feat: sum query for reports

src/app/core/export/query.service.spec.ts

@@ -622,6 +622,20 @@ describe("QueryService", () => {
     expect(res).toBe(1);
   });
 
+  it("should allow to sum values", () => {
+    const data = [
+      { a: 1, b: 2 },
+      { a: "4" }, // also allows strings
+      { b: 5 }, // not existing as 0
+      { a: -2 }, // allows negative
+      { a: "three" }, // skips invalid
+    ];
+
+    const res = service.queryData("a:sum", undefined, undefined, data);
+
+    expect(res).toBe(3);
+  });
+
   function queryData(query: string, from?: Date, to?: Date, data?: any) {
     return service
       .cacheRequiredData(query, from, to)

src/app/core/export/query.service.ts

@@ -97,6 +97,7 @@ export class QueryService {
         toArray: this.toArray,
         unique: this.unique,
         count: this.count,
+        sum: this.sum,
         addPrefix: this.addPrefix,
         toEntities: this.toEntities.bind(this),
         getRelated: this.getRelated.bind(this),
@@ -233,6 +234,19 @@ export class QueryService {
     return data ? data.length : 0;
   }
 
+  /**
+   * Returns the (integer) sum of the provided array.
+   * It can also handle integers in strings, e.g. "3"
+   * @param data and integer array
+   * @private
+   */
+  private sum(data: any[]): number {
+    return data.reduce((res, cur) => {
+      const parsed = Number.parseInt(cur);
+      return Number.isNaN(parsed) ? res : res + parsed;
+    }, 0);
+  }
+
   /**
    * Turns a list of ids (with the entity prefix) into a list of entities
    * @param ids the array of ids with entity prefix