Fixed grid component, async headings

src/modules/grid/fixtures/grid-async.component.fixture.html

@@ -0,0 +1,7 @@
+<sky-grid fit="scroll" [data]="items">
+  <sky-grid-column
+    id="column1"
+    field="column1"
+    [heading]="asyncHeading | async">
+  </sky-grid-column>
+</sky-grid>

src/modules/grid/fixtures/grid-async.component.fixture.ts

@@ -0,0 +1,24 @@
+import { Component } from '@angular/core';
+
+import { BehaviorSubject } from 'rxjs/BehaviorSubject';
+
+@Component({
+  selector: 'sky-test-cmp',
+  templateUrl: './grid-async.component.fixture.html'
+})
+export class GridAsyncTestComponent {
+  public items: Array<any> = [
+    { 'id': 1, 'name': 'Windstorm', 'email': 'windstorm@gmail.com' },
+    { 'id': 2, 'name': 'Bombasto', 'email': 'bombasto@gmail.com' },
+    { 'id': 3, 'name': 'Magneta', 'email': 'magenta@gmail.com' },
+    { 'id': 4, 'name': 'Tornado', 'email': 'tornado@gmail.com' }
+  ];
+
+  public asyncHeading = new BehaviorSubject<string>(undefined);
+
+  constructor() {
+    setTimeout(() => {
+      this.asyncHeading.next('updated');
+    }, 100);
+  }
+}

src/modules/grid/fixtures/grid-fixtures.module.ts

@@ -6,12 +6,14 @@ import { SkyGridModule } from '../';
 import { GridTestComponent } from './grid.component.fixture';
 import { GridEmptyTestComponent } from './grid-empty.component.fixture';
 import { GridDynamicTestComponent } from './grid-dynamic.component.fixture';
+import { GridAsyncTestComponent } from './grid-async.component.fixture';
 
 @NgModule({
   declarations: [
     GridTestComponent,
     GridEmptyTestComponent,
-    GridDynamicTestComponent
+    GridDynamicTestComponent,
+    GridAsyncTestComponent
   ],
   imports: [
     CommonModule,
@@ -20,7 +22,8 @@ import { GridDynamicTestComponent } from './grid-dynamic.component.fixture';
   exports: [
     GridTestComponent,
     GridEmptyTestComponent,
-    GridDynamicTestComponent
+    GridDynamicTestComponent,
+    GridAsyncTestComponent
   ]
 })
 export class GridFixturesModule { }

src/modules/grid/grid-column.component.ts

@@ -1,34 +1,45 @@
 import {
+  ChangeDetectionStrategy,
   Component,
-  Input,
   ContentChildren,
+  EventEmitter,
+  Input,
+  OnChanges,
+  SimpleChanges,
   TemplateRef,
-  QueryList,
-  ChangeDetectionStrategy
+  QueryList
 } from '@angular/core';
 
 @Component({
   selector: 'sky-grid-column',
   template: '<ng-content></ng-content>',
   changeDetection: ChangeDetectionStrategy.OnPush
 })
-export class SkyGridColumnComponent {
+export class SkyGridColumnComponent implements OnChanges {
   @Input()
   public id: string;
+
   @Input()
   public heading: string;
+
   @Input()
   public width: number;
+
   @Input()
   public hidden: boolean;
+
   @Input()
   public locked: boolean;
+
   @Input()
   public field: string;
+
   @Input()
   public type: string;
+
   @Input()
   public description: string;
+
   @Input()
   public isSortable: boolean = true;
 
@@ -40,15 +51,28 @@ export class SkyGridColumnComponent {
   public templateInput: TemplateRef<any>;
   /* tslint:enable:no-input-rename */
 
+  public headingChanges: EventEmitter<string> = new EventEmitter<string>();
+
   @ContentChildren(TemplateRef)
   private templates: QueryList<TemplateRef<any>>;
 
