Dashboards: support merging in new panels and options (#37905)

public/app/features/dashboard/dashgrid/DashboardGrid.tsx

@@ -29,7 +29,7 @@ export interface State {
 }
 
 export class DashboardGrid extends PureComponent<Props, State> {
-  private panelMap: { [id: string]: PanelModel } = {};
+  private panelMap: { [key: string]: PanelModel } = {};
   private eventSubs = new Subscription();
   private windowHeight = 1200;
   private windowWidth = 1920;
@@ -57,8 +57,10 @@ export class DashboardGrid extends PureComponent<Props, State> {
     this.panelMap = {};
 
     for (const panel of this.props.dashboard.panels) {
-      const stringId = panel.id.toString();
-      this.panelMap[stringId] = panel;
+      if (!panel.key) {
+        panel.key = `panel-${panel.id}-${Date.now()}`;
+      }
+      this.panelMap[panel.key] = panel;
 
       if (!panel.gridPos) {
         console.log('panel without gridpos');
@@ -66,7 +68,7 @@ export class DashboardGrid extends PureComponent<Props, State> {
       }
 
       const panelPos: any = {
-        i: stringId,
+        i: panel.key,
         x: panel.gridPos.x,
         y: panel.gridPos.y,
         w: panel.gridPos.w,
@@ -159,16 +161,15 @@ export class DashboardGrid extends PureComponent<Props, State> {
 
     for (const panel of this.props.dashboard.panels) {
       const panelClasses = classNames({ 'react-grid-item--fullscreen': panel.isViewing });
-      const itemKey = panel.id.toString();
 
       // Update is in view state
       panel.isInView = this.isInView(panel);
 
       panelElements.push(
         <GrafanaGridItem
-          key={itemKey}
+          key={panel.key}
           className={panelClasses}
-          data-panelid={itemKey}
+          data-panelid={panel.id}
           gridPos={panel.gridPos}
           gridWidth={gridWidth}
           windowHeight={this.windowHeight}
@@ -176,7 +177,7 @@ export class DashboardGrid extends PureComponent<Props, State> {
           isViewing={panel.isViewing}
         >
           {(width: number, height: number) => {
-            return this.renderPanel(panel, width, height, itemKey);
+            return this.renderPanel(panel, width, height, panel.key);
           }}
         </GrafanaGridItem>
       );

public/app/features/dashboard/state/DashboardModel.ts

@@ -34,6 +34,7 @@ import {
   TimeRange,
   TimeZone,
   UrlQueryValue,
+  PanelModel as IPanelModel,
 } from '@grafana/data';
 import { CoreEvents, DashboardMeta, KioskMode } from 'app/types';
 import { GetVariables, getVariables } from 'app/features/variables/state/selectors';
@@ -43,6 +44,7 @@ import { dispatch } from '../../../store/store';
 import { isAllVariable } from '../../variables/utils';
 import { DashboardPanelsChangedEvent, RefreshEvent, RenderEvent, TimeRangeUpdatedEvent } from 'app/types/events';
 import { getTimeSrv } from '../services/TimeSrv';
+import { mergePanels, PanelMergeInfo } from '../utils/panelMerge';
 
 export interface CloneOptions {
   saveVariables?: boolean;
@@ -241,6 +243,26 @@ export class DashboardModel {
     return copy;
   }
 
+  /**
+   * This will load a new dashboard, but keep existing panels unchanged
+   *
+   * This function can be used to implement:
+   * 1. potentially faster loading dashboard loading
+   * 2. dynamic dashboard behavior
+   * 3. "live" dashboard editing
+   *
+   * @internal and experimental
+   */
+  updatePanels(panels: IPanelModel[]): PanelMergeInfo {
+    const info = mergePanels(this.panels, panels ?? []);
+    if (info.changed) {
+      this.panels = info.panels ?? [];
+      this.sortPanelsByGridPos();
+      this.events.publish(new DashboardPanelsChangedEvent());
+    }
+    return info;
+  }
+
   private getPanelSaveModels() {
     return this.panels
       .filter((panel: PanelModel) => {
@@ -562,9 +584,9 @@ export class DashboardModel {
       return sourcePanel;
     }
 
-    const clone = new PanelModel(sourcePanel.getSaveModel());
-
-    clone.id = this.getNextPanelId();
+    const m = sourcePanel.getSaveModel();
+    m.id = this.getNextPanelId();
+    const clone = new PanelModel(m);
 
