DEV Community

Alvaro Guimarães
Alvaro Guimarães

Posted on

React na Prática: Melhorando Formulários com Hooks.

#webdev #javascript #beginners #react

Trabalhando com formulários

Um caso comum é a lógica de lidar com formulários, que pode ser extraída para um hook customizado.

// form.tsx
import { FormEventHandler, useState } from "react";

function Forms() {
  const [title, setTitle] = useState("");
  const [price, setPrice] = useState("");
  const [description, setDescription] = useState("");
  const [image, setImage] = useState("");
  const [category, setCategory] = useState("");

  const [data, setData] = useState<any>(null);
  const [isLoading, setIsLoading] = useState(false);
  const [error, setError] = useState<any>(null);

  const handleSubmit: FormEventHandler<HTMLFormElement> = async (e) => {
    try {
      setIsLoading(true);

      e.preventDefault();

      const response = await fetch("https://fakestoreapi.com/products", {
        method: "POST",
        body: JSON.stringify({
          title,
          price,
          description,
          image,
          category,
        }),
      });

      const data = await response.json();

      setData(data);
    } catch (e) {
      setError(e);
    } finally {
      setIsLoading(false);
    }
  };

  return (
    <form
      style={{ display: "flex", flexFlow: "column", gap: 10 }}
      onSubmit={handleSubmit}
    >
      <label htmlFor="name">Title:</label>
      <input
        type="text"
        id="title"
        name="title"
        value={title}
        onChange={({ target: { value } }) => setTitle(value)}
      />

      <label htmlFor="price">Price:</label>
      <input
        type="number"
        id="price"
        name="price"
        value={price}
        onChange={({ target: { value } }) => setPrice(value)}
      />

      <label htmlFor="description">Description:</label>
      <textarea
        id="description"
        name="description"
        value={description}
        onChange={({ target: { value } }) => setDescription(value)}
      />

      <label htmlFor="image">Image:</label>
      <input
        type="url"
        id="image"
        name="image"
        onChange={({ target: { value } }) => setImage(value)}
      />

      <label htmlFor="category">Category:</label>
      <select
        id="category"
        name="category"
        value={category}
        onChange={({ target: { value } }) => setCategory(value)}
      >
        <option value="electronics">electronics</option>
        <option value="jewelery">jewelery</option>
        <option value="men's clothing">men's clothing</option>
        <option value="women's clothing">women's clothing</option>
      </select>

      <button disabled={isLoading} type="submit">
        Send
      </button>

      <div>Error: {JSON.stringify(error)}</div>
      <div>Response: {JSON.stringify(data)}</div>
    </form>
  );
}

export default Forms;
Enter fullscreen mode Exit fullscreen mode

No cerne, esse componente lida com a ideia de criar um produto, tem um estado
para cada campo de formulário e para os estados do formulário.

A reescrita desse componente pode ser feita em etapas. Podemos aproveitar parte do que fizemos no exemplo de lidando com requisições:

Extraindo estados da requisição 

// useMutate.tsx

import { useCallback, useState } from "react";

export type UseMutateParams<T, A> = {
  mutation: (args: A) => Promise<T>;
};

export function useMutate<T, A>({ mutation }: UseMutateParams<T, A>) {
  const [isLoading, setIsLoading] = useState(false);
  const [error, setError] = useState<any>(null);
  const [data, setData] = useState<T | null>(null);

  const mutate = useCallback(
    async (args: A) => {
      try {
        setIsLoading(true);

        const data = await mutation(args);
        setData(data);
      } catch (e) {
        setError(e);
      } finally {
        setIsLoading(false);
      }
    },
    [mutation],
  );

  return {
    isLoading,
    error,
    data,
    mutate,
  };
}
Enter fullscreen mode Exit fullscreen mode 
// Form.tsx
import { FormEventHandler, useState } from "react";
import { useMutate } from "../hooks/useMutate.tsx";

function Forms() {
  const [title, setTitle] = useState("");
  const [price, setPrice] = useState("");
  const [description, setDescription] = useState("");
  const [image, setImage] = useState("");
  const [category, setCategory] = useState("");

  const { mutate, data, isLoading, error } = useMutate({
    mutation: async (body) => {
      const response = await fetch("https://fakestoreapi.com/products", {
        method: "POST",
        body: JSON.stringify(body),
      });

      return response.json();
    },
  });

  const handleSubmit: FormEventHandler<HTMLFormElement> = async (e) => {
    e.preventDefault();

    await mutate(
      JSON.stringify({
        title,
        price,
        description,
        category,
        image,
      }),
    );
  };

  return (
    <form
      style={{ display: "flex", flexFlow: "column", gap: 10 }}
      onSubmit={handleSubmit}
    >
      <label htmlFor="name">Title:</label>
      <input
        type="text"
        id="title"
        name="title"
        value={title}
        onChange={({ target: { value } }) => setTitle(value)}
      />

      <label htmlFor="price">Price:</label>
      <input
        type="number"
        id="price"
        name="price"
        value={price}
        onChange={({ target: { value } }) => setPrice(value)}
      />

      <label htmlFor="description">Description:</label>
      <textarea
        id="description"
        name="description"
        value={description}
        onChange={({ target: { value } }) => setDescription(value)}
      />

