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Youssef Zidan
Youssef Zidan

Posted on • Updated on

Formik Components.

Formik Components

Formik provides a few Components to be used that will save us more time, reduce code duplication, and make the code more consistent and organized.

Login Form With Formik Components

  • Import Formik, Form, Field and ErrorMessage from formik.
  • Wrap and return the entire form inside <Formik> Component with formik as a parameter.
  • Add initialValues, onSubmit and validationSchema as Props to <Formik> Component.
  • Replace the native <form> element with the <Form> Component.
  • Wrap and return the label, input, and the validation div message inside <Field> with formikField as a parameter.
  • Add the name attribute to the <Field> component instead of the <input> element.
  • spread {...formikField.field} inside the <input> element.
  • Wrap and return the validation div inside <ErrorMessage> component with ErrMessage as a parameter and add the name attribute to it.
  • log formikField inside a <pre> to see the entire formikField object.
import React from "react";
import { Formik, Form, Field, ErrorMessage } from "formik";
import * as yup from "yup";

/**
 * LoginFormikComponents Component
 */
const LoginFormikComponents = () => {
  const initialValues = {
    email: "",
    password: "",
    rememberMe: false,
  };
  const onSubmit = (values) => console.log(JSON.stringify(values, null, 4));
  const validationSchema = yup.object({
    email: yup
      .string()
      .email("Please enter a valid email address")
      .required("Email field is required"),
    password: yup.string().required("Password field is required"),
  });

  return (
    <Formik
      initialValues={initialValues}
      onSubmit={onSubmit}
      validationSchema={validationSchema}
    >
      {(formik) => {
        return (
          <Form>
            <div style={{ padding: 20 }}>
              <Field name="email">
                {(formikField) => {
                  return (
                    <>
                      <label htmlFor="email" style={{ display: "block" }}>
                        email
                      </label>
                      <input type="email" id="email" {...formikField.field} />
                      <ErrorMessage name="email">
                        {(errMessage) => {
                          return (
                            <div style={{ color: "red" }}>{errMessage}</div>
                          );
                        }}
                      </ErrorMessage>
                      <pre>{JSON.stringify(formikField, null, 4)}</pre>
                    </>
                  );
                }}
              </Field>

              <Field name="password">
                {(formikField) => {
                  return (
                    <>
                      <label htmlFor="password" style={{ display: "block" }}>
                        password
                      </label>
                      <input
                        type="password"
                        id="password"
                        {...formikField.field}
                      />
                      <ErrorMessage name="password">
                        {(errMessage) => {
                          return (
                            <div style={{ color: "red" }}>{errMessage}</div>
                          );
                        }}
                      </ErrorMessage>
                      <pre>{JSON.stringify(formikField, null, 4)}</pre>
                    </>
                  );
                }}
              </Field>

              <Field name="rememberMe">
                {(formikField) => {
                  return (
                    <>
                      <label htmlFor="rememberMe" style={{ display: "block" }}>
                        remember me
                      </label>
                      <input
                        type="checkbox"
                        id="rememberMe"
                        defaultChecked={formikField.field.value}
                        {...formikField.field}
                      />
                      <pre>{JSON.stringify(formikField, null, 4)}</pre>
                    </>
                  );
                }}
              </Field>
              <button style={{ display: "block" }}>submit</button>
            </div>
            <pre>{JSON.stringify(formik, null, 4)}</pre>
          </Form>
        );
      }}
    </Formik>
  );
};
export default LoginFormikComponents;
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Formik Reusable Components

As we can see inside each <Field> component there are

  • <label>
  • <input>
  • <ErrorMessage>

So, it's a good chance to create a Reusable Component that includes all of that.

FormikErrorMessage.jsx

import React from "react";
import { ErrorMessage } from "formik";

/**
 * FormikErrorMessage Component
 */
const FormikErrorMessage = ({ name }) => {
  return (
    <ErrorMessage name={name}>
      {(errMessage) => {
        return <div style={{ color: "red" }}>{errMessage}</div>;
      }}
    </ErrorMessage>
  );
};

export default FormikErrorMessage;
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FormikField.jsx

import React from "react";
import { Field } from "formik";
import FormikErrorMessage from "./FormikErrorMessage";

/**
 * FormikField Component
 */
const FormikField = ({ name, type, label }) => {
  return (
    <Field name={name}>
      {(formikField) => {
        return (
          <>
            <label htmlFor={name} style={{ display: "block" }}>
              {label}
            </label>
            <input
              type={type}
              id={name}
              {...formikField.field}
              defaultChecked={formikField.field.value}
            />
            <FormikErrorMessage name={name} />
            <pre>{JSON.stringify(formikField, null, 4)}</pre>
          </>
        );
      }}
    </Field>
  );
};

export default FormikField;
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And here is the final code after using the reusable components.

LoginFormikComponentsShared.jsx

import React from "react";
import { Formik, Form } from "formik";
import * as yup from "yup";
import FormikField from "./shared/FormikField";

/**
 * LoginFormikComponents Component
 */
const LoginFormikComponents = () => {
  const initialValues = {
    email: "",
    password: "",
    rememberMe: false,
  };
  const onSubmit = (values) => console.log(JSON.stringify(values, null, 4));
  const validationSchema = yup.object({
    email: yup
      .string()
      .email("Please enter a valid email address")
      .required("Email field is required"),
    password: yup.string().required("Password field is required"),
  });

  return (
    <Formik
      initialValues={initialValues}
      onSubmit={onSubmit}
      validationSchema={validationSchema}
    >
      {(formik) => {
        return (
          <Form>
            <div style={{ padding: 20 }}>
              <FormikField label="Email" name="email" type="email" />
              <FormikField label="Password" name="password" type="password" />
              <FormikField
                label="Remember Me"
                name="rememberMe"
                type="checkbox"
              />
              <button style={{ display: "block" }}>submit</button>
            </div>
            <pre>{JSON.stringify(formik, null, 4)}</pre>
          </Form>
        );
      }}
    </Formik>
  );
};
export default LoginFormikComponents;

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