Introdution
In this article,we are gonna enumerate some kinds of form submitting with trpc concretely, globally in detail. If need, please see 《NextJs 14 从入门到精通之tRPC快速入门》
Prepare trpc base enviroment
Form component typically is used in Client Component, you can submmit with http request or call server action directly. So we start along this thought
We need to create tRPC appRouter at first
bun add @trpc/server@next @trpc/client@next
ts
import { initTRPC } from '@trpc/server';
import { db } from '@/server/db';
export const createTRPCContext = async (opts: {
req?: NextRequest;
}) => {
// get session
const session = { user: {userId: 'xxx'}, sessionId: 'xxxx' };
return {
db,
session,
...opts,
};
};
const t = initTRPC.context<typeof createTRPCContext>().create()
const publicProcedure = t.procedure;
const protectedProcedure = t.procedure.use(({ ctx, next }) => {
if (!ctx.session || !ctx.session.userId) {
throw new TRPCError({ code: 'UNAUTHORIZED' });
}
return next({
ctx: {
// infers the `session` as non-nullable
session: {
...ctx.session,
userId: ctx.session.userId,
},
},
});
});
export const appRouter = t.router({
createUser: protectedProcedure
.input(z.object({
name: z.string(),
password: z.string()
}))
.mutation(async ({ ctx, input }) => {
const { userId } = ctx;
const data = await ctx.db.user.create({
data: {...input, userId }
})
return { status: 200, data, message: 'success' }
})
})Http Request with tRPC
Firstly, make tRPC appRouter match NextJs api-router
ts
// src/app/api/trpc/[...trpc]/route.ts
import { fetchRequestHandler } from '@trpc/server/adapters/fetch';
import { appRouter } from '@/server/api/root';
import { createTRPCContext } from '@/server/api/trpc';
const handler = (req: NextRequest) =>
fetchRequestHandler({
endpoint: '/api/trpc',
req,
router: appRouter,
createContext: () => createTRPCContext(),
onError: ({ path, error }) => {
console.log('------', error);
},
});
export { handler as GET, handler as POST };Secondly, Create tRPC Client with react-query
bun add @trpc/react-query@next @tanstack/react-query
tsx
// tRPCReact.ts
import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
import { createTRPCReact } from '@trpc/react-query';
import { unstable_httpBatchStreamLink } from '@trpc/client';
import { useState } from 'react';
const createQueryClient = () => new QueryClient();
let clientQueryClientSingleton: QueryClient | undefined = undefined;
const getQueryClient = () => {
if (typeof window === 'undefined') {
return createQueryClient();
}
return (clientQueryClientSingleton ??= createQueryClient());
};
export const api = createTRPCReact<AppRouter>();
export function TRPCReactProvider(props: { children: React.ReactNode }) {
const queryClient = getQueryClient();
const [trpcClient] = useState(() =>
api.createClient({
links: [
unstable_httpBatchStreamLink({
url: 'http:localhost:3000/api/trpc',
}),
],
})
);
return (
<QueryClientProvider client={queryClient}>
<api.Provider client={trpcClient} queryClient={queryClient}>
{props.children}
</api.Provider>
</QueryClientProvider>
);
}Thirdly, used in form component
- To use react-query, your component must be wrapped with TRPCReactProvider before.
ts
export default function RootLayout({ children }) {
return (
<html lang="en">
<body>
<TRPCReactProvider>{children}</TRPCReactProvider>
</body>
</html>
)
}- In form component.
tsx
'use client';
import { api } from 'tRPCReact';
export function Form() {
const create = api.createUser.useMutation({
onSuccess: () => {}
onError: (e) => {}
})
return (
<form>
{/* ... */}
<button onClick={() => create.mutate({
name, password
})} >Submit</button>
</form>
)
}Server Action with tRPC's createCaller
NextJs 14 supports calling server action directly for form submmiting. And similarly，tRPC supports server side calls. so we can do following this:
- Go back to the file of appRouter, export default createCallerFactory
ts
// ...
const t = initTRPC.context<typeof createTRPCContext>().create()
// ...
export const createCallerFactory = t.createCallerFactory;- Create trpc caller
ts
// tRPCServer
const createCaller = createCallerFactory(appRouter);
export const api = createCaller(() => createTRPCContext());- Used in form component
tsx
'use client';
import { api } from 'tRPCServer';
export function Form() {
const create = async (formData, FormData) {
'use server'
try {
api.createUser(formData)
} catch (e) {}
}
return (
<form action={create}>
{/* ... */}
</form>
)
}Server Action with tRPC's experimental_caller
This is an experimental feature, we should not better to use it. it's based on top of procedure, likely a middleware, finally return a new procedure.
And we will not use the previous defined appRouter. we should re-write the inner logic.
so we can do by following:
- Export default createCallerFactory
ts
// ....
const t = initTRPC.context<typeof createTRPCContext>().create();
// ....
// experimental: form action
export const createActionCaller = protectedProcedure.experimental_caller;- Create a file for createActionCaller
ts
// tRPCAction
import { experimental_nextAppDirCaller } from '@trpc/server/adapters/next-app-dir';
export const tRPCAction = createActionCaller(
experimental_nextAppDirCaller({
createContext: () => createTRPCContext()
})
);- Define a Server Action as a file and write business logic
ts
'use server';
import { tRPCAction } from 'tRPCAction';
import { z } from 'zod';
export const createUserAction = tRPCAction
.input(z.object({
name: z.string(),
password: z.string()
}))
.mutation(async ({ ctx, input }) => {
const { userId } = ctx;
const data = await ctx.db.user.create({
data: {...input, userId }
})
return { status: 200, data, message: 'success' }
})- Used in form component
tsx
'use client';
import { createUserAction } from 'actions';
export function Form() {
return (
<form action={createUserAction}>
{/* ... */}
</form>
)
}Summarize
In Next.js 14, using server Actions to submit a form and call tRPC's createCaller is a straightforward way. Both offer different ways to invoke server-side code, depending on your needs and development style. Here is an explanation of the two ways:
-
createCaller is a way to call the server-side tRPC endpoint directly. It is suitable for situations where you need to call the tRPC endpoint directly in server-side code, such as during server Actions or other server-side processing.
-
experimental_caller provides an experimental method for calling tRPC methods on the server side. It is a more straightforward API, but because it is experimental, it may change in future releases
In fact, I suggest to use createCaller, because this way is used directly and once appRouter logic is defined. we can use server side call and server action.