+  public ngOnChanges(changes: SimpleChanges) {
+    if (changes.heading && changes.heading.firstChange === false) {
+      this.heading = changes.heading.currentValue;
+      this.headingChanges.emit(this.heading);
+    }
+  }
+
   public get template(): TemplateRef<any> {
-    return (this.templates.length > 0 ? this.templates.first : undefined) || this.templateInput;
+    if (this.templates.length > 0) {
+      return this.templates.first;
+    }
+
+    return this.templateInput;
   }
 
   private search(value: any, searchText: string): boolean {
-    /* tslint:disable */
+    /* tslint:disable:no-null-keyword */
     if (value !== undefined && value !== null) {
       return value.toString().toLowerCase().indexOf(searchText) !== -1;
     }

src/modules/grid/grid.component.spec.ts

@@ -20,6 +20,9 @@ import {
 import {
   GridDynamicTestComponent
 } from './fixtures/grid-dynamic.component.fixture';
+
+import { GridAsyncTestComponent } from './fixtures/grid-async.component.fixture';
+
 import {
   SkyGridModule,
   SkyGridComponent,
@@ -702,4 +705,40 @@ describe('Grid Component', () => {
     });
   });
 
+  describe('async headings', () => {
+    it('should handle async column headings', (done: any) => {
+      let component: GridAsyncTestComponent;
+      let fixture: ComponentFixture<GridAsyncTestComponent>;
+      let nativeElement: HTMLElement;
+      let element: DebugElement;
+
+      TestBed.configureTestingModule({
+        imports: [
+          GridFixturesModule,
+          SkyGridModule
+        ]
+      });
+
+      fixture = TestBed.createComponent(GridAsyncTestComponent);
+      nativeElement = fixture.nativeElement as HTMLElement;
+      element = fixture.debugElement as DebugElement;
+      component = fixture.componentInstance;
+
+      fixture.detectChanges();
+
+      expect(getColumnHeader('column1', element).nativeElement.textContent.trim())
+        .toBe('');
+
+      fixture.detectChanges();
+
+      setTimeout(() => {
+        fixture.detectChanges();
+        fixture.whenStable().then(() => {
+          expect(getColumnHeader('column1', element).nativeElement.textContent.trim())
+            .toBe('updated');
+          done();
+        });
+      }, 110);
+    });
+  });
 });

src/modules/grid/grid.component.ts

@@ -1,6 +1,7 @@
 import {
   Component,
   Input,
+  OnDestroy,
   Output,
   ContentChildren,
   QueryList,
@@ -11,18 +12,22 @@ import {
   EventEmitter,
   OnChanges
 } from '@angular/core';
+
+import { BehaviorSubject } from 'rxjs/BehaviorSubject';
+import { Observable } from 'rxjs/Observable';
+import { Subscription } from 'rxjs/Subscription';
+
 import { DragulaService } from 'ng2-dragula/ng2-dragula';
+
+import {
+  ListItemModel,
+  ListSortFieldSelectorModel
+} from '../list/state';
+
 import { SkyGridColumnComponent } from './grid-column.component';
 import { SkyGridColumnModel } from './grid-column.model';
-import { ListItemModel } from '../list/state';
 import { SkyGridAdapterService } from './grid-adapter.service';
 
-import { ListSortFieldSelectorModel } from '../list/state';
-
-import { BehaviorSubject } from 'rxjs/BehaviorSubject';
-
-import { Observable } from 'rxjs/Observable';
-
 @Component({
   selector: 'sky-grid',
   templateUrl: './grid.component.html',
@@ -33,8 +38,7 @@ import { Observable } from 'rxjs/Observable';
   ],
   changeDetection: ChangeDetectionStrategy.OnPush
 })
-export class SkyGridComponent implements AfterContentInit, OnChanges {
-
+export class SkyGridComponent implements AfterContentInit, OnChanges, OnDestroy {
   @Input()
   public selectedColumnIds: Array<string>;
 
@@ -65,21 +69,27 @@ export class SkyGridComponent implements AfterContentInit, OnChanges {
   @Output()
   public sortFieldChange = new EventEmitter<ListSortFieldSelectorModel>();
 
-  public displayedColumns: Array<SkyGridColumnModel> = new Array<SkyGridColumnModel>();
-
-  public items: Array<any> = new Array<any>();
+  public items: Array<any>;
+  public displayedColumns: Array<SkyGridColumnModel>;
+  public currentSortField: BehaviorSubject<ListSortFieldSelectorModel>;
 
