fix(eclwatch): display error message in WUResult table

catch exception thrown in wuResult.fetchRows() and pass that message
back to the dgrid table to display instead of the normal noDataMessage

HPCC-32576 (Viewing a file does not pass back errors to the user)

Signed-off-by: Jeremy Clements <79224539+jeclrsg@users.noreply.github.com>

Author: jeclrsg

packages/dgrid/src/Common.ts

@@ -23,6 +23,8 @@ export class Common extends HTMLWidget {
     noDataMessage: publish<this, string>;
     @publish("loading...", "string", "Loading Message")
     loadingMessage: publish<this, string>;
+    @publish("An exception has occurred", "string", "Exception Message")
+    exceptionMessage: publish<this, string>;
     @publish(false, "boolean", "Enable paging")
     pagination: publish<this, boolean>;
     @publish(25, "number", "Page size")
@@ -58,7 +60,7 @@ export class Common extends HTMLWidget {
             const retVal = [];
             for (const id in this._dgrid.selection) {
                 if (this._dgrid.selection[id]) {
-                const storeItem = this._store.get(+id);
+                    const storeItem = this._store.get(+id);
                     retVal.push(this.rowToObj(storeItem));
                 }
             }

packages/eclwatch/src/WUResult.ts

@@ -92,7 +92,13 @@ export class WUResult extends Common {
             const result = this.calcResult();
             if (result) {
                 result.fetchXMLSchema().then(schema => {
-                    this._localStore = new Store(result, schema, this.renderHtml(), this.filter());
+                    this._localStore = new Store(result, schema, this.renderHtml(), this.filter(), (msg) => {
+                        this.exceptionMessage(msg);
+                        if (this._dgrid) {
+                            this._dgrid.noDataMessage = `<span class='dojoxGridNoData'>${this.exceptionMessage()}</span>`;
+                            this._dgrid.refresh();
+                        }
+                    });
                     this._dgrid?.set("columns", this._localStore.columns());
                     this._dgrid?.set("collection", this._localStore);
                 });

packages/eclwatch/src/WUResultStore.ts

@@ -1,4 +1,4 @@
-import { ResultFilter, Result, XSDSchema, XSDXMLNode } from "@hpcc-js/comms";
+import { Exception, ResultFilter, Result, XSDSchema, XSDXMLNode } from "@hpcc-js/comms";
 import { ColumnType, Deferred, domConstruct, QueryResults, RowFormatter } from "@hpcc-js/dgrid";
 
 function entitiesEncode(str) {
@@ -26,13 +26,16 @@ export class Store {
     protected _cache: { [key: string]: Promise<{ totalLength: number, data: any[] }> } = {};
     private rowFormatter: RowFormatter;
     protected _filter: ResultFilter = {};
+    private onError?: (msg: string) => void;
+    private _lastError: string | null = null;
 
-    constructor(wuResult: Result, schema: XSDSchema, renderHtml: boolean, filter: ResultFilter = {}) {
+    constructor(wuResult: Result, schema: XSDSchema, renderHtml: boolean, filter: ResultFilter = {}, onError?: (msg: string) => void) {
         this.wuResult = wuResult;
         this.schema = schema;
         this._columns = this.schema2Columns(this.schema.root);
         this.rowFormatter = new RowFormatter(this._columns, renderHtml);
         this._filter = filter;
+        this.onError = onError;
     }
 
     columns() {
@@ -182,11 +185,25 @@ export class Store {
                     return formattedRow;
                 })
             };
+        }).catch((err: Exception) => {
+            this._lastError = err.Message || "An exception has occurred";
+            if (this.onError) {
+                this.onError(this._lastError);
+            }
+            return { totalLength: 0, data: [] };
         });
         this._cache[cacheKey] = retVal;
         return retVal;
     }
 
+    hasError() {
+        return !!this._lastError;
+    }
+
+    getLastError() {
+        return this._lastError;
+    }
+
     fetchRange(options): Promise<any[]> {
         const retVal = new Deferred();
         this._request(options.start, options.end).then(response => retVal.resolve(response));