如何正确使用 Formik 的 setError 方法? (反应库)

How to properly use Formik's setError method? (React library)

我正在使用 React 与后端通信。现在正在尝试正确实施 Formik(表单库)。

主要问题: 如何正确使用 Formik 的 setError 方法?

客户端验证错误正确显示,但现在我正在尝试 set/show 后端验证错误,这些错误返回状态代码为 400 的响应。

Link 关于我尝试使用的方法的文档

我在下面代码中名为 handle400Error 的方法中使用了这个方法。

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>
    );
  }

我刚刚解决了我自己的问题。

我需要使用:

setErrors( errors )

而不是:

setErrors({ errors })

Formik 作者在这里...

setError 原为 deprecated in v0.8.0 并重命名为 setStatus。您可以在 handleSubmit 函数中使用 setErrors(errors)setStatus(whateverYouWant) 来获得您想要的行为,如下所示:

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

使用 setStatussetErrors 有什么区别?

如果您使用 setErrors,您的错误将被 Formik 的下一个 validatevalidationSchema 调用消除,这可以由用户键入(更改事件)或模糊触发输入(模糊事件)。注意:这是假设您没有手动将 validateOnChangevalidateOnBlur 属性设置为 false(默认情况下它们是 true)。

恕我直言 setStatus 在这里实际上是理想的,因为它将错误消息放在 Formik 状态的单独部分。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 status 的存在或值对阻止下一次表单提交没有影响。 Formik 仅中止 submission process if validation fails.

处理这种情况的另一种方法是为您的 api 错误分配一个特定的键,并使用 setStatus 来显示状态消息。

__handleSubmit = (values, {setStatus, setErrors}) => {
  return this.props.onSubmit(values)
    .then(() => {
      setStatus("User was updated successfully.");
    })
    .catch((err) => {
      setErrors({api: _.get(err, ["message"])});
    });
}

然后任何验证错误都会出现在字段旁边,任何 api 错误可能会出现在底部:

<Formik
  validationSchema={LoginSchema}
  initialValues={{login: ""}}
  onSubmit={this.__handleSubmit}
>
  {({isSubmitting, status, errors, values, setFieldValue}) => (
    <Form className={classNames("form")}>
      <FormGroup>
        <InputGroup>
          <InputGroup.Text>
            <FontAwesomeIcon icon={faUser} fixedWidth />
          </InputGroup.Text>
          <Field
            name="login"
            type={"text"}
            placeholder="Login"
            className="form-control"
          />
        </InputGroup>
        <ErrorMessage name="login" />
      </FormGroup>
      <Button type="submit" variant="primary" disabled={isSubmitting}>
        Submit
      </Button>
      {errors && _.has(errors, ["api"]) && <div className="text-danger">{_.get(errors, ["api"])}</div>}
      {status && <div className="text-success">{status}</div>}
    </Form>
  )}
</Formik>

不要忘记模式...

const LoginSchema = Yup.object().shape({
  login: Yup.string()
    .min(4, 'Too Short!')
    .max(70, 'Too Long!')
    .required('Login is required'),
});

api 错误消息将显示到 Formik 的下一次验证调用(即用户正在修复某些东西)。但是 status 消息将一直存在,直到您清除它(使用计时器或淡入淡出)。

<Formik
  validationSchema={schema}
  initialValues={{ email: '', pswrd: '' }}
  onSubmit={(values, actions) => {
    // initialise error status <---- 1
    actions.setStatus(undefined); 

    setTimeout(() => {

      // setting error status <---- 2
      actions.setStatus({
        email: 'This is email already exists.',
        pswrd: 'This is password is incorrect',
      });

    }, 500);
  }}
  // destructuring status <---- 3
  render={({ handleSubmit, handleChange, handleBlur, values, errors, status }) => (
    <form onSubmit={handleSubmit}>
      <input
        type="text"
        name="email"
        value={values['email']}
        onChange={handleChange}
        onBlur={handleBlur}
      />
      <input
        type="text"
        name="pswrd"
        value={values['pswrd']}
        onChange={handleChange}
        onBlur={handleBlur}
      />
      <button type="submit">Submit</button>

      // using error status <---- 4
      {status && status.email ? (
        <div>API Error: {status.email}</div>
      ) : (
        errors.email && <div>Validation Error: {errors.email}</div>
      )}

      {status && status.pswrd ? (
        <div>API Error: {status.pswrd}</div>
      ) : (
        errors.pswrd && <div>Validation Error: {errors.pswrd}</div>
      )}
    </form>
  )}
/>
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