Add accounts list as a provider

moneymgr_web/src/hooks/AccountsListProvider.tsx

@@ -0,0 +1,68 @@
+import React from "react";
+import { Account, AccountApi, AccountsList } from "../api/AccountApi";
+import { AsyncWidget } from "../widgets/AsyncWidget";
+
+interface AccountContext {
+  list: AccountsList;
+  reload: () => void;
+  get(id: number): Account | null;
+}
+
+const AccountContextK = React.createContext<AccountContext | null>(null);
+
+export function AccountsListProvider(
+  p: React.PropsWithChildren
+): React.ReactElement {
+  const [list, setList] = React.useState<AccountsList | null>(null);
+
+  const loadKey = React.useRef(1);
+
+  const loadPromise = React.useRef<(() => void) | null>(null);
+
+  const load = async () => {
+    setList(await AccountApi.GetList());
+  };
+
+  const onReload = async () => {
+    loadKey.current += 1;
+    setList(null);
+
+    return new Promise<void>((res) => {
+      loadPromise.current = () => {
+        res();
+      };
+    });
+  };
+
+  return (
+    <AsyncWidget
+      loadKey={loadKey.current}
+      load={load}
+      errMsg="Failed to load the list of accounts!"
+      build={() => {
+        if (loadPromise.current != null) {
+          loadPromise.current();
+          loadPromise.current = null;
+        }
+
+        return (
+          <AccountContextK
+            value={{
+              list: list!,
+              get(id) {
+                return list!.get(id);
+              },
+              reload: onReload,
+            }}
+          >
+            {p.children}
+          </AccountContextK>
+        );
+      }}
+    />
+  );
+}
+
+export function useAccounts(): AccountContext {
+  return React.use(AccountContextK)!;
+}