     // insert after source panel + value index
     this.panels.splice(sourcePanelIndex + valueIndex, 0, clone);
@@ -726,6 +748,7 @@ export class DashboardModel {
   updateRepeatedPanelIds(panel: PanelModel, repeatedByRow?: boolean) {
     panel.repeatPanelId = panel.id;
     panel.id = this.getNextPanelId();
+    panel.key = `${panel.id}`;
     panel.repeatIteration = this.iteration;
     if (repeatedByRow) {
       panel.repeatedByRow = true;

public/app/features/dashboard/state/PanelModel.ts

@@ -65,6 +65,7 @@ const notPersistedProperties: { [str: string]: boolean } = {
   configRev: true,
   getDisplayTitle: true,
   dataSupport: true,
+  key: true,
 };
 
 // For angular panels we need to clean up properties when changing type
@@ -177,6 +178,7 @@ export class PanelModel implements DataConfigSource, IPanelModel {
   cachedPluginOptions: Record<string, PanelOptionsCache> = {};
   legend?: { show: boolean; sort?: string; sortDesc?: boolean };
   plugin?: PanelPlugin;
+  key: string; // unique in dashboard, changes will force a react reload
 
   /**
    * The PanelModel event bus only used for internal and legacy angular support.
@@ -190,6 +192,7 @@ export class PanelModel implements DataConfigSource, IPanelModel {
     this.events = new EventBusSrv();
     this.restoreModel(model);
     this.replaceVariables = this.replaceVariables.bind(this);
+    this.key = this.id ? `${this.id}` : `panel-${Math.floor(Math.random() * 100000)}`;
   }
 
   /** Given a persistened PanelModel restores property values */

public/app/features/dashboard/utils/panelMerge.test.ts

@@ -0,0 +1,132 @@
+import { PanelModel } from '@grafana/data';
+import { DashboardModel } from '../state/DashboardModel';
+
+describe('Merge dashbaord panels', () => {
+  describe('simple changes', () => {
+    let dashboard: DashboardModel;
+    let rawPanels: PanelModel[];
+
+    beforeEach(() => {
+      dashboard = new DashboardModel({
+        title: 'simple title',
+        panels: [
+          {
+            id: 1,
+            type: 'timeseries',
+          },
+          {
+            id: 2,
+            type: 'timeseries',
+          },
+          {
+            id: 3,
+            type: 'table',
+            fieldConfig: {
+              defaults: {
+                thresholds: {
+                  mode: 'absolute',
+                  steps: [
+                    { color: 'green', value: -Infinity }, // save model has this as null
+                    { color: 'red', value: 80 },
+                  ],
+                },
+                mappings: [],
+                color: { mode: 'thresholds' },
+              },
+              overrides: [],
+            },
+          },
+        ],
+      });
+      rawPanels = dashboard.getSaveModelClone().panels;
+    });
+
+    it('should load and support noop', () => {
+      expect(dashboard.title).toBe('simple title');
+      expect(dashboard.panels.length).toEqual(rawPanels.length);
+
+      const info = dashboard.updatePanels(rawPanels);
+      expect(info.changed).toBeFalsy();
+      expect(info.actions).toMatchInlineSnapshot(`
+        Object {
+          "add": Array [],
+          "noop": Array [
+            1,
+            2,
+            3,
+          ],
+          "remove": Array [],
+          "replace": Array [],
+          "update": Array [],
+        }
+      `);
+    });
+
+    it('should identify an add', () => {
+      rawPanels.push({
+        id: 7,
+        type: 'canvas',
+      } as any);
+
+      const info = dashboard.updatePanels(rawPanels);
+      expect(info.changed).toBeTruthy();
+      expect(info.actions['add']).toEqual([7]);
+    });
+
+    it('should identify a remove', () => {
+      rawPanels.shift();
+
+      const info = dashboard.updatePanels(rawPanels);
+      expect(info.changed).toBeTruthy();
+      expect(info.actions['remove']).toEqual([1]);
+    });
+
+    it('should allow change in key order for nested elements', () => {
+      (rawPanels[2] as any).fieldConfig = {
+        defaults: {
+          color: { mode: 'thresholds' },
+          mappings: [],
+          thresholds: {
+            steps: [
+              { color: 'green', value: null },
+              { color: 'red', value: 80 },
+            ],
+            mode: 'absolute',
+          },
+        },
+        overrides: [],
+      };
+
+      // Same config, different order
+      const js0 = JSON.stringify(dashboard.panels[2].fieldConfig);
+      const js1 = JSON.stringify(rawPanels[2].fieldConfig);
+      expect(js1).not.toEqual(js0);
+      expect(js1.length).toEqual(js0.length);
+
+      // no real changes here
+      const info = dashboard.updatePanels(rawPanels);
+      expect(info.changed).toBeFalsy();
+    });
+
+    it('should replace a type change', () => {
+      (rawPanels[1] as any).type = 'canvas';
+
+      const info = dashboard.updatePanels(rawPanels);
+      expect(info.changed).toBeTruthy();
+      expect(info.actions).toMatchInlineSnapshot(`
+        Object {
+          "add": Array [],
+          "noop": Array [
+            1,
+            3,
+          ],
+          "remove": Array [],
+          "replace": Array [
+            2,
+          ],
+          "update": Array [],
+        }
+      `);
+    });
+  });
+});

