more angular wrapper code

demo/angular/src/app/app.component.html

@@ -35,7 +35,6 @@
   <button (click)="newLayoutNgFor()">new layout</button>
   <gridstack [options]="gridOptions" (changeCB)="onChange($event)" (resizeStopCB)="onResizeStop($event)">
     <gridstack-item *ngFor="let n of items; trackBy: identify" [options]="n">
-      {{n.content}}
     </gridstack-item>
   </gridstack>
 </div>
@@ -46,6 +45,9 @@
   <button (click)="delete()">remove item</button>
   <button (click)="modify()">modify item</button>
   <button (click)="newLayout()">new layout</button>
+  <button (click)="saveGrid()">Save</button>
+  <button (click)="clearGrid()">Clear</button>
+  <button (click)="loadGrid()">Load</button>
   <gridstack [options]="gridOptionsFull" (changeCB)="onChange($event)" (resizeStopCB)="onResizeStop($event)">
   </gridstack>
 </div>
@@ -57,8 +59,8 @@
   <button (click)="delete()">remove item</button>
   <button (click)="modify()">modify item</button>
   <button (click)="newLayout()">new layout</button>
-  <button (click)="clearGrid()">Clear</button>
   <button (click)="saveGrid()">Save</button>
+  <button (click)="clearGrid()">Clear</button>
   <button (click)="loadGrid()">Load</button>
   <!-- TODO: addGrid() in code for testing instead ? -->
   <gridstack [options]="nestedGridOptions" (changeCB)="onChange($event)" (resizeStopCB)="onResizeStop($event)">

demo/angular/src/app/app.module.ts

@@ -3,11 +3,12 @@ import { BrowserModule } from '@angular/platform-browser';
 
 import { AppComponent } from './app.component';
 import { GridstackItemComponent } from './gridstack-item.component';
-import { GridstackComponent } from './gridstack.component';
+import { GridstackComponent, gsCreateNgComponents, gsSaveAdditionNgInfo } from './gridstack.component';
 import { AngularNgForTestComponent } from './ngFor';
 import { AngularNgForCmdTestComponent } from './ngFor_cmd';
 import { AngularSimpleComponent } from './simple';
 import { AComponent, BComponent, CComponent } from './dummy.component';
+import { GridStack } from 'gridstack';
 
 @NgModule({
     declarations: [
@@ -34,10 +35,9 @@ import { AComponent, BComponent, CComponent } from './dummy.component';
 export class AppModule {
   constructor() {
     // register all our dynamic components created in the grid
-    GridstackComponent.selectorToType = {
-      'app-a': AComponent,
-      'app-b': BComponent,
-      'app-c': CComponent,
-    };
+    GridstackComponent.addComponentToSelectorType([AComponent, BComponent, CComponent]);
+    // set globally our method to create the right widget type
+    GridStack.addRemoveCB = gsCreateNgComponents; // DONE in case switcher onShow() as well
+    GridStack.saveCB = gsSaveAdditionNgInfo;
   }
 }

demo/angular/src/app/gridstack-item.component.ts

@@ -3,7 +3,7 @@
  * Copyright (c) 2022 Alain Dumesny - see GridStack root license
  */
 
-import { ChangeDetectionStrategy, Component, ElementRef, Input, ViewChild, ViewContainerRef, OnDestroy } from '@angular/core';
+import { Component, ElementRef, Input, ViewChild, ViewContainerRef, OnDestroy } from '@angular/core';
 import { GridItemHTMLElement, GridStackNode } from 'gridstack';
 
 /** store element to Ng Class pointer back */
@@ -28,7 +28,7 @@ export interface GridItemCompHTMLElement extends GridItemHTMLElement {
   styles: [`
     :host { display: block; }
   `],
-  changeDetection: ChangeDetectionStrategy.OnPush,
+  // changeDetection: ChangeDetectionStrategy.OnPush, // IFF you want to optimize and control when ChangeDetection needs to happen...
 })
 export class GridstackItemComponent implements OnDestroy {
 
@@ -42,8 +42,7 @@ export class GridstackItemComponent implements OnDestroy {
       this.el.gridstackNode.grid.update(this.el, val);
     } else {
       // store our custom element in options so we can update it and not re-create a generic div!
-      val.el = this.el;
-      this._options = val;
+      this._options = {...val, el: this.el};
     }
   }
   /** return the latest grid options (from GS once built, otherwise initial values) */

demo/angular/src/app/gridstack.component.ts

@@ -3,8 +3,8 @@
  * Copyright (c) 2022 Alain Dumesny - see GridStack root license
  */
 
