common/edit-dialog/correspondent-edit-dialog/correspondent-edit-dialog.component'
@@ -164,7 +165,10 @@ export class BulkEditorComponent
       this.tagService
         .listAll()
         .pipe(first())
-        .subscribe((result) => (this.tagSelectionModel.items = result.results))
+        .subscribe(
+          (result) =>
+            (this.tagSelectionModel.items = flattenTags(result.results))
+        )
     }
     if (
       this.permissionService.currentUserCan(
@@ -648,7 +652,7 @@ export class BulkEditorComponent
       )
       .pipe(takeUntil(this.unsubscribeNotifier))
       .subscribe(({ newTag, tags }) => {
-        this.tagSelectionModel.items = tags.results
+        this.tagSelectionModel.items = flattenTags(tags.results)
         this.tagSelectionModel.toggle(newTag.id)
       })
   }

src-ui/src/app/components/document-list/filter-editor/filter-editor.component.spec.ts

@@ -589,7 +589,7 @@ describe('FilterEditorComponent', () => {
     expect(component.tagSelectionModel.logicalOperator).toEqual(
       LogicalOperator.And
     )
-    expect(component.tagSelectionModel.getSelectedItems()).toEqual(tags)
+    expect(component.tagSelectionModel.getSelectedItems()).toMatchObject(tags)
     // coverage
     component.filterRules = [
       {
@@ -615,7 +615,7 @@ describe('FilterEditorComponent', () => {
     expect(component.tagSelectionModel.logicalOperator).toEqual(
       LogicalOperator.Or
     )
-    expect(component.tagSelectionModel.getSelectedItems()).toEqual(tags)
+    expect(component.tagSelectionModel.getSelectedItems()).toMatchObject(tags)
     // coverage
     component.filterRules = [
       {
@@ -652,7 +652,7 @@ describe('FilterEditorComponent', () => {
     expect(component.tagSelectionModel.logicalOperator).toEqual(
       LogicalOperator.And
     )
-    expect(component.tagSelectionModel.getExcludedItems()).toEqual(tags)
+    expect(component.tagSelectionModel.getExcludedItems()).toMatchObject(tags)
     // coverage
     component.filterRules = [
       {

src-ui/src/app/components/document-list/filter-editor/filter-editor.component.ts

@@ -97,6 +97,7 @@ import {
   CustomFieldQueryExpression,
 } from 'src/app/utils/custom-field-query-element'
 import { filterRulesDiffer } from 'src/app/utils/filter-rules'
+import { flattenTags } from 'src/app/utils/flatten-tags'
 import {
   CustomFieldQueriesModel,
   CustomFieldsQueryDropdownComponent,
@@ -1134,7 +1135,7 @@ export class FilterEditorComponent
     ) {
       this.loadingCountTotal++
       this.tagService.listAll().subscribe((result) => {
-        this.tagSelectionModel.items = result.results
+        this.tagSelectionModel.items = flattenTags(result.results)
         this.maybeCompleteLoading()
       })
     }

src-ui/src/app/components/manage/correspondent-list/correspondent-list.component.ts

@@ -1,4 +1,4 @@
-import { NgClass, TitleCasePipe } from '@angular/common'
+import { NgClass, NgTemplateOutlet, TitleCasePipe } from '@angular/common'
 import { Component, inject } from '@angular/core'
 import { FormsModule, ReactiveFormsModule } from '@angular/forms'
 import {
@@ -30,6 +30,7 @@ import { ManagementListComponent } from '../management-list/management-list.comp
     FormsModule,
     ReactiveFormsModule,
     NgClass,
+    NgTemplateOutlet,
     NgbDropdownModule,
     NgbPaginationModule,
     NgxBootstrapIconsModule,

src-ui/src/app/components/manage/document-type-list/document-type-list.component.ts

