如何正确使用Formik的setError方法？（反应库）

Question

我正在使用React与后端通信。现在尝试正确实现Formik（表单库）。

主要问题： 如何正确使用Formik的setError方法？

客户端验证错误可以正确显示，但是现在我尝试设置/显示后端验证错误，这些错误将通过状态码400的响应返回。

链接到我尝试使用的方法的文档

我在下面的代码中名为handle400Error的方法中使用此方法。

我的React（和Formik）代码：

import React, { Component } from "react";
import axios from "axios";
import { Formik } from "formik";
import * as Yup from "yup";
import styled from "styled-components";
import FormError from "../formError";

const Label = styled.label``;

class LoginForm extends Component {
  initialValues = {
    password: "",
    username: ""
  };

  getErrorsFromValidationError = validationError => {
    const FIRST_ERROR = 0;
    return validationError.inner.reduce((errors, error) => {
      return {
        ...errors,
        [error.path]: error.errors[FIRST_ERROR]
      };
    }, {});
  };

  getValidationSchema = values => {
    return Yup.object().shape({
      password: Yup.string()
        .min(6, "Password must be at least 6 characters long")
        .required("Password is required!"),
      username: Yup.string()
        .min(5, "Username must be at least 5 characters long")
        .max(40, "Username can not be longer than 40 characters")
        .required("Username is required")
    });
  };

  handleSubmit = async (values, { setErrors }) => {
    console.log("handleSubmit");

    try {
      const response = await axios.post(
        "http://127.0.0.1:8000/rest-auth/login/",
        values
      );
      const loginToken = response.data["key"];
      this.handleLoginSuccess(loginToken);
    } catch (exception) {
      // Expected: 400 status code
      if (exception.response && exception.response.status === 400) {
        // Display server validation errors
        this.handle400Error(exception.response.data, setErrors);
      }
      console.log("exception", exception);
      console.log("exception.response", exception.response);
    }
  };

  handle400Error = (backendErrors, setErrors) => {
    let errors = {};
    for (let key in backendErrors) {
      errors[key] = backendErrors[key][0]; // for now only take the first error of the array
    }
    console.log("errors object", errors);
    setErrors({ errors });
  };

  handleUnexpectedError = () => {};

  handleLoginSuccess = loginToken => {
    console.log("handleLoginSuccess");
    this.props.setGreeneryAppState({
      loginToken: loginToken
    });
    this.props.history.replace(`/${this.props.locale}/`);
  };

  validate = values => {
    const validationSchema = this.getValidationSchema(values);
    try {
      validationSchema.validateSync(values, { abortEarly: false });
      return {};
    } catch (error) {
      return this.getErrorsFromValidationError(error);
    }
  };

  render() {
    return (
      <React.Fragment>
        <h1>Login</h1>
        <Formik
          initialValues={this.initialValues}
          validate={this.validate}
          validationSchema={this.validationSchema}
          onSubmit={this.handleSubmit}
          render={({
            errors,
            touched,
            values,
            handleBlur,
            handleChange,
            handleSubmit
          }) => (
            <form onSubmit={handleSubmit}>
              {errors.non_field_errors && (
                <formError>{errors.non_field_errors}</formError>
              )}
              <Label>Username</Label>
              <input
                onChange={handleChange}
                onBlur={handleBlur}
                value={values.username}
                type="text"
                name="username"
                placeholder="Enter username"
              />
              {touched.username &&
                errors.username && <FormError>{errors.username}</FormError>}
              <Label>Password</Label>
              <input
                onChange={handleChange}
                onBlur={handleBlur}
                value={values.password}
                type="password"
                name="password"
                placeholder="Enter password"
              />
              {touched.password &&
                errors.password && <FormError>{errors.password}</FormError>}
              <button type="submit">Log in</button>
            </form>
          )}
        />
      </React.Fragment>
    );
  }

Answer 1

Formik作者在这里...

setError在v0.8.0中已弃用，并重命名为setStatus。您可以使用setErrors(errors)或setStatus(whateverYouWant)在handleSubmit函数中获得所需的行为，如下所示：

handleSubmit = async (values, { setErrors, resetForm }) => {
   try {
     // attempt API call
   } catch(e) {
     setErrors(transformMyApiErrors(e))
     // or setStatus(transformMyApiErrors(e))
   }
}

setStatusvs.和有setErrors什么区别？

如果使用setErrors，您的错误将被Formik的下一个validate或validationSchema调用清除，这些错误可以由用户键入（更改事件）或模糊输入（模糊事件）触发。注意：这是假设您尚未手动设置validateOnChange和设置validateOnBlur道具false（它们是true默认设置）。

IMHO setStatus实际上是理想的选择，因为它将错误消息放置在Formik状态的单独部分中。然后，您可以像这样决定如何/何时向最终用户显示此消息。

// status can be whatever you want
{!!status && <FormError>{status}</FormError>}
// or mix it up, maybe transform status to mimic errors shape and then ...
{touched.email && (!!errors.email && <FormError>{errors.email}</FormError>) || (!!status && <FormError>{status.email}</FormError>) }

请注意，的存在或价值对status阻止下次提交表单没有影响。如果验证失败， Formik仅中止提交过程。

Answer 2

const formik = useFormik({
    initialValues:{
        email:"",password:"",username:""
    },
    validationSchema:validation_schema,
    onSubmit:(values) => {
        const {email,password,username} = values
        // ......
    }
});


formik.setErrors({email:"Is already taken"}) // error message for email field