YiXu Zhang

YiXu Zhang

1602555090

React Form Validation With Formik And Yup

Forms are an integral part of how users interact with our websites and web applications. Validating the data the user passes through the form is a critical aspect of our jobs as web developers. However, it doesn’t have to be a pain-staking process. In this article, we’ll learn how Formik handles the state of the form data, validates the data, and handles form submission.

As developers, it is our job to ensure that when users interact with the forms we set up, the data they send across is in the form we expect.

In this article, we will learn how to handle form validation and track the state of forms without the aid of a form library. Next, we will see how the Formik library works. We’ll learn how it can be used incrementally with HTML input fields and custom validation rules. Then we will set up form validation using Yup and Formik’s custom components and understand how Yup works well with Formik in handling Form validation. We will implement these form validation methods to validate a simple sign up form I have set up.

Note: This article requires a basic understanding of React.

Form Validation In React

On its own, React is powerful enough for us to be able to set up custom validation for our forms. Let’s see how to do that. We’ll start by creating our form component with initial state values. The following sandbox holds the code for our form:

Form validation without the use of a library

const Form = () => {
  const intialValues = { email: "", password: "" };
  const [formValues, setFormValues] = useState(intialValues);
  const [formErrors, setFormErrors] = useState({});
  const [isSubmitting, setIsSubmitting] = useState(false);
}

With the useState hook, we set state variables for the formValues, formErrors and isSubmitting.

  • The formValues variable holds the data the user puts into the input fields.
  • The formErrors variable holds the errors for each input field.
  • The isSubmitting variable is a boolean that tracks if the form is being submitted or not. This will be true only when there are no errors in the form.
const submitForm = () => {
    console.log(formValues);
  };

 const handleChange = (e) => {
    const { name, value } = e.target;
    setFormValues({ ...formValues, [name]: value });
  };

const handleSubmit = (e) => {
    e.preventDefault();
    setFormErrors(validate(formValues));
    setIsSubmitting(true);
  };

const validate = (values) => {
    let errors = {};
    const regex = /^[^\s@]+@[^\s@]+\.[^\s@]{2,}$/i;
    if (!values.email) {
      errors.email = "Cannot be blank";
    } else if (!regex.test(values.email)) {
      errors.email = "Invalid email format";
    }
    if (!values.password) {
      errors.password = "Cannot be blank";
    } else if (values.password.length < 4) {
      errors.password = "Password must be more than 4 characters";
    }
    return errors;
  };

useEffect(() => {
    if (Object.keys(formErrors).length === 0 && isSubmitting) {
      submitForm();
    }
  }, [formErrors]);

Here, we have 4 form handlers and a useEffect set up to handle the functionality of our form.

  • handleChange
  • This keeps the inputs in sync with the formValues state and updates the state as the user types.
  • validate
  • We pass in the formValues object as a argument to this function, then based on the email and password meeting the validation tests, the errors object is populated and returned.
  • handleSubmit
  • Whenever the form is submitted, the formErrors state variable is populated with whatever errors may exist using the setFormErrors(validate(formValues)) method.
  • useEffect
  • Here, we check if the formErrors object is empty, and if isSubmitting is true. If this check holds true, then the submitForm() helper is called. It has single dependency, which is the formErrors object. This means it only runs when the formErrors object changes.
  • submitForm: this handles the submission of the form data.
return (
    <div className="container">
      <h1>Sign in to continue</h1>
      {Object.keys(formErrors).length === 0 && isSubmitting && (
         Signed in successfully
      )}
      <form onSubmit={handleSubmit} noValidate>
        <div className="form-row">
          <label htmlFor="email">Email</label>
          <input
            type="email"
            name="email"
            id="email"
            value={formValues.email}
            onChange={handleChange}
            className={formErrors.email && "input-error"}
          />
          {formErrors.email && (
             {formErrors.email}
          )}
        </div>
        <div className="form-row">
          <label htmlFor="password">Password</label>
          <input
            type="password"
            name="password"
            id="password"
            value={formValues.password}
            onChange={handleChange}
            className={formErrors.password && "input-error"}
          />
          {formErrors.password && (
             {formErrors.password}
          )}
        </div>
        <button type="submit">Sign In</button>
      </form>
    </div>
  );

Here, we pass in the handleChange helper functions to the inputs’ onChange attribute. We link the value of the inputs to the formValues object, making them controlled inputs. From the React docs, controlled inputs are inputs whose values are controlled by React. An input-error style is applied if there are any errors related to that specific input field. An error message is conditionally displayed beneath each input if there are any errors related to that specific input field. Finally, we check if there are any errors in the errors object and if isSubmitting is true. If these conditions hold true, then we display a message notifying the user that they signed in successfully.

With this, we have a fully functional and validated form set up without the aid of a library. However, a form library like Formik with the aid of Yup can simplify the complexities of handling forms for us.

#react #javascript #programming #developer #web-development

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React Form Validation With Formik And Yup
Autumn  Blick

Autumn Blick

1598839687

How native is React Native? | React Native vs Native App Development

If you are undertaking a mobile app development for your start-up or enterprise, you are likely wondering whether to use React Native. As a popular development framework, React Native helps you to develop near-native mobile apps. However, you are probably also wondering how close you can get to a native app by using React Native. How native is React Native?

In the article, we discuss the similarities between native mobile development and development using React Native. We also touch upon where they differ and how to bridge the gaps. Read on.

