React Formik：如何使用自定义onChange和onBlur [英] React Formik : how to use custom onChange and onBlur

问题描述

我开始使用 formik 库进行反应，我无法弄明白使用道具handleChange和handleBlur。

I'm starting out with the formik library for react, and I can't figure out the usage of the props handleChange and handleBlur.

根据文档，handleBlur可以设置为< Formik /> 上的道具，然后必须手动传递下到< input /> 。

According to the docs, handleBlur can be set as a prop on a <Formik/>, and then has to be passed manually down to the <input/>.

我试过了，没有成功：
（为了更清楚，我保留了关于handleBlur的代码）

I've tried that, with no success : (I'm keeping the code about handleBlur for more clarity)

import React from "react";
import { Formik, Field, Form } from "formik";
import { indexBy, map, compose } from "ramda";
import { withReducer } from "recompose";

const MyInput = ({ field, form, handleBlur, ...rest }) =>
  <div>
    <input {...field} onBlur={handleBlur} {...rest} />
    {form.errors[field.name] &&
      form.touched[field.name] &&
      <div>
        {form.errors[field.name]}
      </div>}
  </div>;

const indexById = indexBy(o => o.id);
const mapToEmpty = map(() => "");

const EmailsForm = ({ fieldsList }) =>
  <Formik
    initialValues={compose(mapToEmpty, indexById)(fieldsList)}
    validate={values => {
      // console.log("validate", { values });
      const errors = { values };
      return errors;
    }}
    onSubmit={values => {
      console.log("onSubmit", { values });
    }}
    handleBlur={e => console.log("bluuuuurr", { e })}
    render={({ isSubmitting, handleBlur }) =>
      <Form>
        <Field
          component={MyInput}
          name="email"
          type="email"
          handleBlur={handleBlur}
        />
        <button type="submit" disabled={isSubmitting}>
          Submit
        </button>
      </Form>}
  />;

这种方法有什么问题？
如何实际使用handleBlur和handleChange？

What is wrong with this approach ? How are handleBlur and handleChange actually supposed to be used ?

推荐答案

你需要删除第一个 handleBlur 来自 Formik 因为模糊事件仅在字段级别有效，并且在您的Field元素中执行以下操作：

You'll need to remove the first handleBlur from Formik as blur event is only valid on the field level and do something like the followings in your Field element:

<Field
    component={MyInput}
    name="email"
    type="email"
    handleBlur={e => {
        // call the built-in handleBur
        handleBlur(e)
        // and do something about e
        let someValue = e.currentTarget.value
        ...
    }}
/>

参见 https://github.com/jaredpalmer/formik/issues/157

这篇关于React Formik：如何使用自定义onChange和onBlur的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！