從 v1.x 遷移到 v2.x

1 // Reset to `initialValues`
2 formik.resetForm();
3 // Reset form and set the next `initialValues` of the form
4 formik.resetForm({ name: '', email: '' });

1 // Reset the form. This will set the next initial state of
2 // Formik to the `initialValues`, `initialErrors`, `initialTouched`,
3 // `initialStatus` props.
4 formik.resetForm();
5 
6 // Reset the form back to `initialXXXX` but change next
7 // `initialValues` to a custom value
8 formik.resetForm({
9   values: { name: 'Custom initial values', email: '' },
10 });
11 
12 // Reset form back to `initialXXXX`, but change next `initialValues`
13 // and `initialErrors` of the form
14 formik.resetForm({
15   values: { name: '', email: '' },
16   errors: { name: 'Something special' },
17 });
18 
19 // Reset form back to `initialXXXX`, but change next `initialStatus` to 'Foo'
20 formik.resetForm({
21   status: 'Foo',
22 });

1 <button disabled={!isValid || !dirty} type="submit">
2   Submit
3 </button>

 import { FormikActions } from 'formik';

 import { FormikHelpers as FormikActions } from 'formik';

 type Props = FieldProps<FormValues>;

 type Props = FieldProps<FieldValue, FormValues>;

1 import React from 'react';
2 import { Formik, Field, Form } from 'formik';
3 import { Debug } from './Debug';
4 
5 const sleep = ms => new Promise(resolve => setTimeout(resolve, ms));
6 
7 const CheckboxExample = () => (
8   <div>
9     <h1>Checkboxes</h1>
10     <p>
11       This example demonstrates how to properly create checkboxes with Formik.
12     </p>
13     <Formik
14       initialValues={{
15         isAwesome: false,
16         terms: false,
17         newsletter: false,
18         jobType: ['designer'],
19         location: [],
20       }}
21       onSubmit={async values => {
22         await sleep(1000);
23         alert(JSON.stringify(values, null, 2));
24       }}
25     >
26       {({ isSubmitting, getFieldProps, handleChange, handleBlur, values }) => (
27         <Form>
28           {/* 
29             This first checkbox will result in a boolean value being stored.
30           */}
31           <div className="label">Basic Info</div>
32           <label>
33             <Field type="checkbox" name="isAwesome" />
34             Are you awesome?
35           </label>
36           {/* 
37             Multiple checkboxes with the same name attribute, but different
38             value attributes will be considered a "checkbox group". Formik will automagically
39             bind the checked values to a single array for your benefit. All the add and remove
40             logic will be taken care of for you.
41           */}
42           <div className="label">
43             What best describes you? (check all that apply)
44           </div>
45           <label>
46             <Field type="checkbox" name="jobType" value="designer" />
47             Designer
48           </label>
49           <label>
50             <Field type="checkbox" name="jobType" value="developer" />
51             Developer
52           </label>
53           <label>
54             <Field type="checkbox" name="jobType" value="product" />
55             Product Manager
56           </label>
57           {/*
58            You do not _need_ to use <Field>/useField to get this behavior, 
59            using handleChange, handleBlur, and values works as well. 
60           */}
61           <label>
62             <input
63               type="checkbox"
64               name="jobType"
65               value="founder"
66               checked={values.jobType.includes('founder')}
67               onChange={handleChange}
68               onBlur={handleBlur}
69             />
70             CEO / Founder
71           </label>
72 
73           {/* 
74            The <select> element will also behave the same way if 
75            you pass `multiple` prop to it. 
76           */}
77           <label htmlFor="location">Where do you work?</label>
78           <Field
79             component="select"
80             id="location"
81             name="location"
82             multiple={true}
83           >
84             <option value="NY">New York</option>
85             <option value="SF">San Francisco</option>
86             <option value="CH">Chicago</option>
87             <option value="OTHER">Other</option>
88           </Field>
89           <label>
90             <Field type="checkbox" name="terms" />I accept the terms and
91             conditions.
92           </label>
93           {/* Here's how you can use a checkbox to show / hide another field */}
94           {!!values.terms ? (
95             <div>
96               <label>
97                 <Field type="checkbox" name="newsletter" />
98                 Send me the newsletter <em style={{ color: 'rebeccapurple' }}>
99                   (This is only shown if terms = true)
100                 </em>
101               </label>
102             </div>
103           ) : null}
104           <button type="submit" disabled={isSubmitting}>
105             Submit
106           </button>
107           <Debug />
108         </Form>
109       )}
110     </Formik>
111   </div>
112 );
113 
114 export default CheckboxExample;

1 // <input className="form-input" placeholder="Jane"  />
2 <Field name="firstName" className="form-input" placeholder="Jane" />
3 
4 // <textarea className="form-textarea"/></textarea>
5 <Field name="message" as="textarea"  className="form-textarea"/>
6 
7 // <select className="my-select"/>
8 <Field name="colors" as="select" className="my-select">
9   <option value="red">Red</option>
10   <option value="green">Green</option>
11   <option value="blue">Blue</option>
12 </Field>
13 
14 // with styled-components/emotion
15 const MyStyledInput = styled.input`
16   padding: .5em;
17   border: 1px solid #eee;
18   /* ... */
19 `
20 const MyStyledTextarea = MyStyledInput.withComponent('textarea');
21 
22 // <input className="czx_123" placeholder="google.com"  />
23 <Field name="website" as={MyStyledInput} placeholder="google.com"/>
24 
25 // <textarea placeholder="Post a message..." rows={5}></textarea>
26 <Field name="message" as={MyStyledTextArea} placeholder="Post a message.." rows={4}/>

1 export interface FieldInputProps<Value> {
2   /** Value of the field */
3   value: Value;
4   /** Name of the field */
5   name: string;
6   /** Multiple select? */
7   multiple?: boolean;
8   /** Is the field checked? */
9   checked?: boolean;
10   /** Change event handler */
11   onChange: FormikHandlers['handleChange'];
12   /** Blur event handler */
13   onBlur: FormikHandlers['handleBlur'];
14 }

1 export interface FieldMetaProps<Value> {
2   /** Value of the field */
3   value: Value;
4   /** Error message of the field */
5   error?: string;
6   /** Has the field been visited? */
7   touched: boolean;
8   /** Initial value of the field */
9   initialValue?: Value;
10   /** Initial touched state of the field */
11   initialTouched: boolean;
12   /** Initial error message of the field */
13   initialError?: string;
14 }

1 - <Field name="firstName" render={props => ....} />
2 + <Field name="firstName">{props => ... }</Field>