A brief introduction to React Native

Let’s briefly set the context first. We will briefly touch upon what React Native is and how it differs from earlier hybrid frameworks.

React Native is a popular JavaScript framework that Facebook has created. You can use this open-source framework to code natively rendering Android and iOS mobile apps. You can use it to develop web apps too.

Facebook has developed React Native based on React, its JavaScript library. The first release of React Native came in March 2015. At the time of writing this article, the latest stable release of React Native is 0.62.0, and it was released in March 2020.

Although relatively new, React Native has acquired a high degree of popularity. The “Stack Overflow Developer Survey 2019” report identifies it as the 8th most loved framework. Facebook, Walmart, and Bloomberg are some of the top companies that use React Native.

The popularity of React Native comes from its advantages. Some of its advantages are as follows:

  • Performance: It delivers optimal performance.
  • Cross-platform development: You can develop both Android and iOS apps with it. The reuse of code expedites development and reduces costs.
  • UI design: React Native enables you to design simple and responsive UI for your mobile app.
  • 3rd party plugins: This framework supports 3rd party plugins.
  • Developer community: A vibrant community of developers support React Native.

Why React Native is fundamentally different from earlier hybrid frameworks

Are you wondering whether React Native is just another of those hybrid frameworks like Ionic or Cordova? It’s not! React Native is fundamentally different from these earlier hybrid frameworks.

React Native is very close to native. Consider the following aspects as described on the React Native website:

  • Access to many native platforms features: The primitives of React Native render to native platform UI. This means that your React Native app will use many native platform APIs as native apps would do.
  • Near-native user experience: React Native provides several native components, and these are platform agnostic.
  • The ease of accessing native APIs: React Native uses a declarative UI paradigm. This enables React Native to interact easily with native platform APIs since React Native wraps existing native code.

Due to these factors, React Native offers many more advantages compared to those earlier hybrid frameworks. We now review them.

#android app #frontend #ios app #mobile app development #benefits of react native #is react native good for mobile app development #native vs #pros and cons of react native #react mobile development #react native development #react native experience #react native framework #react native ios vs android #react native pros and cons #react native vs android #react native vs native #react native vs native performance #react vs native #why react native #why use react native

Yogi Gurjar

1600308055

Laravel 8 Form Validation Tutorial

Laravel 8 form validation example. In this tutorial, i will show you how to submit form with validation in laravel 8.

And you will learn how to store form data in laravel 8. Also validate form data before store to db.

How to Validate Form Data in Laravel 8

  1. Step 1 – Install Laravel 8 Application
  2. Step 2 – Configuring Database using Env File
  3. Step 3 – Create Model & Migration File For Form
  4. Step 4 – Create Routes
  5. Step 5 – Creating Controller
  6. Step 6 – Create Blade File For Form
  7. Step 7 – Start Development Server
  8. Step 8 – Run Laravel 8 Form Validation App On Browser

https://laratutorials.com/laravel-8-form-validation-example-tutorial/

#laravel 8 form validation #laravel 8 form validation tutorial #laravel 8 form validation - google search #how to validate form data in laravel 8 #form validation in laravel 8

React Dev

React Dev

1642479163

Check out the Powerful Validation using Yup with Formik | React Forms

In this tutorial we will check out the powerful validation we can do by integrating Yup with Formik!

Formik is a free and open source, lightweight library for ReactJS or React Native and addresses three key pain points of form creation:

  1. How the form state is manipulated.
  2. How form validation and error messages are handled.
  3. How form submission is handled.

The Formik library was written by Jared Palmer out of his frustration when building React forms, seeking to standardize the input components and flow of form submission. The idea was to keep things organized and in one place, simplifying testing, refactoring, and reasoning about your forms.

Resources:

Starting Code: https://github.com/angle943/formik-material-ui 
Formik Website: https://jaredpalmer.com/formik/docs/overview 
Yup website: https://github.com/jquense/yup 
Password Regex: https://www.thepolyglotdeveloper.com/2015/05/use-regex-to-test-password-strength-in-javascript/ 

Finished Code: https://github.com/angle943/advanced-formik-validations-with-yup 

Subscribe: https://www.youtube.com/c/JustinKimJS/featured 

#react  #formik  #Yup #typescript  #form 

Hayden Slater

1599277908

Validating React Forms With React-Hook-Form

Validating inputs is very often required. For example, when you want to make sure two passwords inputs are the same, an email input should in fact be an email or that the input is not too long. This is can be easily done using React Hook From. In this article, I will show you how.

Required Fields

The most simple, yet very common, validation is to make sure that an input component contains input from the user. React Hook Form basic concept is to register input tags to the form by passing register() to the tag’s ref attribute. As we can see here:

#react-native #react #react-hook-form #react-hook

Laravel 8 Form Validation Example

In this tutorial we will see laravel 8 form validation example, form validation in laravel is very common functionalities and it is use in each and every website to validate form field.

Here, We will use has function in session to check error message in laravel 8. using this example you can check simple form validation as well as you can create your own custom validation in laravel 8.

Laravel 8 Form Validation Example

https://websolutionstuff.com/post/laravel-8-form-validation-example


Read Also : Laravel 8 CRUD Operation Example

https://websolutionstuff.com/post/laravel-8-crud-operation-example

#laravel 8 form validation example #form validation #how to validate form in laravel 8 #form validation in laravel #laravel #laravel8