added page component

scm-ui/src/components/Page.js

@@ -0,0 +1,46 @@
+//@flow
+import * as React from "react";
+import Loading from "./Loading";
+import ErrorNotification from "./ErrorNotification";
+
+type Props = {
+  title: string,
+  subtitle?: string,
+  loading?: boolean,
+  error?: Error,
+  children: React.Node
+};
+
+class Page extends React.Component<Props> {
+  render() {
+    const { title, error } = this.props;
+    return (
+      <section className="section">
+        <div className="container">
+          <h1 className="title">{title}</h1>
+          {this.renderSubtitle()}
+          <ErrorNotification error={error} />
+          {this.renderContent()}
+        </div>
+      </section>
+    );
+  }
+
+  renderSubtitle() {
+    const { subtitle } = this.props;
+    if (subtitle) {
+      return <h2 className="subtitle">Users</h2>;
+    }
+    return null;
+  }
+
+  renderContent() {
+    const { loading, children } = this.props;
+    if (loading) {
+      return <Loading />;
+    }
+    return children;
+  }
+}
+
+export default Page;