-import { AfterContentInit, ChangeDetectionStrategy, Component, ContentChildren, ElementRef, EventEmitter, Input,
-  NgZone, OnDestroy, OnInit, Output, QueryList, Type, ViewChild, ViewContainerRef, createComponent, EnvironmentInjector } from '@angular/core';
+import { AfterContentInit, Component, ContentChildren, ElementRef, EventEmitter, Input,
+  OnDestroy, OnInit, Output, QueryList, Type, ViewChild, ViewContainerRef, reflectComponentType } from '@angular/core';
 import { Subject } from 'rxjs';
 import { takeUntil } from 'rxjs/operators';
 import { GridHTMLElement, GridItemHTMLElement, GridStack, GridStackNode, GridStackOptions, GridStackWidget } from 'gridstack';
@@ -17,7 +17,6 @@ export type elementCB = {event: Event, el: GridItemHTMLElement};
 export type nodesCB = {event: Event, nodes: GridStackNode[]};
 export type droppedCB = {event: Event, previousNode: GridStackNode, newNode: GridStackNode};
 
-
 /** extends to store Ng Component selector, instead/inAddition to content */
 export interface NgGridStackWidget extends GridStackWidget {
   type?: string; // component type to create as content
@@ -31,6 +30,7 @@ export interface GridCompHTMLElement extends GridHTMLElement {
   _gridComp?: GridstackComponent;
 }
 
+/** selector string to runtime Type mapping */
 export type SelectorToType = {[key: string]: Type<Object>};
 
 /**
@@ -49,7 +49,7 @@ export type SelectorToType = {[key: string]: Type<Object>};
   styles: [`
     :host { display: block; }
   `],
-  changeDetection: ChangeDetectionStrategy.OnPush,
+  // changeDetection: ChangeDetectionStrategy.OnPush, // IFF you want to optimize and control when ChangeDetection needs to happen...
 })
 export class GridstackComponent implements OnInit, AfterContentInit, OnDestroy {
 
@@ -97,8 +97,14 @@ export class GridstackComponent implements OnInit, AfterContentInit, OnDestroy {
    * Unfortunately Ng doesn't provide public access to that mapping.
    */
   public static selectorToType: SelectorToType = {};
-  public static addSelector(key: string, type: Type<Object>) {
-    GridstackComponent.selectorToType[key] = type;
+  /** add a list of ng Component to be mapped to selector */
+  public static addComponentToSelectorType(typeList: Array<Type<Object>>) {
+    typeList.forEach(type => GridstackComponent.selectorToType[ GridstackComponent.getSelector(type) ] = type);
+  }
+  /** return the ng Component selector */
+  public static getSelector(type: Type<Object>): string {
+    const mirror = reflectComponentType(type)!;
+    return mirror.selector;
   }
 
   private _options?: GridStackOptions;
@@ -107,7 +113,8 @@ export class GridstackComponent implements OnInit, AfterContentInit, OnDestroy {
   private ngUnsubscribe: Subject<void> = new Subject();
 
   constructor(
-    private readonly zone: NgZone,
+    // private readonly zone: NgZone,
+    // private readonly cd: ChangeDetectorRef,
     private readonly elementRef: ElementRef<GridCompHTMLElement>,
   ) {
     this.el._gridComp = this;
@@ -118,19 +125,19 @@ export class GridstackComponent implements OnInit, AfterContentInit, OnDestroy {
     this.loaded = !!this.options?.children?.length;
     this._grid = GridStack.init(this._options, this.el);
     delete this._options; // GS has it now
+
+    this.checkEmpty();
   }
 
