Course Content
Expert React
Expert React
4. Formik
6. Next Steps
Custom Formik Hook
Step 3: Creating the Form Component
In our app, we will create a form component called Form.jsx
. Let's start by setting up the basic structure of our component.
Code explanation: The Form
component is a functional component that will serve as our custom form component. It currently renders a placeholder <div>
for the form markup, which we'll fill in later.
Step 4: Setting up Formik
We will use the useFormik
hook to initialize Formik and handle form-related functionality inside the Form
component. This is where the process differs from the standard useState
approach. Let's add the necessary code to set up Formik.
Code explanation:
- Line 2:
useFormik
is a hook imported from theformik
package. It allows us to create a Formik instance to handle form-related functionality. - Line 5: The
formik
constant stores the return value ofuseFormik
, which provides properties and methods for managing form state, field values, validation, and submission. - Line 6-8:
initialValues
represents the initial values of the form fields. We can specify an object with keys corresponding to field names and values representing the initial values. - Line 9-11:
onSubmit
is a callback function that will be executed when the form is submitted. We can define this function separately to handle the form submission and perform actions like making API calls or updating the application's state. - Line 12-14:
validate
(optional) is a validation function used to validate the form fields. This function will be called during form submission or field changes. We can define our validation logic within this function and return an object with errors corresponding to the failed validation fields.
Note
In these steps, we learned how to create a custom form component using Formik in a React app.
Complete code
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