feature: add enumValueFromString()

refs #328

src/util/enum.ts

@@ -17,6 +17,9 @@
  *  }
  */
 // tslint:disable-next-line:max-line-length
+
+import { Session } from "../session";
+
 // see https://stackoverflow.com/questions/21293063/how-to-programmatically-enumerate-an-enum-type-in-typescript-0-9-5#21294925
 export class EnumEx {
     /**
@@ -44,3 +47,19 @@ export class EnumEx {
         return Object.keys(e).map((k) => e[k]);
     }
 }
+
+
+/**
+ * get enum numerical value from enum class name and value as a string
+ * @param enumClass enum class name
+ * @param enumValueName enum value as a string
+ * @returns enum numerical value
+ */
+export function enumValueFromString(enumClass: string, enumValueName: string): any {
+    // !! property names must be unique throughout JaLHyd !!
+    const enumValues = Session.enumFromProperty[enumClass];
+    if (enumValues) {
+        return enumValues[enumValueName];
+    }
+    throw new Error("unknown enum class ${enumClass}");
+}