@@ -1,4 +1,4 @@
-import { NgClass, TitleCasePipe } from '@angular/common'
+import { NgClass, NgTemplateOutlet, TitleCasePipe } from '@angular/common'
 import { Component, inject } from '@angular/core'
 import { FormsModule, ReactiveFormsModule } from '@angular/forms'
 import {
@@ -28,6 +28,7 @@ import { ManagementListComponent } from '../management-list/management-list.comp
     FormsModule,
     ReactiveFormsModule,
     NgClass,
+    NgTemplateOutlet,
     NgbDropdownModule,
     NgbPaginationModule,
     NgxBootstrapIconsModule,

src-ui/src/app/components/manage/management-list/management-list.component.html

@@ -54,61 +54,7 @@
         </tr>
       }
       @for (object of data; track object) {
-        <tr (click)="toggleSelected(object); $event.stopPropagation();" class="data-row fade" [class.show]="show">
-          <td>
-            <div class="form-check m-0 ms-2 me-n2">
-              <input type="checkbox" class="form-check-input" id="{{typeName}}{{object.id}}" [checked]="selectedObjects.has(object.id)" (click)="toggleSelected(object); $event.stopPropagation();">
-              <label class="form-check-label" for="{{typeName}}{{object.id}}"></label>
-            </div>
-          </td>
-          <td scope="row"><button class="btn btn-link ms-0 ps-0 text-start" (click)="userCanEdit(object) ? openEditDialog(object) : null; $event.stopPropagation()">{{ object.name }}</button> </td>
-          <td scope="row" class="d-none d-sm-table-cell">{{ getMatching(object) }}</td>
-          <td scope="row">{{ object.document_count }}</td>
-          @for (column of extraColumns; track column) {
-            <td scope="row" [ngClass]="{ 'd-none d-sm-table-cell' : column.hideOnMobile }">
-              @if (column.rendersHtml) {
-                <div [innerHtml]="column.valueFn.call(null, object) | safeHtml"></div>
-              } @else if (column.monospace) {
-                <span class="font-monospace">{{ column.valueFn.call(null, object) }}</span>
-              } @else {
-                {{ column.valueFn.call(null, object) }}
-              }
-            </td>
-          }
-          <td scope="row">
-            <div class="btn-toolbar gap-2">
-              <div class="btn-group d-block d-sm-none">
-                <div ngbDropdown container="body" class="d-inline-block">
-                  <button type="button" class="btn btn-link" id="actionsMenuMobile" (click)="$event.stopPropagation()" ngbDropdownToggle>
-                    <i-bs name="three-dots-vertical"></i-bs>
-                  </button>
-                  <div ngbDropdownMenu aria-labelledby="actionsMenuMobile">
-                    <button (click)="openEditDialog(object)" *pngxIfPermissions="{ action: PermissionAction.Change, type: permissionType }" ngbDropdownItem i18n>Edit</button>
-                    <button class="text-danger" (click)="openDeleteDialog(object)" *pngxIfPermissions="{ action: PermissionAction.Delete, type: permissionType }" ngbDropdownItem i18n>Delete</button>
-                    @if (object.document_count > 0) {
-                      <button (click)="filterDocuments(object)" *pngxIfPermissions="{ action: PermissionAction.View, type: PermissionType.Document }" ngbDropdownItem i18n>Filter Documents ({{ object.document_count }})</button>
-                    }
-                  </div>
-                </div>
-              </div>
-              <div class="btn-group d-none d-sm-inline-block">
-                <button class="btn btn-sm btn-outline-secondary" (click)="openEditDialog(object); $event.stopPropagation();" *pngxIfPermissions="{ action: PermissionAction.Change, type: permissionType }" [disabled]="!userCanEdit(object)">
-                  <i-bs width="1em" height="1em" name="pencil"></i-bs>&nbsp;<ng-container i18n>Edit</ng-container>
-                </button>
-                <button class="btn btn-sm btn-outline-danger" (click)="openDeleteDialog(object); $event.stopPropagation();" *pngxIfPermissions="{ action: PermissionAction.Delete, type: permissionType }" [disabled]="!userCanDelete(object)">
-                  <i-bs width="1em" height="1em" name="trash"></i-bs>&nbsp;<ng-container i18n>Delete</ng-container>
-                </button>
-              </div>
-              @if (object.document_count > 0) {
-                <div class="btn-group d-none d-sm-inline-block">
-                  <button class="btn btn-sm btn-outline-secondary" (click)="filterDocuments(object); $event.stopPropagation();" *pngxIfPermissions="{ action: PermissionAction.View, type: PermissionType.Document }">
-                    <i-bs width="1em" height="1em" name="filter"></i-bs>&nbsp;<ng-container i18n>Documents</ng-container><span class="badge bg-light text-secondary ms-2">{{ object.document_count }}</span>