   /** wait until after all DOM is ready to init gridstack children (after angular ngFor and sub-components run first) */
   public ngAfterContentInit(): void {
-    this.zone.runOutsideAngular(() => {
-      // track whenever the children list changes and update the layout...
-      this.gridstackItems?.changes
-        .pipe(takeUntil(this.ngUnsubscribe))
-        .subscribe(() => this.updateAll());
-      // ...and do this once at least unless we loaded children already
-      if (!this.loaded) this.updateAll();
-      this.hookEvents(this.grid);
-    });
+    // track whenever the children list changes and update the layout...
+    this.gridstackItems?.changes
+      .pipe(takeUntil(this.ngUnsubscribe))
+      .subscribe(() => this.updateAll());
+    // ...and do this once at least unless we loaded children already
+    if (!this.loaded) this.updateAll();
+    this.hookEvents(this.grid);
   }
 
   public ngOnDestroy(): void {
@@ -158,32 +165,35 @@ export class GridstackComponent implements OnInit, AfterContentInit, OnDestroy {
   /** check if the grid is empty, if so show alternative content */
   public checkEmpty() {
     if (!this.grid) return;
-    this.isEmpty = !this.grid.engine.nodes.length;
+    const isEmpty = !this.grid.engine.nodes.length;
+    if (isEmpty === this.isEmpty) return;
+    this.isEmpty = isEmpty;
+    // this.cd.detectChanges();
   }
 
   /** get all known events as easy to use Outputs for convenience */
   private hookEvents(grid?: GridStack) {
     if (!grid) return;
     grid
-    .on('added', (event: Event, nodes: GridStackNode[]) => this.zone.run(() => { this.checkEmpty(); this.addedCB.emit({event, nodes}); }))
-    .on('change', (event: Event, nodes: GridStackNode[]) => this.zone.run(() => this.changeCB.emit({event, nodes})))
-    .on('disable', (event: Event) => this.zone.run(() => this.disableCB.emit({event})))
-    .on('drag', (event: Event, el: GridItemHTMLElement) => this.zone.run(() => this.dragCB.emit({event, el})))
-    .on('dragstart', (event: Event, el: GridItemHTMLElement) => this.zone.run(() => this.dragStartCB.emit({event, el})))
-    .on('dragstop', (event: Event, el: GridItemHTMLElement) => this.zone.run(() => this.dragStopCB.emit({event, el})))
-    .on('dropped', (event: Event, previousNode: GridStackNode, newNode: GridStackNode) => this.zone.run(() => this.droppedCB.emit({event, previousNode, newNode})))
-    .on('enable', (event: Event) => this.zone.run(() => this.enableCB.emit({event})))
-    .on('removed', (event: Event, nodes: GridStackNode[]) => this.zone.run(() => { this.checkEmpty(); this.removedCB.emit({event, nodes}); }))
-    .on('resize', (event: Event, el: GridItemHTMLElement) => this.zone.run(() => this.resizeCB.emit({event, el})))
-    .on('resizestart', (event: Event, el: GridItemHTMLElement) => this.zone.run(() => this.resizeStartCB.emit({event, el})))
-    .on('resizestop', (event: Event, el: GridItemHTMLElement) => this.zone.run(() => this.resizeStopCB.emit({event, el})))
+    .on('added', (event: Event, nodes: GridStackNode[]) => { this.checkEmpty(); this.addedCB.emit({event, nodes}); })
+    .on('change', (event: Event, nodes: GridStackNode[]) => this.changeCB.emit({event, nodes}))
+    .on('disable', (event: Event) => this.disableCB.emit({event}))
+    .on('drag', (event: Event, el: GridItemHTMLElement) => this.dragCB.emit({event, el}))
+    .on('dragstart', (event: Event, el: GridItemHTMLElement) => this.dragStartCB.emit({event, el}))
+    .on('dragstop', (event: Event, el: GridItemHTMLElement) => this.dragStopCB.emit({event, el}))
+    .on('dropped', (event: Event, previousNode: GridStackNode, newNode: GridStackNode) => this.droppedCB.emit({event, previousNode, newNode}))
+    .on('enable', (event: Event) => this.enableCB.emit({event}))
+    .on('removed', (event: Event, nodes: GridStackNode[]) => { this.checkEmpty(); this.removedCB.emit({event, nodes}); })
+    .on('resize', (event: Event, el: GridItemHTMLElement) => this.resizeCB.emit({event, el}))
+    .on('resizestart', (event: Event, el: GridItemHTMLElement) => this.resizeStartCB.emit({event, el}))
+    .on('resizestop', (event: Event, el: GridItemHTMLElement) => this.resizeStopCB.emit({event, el}))
   }
 }
 
