Javascript Redux表单验证在onChange处理程序函数之后运行
我有以下redux表单:Javascript Redux表单验证在onChange处理程序函数之后运行,javascript,redux,redux-form,Javascript,Redux,Redux Form,我有以下redux表单: import React, { Component } from 'react'; import { connect } from 'react-redux'; import { Field, reduxForm, getFormSyncErrors } from 'redux-form'; import { createExpense } from '../../actions'; import { validateName, validateImage } fro
import React, { Component } from 'react';
import { connect } from 'react-redux';
import { Field, reduxForm, getFormSyncErrors } from 'redux-form';
import { createExpense } from '../../actions';
import { validateName, validateImage } from '../../helpers/expense_utils';
import { renderInputField, validate, renderTextAreaField, renderDropzoneField } from '../../helpers/form_utils';
const validators = [
{
field: 'title',
validator: validateName
},
{
field: 'description',
validator: validateDescription
},
{
field: 'amount',
validator: validateAmount
},
{
field: 'image',
validator: validateImage
}
];
class NewExpense extends Component {
constructor(props) {
super(props);
this.state = {
error: undefined,
imagePreviewUrl: undefined
};
}
_onSubmit = values => {
let formData = new FormData();
formData.append('title', values.title);
formData.append('description', values.description);
formData.append('amount', values.amount);
formData.append('file', values.image[0]);
this.props.createExpense(formData, this.props.groupId, () => this.props.onClose(), error => this.setState({error: error}));
}
_onImagePreviewChange = files => {
//this.props.inputErrors.image is one step behind
this.setState({
imagePreviewUrl: files[0].preview
});
}
render() {
const { handleSubmit } = this.props;
const { imagePreviewUrl } = this.state;
return (
<div>
<form onSubmit={ handleSubmit(this._onSubmit.bind(this)) }>
<Field name="title" label="Name" type="text" component={ renderInputField }/>
<Field onChange={this._onImagePreviewChange.bind(this)} previewUrl={ imagePreviewUrl } name="image" label="Image" component={ renderDropzoneField } />
<button type="submit" className="btn btn-primary">Create</button>
<button type="button" className="btn btn-primary" onClick={this.props.onClose}>Cancel</button>
</form>
{ this.state.error ? <span>{this.state.error}</span> : <noscript/> }
</div>
);
}
}
export default connect(state => ({
inputErrors: getFormSyncErrors('NewExpense')(state)
}), { createExpense })(reduxForm({
validate,
form:'NewExpense',
validators
})(NewExpense));
import React,{Component}来自'React';
从'react redux'导入{connect};
从'redux form'导入{Field,reduxForm,getFormSyncErrors};
从“../../actions”导入{createExpense};
从“../../helpers/expense_utils”导入{validateName,validateImage};
从“../../helpers/form_utils”导入{renderInputField,validate,renderTextAreaField,renderDropzoneField};
常量验证器=[
{
字段:“标题”,
验证程序:validateName
},
{
字段:“说明”,
验证器:validateDescription
},
{
字段:“金额”,
验证器:validateAmount
},
{
字段:“图像”,
验证器:validateImage
}
];
类NewExpense扩展组件{
建造师(道具){
超级(道具);
此.state={
错误:未定义,
imagePreviewUrl:未定义
};
}
_onSubmit=值=>{
设formData=new formData();
formData.append('title',values.title);
formData.append('description',values.description);
formData.append('amount',value.amount);
formData.append('file',values.image[0]);
this.props.createExpense(formData,this.props.groupId,()=>this.props.onClose(),error=>this.setState({error:error}));
}
_onImagePreviewChange=文件=>{
//此.props.inputErrors.image落后一步
这是我的国家({
imagePreviewUrl:文件[0]。预览
});
}
render(){
const{handleSubmit}=this.props;
const{imagePreviewUrl}=this.state;
返回(
创造
取消
{this.state.error?{this.state.error}:}
);
}
}
导出默认连接(状态=>({
输入者:getFormSyncErrors('NewExpense')(状态)
}),{createExpense})(reduxForm({
验证
表格:'NewExpense',
验证器
})(新费用);
我想访问\u onImagePreviewChange
中表单的字段级错误,并在MapStateTops
中设置输入错误
问题是验证函数在onChange
handler函数之后运行。因此,错误消息总是过时的。例如,如果用户选择了一个不允许类型的文件,消息将是未定义的
,下一次如果用户选择了允许类型的文件,这一次它将不会是未定义的
,因为在上一步中分配了一个错误
为什么会发生这种情况?我应该如何修复它?验证只能在某些字段更改后运行,这就是为什么第一次使用无效值调用\u onImagePreviewChange
时,仍然没有验证错误(如您所说,验证落后一步)
我建议使用componentWillReceiveProps
方法,在此方法中访问下一个和当前的验证错误,检查是否修复或生成了某些错误,并采取需要采取的措施。例如:
componentWillReceiveProps(newProps) {
// here newProps.inputErrors is up-to-date while this.props.inputErrors is the current
if (newProps.inputErrors && newProps.inputErrors !== this.props.inputErrors) {
console.log(newProps.inputErrors); // up-to-date input errors
if (newProps.inputErrors.image) {
// clear invalid image field if you need to
this.props.change('image', '');
}
}
}
您应该使用this.props.change
而不是this.setState({preview:undefined})
,对吗?是的,这取决于您需要什么:this.props.change
重置无效字段,setState
只会隐藏预览,但会使字段无效。