      <label htmlFor="image">Image:</label>
      <input
        type="url"
        id="image"
        name="image"
        onChange={({ target: { value } }) => setImage(value)}
      />

      <label htmlFor="category">Category:</label>
      <select
        id="category"
        name="category"
        value={category}
        onChange={({ target: { value } }) => setCategory(value)}
      >
        <option value="electronics">electronics</option>
        <option value="jewelery">jewelery</option>
        <option value="men's clothing">men's clothing</option>
        <option value="women's clothing">women's clothing</option>
      </select>

      <button disabled={isLoading} type="submit">
        Send
      </button>

      <div>Error: {JSON.stringify(error)}</div>
      <div>Response: {JSON.stringify(data)}</div>
    </form>
  );
}

export default Forms;
Enter fullscreen mode Exit fullscreen mode

Descontrolando campos de formulário 

import { FormEventHandler } from "react";
import { useMutate } from "../hooks/useMutate.tsx";

function Forms() {
  const { mutate, data, isLoading, error } = useMutate({
    mutation: async (body) => {
      const response = await fetch("https://fakestoreapi.com/products", {
        method: "POST",
        body: JSON.stringify(body),
      });

      return response.json();
    },
  });

  const handleSubmit: FormEventHandler<HTMLFormElement> = async (event) => {
    event.preventDefault();

    const form = event.target as HTMLFormElement;
    const formData = new FormData(form);

    await mutate(
      JSON.stringify({
        title: formData.get("title"),
        price: formData.get("price"),
        description: formData.get("description"),
        category: formData.get("category"),
        image: formData.get("image"),
      }),
    );
  };

  return (
    <form
      style={{ display: "flex", flexFlow: "column", gap: 10 }}
      onSubmit={handleSubmit}
    >
      <label htmlFor="name">Title:</label>
      <input type="text" id="title" name="title" />

      <label htmlFor="price">Price:</label>
      <input type="number" id="price" name="price" />

      <label htmlFor="description">Description:</label>
      <textarea id="description" name="description" />

      <label htmlFor="image">Image:</label>
      <input type="url" id="image" name="image" />

      <label htmlFor="category">Category:</label>
      <select id="category" name="category">
        <option value="electronics">electronics</option>
        <option value="jewelery">jewelery</option>
        <option value="men's clothing">men's clothing</option>
        <option value="women's clothing">women's clothing</option>
      </select>

      <button disabled={isLoading} type="submit">
        Send
      </button>

      <div>Error: {JSON.stringify(error)}</div>
      <div>Response: {JSON.stringify(data)}</div>
    </form>
  );
}

export default Forms;
Enter fullscreen mode Exit fullscreen mode

Movendo a Requisição para o seu próprio Hook 

// useProductCreate.tsx
import { useMutate } from "./useMutate.tsx";

async function fetchProductCreate(body) {
  const response = await fetch("https://fakestoreapi.com/products", {
    method: "POST",
    body: JSON.stringify(body),
  });

  return response.json();
}

export function useProductCreate() {
  return useMutate({
    mutation: (formData: FormData) => {
      const payload = {
        title: formData.get("title"),
        price: formData.get("price"),
        description: formData.get("description"),
        category: formData.get("category"),
        image: formData.get("image"),
      };

      return fetchProductCreate(payload);
    },
  });
}
Enter fullscreen mode Exit fullscreen mode 
// Form.tsx

import { FormEventHandler } from "react";
import { useProductCreate } from "../hooks/useProductCreate";

function Forms() {
  const { data, mutate, isLoading, error } = useProductCreate();

  const handleSubmit: FormEventHandler<HTMLFormElement> = async (event) => {
    event.preventDefault();

    const formData = new FormData(event.target as HTMLFormElement);

    await mutate(formData);
  };

  return (
    <form
      style={{ display: "flex", flexFlow: "column", gap: 10 }}
      onSubmit={handleSubmit}
    >
      <label htmlFor="name">Title:</label>
      <input type="text" id="title" name="title" />

      <label htmlFor="price">Price:</label>
      <input type="number" id="price" name="price" />

      <label htmlFor="description">Description:</label>
      <textarea id="description" name="description" />

      <label htmlFor="image">Image:</label>
      <input type="url" id="image" name="image" />

      <label htmlFor="category">Category:</label>
      <select id="category" name="category">
        <option value="electronics">electronics</option>
        <option value="jewelery">jewelery</option>
        <option value="men's clothing">men's clothing</option>
        <option value="women's clothing">women's clothing</option>
      </select>

      <button disabled={isLoading} type="submit">
        Send
      </button>

      <div>Error: {JSON.stringify(error)}</div>
      <div>Response: {JSON.stringify(data)}</div>
    </form>
  );
}

export default Forms;
Enter fullscreen mode Exit fullscreen mode

Top comments (0)

Read next

mrkandreev profile image

Vaadin Flow for AdminUI

Mark Andreev -

sarthak_niranjan_3bd6cb5f profile image

Shadcn UI for Beginners: The Ultimate Step-by-Step Tutorial

Sarthak Niranjan -

hijazi313 profile image

Next.js 14+ Performance Optimization: Modern Approaches for Production Applications

Muhammad Hamza -

authandpay profile image

Building a SaaS with Authentication, Payments & Multitenancy? Stop Reinventing the Wheel! 🚀

AuthAndPay -