Metadata

程序 metadata 讓您可以新增一個程序特定的選用 meta 屬性，此屬性會在所有 中間件 函數參數中提供。

提示

如果您想為您的應用程式公開相容於 REST 的端點，請將 metadata 與 trpc-openapi 一起使用。

建立具有類型化 metadata 的路由器

tsx
import { initTRPC } from '@trpc/server';
// [...]
interface Meta {
  authRequired: boolean;
}
export const t = initTRPC.context<Context>().meta<Meta>().create();
export const appRouter = t.router({
  // [...]
});

tsx
import { initTRPC } from '@trpc/server';
// [...]
interface Meta {
  authRequired: boolean;
}
export const t = initTRPC.context<Context>().meta<Meta>().create();
export const appRouter = t.router({
  // [...]
});

針對每個路由驗證設定的範例

server.ts
tsx
import { initTRPC } from '@trpc/server';
// [...]
interface Meta {
  authRequired: boolean;
}
export const t = initTRPC.context<Context>().meta<Meta>().create();
export const authedProcedure = t.procedure.use(async (opts) => {
  const { meta, next, ctx } = opts;
  // only check authorization if enabled
  if (meta?.authRequired && !ctx.user) {
    throw new TRPCError({ code: 'UNAUTHORIZED' });
  }
  return next();
});
export const appRouter = t.router({
  hello: authedProcedure.meta({ authRequired: false }).query(() => {
    return {
      greeting: 'hello world',
    };
  }),
  protectedHello: authedProcedure.meta({ authRequired: true }).query(() => {
    return {
      greeting: 'hello-world',
    };
  }),
});

server.ts
tsx
import { initTRPC } from '@trpc/server';
// [...]
interface Meta {
  authRequired: boolean;
}
export const t = initTRPC.context<Context>().meta<Meta>().create();
export const authedProcedure = t.procedure.use(async (opts) => {
  const { meta, next, ctx } = opts;
  // only check authorization if enabled
  if (meta?.authRequired && !ctx.user) {
    throw new TRPCError({ code: 'UNAUTHORIZED' });
  }
  return next();
});
export const appRouter = t.router({
  hello: authedProcedure.meta({ authRequired: false }).query(() => {
    return {
      greeting: 'hello world',
    };
  }),
  protectedHello: authedProcedure.meta({ authRequired: true }).query(() => {
    return {
      greeting: 'hello-world',
    };
  }),
});

預設 meta、串連和淺層合併

您可以為您的 meta 類型設定預設值，如果您在基本程序上串連 meta，它將會被淺層合併。

tsx
import { initTRPC } from '@trpc/server';
interface Meta {
  authRequired: boolean;
  role?: 'user' | 'admin'
}
export const t = initTRPC
  .context<Context>()
  .meta<Meta>()
  .create({
    // Set a default value
    defaultMeta: { authRequired: false }
  });
const publicProcedure = t.procedure
// ^ Default Meta: { authRequired: false }
const authProcedure = publicProcedure
  .use(authMiddleware)
  .meta({
    authRequired: true;
    role: 'user'
  });
// ^ Meta: { authRequired: true, role: 'user' }
const adminProcedure = authProcedure
  .meta({
    role: 'admin'
  });
// ^ Meta: { authRequired: true, role: 'admin' }

tsx
import { initTRPC } from '@trpc/server';
interface Meta {
  authRequired: boolean;
  role?: 'user' | 'admin'
}
export const t = initTRPC
  .context<Context>()
  .meta<Meta>()
  .create({
    // Set a default value
    defaultMeta: { authRequired: false }
  });
const publicProcedure = t.procedure
// ^ Default Meta: { authRequired: false }
const authProcedure = publicProcedure
  .use(authMiddleware)
  .meta({
    authRequired: true;
    role: 'user'
  });
// ^ Meta: { authRequired: true, role: 'user' }
const adminProcedure = authProcedure
  .meta({
    role: 'admin'
  });
// ^ Meta: { authRequired: true, role: 'admin' }