public/app/features/dashboard/utils/panelMerge.ts

@@ -0,0 +1,131 @@
+import { PanelModel as IPanelModel } from '@grafana/data';
+import { isEqualWith } from 'lodash';
+import { PanelModel } from '../state';
+
+export interface PanelMergeInfo {
+  changed: boolean;
+  panels: PanelModel[];
+  actions: Record<string, number[]>;
+}
+
+// Values that are safe to change without a full panel unmount/remount
+// TODO: options and fieldConfig should also be supported
+const mutableKeys = new Set<keyof PanelModel>(['gridPos', 'title', 'description', 'transparent']);
+
+export function mergePanels(current: PanelModel[], data: IPanelModel[]): PanelMergeInfo {
+  const panels: PanelModel[] = [];
+  const info = {
+    changed: false,
+    actions: {
+      add: [] as number[],
+      remove: [] as number[],
+      replace: [] as number[],
+      update: [] as number[],
+      noop: [] as number[],
+    },
+    panels,
+  };
+
+  let nextId = 0;
+  const inputPanels = new Map<number, IPanelModel>();
+  for (let p of data) {
+    let { id } = p;
+    if (!id) {
+      if (!nextId) {
+        nextId = findNextPanelID([current, data]);
+      }
+      id = nextId++;
+      p = { ...p, id }; // clone with new ID
+    }
+    inputPanels.set(id, p);
+  }
+
+  for (const panel of current) {
+    const target = inputPanels.get(panel.id) as PanelModel;
+    if (!target) {
+      info.changed = true;
+      info.actions.remove.push(panel.id);
+      panel.destroy();
+      continue;
+    }
+    inputPanels.delete(panel.id);
+
+    // Fast comparison when working with the same panel objects
+    if (target === panel) {
+      panels.push(panel);
+      info.actions.noop.push(panel.id);
+      continue;
+    }
+
+    // Check if it is the same type
+    if (panel.type === target.type) {
+      const save = panel.getSaveModel();
+      let isNoop = true;
+      let doUpdate = false;
+      for (const [key, value] of Object.entries(target)) {
+        if (!isEqualWith(value, save[key], infinityEqualsNull)) {
+          info.changed = true;
+          isNoop = false;
+          if (mutableKeys.has(key as any)) {
+            (panel as any)[key] = value;
+            doUpdate = true;
+          } else {
+            doUpdate = false;
+            break; // needs full replace
+          }
+        }
+      }
+
+      if (isNoop) {
+        panels.push(panel);
+        info.actions.noop.push(panel.id);
+        continue;
+      }
+
+      if (doUpdate) {
+        panels.push(panel);
+        info.actions.update.push(panel.id);
+        continue;
+      }
+    }
+    panel.destroy();
+
+    const next = new PanelModel(target);
+    next.key = `${next.id}-update-${Date.now()}`; // force react invalidate
+    panels.push(next);
+    info.changed = true;
+    info.actions.replace.push(panel.id);
+  }
+
+  // Add the new panels
+  for (const t of inputPanels.values()) {
+    panels.push(new PanelModel(t));
+    info.changed = true;
+    info.actions.add.push(t.id);
+  }
+
+  return info;
+}
+
+// Since +- Infinity are saved as null in JSON, we need to make them equal here also
+function infinityEqualsNull(a: any, b: any) {
+  if (a == null && (b === Infinity || b === -Infinity || b == null)) {
+    return true;
+  }
+  if (b == null && (a === Infinity || a === -Infinity || a == null)) {
+    return true;
+  }
+  return undefined; // use default comparison
+}
+
+function findNextPanelID(args: IPanelModel[][]): number {
+  let max = 0;
+  for (const panels of args) {
+    for (const panel of panels) {
+      if (panel.id > max) {
+        max = panel.id;
+      }
+    }
+  }
+  return max + 1;
+}