-                  </button>
-                </div>
-              }
-            </div>
-          </td>
-        </tr>
+        <ng-container [ngTemplateOutlet]="objectRow" [ngTemplateOutletContext]="{ object: object, depth: 0 }"></ng-container>
       }
     </tbody>
   </table>
@@ -129,3 +75,72 @@
     }
   </div>
 }
+
+<ng-template #objectRow let-object="object" let-depth="depth">
+  <tr (click)="toggleSelected(object); $event.stopPropagation();" class="data-row fade" [class.show]="show">
+    <td>
+      <div class="form-check m-0 ms-2 me-n2">
+        <input type="checkbox" class="form-check-input" id="{{typeName}}{{object.id}}" [checked]="selectedObjects.has(object.id)" (click)="toggleSelected(object); $event.stopPropagation();">
+        <label class="form-check-label" for="{{typeName}}{{object.id}}"></label>
+      </div>
+    </td>
+    <td scope="row" class="name-cell" style="--depth: {{depth}}">
+      @if (depth > 0) {
+        <div class="indicator"></div>
+      }
+      <button class="btn btn-link ms-0 ps-0 text-start" (click)="userCanEdit(object) ? openEditDialog(object) : null; $event.stopPropagation()">{{ object.name }}</button>
+    </td>
+    <td scope="row" class="d-none d-sm-table-cell">{{ getMatching(object) }}</td>
+    <td scope="row">{{ getDocumentCount(object) }}</td>
+    @for (column of extraColumns; track column) {
+      <td scope="row" [ngClass]="{ 'd-none d-sm-table-cell' : column.hideOnMobile }">
+        @if (column.rendersHtml) {
+          <div [innerHtml]="column.valueFn.call(null, object) | safeHtml"></div>
+        } @else if (column.monospace) {
+          <span class="font-monospace">{{ column.valueFn.call(null, object) }}</span>
+        } @else {
+          {{ column.valueFn.call(null, object) }}
+        }
+      </td>
+    }
+    <td scope="row">
+      <div class="btn-toolbar gap-2">
+        <div class="btn-group d-block d-sm-none">
+          <div ngbDropdown container="body" class="d-inline-block">
+            <button type="button" class="btn btn-link" id="actionsMenuMobile" (click)="$event.stopPropagation()" ngbDropdownToggle>
+              <i-bs name="three-dots-vertical"></i-bs>
+            </button>
+            <div ngbDropdownMenu aria-labelledby="actionsMenuMobile">
+              <button (click)="openEditDialog(object)" *pngxIfPermissions="{ action: PermissionAction.Change, type: permissionType }" ngbDropdownItem i18n>Edit</button>
+              <button class="text-danger" (click)="openDeleteDialog(object)" *pngxIfPermissions="{ action: PermissionAction.Delete, type: permissionType }" ngbDropdownItem i18n>Delete</button>
+              @if (getDocumentCount(object) > 0) {
+                <button (click)="filterDocuments(object)" *pngxIfPermissions="{ action: PermissionAction.View, type: PermissionType.Document }" ngbDropdownItem i18n>Filter Documents ({{ getDocumentCount(object) }})</button>
+              }
+            </div>
+          </div>
+        </div>
+        <div class="btn-group d-none d-sm-inline-block">
+          <button class="btn btn-sm btn-outline-secondary" (click)="openEditDialog(object); $event.stopPropagation();" *pngxIfPermissions="{ action: PermissionAction.Change, type: permissionType }" [disabled]="!userCanEdit(object)">
+            <i-bs width="1em" height="1em" name="pencil"></i-bs>&nbsp;<ng-container i18n>Edit</ng-container>
+          </button>
+          <button class="btn btn-sm btn-outline-danger" (click)="openDeleteDialog(object); $event.stopPropagation();" *pngxIfPermissions="{ action: PermissionAction.Delete, type: permissionType }" [disabled]="!userCanDelete(object)">
+            <i-bs width="1em" height="1em" name="trash"></i-bs>&nbsp;<ng-container i18n>Delete</ng-container>
+          </button>
+        </div>
+        @if (getDocumentCount(object) > 0) {
+          <div class="btn-group d-none d-sm-inline-block">
+            <button class="btn btn-sm btn-outline-secondary" (click)="filterDocuments(object); $event.stopPropagation();" *pngxIfPermissions="{ action: PermissionAction.View, type: PermissionType.Document }">
+              <i-bs width="1em" height="1em" name="filter"></i-bs>&nbsp;<ng-container i18n>Documents</ng-container><span class="badge bg-light text-secondary ms-2">{{ getDocumentCount(object) }}</span>
+            </button>
+          </div>
+        }
+      </div>
+    </td>
+  </tr>
+
+  @if (object.children && object.children.length > 0) {
+    @for (child of object.children; track child) {
+      <ng-container [ngTemplateOutlet]="objectRow" [ngTemplateOutletContext]="{ object: child, depth: depth + 1 }"></ng-container>
+    }
+  }
+</ng-template>

