1 files changed, 54 insertions, 0 deletions
diff --git a/packages/exchange-backoffice-ui/src/forms/FormProvider.tsx b/packages/exchange-backoffice-ui/src/forms/FormProvider.tsx
new file mode 100644
index 000000000..c9b6783e6
--- /dev/null
+++ b/packages/exchange-backoffice-ui/src/forms/FormProvider.tsx
@@ -0,0 +1,54 @@
+import { AbsoluteTime, TranslatedString } from "@gnu-taler/taler-util";
+import { ComponentChildren, VNode, createContext, h } from "preact";
+import { StateUpdater, useMemo } from "preact/hooks";
+
+export interface FormType<T> {
+  initialValue: Partial<T>;
+  value: Partial<T>;
+  onUpdate: StateUpdater<T>;
+  computeFormState?: (v: T) => FormState<T>;
+}
+
+//@ts-ignore
+export const FormContext = createContext<FormType<any>>({});
+
+type FormState<T> = {
+  [field in keyof T]?: T[field] extends AbsoluteTime
+    ? Partial<InputFieldState>
+    : T[field] extends object
+    ? FormState<T[field]>
+    : Partial<InputFieldState>;
+};
+
+export interface InputFieldState {
+  /* should show the error */
+  error?: TranslatedString;
+  /* should not allow to edit */
+  readonly: boolean;
+  /* should show as disable */
+  disabled: boolean;
+  /* should not show */
+  hidden: boolean;
+}
+
+export function FormProvider<T>({
+  children,
+  state,
+  computeFormState,
+}: {
+  state: [Partial<T>, StateUpdater<T>];
+  computeFormState?: (v: T) => FormState<T>;
+  children: ComponentChildren;
+}): VNode {
+  const [value, onUpdate] = state;
+  const initialValue = useMemo(() => value, []);
+  const contextValue = useMemo(
+    () => ({ initialValue, value, onUpdate, computeFormState }),
+    [value, onUpdate, computeFormState],
+  );
+  return (
+    <FormContext.Provider value={contextValue}>
+      <form>{children}</form>
+    </FormContext.Provider>
+  );
+}