元数据

非官方测试版翻译

本页面由 PageTurner AI 翻译（测试版）。未经项目官方认可。 发现错误？ 报告问题 →

过程元数据允许您添加可选的、过程特定的 meta 属性，该属性将在所有中间件函数参数中可用。

技巧

若需为应用提供 REST 兼容的端点，请结合使用元数据与 trpc-openapi。

创建带有类型化元数据的路由器

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({
  // [...]
});

按路由认证设置示例

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',
    };
  }),
});

默认元数据、链式操作与浅层合并

您可为元数据类型设置默认值，若在基础过程之上链式添加元数据，系统将执行浅层合并。

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' }