src-ui/src/app/components/manage/management-list/management-list.component.scss

@@ -10,3 +10,17 @@ tbody tr:last-child td {
 .form-check {
     min-height: 0;
 }
+
+td.name-cell {
+    padding-left: calc(calc(var(--depth) - 1) * 1.1rem);
+
+    .indicator {
+        display: inline-block;
+        width: .8rem;
+        height: .8rem;
+        border-left: 1px solid var(--bs-secondary);
+        border-bottom: 1px solid var(--bs-secondary);
+        margin-right: .25rem;
+        margin-left: .5rem;
+    }
+}

src-ui/src/app/components/manage/management-list/management-list.component.ts

@@ -79,6 +79,7 @@ export abstract class ManagementListComponent<T extends MatchingModel>
   @ViewChildren(SortableDirective) headers: QueryList<SortableDirective>
 
   public data: T[] = []
+  private unfilteredData: T[] = []
 
   public page = 1
 
@@ -132,6 +133,18 @@ export abstract class ManagementListComponent<T extends MatchingModel>
     this.reloadData()
   }
 
+  protected filterData(data: T[]): T[] {
+    return data
+  }
+
+  getDocumentCount(object: MatchingModel): number {
+    return (
+      object.document_count ??
+      this.unfilteredData.find((d) => d.id == object.id)?.document_count ??
+      0
+    )
+  }
+
   reloadData(extraParams: { [key: string]: any } = null) {
     this.loading = true
     this.clearSelection()
@@ -148,7 +161,8 @@ export abstract class ManagementListComponent<T extends MatchingModel>
       .pipe(
         takeUntil(this.unsubscribeNotifier),
         tap((c) => {
-          this.data = c.results
+          this.unfilteredData = c.results
+          this.data = this.filterData(c.results)
           this.collectionSize = c.count
         }),
         delay(100)

src-ui/src/app/components/manage/storage-path-list/storage-path-list.component.ts

@@ -1,4 +1,4 @@
-import { NgClass, TitleCasePipe } from '@angular/common'
+import { NgClass, NgTemplateOutlet, TitleCasePipe } from '@angular/common'
 import { Component, inject } from '@angular/core'
 import { FormsModule, ReactiveFormsModule } from '@angular/forms'
 import {
@@ -30,6 +30,7 @@ import { ManagementListComponent } from '../management-list/management-list.comp
     FormsModule,
     ReactiveFormsModule,
     NgClass,
+    NgTemplateOutlet,
     NgbDropdownModule,
     NgbPaginationModule,
     NgxBootstrapIconsModule,

src-ui/src/app/components/manage/tag-list/tag-list.component.ts

@@ -1,4 +1,4 @@
-import { NgClass, TitleCasePipe } from '@angular/common'
+import { NgClass, NgTemplateOutlet, TitleCasePipe } from '@angular/common'
 import { Component, inject } from '@angular/core'
 import { FormsModule, ReactiveFormsModule } from '@angular/forms'
 import {
@@ -30,6 +30,7 @@ import { ManagementListComponent } from '../management-list/management-list.comp
     FormsModule,
     ReactiveFormsModule,
     NgClass,
+    NgTemplateOutlet,
     NgbDropdownModule,
     NgbPaginationModule,
     NgxBootstrapIconsModule,
@@ -59,4 +60,8 @@ export class TagListComponent extends ManagementListComponent<Tag> {
   getDeleteMessage(object: Tag) {
     return $localize`Do you really want to delete the tag "${object.name}"?`
   }
+
+  filterData(data: Tag[]) {
+    return data.filter((tag) => !tag.parent)
+  }
 }

src-ui/src/app/data/tag.ts

@@ -6,4 +6,12 @@ export interface Tag extends MatchingModel {
   text_color?: string
 
   is_inbox_tag?: boolean
+
+  parent?: number // Tag ID
+
+  children?: Tag[] // read-only
+
+  // UI-only: computed depth and order for hierarchical dropdowns
+  depth?: number
+  orderIndex?: number
 }

