javascript - let files = event.target.files; does not have a file - Stack Overflow

admin管理员组

文章数量:1422062

I have the following react ponent, but in the for statement, it never steps into the for loop, like files array is empty, so file is never sent to the server.

import React, { Component } from 'react';
import { Row, Col } from 'antd';
import PageHeader from '../../ponents/utility/pageHeader';
import Box from '../../ponents/utility/box';
import LayoutWrapper from '../../ponents/utility/layoutWrapper.js';
import ContentHolder from '../../ponents/utility/contentHolder';
import basicStyle from '../../settings/basicStyle';
import IntlMessages from '../../ponents/utility/intlMessages';
import { adalApiFetch } from '../../adalConfig';

export default class extends Component {
  constructor(props) {
    super(props);
    this.state = {TenantId: '', TenantUrl: '', TenantPassword: '' };
    this.handleChangeTenantUrl = this.handleChangeTenantUrl.bind(this);
    this.handleChangeTenantPassword = this.handleChangeTenantPassword.bind(this);
    this.handleChangeTenantId= this.handleChangeTenantId.bind(this);
    this.handleSubmit = this.handleSubmit.bind(this);
  };


  handleChangeTenantUrl(event){
    this.setState({TenantUrl: event.target.value});
  }

  handleChangeTenantPassword(event){
    this.setState({TenantPassword: event.target.value});
  }

  handleChangeTenantId(event){
    this.setState({TenantId: event.target.value});
  }

  handleSubmit(event){
    event.preventDefault();

    let data = new FormData();
    //Append files to form data
    let files = event.target.files;
    for (let i = 0; i < files.length; i++) {
      data.append("file", files[i], files[i].name);
    }

    //add other objects or params
    data.append("TenantId", this.state.TenantId);
    data.append("TenantUrl", this.state.TenantUrl);
    data.append("TenantPassword", this.state.TenantPassword);


    const options = {
      method: 'put',
      body: data,
      config: {
        headers: {
          'Content-Type': 'multipart/form-data'
        }
      }
    };

    adalApiFetch(fetch, "/Tenant", options)
      .then(response => response.json())
      .then(responseJson => {
        if (!this.isCancelled) {
          this.setState({ data: responseJson });
        }
      })
      .catch(error => {
        console.error(error);
      });
  }


  upload(e){
      let data = new FormData();
      //Append files to form data
      let files = e.target.files;
      for (let i = 0; i < files.length; i++) {
        data.append('content', files[i], files[i].name);
      }      
  }

  render(){
    const { data } = this.state;
    const { rowStyle, colStyle, gutter } = basicStyle;

    return (
      <div>
        <LayoutWrapper>
        <PageHeader>{<IntlMessages id="pageTitles.TenantAdministration" />}</PageHeader>
        <Row style={rowStyle} gutter={gutter} justify="start">
          <Col md={12} sm={12} xs={24} style={colStyle}>
            <Box
              title={<IntlMessages id="pageTitles.TenantAdministration" />}
              subtitle={<IntlMessages id="pageTitles.TenantAdministration" />}
            >
              <ContentHolder>
              <form onSubmit={this.handleSubmit}>
                <label>
                  TenantId:
                  <input type="text" value={this.state.TenantId} onChange={this.handleChangeTenantId} />
                </label>
                <label>
                  TenantUrl:
                  <input type="text" value={this.state.TenantUrl} onChange={this.handleChangeTenantUrl} />
                </label>
                <label>
                  TenantPassword:
                  <input type="text" value={this.state.TenantPassword} onChange={this.handleChangeTenantPassword} />
                </label>
                <label>
                  Certificate:
                  <input onChange = { e => this.upload(e) } type = "file" id = "files" ref = { file => this.fileUpload } />
                </label>             
              <input type="submit" value="Submit" />
              </form>
              </ContentHolder>
            </Box>
          </Col>
        </Row>
      </LayoutWrapper>
      </div>
    );
  }
}

I have the following react ponent, but in the for statement, it never steps into the for loop, like files array is empty, so file is never sent to the server.

import React, { Component } from 'react';
import { Row, Col } from 'antd';
import PageHeader from '../../ponents/utility/pageHeader';
import Box from '../../ponents/utility/box';
import LayoutWrapper from '../../ponents/utility/layoutWrapper.js';
import ContentHolder from '../../ponents/utility/contentHolder';
import basicStyle from '../../settings/basicStyle';
import IntlMessages from '../../ponents/utility/intlMessages';
import { adalApiFetch } from '../../adalConfig';

export default class extends Component {
  constructor(props) {
    super(props);
    this.state = {TenantId: '', TenantUrl: '', TenantPassword: '' };
    this.handleChangeTenantUrl = this.handleChangeTenantUrl.bind(this);
    this.handleChangeTenantPassword = this.handleChangeTenantPassword.bind(this);
    this.handleChangeTenantId= this.handleChangeTenantId.bind(this);
    this.handleSubmit = this.handleSubmit.bind(this);
  };


  handleChangeTenantUrl(event){
    this.setState({TenantUrl: event.target.value});
  }

  handleChangeTenantPassword(event){
    this.setState({TenantPassword: event.target.value});
  }

  handleChangeTenantId(event){
    this.setState({TenantId: event.target.value});
  }

  handleSubmit(event){
    event.preventDefault();

    let data = new FormData();
    //Append files to form data
    let files = event.target.files;
    for (let i = 0; i < files.length; i++) {
      data.append("file", files[i], files[i].name);
    }

