fix an issue where grid options were copied over on route change, that caused weird behaviors in next grid

Author: Ghislain Beaulac

src/app/modules/angular-slickgrid/components/angular-slickgrid.component.ts

@@ -20,7 +20,7 @@ import 'slickgrid/plugins/slick.headermenu';
 import 'slickgrid/plugins/slick.rowmovemanager';
 import 'slickgrid/plugins/slick.rowselectionmodel';
 import { AfterViewInit, Component, EventEmitter , Injectable, Input, Output, OnInit } from '@angular/core';
-import { castToPromise } from './../services/utilities';
+import { castToPromise, immutableMerge } from './../services/utilities';
 import { GlobalGridOptions } from './../global-grid-options';
 import { CellArgs, Column, FormElementType, GridOption } from './../models';
 import { ControlAndPluginService, FilterService, GridEventService, SortService, ResizerService } from './../services';
@@ -179,7 +179,8 @@ export class AngularSlickgridComponent implements AfterViewInit, OnInit {
     if (this.gridOptions.enableFiltering) {
       this.gridOptions.showHeaderRow = true;
     }
-    const options = { ...GlobalGridOptions, ...this.gridOptions };
+    // use an immutable merge to avoid changing properties in GlobalGridOptions when changing route
+    const options = immutableMerge(GlobalGridOptions, this.gridOptions);
     return options;
   }
 

src/app/modules/angular-slickgrid/services/utilities.ts

@@ -5,6 +5,7 @@ import 'rxjs/add/operator/take';
 import 'rxjs/add/operator/toPromise';
 import * as moment_ from 'moment-mini';
 const moment: any = (<any>moment_).default || moment_; // patch to fix rollup "moment has no default export" issue, document here https://github.com/rollup/rollup/issues/670
+import _ from 'lodash';
 
 /**
  * Try casting an input of type Promise | Observable into a Promise type.
@@ -228,3 +229,17 @@ export function parseUtcDate(inputDateString: string, useUtc: boolean): string |
 
   return date;
 }
+
+export function immutableMerge(...args) {
+  if (args.length === 0) {
+    return {};
+  }
+  if (args.length === 1) {
+    return args[0];
+  }
+  if (args.length === 2) {
+    return _.merge(_.cloneDeep(args[0]), args[1]);
+  } else {
+    return immutableMerge(_.first(args), immutableMerge(_.rest(args)));
+  }
+}