[ 卡卡 DAY 24 ] - React Native 表单套件用 Formik 搭配 Yup 验证（下）

经过 Day23 的讲解，大家应该都有初步的了解及安装完毕吧 XD
今天我们来运用 Formik 搭配 Yup 做个简单表单画面吧！

建立 Formik UI 画面

components/ Button.js

import React from 'react';
import {TouchableOpacity, Text, StyleSheet} from 'react-native';

const Button = ({label, onPress}) => {
  return (
    <TouchableOpacity style={styles.btn} activeOpacity={0.7} onPress={onPress}>
      <Text style={styles.btnText}>{label}</Text>
    </TouchableOpacity>
  );
};

const styles = StyleSheet.create({
  btn: {
    borderRadius: 8,
    height: 50,
    width: '100%',
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: 'black',
    marginTop: 20,
  },
  btnText: {fontSize: 18, color: 'white', textTransform: 'uppercase'},
});

export default Button;

components/ Input.js

想更了解 TextInput 可以看看这个！

import React from 'react';
import {TextInput as RNTextInput, View, StyleSheet, Text} from 'react-native';

// ...otherProps 是除了label其他没提到的 props(ES9)
const Input = ({label, ...otherProps}) => {
    const validationColor =  '#223e4b';
    return (
        <View style={[styles.input,{borderColor:validationColor}]}>
        <View style={{padding: 8}}>
            <Text>{label}</Text>
        </View>
        <View style={{flex: 1}}>
            <RNTextInput
            underlineColorAndroid="transparent"
            placeholderTextColor="#ccc"
            {...otherProps}
            />
        </View>
        </View>
    );
};
const styles = StyleSheet.create({
  input: {
    flexDirection: 'row',
    alignItems: 'center',
    height: 48,
    borderRadius: 8,
    borderWidth: StyleSheet.hairlineWidth,
    padding: 8,
    marginVertical: 10,
  },
});

export default Input;

screens/ Formik.js

这次来试试用 useFormik 的方式

import React from 'react';
import {StyleSheet, View, Text, ScrollView} from 'react-native';
import {fonts} from '@src/constants';
import Input from '@src/components/Input';
import Button from '@src/components/Button';
import * as yup from 'yup';
// 引入 useFormik
import {useFormik} from 'formik';


const Formik = () => {
    // 使用 useFormik
  const {handleChange, handleSubmit, values} = useFormik({
    initialValues: {name: '', email: '', password: ''},
    onSubmit: values =>
      alert(
        `Name: ${values.name},Email: ${values.email}, Password: ${values.password}`,
      ),
  });
  return (
    <ScrollView style={styles.container}>
      <View style={styles.textBox}>
        <Text style={[styles.text, fonts.h1]}>欢迎来到卡卡塔罗</Text>
        <Text style={(fonts.p, styles.textContent)}>
          如果您有什麽需要或着回馈欢迎留言也或着想预约算塔罗牌也欢迎留言，谢谢您
        </Text>
      </View>

      <View style={styles.formBox}>
        <Input
          onChangeText={handleChange('name')}
          label="Name"
          placeholder="Enter your name"
          autoCapitalize="none"
          autoCompleteType="email"
          keyboardType="default"
          keyboardAppearance="dark"
          returnKeyType="next"
          returnKeyLabel="next"
        />
        <Input
          onChangeText={handleChange('email')}
          label="Mail"
          placeholder="Enter your email"
          autoCapitalize="none"
          autoCompleteType="email"
          keyboardType="email-address"
          keyboardAppearance="dark"
          returnKeyType="next"
          returnKeyLabel="next"
        />
        <Input
          onChangeText={handleChange('phone')}
          label="Phone"
          placeholder="Enter your phone"
          secureTextEntry
          autoCompleteType="phone-pad"
          autoCapitalize="none"
          keyboardAppearance="dark"
          returnKeyType="go"
          returnKeyLabel="go"
        />
        <Button label="submit" color="maroon" onPress={handleSubmit} />
      </View>
    </ScrollView>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: 'rgb(246,246,246)',
    paddingHorizontal: 20,
  },
  textBox: {
    justifyContent: 'center',
    alignItems: 'center',
    paddingVertical: 50,
  },
  textTitle: {color: '#aaa'},
  textContent: {color: '#aaa', lineHeight: 20, marginTop: 10},
  formBox: {
    width: '100%',
    alignItems: 'center',
    justifyContent: 'center',
  },
  input: {
    width: '100%',
    textAlign: 'center',
    borderWidth: 1,
    borderColor: '#ddd',
    padding: 10,
    fontSize: 18,
    margin: 10,
  },
  errorText: {
    textAlign: 'center',
    color: 'crimson',
    marginBottom: 10,
  },
});

export default Formik;

加入 Yup 验证机制

引入

import {
  number as yupNumber,
  object as yupObject,
  string as yupString,
  ValidationError,
} from 'yup';

建立验证规则

用堆叠的方式来验证，如下面的 code
name：字串必填
email：字串 email 验证必填
phone：字串符合 phoneRegExp 必填

  const phoneRegExp =
    /^((\\+[1-9]{1,4}[ \\-]*)|(\\([0-9]{2,3}\\)[ \\-]*)|([0-9]{2,4})[ \\-]*)*?[0-9]{3,4}?[ \\-]*[0-9]{3,4}?$/;

  const Schema = yupObject().shape({
    name: yupString().required('Required'),
    email: yupString().email('Invalid email').required('Required'),
    phone: yupString()
      .matches(phoneRegExp, 'Phone number is not valid')
      .required('Required'),
  });