 /**
- * called by GS when a new item needs to be created, which we do as a Angular component, or deleted (skip)
+ * can be used when a new item needs to be created, which we do as a Angular component, or deleted (skip)
  **/
-function createNgComponents(host: GridCompHTMLElement | HTMLElement, w: NgGridStackWidget | GridStackOptions, add: boolean, isGrid: boolean): HTMLElement | undefined {
+export function gsCreateNgComponents(host: GridCompHTMLElement | HTMLElement, w: NgGridStackWidget | GridStackOptions, add: boolean, isGrid: boolean): HTMLElement | undefined {
   if (add) {
     if (!host) return;
     // create the grid item dynamically - see https://angular.io/docs/ts/latest/cookbook/dynamic-component-loader.html
@@ -217,14 +227,10 @@ function createNgComponents(host: GridCompHTMLElement | HTMLElement, w: NgGridSt
 }
 
 /**
- * called when saving the grid - put the extra info of type, otherwise content
+ * can be used when saving the grid - make sure we save the content from the field (not HTML as we get ng markups)
+ * and can put the extra info of type, otherwise content
  */
-function saveAdditionNgInfo(n: NgGridStackNode, w: NgGridStackWidget) {
-  // NOT needed as we get that by default in this case
-  // if (n.type) w.type = n.type;
-  // else if (n.content) w.content = n.content;
+export function gsSaveAdditionNgInfo(n: NgGridStackNode, w: NgGridStackWidget) {
+  if (n.type) w.type = n.type;
+  else if (n.content) w.content = n.content;
 }
-
-// set globally our method to create the right widget type
-GridStack.addRemoveCB = createNgComponents;
-GridStack.saveCB = saveAdditionNgInfo;

demo/angular/src/app/simple.ts

@@ -17,7 +17,7 @@
    // gridstack.min.css and other custom styles should be included in global styles.scss
  })
  export class AngularSimpleComponent implements OnInit {
-   private items: GridStackWidget[] = [
+   public items: GridStackWidget[] = [
      { x: 0, y: 0, w: 9, h: 6, content: '0' },
      { x: 9, y: 0, w: 3, h: 3, content: '1' },
      { x: 9, y: 3, w: 3, h: 3, content: '2' },

src/gridstack-engine.ts

@@ -538,7 +538,7 @@ export class GridStackEngine {
 
   public removeAll(removeDOM = true): GridStackEngine {
     delete this._layouts;
-    if (this.nodes.length === 0) return this;
+    if (!this.nodes.length) return this;
     removeDOM && this.nodes.forEach(n => n._removeDOM = true); // let CB remove actual HTML (used to set _id to null, but then we loose layout info)
     this.removedNodes = this.nodes;
     this.nodes = [];

src/gridstack.ts

@@ -178,12 +178,12 @@ export class GridStack {
    * add = false: the item will be removed from DOM (if not already done)
    * grid = true|false for grid vs grid-items
    */
-  public static addRemoveCB: AddRemoveFcn;
+  public static addRemoveCB?: AddRemoveFcn;
 
   /**
    * callback during saving to application can inject extra data for each widget, on top of the grid layout properties
    */
-  public static saveCB: SaveFcn;
+  public static saveCB?: SaveFcn;
 
   /** scoping so users can call GridStack.Utils.sort() for example */
   public static Utils = Utils;
@@ -899,11 +899,11 @@ export class GridStack {
     if (!removeDOM) {
       this.removeAll(removeDOM);
       this.el.classList.remove(this._styleSheetClass);
+      this.el.removeAttribute('gs-current-row');
     } else {
       this.el.parentNode.removeChild(this.el);
     }
     this._removeStylesheet();
-    this.el.removeAttribute('gs-current-row');
     if (this.parentGridItem) delete this.parentGridItem.subGrid;
     delete this.parentGridItem;
     delete this.opts;
@@ -1286,7 +1286,7 @@ export class GridStack {
   /** @internal */
   protected _triggerAddEvent(): GridStack {
     if (this.engine.batchMode) return this;
-    if (this.engine.addedNodes && this.engine.addedNodes.length > 0) {
+    if (this.engine.addedNodes?.length) {
       if (!this._ignoreLayoutsNodeChange) {
         this.engine.layoutsNodesChange(this.engine.addedNodes);
       }
@@ -1301,7 +1301,7 @@ export class GridStack {
   /** @internal */
   public _triggerRemoveEvent(): GridStack {
     if (this.engine.batchMode) return this;
-    if (this.engine.removedNodes && this.engine.removedNodes.length > 0) {
+    if (this.engine.removedNodes?.length) {
       this._triggerEvent('removed', this.engine.removedNodes);
       this.engine.removedNodes = [];
     }