    //add other objects or params
    data.append("TenantId", this.state.TenantId);
    data.append("TenantUrl", this.state.TenantUrl);
    data.append("TenantPassword", this.state.TenantPassword);


    const options = {
      method: 'put',
      body: data,
      config: {
        headers: {
          'Content-Type': 'multipart/form-data'
        }
      }
    };

    adalApiFetch(fetch, "/Tenant", options)
      .then(response => response.json())
      .then(responseJson => {
        if (!this.isCancelled) {
          this.setState({ data: responseJson });
        }
      })
      .catch(error => {
        console.error(error);
      });
  }


  upload(e){
      let data = new FormData();
      //Append files to form data
      let files = e.target.files;
      for (let i = 0; i < files.length; i++) {
        data.append('content', files[i], files[i].name);
      }      
  }

  render(){
    const { data } = this.state;
    const { rowStyle, colStyle, gutter } = basicStyle;

    return (
      <div>
        <LayoutWrapper>
        <PageHeader>{<IntlMessages id="pageTitles.TenantAdministration" />}</PageHeader>
        <Row style={rowStyle} gutter={gutter} justify="start">
          <Col md={12} sm={12} xs={24} style={colStyle}>
            <Box
              title={<IntlMessages id="pageTitles.TenantAdministration" />}
              subtitle={<IntlMessages id="pageTitles.TenantAdministration" />}
            >
              <ContentHolder>
              <form onSubmit={this.handleSubmit}>
                <label>
                  TenantId:
                  <input type="text" value={this.state.TenantId} onChange={this.handleChangeTenantId} />
                </label>
                <label>
                  TenantUrl:
                  <input type="text" value={this.state.TenantUrl} onChange={this.handleChangeTenantUrl} />
                </label>
                <label>
                  TenantPassword:
                  <input type="text" value={this.state.TenantPassword} onChange={this.handleChangeTenantPassword} />
                </label>
                <label>
                  Certificate:
                  <input onChange = { e => this.upload(e) } type = "file" id = "files" ref = { file => this.fileUpload } />
                </label>             
              <input type="submit" value="Submit" />
              </form>
              </ContentHolder>
            </Box>
          </Col>
        </Row>
      </LayoutWrapper>
      </div>
    );
  }
}

• javascript
• reactjs

Share Improve this question Follow asked Jul 19, 2018 at 18:44 Luis ValenciaLuis Valencia 34.1k9999 gold badges311311 silver badges532532 bronze badges 2

• Would it not be better to put the files in state first, and then use these files from the state in your handleSubmit method, and put them in the formData before the request? – Tholle Commented Jul 19, 2018 at 18:48
• no idea how to do that – Luis Valencia Commented Jul 19, 2018 at 18:58

Add a ment  | 

1 Answer 1

Sorted by: Reset to default 2

I have modified the required functions should work now.

constructor(props) {
    super(props);
    this.state = {TenantId: '', TenantUrl: '', TenantPassword: '', selectedFiles: null };
    this.handleChangeTenantUrl = this.handleChangeTenantUrl.bind(this);
    this.handleChangeTenantPassword = this.handleChangeTenantPassword.bind(this);
    this.handleChangeTenantId= this.handleChangeTenantId.bind(this);
    this.handleSubmit = this.handleSubmit.bind(this);
  };

upload(e){
      let files = e.target.files;
      this.setState({ 'selectedFiles': files })
  }

handleSubmit(event){
    event.preventDefault();

    let data = new FormData();
    //Append files to form data
    let files = this.state.files;
    for (let i = 0; i < files.length; i++) {
      data.append("file", files[i], files[i].name);
    }

    //add other objects or params
    data.append("TenantId", this.state.TenantId);
    data.append("TenantUrl", this.state.TenantUrl);
    data.append("TenantPassword", this.state.TenantPassword);


    const options = {
      method: 'put',
      body: data,
      config: {
        headers: {
          'Content-Type': 'multipart/form-data'
        }
      }
    };

    adalApiFetch(fetch, "/Tenant", options)
      .then(response => response.json())
      .then(responseJson => {
        if (!this.isCancelled) {
          this.setState({ data: responseJson });
        }
      })
      .catch(error => {
        console.error(error);
      });
  }

本文标签： javascriptlet fileseventtargetfiles does not have a fileStack Overflow