src-ui/src/app/utils/flatten-tags.spec.ts

@@ -0,0 +1,63 @@
+import type { Tag } from '../data/tag'
+import { flattenTags } from './flatten-tags'
+
+describe('flattenTags', () => {
+  it('returns empty array for empty input', () => {
+    expect(flattenTags([])).toEqual([])
+  })
+
+  it('orders roots and children by name (case-insensitive, numeric) and sets depth/orderIndex', () => {
+    const input: Tag[] = [
+      { id: 11, name: 'A-root' },
+      { id: 10, name: 'B-root' },
+      { id: 101, name: 'Child 10', parent: 11 },
+      { id: 102, name: 'child 2', parent: 11 },
+      { id: 201, name: 'beta', parent: 10 },
+      { id: 202, name: 'Alpha', parent: 10 },
+      { id: 103, name: 'Sub 1', parent: 102 },
+    ]
+
+    const flat = flattenTags(input)
+
+    const names = flat.map((t) => t.name)
+    expect(names).toEqual([
+      'A-root',
+      'child 2',
+      'Sub 1',
+      'Child 10',
+      'B-root',
+      'Alpha',
+      'beta',
+    ])
+
+    expect(flat.map((t) => t.depth)).toEqual([0, 1, 2, 1, 0, 1, 1])
+    expect(flat.map((t) => t.orderIndex)).toEqual([0, 1, 2, 3, 4, 5, 6])
+
+    // Children are rebuilt
+    const aRoot = flat.find((t) => t.name === 'A-root')
+    expect(new Set(aRoot.children?.map((c) => c.name))).toEqual(
+      new Set(['child 2', 'Child 10'])
+    )
+
+    const bRoot = flat.find((t) => t.name === 'B-root')
+    expect(new Set(bRoot.children?.map((c) => c.name))).toEqual(
+      new Set(['Alpha', 'beta'])
+    )
+
+    const child2 = flat.find((t) => t.name === 'child 2')
+    expect(new Set(child2.children?.map((c) => c.name))).toEqual(
+      new Set(['Sub 1'])
+    )
+  })
+
+  it('excludes orphaned nodes (with missing parent)', () => {
+    const input: Tag[] = [
+      { id: 1, name: 'Root' },
+      { id: 2, name: 'Child', parent: 1 },
+      { id: 3, name: 'Orphan', parent: 999 }, // missing parent
+    ]
+
+    const flat = flattenTags(input)
+    expect(flat.map((t) => t.name)).toEqual(['Root', 'Child'])
+  })
+})

src-ui/src/app/utils/flatten-tags.ts

@@ -0,0 +1,35 @@
+import { Tag } from '../data/tag'
+
+export function flattenTags(all: Tag[]): Tag[] {
+  const map = new Map<number, Tag>(
+    all.map((t) => [t.id, { ...t, children: [] }])
+  )
+  // rebuild children
+  for (const t of map.values()) {
+    if (t.parent) {
+      const p = map.get(t.parent)
+      p?.children.push(t)
+    }
+  }
+  const roots = Array.from(map.values()).filter((t) => !t.parent)
+  const sortByName = (a: Tag, b: Tag) =>
+    a.name.localeCompare(b.name, undefined, {
+      sensitivity: 'base',
+      numeric: true,
+    })
+  const ordered: Tag[] = []
+  let idx = 0
+  const walk = (node: Tag, depth: number) => {
+    node.depth = depth
+    node.orderIndex = idx++
+    ordered.push(node)
+    if (node.children?.length) {
+      for (const child of [...node.children].sort(sortByName)) {
+        walk(child, depth + 1)
+      }
+    }
+  }
+  roots.sort(sortByName)
+  roots.forEach((r) => walk(r, 0))
+  return ordered
+}

src-ui/src/main.ts

@@ -55,6 +55,7 @@ import {
   checkLg,
   chevronDoubleLeft,
   chevronDoubleRight,
+  chevronRight,
   clipboard,
   clipboardCheck,
   clipboardCheckFill,
@@ -94,6 +95,7 @@ import {
   infoCircle,
   journals,
   link,
+  listNested,
   listTask,
   listUl,
   microsoft,
@@ -265,6 +267,7 @@ const icons = {
   checkLg,
   chevronDoubleLeft,
   chevronDoubleRight,
+  chevronRight,
   clipboard,
   clipboardCheck,
   clipboardCheckFill,
@@ -304,6 +307,7 @@ const icons = {
   infoCircle,
   journals,
   link,
+  listNested,
   listTask,
   listUl,
   microsoft,