fec-state-management

Front-end status management

Purpose

Determine clear ownership of front-end state to avoid global store bloat, duplicate caching, and derived state synchronization errors.

Procedure

1. Classify status sources first

Don't choose Redux, Zustand, Pinia or Context first. First mark each state to its unique owner, and then decide on the tool.

Status Type	Typical Example	Default Attribution
Local UI state	Pop-up window switch, tab, expand row, hover editing state	In-component state / ref
Form status	Input value, dirty field, validation error, submitting	Form library or form component
Server status	List, details, paging results, remote errors	Request cache library
URL status	Search terms, filter, sort, page number, selected tab	Routing parameters / search params
Global client status	Login users, topics, permission snapshots, shopping cart drafts	Global store
Browser persistent state	Drafts, preferences, offline queues retained across refreshes	Storage layer + state adapter

type ReportsStateMap = {
  search: "url";
  selectedReportId: "url";
  reports: "server-state-cache";
  isFilterPanelOpen: "local-ui";
  draftColumns: "browser-persistence";
};

2. Keep it minimal

Do not save a new copy of a value that can be inferred from props, server state, URL, or existing state.

interface Invoice {
  id: string;
  status: "draft" | "sent" | "paid";
}

function InvoiceList({ invoices }: { invoices: Invoice[] }) {
  const paidInvoices = invoices.filter((invoice) => invoice.status === "paid");

  return <span>{paidInvoices.length}</span>;
}

3. Select the React global state solution

Priority is given to localization and combination in React; the global store is only introduced when cross-page, cross-feature or unified actions are required.

import { create } from "zustand";

interface WorkspaceState {
  activeWorkspaceId: string | null;
  setActiveWorkspaceId: (workspaceId: string) => void;
}

export const useWorkspaceStore = create<WorkspaceState>((set) => ({
  activeWorkspaceId: null,
  setActiveWorkspaceId: (activeWorkspaceId) => set({ activeWorkspaceId }),
}));

Decision order:

1. Use only in one component or a small subtree: useState / useReducer.
2. Low-frequency global configuration or dependency injection: Context.
3. Moderately complex business status: Zustand or Jotai, priority will be given based on the existing selection of the warehouse.
4. Large applications, strict action flow, auditing or time travel debugging: Redux Toolkit.
5. Remote data: Use the data acquisition skill to manage query keys, cache and invalidation policies.

4. Select Vue global state solution

In Vue 3, use provide/inject for local cross-level transfer; use Pinia or the existing store of the project for global business status.

import { computed, readonly, ref } from "vue";
import { defineStore } from "pinia";

export const useSessionStore = defineStore("session", () => {
  const userId = ref<string | null>(null);
  const isSignedIn = computed(() => userId.value !== null);

  function signIn(nextUserId: string) {
    userId.value = nextUserId;
  }

  return {
    userId: readonly(userId),
    isSignedIn,
    signIn,
  };
});

5. Clarify status boundaries and migration steps

When reconstructing the state, first make a state list, and then gradually move the read and write entries. Each step should keep the behavior verifiable.

interface StateMigrationItem {
  name: string;
  currentOwner: "component" | "context" | "store" | "query-cache" | "url";
  targetOwner: "component" | "context" | "store" | "query-cache" | "url";
  verification: string;
}

const migrationPlan: StateMigrationItem[] = [
  {
    name: "dashboard filters",
    currentOwner: "store",
    targetOwner: "url",
    verification: "refreshing the page preserves filters through search params",
  },
];

Detailed reference

Load references/state-patterns.md when you need Store shape examples, selector patterns, URL state synchronization, persistence adapters, SSR boundaries, or review checklists.

Constraints

• Do not copy the server response to the global store; caching, invalidation and retries belong to the data acquisition layer.
• Do not promote each field of the form to the global store; cross-step sharing is also handled first by the form context or submit draft adapter.
• No need to use Context to carry large objects that change frequently; it will expand the re-rendering range.
• Persistence state must specify field whitelist, version number, expiration policy and sensitive data exclusion.
• In SSR scenarios, do not create a singleton store with user data at the top level of the module.

Expected Output

Output status attribution list, selection reasons, store/API boundaries and verification steps. Key behaviors such as loading/error/empty, refresh, rollback, cross-routing, and permission changes should be retained during implementation.