More refactoring

UI/InputElement/Validators/NatValidator.ts

@@ -0,0 +1,30 @@
+import IntValidator from "./IntValidator"
+import { Translation } from "../../i18n/Translation"
+import Translations from "../../i18n/Translations"
+
+export default class NatValidator extends IntValidator {
+    constructor(name?: string, explanation?: string) {
+        super(name ?? "nat", explanation ?? "A  whole, positive number or zero")
+    }
+
+    isValid(str): boolean {
+        if (str === undefined) {
+            return false
+        }
+        str = "" + str
+
+        return str.indexOf(".") < 0 && !isNaN(Number(str)) && Number(str) >= 0
+    }
+
+    getFeedback(s: string): Translation {
+        const spr = super.getFeedback(s)
+        if (spr !== undefined) {
+            return spr
+        }
+        const n = Number(s)
+        if (n < 0) {
+            return Translations.t.validation.nat.mustBePositive
+        }
+        return undefined
+    }
+}