Awesome

RVF

(Formerly Remix Validated Form)

Easy form validation and state management for React.

Progressively enhanced

RVF leans into native form APIs, so it's easy to add to your existing forms. It even works without JavaScript on the client if you're using a server-rendered framework like Remix.

Powerful

When you need to scale up and write bigger, more complicated forms, RVF can scale with you.

Easily manages nested objects and arrays in at typesafe way -- even when they're recursive.
Set default values for the whole form in one place.
Re-use your validation on the server.

Docs

The docs are located a rvf-js.io.

Simple example

[!Note] See this example in action on the documention site.

<details> <summary>Plain React</summary>

import { useForm } from "@rvf/react";
import { withZod } from "@rvf/zod";
import { z } from "zod";
import { MyInput } from "~/fields/MyInput";
import { Button } from "~/ui/button";
import { createProject } from "./api";
import { ErrorMessage } from "~/fields/ErrorMessage";
import { showToastMessage } from "~/lib/utils";
import { EmptyState } from "~/ui/empty-state";

const validator = withZod(
  z.object({
    projectName: z
      .string()
      .min(1, "Projects need a name.")
      .max(50, "Must be 50 characters or less."),
    tasks: z
      .array(
        z.object({
          title: z
            .string()
            .min(1, "Tasks need a title.")
            .max(50, "Must be 50 characters or less."),
          daysToComplete: z.coerce.number({
            required_error: "This is required",
          }),
        }),
      )
      .min(1, "Needs at least one task.")
      .default([]),
  }),
);

export const ReactExample = () => {
  const form = useForm({
    validator,
    defaultValues: {
      projectName: "",
      tasks: [] as Array<{ title: string; daysToComplete: number }>,
      file: "" as File | "",
    },
    handleSubmit: async ({ projectName, tasks }) => {
      await createProject({ name: projectName, tasks });
      return projectName;
    },
    onSubmitSuccess: (projectName) => {
      showToastMessage(`Project ${projectName} created!`);
      form.resetForm();
    },
  });

  return (
    <form {...form.getFormProps()}>
      <MyInput label="Project name" scope={form.scope("projectName")} />

      <div>
        <h3>Tasks</h3>
        {form.error("tasks") && (
          <ErrorMessage>{form.error("tasks")}</ErrorMessage>
        )}
        <hr />

        <ul>
          {form.array("tasks").map((key, item, index) => (
            <li key={key}>
              <MyInput label="Title" scope={item.scope("title")} />
              <MyInput
                label="Days to complete"
                type="number"
                scope={item.scope("daysToComplete")}
              />
              <Button
                variant="ghost"
                type="button"
                onClick={() => form.array("tasks").remove(index)}
              >
                Delete
              </Button>
            </li>
          ))}
          {form.array("tasks").length() === 0 && (
            <EmptyState>No tasks yet</EmptyState>
          )}
        </ul>
      </div>

      <div className="flex justify-between">
        <Button
          variant="secondary"
          type="button"
          onClick={async () => {
            const nextTaskIndex = form.array("tasks").length();
            await form.array("tasks").push({
              daysToComplete: 0,
              title: "",
            });
            form.focus(`tasks[${nextTaskIndex}].title`);
          }}
        >
          Add task
        </Button>
        <Button type="submit" isLoading={form.formState.isSubmitting}>
          Submit
        </Button>
      </div>
    </form>
  );
};

</details> <details> <summary>Remix</summary>

import {
  isValidationErrorResponse,
  useForm,
  validationError,
} from "@rvf/remix";
import { withZod } from "@rvf/zod";
import { z } from "zod";
import { MyInput } from "~/fields/MyInput";
import { Button } from "~/ui/button";
import { createProject } from "./api";
import { ErrorMessage } from "~/fields/ErrorMessage";
import { showToastMessage } from "~/lib/utils";
import { EmptyState } from "~/ui/empty-state";
import { json, useActionData } from "@remix-run/react";
import { ActionFunctionArgs } from "@remix-run/node";

const validator = withZod(
  z.object({
    projectName: z
      .string()
      .min(1, "Projects need a name.")
      .max(50, "Must be 50 characters or less."),
    tasks: z
      .array(
        z.object({
          title: z
            .string()
            .min(1, "Tasks need a title.")
            .max(50, "Must be 50 characters or less."),
          daysToComplete: z.coerce.number({
            required_error: "This is required",
          }),
        }),
      )
      .min(1, "Needs at least one task.")
      .default([]),
  }),
);

export const action = async ({ request }: ActionFunctionArgs) => {
  const data = await validator.validate(await request.formData());
  if (data.error) return validationError(data.error);

  const { projectName, tasks } = data.data;

  await createProject({ name: projectName, tasks });
  return json({ projectName });
};

export const ReactExample = () => {
  const data = useActionData<typeof action>();
  const form = useForm({
    validator,
    defaultValues: {
      projectName: "",
      tasks: [] as Array<{ title: string; daysToComplete: number }>,
    },
    onSubmitSuccess: () => {
      // We know this isn't an error in the success callback, but Typescript doesn't
      if (isValidationErrorResponse(data)) return;

      // This isn't always the best way to show a toast in remix.
      // https://www.jacobparis.com/content/remix-form-toast
      showToastMessage(`Project ${data?.projectName} created!`);
      form.resetForm();
    },
  });

  return (
    <form {...form.getFormProps()}>
      <MyInput label="Project name" scope={form.scope("projectName")} />

      <div>
        <h3>Tasks</h3>
        {form.error("tasks") && (
          <ErrorMessage>{form.error("tasks")}</ErrorMessage>
        )}
        <hr />

        <ul>
          {form.array("tasks").map((key, item, index) => (
            <li key={key}>
              <MyInput label="Title" scope={item.scope("title")} />
              <MyInput
                label="Days to complete"
                type="number"
                scope={item.scope("daysToComplete")}
              />
              <Button
                variant="ghost"
                type="button"
                onClick={() => form.array("tasks").remove(index)}
              >
                Delete
              </Button>
            </li>
          ))}
          {form.array("tasks").length() === 0 && (
            <EmptyState>No tasks yet</EmptyState>
          )}
        </ul>
      </div>

      <div className="flex justify-between">
        <Button
          variant="secondary"
          type="button"
          onClick={async () => {
            const nextTaskIndex = form.array("tasks").length();
            await form.array("tasks").push({
              daysToComplete: 0,
              title: "",
            });
            form.focus(`tasks[${nextTaskIndex}].title`);
          }}
        >
          Add task
        </Button>
        <Button type="submit" isLoading={form.formState.isSubmitting}>
          Submit
        </Button>
      </div>
    </form>
  );
};

</details>

Getting started

Install

RVF can be used with any flavor of React, but there's also an adapter specifically for Remix.

@rvf/remix
@rvf/react

For Remix users:

npm install @rvf/remix

For plain React or other frameworks like Next.js:

npm install @rvf/react

Validation library adapter

There are official adapters available for zod and yup. If you're using a different library, see the Validation library support seciton of the docs..

@rvf/zod
@rvf/yup

For Zod users:

npm install @rvf/zod

For Yup users:

npm install @rvf/yup