1 files changed, 63 insertions, 0 deletions
diff --git a/src/webex/components.ts b/src/webex/components.ts
new file mode 100644
index 000000000..1f5d18731
--- /dev/null
+++ b/src/webex/components.ts
@@ -0,0 +1,63 @@
+/*
+ This file is part of TALER
+ (C) 2016 Inria
+
+ TALER is free software; you can redistribute it and/or modify it under the
+ terms of the GNU General Public License as published by the Free Software
+ Foundation; either version 3, or (at your option) any later version.
+
+ TALER is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+
+/**
+ * General helper React components.
+ */
+
+
+/**
+ * Imports.
+ */
+import * as React from "react";
+
+/**
+ * Wrapper around state that will cause updates to the
+ * containing component.
+ */
+export interface StateHolder<T> {
+  (): T;
+  (newState: T): void;
+}
+
+/**
+ * Component that doesn't hold its state in one object,
+ * but has multiple state holders.
+ */
+export abstract class ImplicitStateComponent<PropType> extends React.Component<PropType, any> {
+  private _implicit = {needsUpdate: false, didMount: false};
+  componentDidMount() {
+    this._implicit.didMount = true;
+    if (this._implicit.needsUpdate) {
+      this.setState({} as any);
+    }
+  }
+  makeState<StateType>(initial: StateType): StateHolder<StateType> {
+    let state: StateType = initial;
+    return (s?: StateType): StateType => {
+      if (s !== undefined) {
+        state = s;
+        if (this._implicit.didMount) {
+          this.setState({} as any);
+        } else {
+          this._implicit.needsUpdate = true;
+        }
+      }
+      return state;
+    };
+  }
+}