ui: add hint to pid input

packages/ui-default/components/problem/create.page.js

@@ -0,0 +1,17 @@
+import { NamedPage } from 'vj/misc/Page';
+import { InfoDialog } from 'vj/components/dialog';
+import tpl from 'vj/utils/tpl';
+import i18n from 'vj/utils/i18n';
+
+export default new NamedPage(['problem_create', 'problem_edit', 'problem_import_syzoj'], () => {
+  $('input[name="pid"]').on('blur', () => {
+    if (/^[0-9]+$/.test($('input[name="pid"]').val())) {
+      new InfoDialog({
+        $body: tpl`
+          <div class="typo">
+            <p>${i18n('Problem ID cannot be a pure number. Leave blank if you want to use numberic id.')}</p>
+          </div>`,
+      }).open();
+    }
+  });
+});