加入验证机制及 errors, touched, and handleBlur

    // errors, touched, handleBlur
    const {handleChange, handleSubmit, handleBlur, values, errors, touched} =
        useFormik({
        validationSchema: Schema, // 加入验证机制
        initialValues: {name: '', email: '', phone: ''},
        onSubmit: values =>
            alert(
            `Name: ${values.name},Email: ${values.email}, phone: ${values.phone}`,
            ),
    });

於所有 Input 加入 errors, touched, handleBlur

<Input
  // ... rest remains same
  onBlur={handleBlur('email')} // 要记得改成正确的name
  error={errors.email} // 要记得改成正确的name
  touched={touched.email} // 要记得改成正确的name
/>

到 Components/ Input.js 加入 touched, error 的 props
判断验证是否成功来改变 input 外框的颜色

import React from 'react';
import {TextInput as RNTextInput, View, StyleSheet, Text} from 'react-native';
    // 加入参数
const Input = ({label, error, touched, ...otherProps}) => {
    // 判断颜色
    const validationColor = !touched ? '#223e4b' : error ? '#FF5A5F' : '#223e4b';
    return (
        <View style={[styles.input, {borderColor: validationColor}]}>
        <View style={{padding: 8}}>
            <Text>{label}</Text>
        </View>
        <View style={{flex: 1}}>
            <RNTextInput
            underlineColorAndroid="transparent"
            placeholderTextColor="#ccc"
            {...otherProps}
            />
        </View>
    </View>
  );
});
const styles = StyleSheet.create({
  input: {
    flexDirection: 'row',
    alignItems: 'center',
    height: 48,
    borderRadius: 8,
    borderWidth: StyleSheet.hairlineWidth,
    padding: 8,
    marginVertical: 10,
  },
});

export default Input;

目前的 Formik.js

import React from 'react';
import {StyleSheet, View, Text, ScrollView} from 'react-native';
import {fonts} from '@src/constants';
import {useFormik} from 'formik';
import Input from '../components/Input';
import Button from '../components/Button';
import {object as yupObject, string as yupString, ValidationError} from 'yup';

const Formik = () => {
  const phoneRegExp =
    /^((\\+[1-9]{1,4}[ \\-]*)|(\\([0-9]{2,3}\\)[ \\-]*)|([0-9]{2,4})[ \\-]*)*?[0-9]{3,4}?[ \\-]*[0-9]{3,4}?$/;

  const Schema = yupObject().shape({
    name: yupString().required('Required'),
    email: yupString().email('Invalid email').required('Required'),
    phone: yupString()
      .matches(phoneRegExp, 'Phone number is not valid')
      .required('Required'),
  });
  const {handleChange, handleSubmit, handleBlur, values, errors, touched} =
    useFormik({
      validationSchema: Schema,
      initialValues: {name: '', email: '', phone: ''},
      onSubmit: values =>
        alert(
          `Name: ${values.name},Email: ${values.email}, phone: ${values.phone}`,
        ),
    });
  return (
    <ScrollView style={styles.container}>
      <View style={styles.textBox}>
        <Text style={[styles.text, fonts.h1]}>欢迎来到卡卡塔罗</Text>
        <Text style={(fonts.p, styles.textContent)}>
          如果您有什麽需要或着回馈欢迎留言也或着想预约算塔罗牌也欢迎留言，谢谢您
        </Text>
      </View>

      <View style={styles.formBox}>
        <Input
          onChangeText={handleChange('name')}
          label="Name"
          placeholder="Enter your name"
          autoCapitalize="none"
          autoCompleteType="email"
          keyboardType="default"
          keyboardAppearance="dark"
          onBlur={handleBlur('name')}
          error={errors.name}
          touched={touched.name}
          returnKeyType="next"
          returnKeyLabel="next"
        />
        <Input
          onChangeText={handleChange('email')}
          label="Mail"
          placeholder="Enter your email"
          autoCapitalize="none"
          autoCompleteType="email"
          keyboardType="email-address"
          keyboardAppearance="dark"
          onBlur={handleBlur('email')}
          error={errors.email}
          touched={touched.email}
          returnKeyType="next"
          returnKeyLabel="next"
        />
        <Input
          onChangeText={handleChange('phone')}
          label="Phone"
          placeholder="Enter your phone"
          autoCompleteType="phone-pad"
          autoCapitalize="none"
          keyboardAppearance="dark"
          onBlur={handleBlur('phone')}
          error={errors.phone}
          touched={touched.phone}
          returnKeyType="go"
          returnKeyLabel="go"
        />
        <Button label="submit" color="maroon" onPress={handleSubmit} />
      </View>
    </ScrollView>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: 'rgb(246,246,246)',
    paddingHorizontal: 20,
  },
  textBox: {
    justifyContent: 'center',
    alignItems: 'center',
    paddingVertical: 50,
  },
  textTitle: {color: '#aaa'},
  textContent: {color: '#aaa', lineHeight: 20, marginTop: 10},
  formBox: {
    width: '100%',
    alignItems: 'center',
    justifyContent: 'center',
  },
  input: {
    width: '100%',
    textAlign: 'center',
    borderWidth: 1,
    borderColor: '#ddd',
    padding: 10,
    fontSize: 18,
    margin: 10,
  },
  errorText: {
    textAlign: 'center',
    color: 'crimson',
    marginBottom: 10,
  },
});

export default Formik;