WiP Validation stil.

help.js

@@ -185,3 +185,53 @@
     alert("Success!");
   }
 })();
+/////////////////////////////////////////////////
+const isPresent = $input => {
+  return $input && $input!=="" && $input != null;
+}
+
+const isNumber = $input => {
+  const simpleNumberRegex = /[+-]?(?:\d*[.,])?\d+/;
+  return $input && $input.length <250 && simpleNumberRegex.test($input);
+
+}
+
+const isInteger = $input => {
+  const simpleIntegerRegex = /^([+-]?[1-9]\d*|0)$/;
+  return $input && $input.length <250 && simpleIntegerRegex.test($input);
+
+}
+
+const validate = (input) => {
+
+  const valid;
+  const errorMsg;
+  const constraint = input.constraint[0];
+
+  switch (constraint) {
+    case "required":
+      valid = isPresent ($(`#${input.dbField}`).val());
+      errorMsg = ["Ovo je obavezno polje."];
+      break;
+    case "numerical":
+      valid = isNumber ($(`#${input.dbField}`).val());
+      errorMsg = ["Unesite brojcanu vrijednost."];
+      break;
+    case "integer":
+      valid = isInteger ($(`#${input.dbField}`).val());
+      errorMsg = ["Unesite cijeli broj."];
+
+      break;
+      default :
+      valid = true;
+    }
+    if (!valid) {
+      const inputField = document.querySelector(`#${input.dbField}`);
+    showErrorsForInput( inputField, errorMsg);
+    return false;
+  } else {
+    return true;
+  }
+
+  }
+