Re-implemented context items.

lib/Language/en/translation.json

@@ -1581,6 +1581,10 @@
     "leftPanel": "Left panel",
     "rightPanel": "Right panel",
     "bothPanels": "Both panels",
+    "bothPanelsMenu": {
+      "browse": "Browse map data",
+      "hideAll": "Hide all"
+    },
     "info": "Compare spatial datasets from your workbench side-by-side on the map.",
     "dataset": {
       "label": "Dataset",

lib/Models/Comparable.ts

@@ -1,3 +1,5 @@
+import { isArrayLike } from "mobx";
+import { isJsonObject } from "../Core/Json";
 import CatalogMemberMixin from "../ModelMixins/CatalogMemberMixin";
 import MappableMixin from "../ModelMixins/MappableMixin";
 import CatalogMemberTraits from "../Traits/TraitsClasses/CatalogMemberTraits";
@@ -25,3 +27,37 @@ export function isComparableItem(item: any): item is Comparable {
     hasTraits(item, SplitterTraits, "splitDirection");
   return isComparable;
 }
+
+/**
+ * Object used to store compare workflow configuration
+ */
+export type CompareConfig = {
+  // ID of the item to show in the left panel
+  leftPanelItemId: string | undefined;
+  // ID of the item to show in the right panel
+  rightPanelItemId: string | undefined;
+  // IDs of context items (items appearing in both panels).
+  contextItemIds: string[];
+};
+
+export function createCompareConfig(json: any = {}): CompareConfig | undefined {
+  if (!isJsonObject(json)) {
+    return undefined;
+  }
+
+  const leftPanelItemId =
+    typeof json.leftPanelItemId === "string" ? json.leftPanelItemId : undefined;
+  const rightPanelItemId =
+    typeof json.rightPanelItemId === "string"
+      ? json.rightPanelItemId
+      : undefined;
+  const contextItemIds = isArrayLike(json.contextItemIds)
+    ? (json.contextItemIds.filter(id => typeof id === "string") as string[])
+    : [];
+
+  return {
+    leftPanelItemId,
+    rightPanelItemId,
+    contextItemIds
+  };
+}

lib/Models/Terria.ts

@@ -67,6 +67,7 @@ import MagdaReference, {
   MagdaReferenceHeaders
 } from "./Catalog/CatalogReferences/MagdaReference";
 import SplitItemReference from "./Catalog/CatalogReferences/SplitItemReference";
+import { CompareConfig, createCompareConfig } from "./Comparable";
 import CommonStrata from "./Definition/CommonStrata";
 import hasTraits from "./Definition/hasTraits";
 import { BaseModel } from "./Definition/Model";
@@ -533,14 +534,9 @@ export default class Terria {
   @observable catalogReferencesLoaded: boolean = false;
 
   /**
-   * Left item in the compare workflow
+   * Configuration for the compare workflow
    */
-  @observable compareLeftItemId?: string;
-
-  /**
-   * Right item in the compare workflow
-   */
-  @observable compareRightItemId?: string;
+  @observable compareConfig: CompareConfig | undefined = undefined;
 
   augmentedVirtuality?: any;
 
@@ -1387,12 +1383,8 @@ export default class Terria {
       this.splitPosition = initData.splitPosition;
     }
 
-    if (isJsonString(initData.compareLeftItemId)) {
-      this.compareLeftItemId = initData.compareLeftItemId;
-    }
-
-    if (isJsonString(initData.compareRightItemId)) {
-      this.compareRightItemId = initData.compareRightItemId;
+    if (isJsonObject(initData.compareConfig)) {
+      this.compareConfig = createCompareConfig(initData.compareConfig);
     }
 
     // Copy but don't yet load the workbench.