-  public currentSortField: BehaviorSubject<ListSortFieldSelectorModel>
-    = new BehaviorSubject<ListSortFieldSelectorModel>({ fieldSelector: '', descending: false });
-
-  @ContentChildren(SkyGridColumnComponent, {descendants: true})
+  @ContentChildren(SkyGridColumnComponent, { descendants: true })
   private columnComponents: QueryList<SkyGridColumnComponent>;
 
+  private subscriptions: Subscription[] = [];
+
   constructor(
     private dragulaService: DragulaService,
     private ref: ChangeDetectorRef,
     private gridAdapter: SkyGridAdapterService
-  ) {}
+  ) {
+    this.displayedColumns = new Array<SkyGridColumnModel>();
+    this.items = new Array<any>();
+    this.currentSortField = new BehaviorSubject<ListSortFieldSelectorModel>({
+      fieldSelector: '',
+      descending: false
+    });
+  }
 
   public ngAfterContentInit() {
     if (this.columnComponents.length !== 0 || this.columns !== undefined) {
@@ -90,22 +100,27 @@ export class SkyGridComponent implements AfterContentInit, OnChanges {
       }
 
       this.transformData();
-
       this.setDisplayedColumns(true);
     }
 
-    this.columnComponents.changes.subscribe((columnComponents) => {
-      this.getColumnsFromComponent();
-      this.setDisplayedColumns(true);
-      this.ref.markForCheck();
+    // Watch for added/removed columns:
+    this.subscriptions.push(
+      this.columnComponents.changes.subscribe(() => this.updateColumns())
+    );
+
+    // Watch for column heading changes:
+    this.columnComponents.forEach((comp: SkyGridColumnComponent) => {
+      this.subscriptions.push(
+        comp.headingChanges.subscribe(() => this.updateColumns())
+      );
     });
 
     this.gridAdapter.initializeDragAndDrop(
-        this.dragulaService,
-        (selectedColumnIds: Array<string>) => {
-          this.onHeaderDrop(selectedColumnIds);
-        }
-      );
+      this.dragulaService,
+      (selectedColumnIds: Array<string>) => {
+        this.onHeaderDrop(selectedColumnIds);
+      }
+    );
   }
 
   // Do an ngOnChanges where changes to selectedColumnIds and data are watched
@@ -125,6 +140,12 @@ export class SkyGridComponent implements AfterContentInit, OnChanges {
     }
   }
 
+  public ngOnDestroy() {
+    this.subscriptions.forEach((subscription: Subscription) => {
+      subscription.unsubscribe();
+    });
+  }
+
   public sortByColumn(column: SkyGridColumnModel) {
     if (column.isSortable) {
       this.currentSortField
@@ -158,17 +179,17 @@ export class SkyGridComponent implements AfterContentInit, OnChanges {
   }
 
   private onHeaderDrop(newColumnIds: Array<string>) {
-     // update selected columnIds
-      this.selectedColumnIds = newColumnIds;
-      this.selectedColumnIdsChange.emit(newColumnIds);
+    // update selected columnIds
+    this.selectedColumnIds = newColumnIds;
+    this.selectedColumnIdsChange.emit(newColumnIds);
 
-      // set new displayed columns
-      this.displayedColumns = this.selectedColumnIds.map(
-        columnId => this.columns.filter(column => column.id === columnId)[0]
-      );
+    // set new displayed columns
+    this.displayedColumns = this.selectedColumnIds.map(
+      columnId => this.columns.filter(column => column.id === columnId)[0]
+    );
 
-      // mark for check because we are using ChangeDetectionStrategy.onPush
-      this.ref.markForCheck();
+    // mark for check because we are using ChangeDetectionStrategy.onPush
+    this.ref.markForCheck();
   }
 
   private setDisplayedColumns(respectHidden: boolean = false) {
@@ -200,8 +221,14 @@ export class SkyGridComponent implements AfterContentInit, OnChanges {
   }
 
   private getColumnsFromComponent() {
-     this.columns = this.columnComponents.map(columnComponent => {
-        return new SkyGridColumnModel(columnComponent.template, columnComponent);
-      });
+    this.columns = this.columnComponents.map(columnComponent => {
+      return new SkyGridColumnModel(columnComponent.template, columnComponent);
+    });
+  }
+
+  private updateColumns() {
+    this.getColumnsFromComponent();
+    this.setDisplayedColumns(true);
+    this.ref.markForCheck();
   }
 }