React-native upload image to amazons s3

Question

I want to upload images from my app to S3 server. I have all data and codes calculated (tested using curl on computer) but I can't figure out how to call 'fetch' correctly. I'm getting response:

'At least one of the pre-conditions you specified did not hold. Condition: Bucket POST must be of the enclosure-type-multipart/form-data'

How can I recreate form-data in react-natives fetch? There is no FormData to which I can append and then send it like in fetches example.

EDIT: Thanks @philipp-von-weitershausen, greate that you have added this feature. However I have some troubles calling it. I'm getting "Unsupported BodyInit type". Found that is because in fetch.js: "support.formData" returns false. What am I missing when I call fetch?

My code example:

 var form = new FormData();
 form.append("FormData", true)
 form.append("name", this.state.invoiceNumber)
 form.append("key", this.state.invoiceNumber)
 form.append("Content-Type", "image/png")
 form.append('file', this.props.uri)
 //alert(FormData.prototype.isPrototypeOf(form))

  fetch(amazon_url,{body: form,mode: "FormData", method: "post", headers: {"Content-Type": "multipart/FormData"}})
          .then((response) => response.json())
          .catch((error) => {
             alert("ERROR " + error)
          })
          .then((responseData) => {
             alert("Succes "+ responseData)
          })
          .done();

Answer 1

Some people asked, so I'm posting how I did it. It was done quiet long time ago so if you have any comments or something is really bad done I'm open to critic ;) Photo is in read from cameraRoll and stored in 'latestPhoto'.

Uploading photo to S3 server:

Step 1: Generate data:

_addTextParam() {
    var textParams = this.state.textParams;
    s3_upload_id = this.makeid()
    textParams.push({ name: "key", value: this.state.upload_path + s3_upload_id + '/' + this.state.att_name + ".jpg" })
    textParams.push({ name: "AWSAccessKeyId", value: this.state.key })
    textParams.push({ name: "acl", value: "public-read" })
    textParams.push({ name: "success_action_status", value: "201" })
    textParams.push({ name: "policy", value: this.state.policy })
    textParams.push({ name: "signature", value: this.state.signature })
    textParams.push({ name: "Content-Type", value: "image/jpeg" })

    this.setState({ textParams: textParams });
  }

Step 2: Send data:

  _send() {

    this._addTextParam()
    var xhr = new XMLHttpRequest();
    xhr.open('POST', "http://" + this.state.fs_domain + "." + this.state.server);
    xhr.onload = () => {
      this.setState({ isUploading: false });
      if (xhr.status !== 201) {
        AlertIOS.alert( 
          'Upload failed',
          'Expected HTTP 200 OK response, got ' + xhr.status + "/" + xhr.responseText
        );
        return;
      }

      if (!xhr.responseText) {
        AlertIOS.alert(
          'Upload failed',
          'No response payload.'
        );
        return;
      }
      var index = xhr.responseText.indexOf( "http://" + this.state.fs_domain + "." + this.state.server);
      if (index === -1) {
        AlertIOS.alert(
          'Upload failed',
          'Invalid response payload.'
        );
        return;
      }
      var url = xhr.responseText.slice(index).split('\n')[0];
      this.state.s3_file_id = xhr.responseText.split('Tag>"')[1].split('"')[0]
      this.state.s3_file_path = xhr.responseText.split('Location>')[1].split('<')[0]
      this.setState({ isUploading: false });
      RCTDeviceEventEmitter.emit('Uploaded')

    };
    var formdata = new FormData();

    this.state.textParams.forEach((param) => {
        formdata.append(param.name, param.value)
      }
    );

    formdata.append('file', {...this.state.latestPhoto, name: (this.state.att_name+".jpg") });

    xhr.send(formdata);
    this.setState({ isUploading: true });

  },

Answer 2

multipart/form-data support for React Native (via the XHR FormData API) for mixed payloads (JS strings + image payloads) is in the works. It should land in GitHub soon.

Answer 3

S3 options:

// this.state.s3options in YourComponent
{
  "url": "https://yourapp.s3.eu-central-1.amazonaws.com",
  "fields": {
    "key": "cache/22d65141b48c5c44eaf93a0f6b0abc30.jpeg",
    "policy": "eyJleHBpcm...1VDE0Mzc1OVoifV19",
    "x-amz-credential": "AK...25/eu-central-1/s3/aws4_request",
    "x-amz-algorithm": "AWS4-HMAC-SHA256",
    "x-amz-date": "20161125T143759Z",
    "x-amz-signature": "87863c360...b9b304bfe650"
  }
}

Component:

class YourComponent extends Component {
  // ...

  // fileSource looks like: {uri: "content://media/external/images/media/13", isStatic: true}
  async uploadFileToS3(fileSource) {
    try {
      var formData = new FormData();
      // Prepare the formData by the S3 options
      Object.keys(this.state.s3options.fields).forEach((key) => {
        formData.append(key, this.state.s3options.fields[key]);
      });
      formData.append('file', {
        uri: fileSource.uri,
        type: 'image/jpeg',
      });
      formData.append('Content-Type', 'image/jpeg')

      var request = new XMLHttpRequest();
      request.onload = function(e) {
        if (e.target.status === 204) {
          // Result in e.target.responseHeaders.Location
          this.setState({avatarSourceRemote: {uri: e.target.responseHeaders.Location}})
        }
      }.bind(this)
      request.open('POST', this.state.s3options.url, true);
      request.setRequestHeader('Content-type', 'multipart/form-data');
      request.send(formData);
    } catch(error) {
      console.error(error);
    }
  }

  // Example display the uploaded image
  render() {
    if (this.state.avatarSourceRemote) {
      return (
        <Image source={this.state.avatarSourceRemote} style={{width: 100, height: 100}} />
      );
    } else {
      return (
        <Text>No Image</Text>
      );
    }
  }
}

Answer 4

@Michał Zubrzycki Thanks, your code for uploading picture worked for me with little changes.

const photo = {
  uri: user.profilePicture,
  type: "image/jpeg",
  name: "photo.jpg"
};
const form = new FormData();
form.append("ProfilePicture", photo);
fetch(Constants.API_USER + "me/profilePicture", {
  body: form,
  method: "PUT",
  headers: {
    "Content-Type": "multipart/form-data",
    Authorization: "Bearer " + user.token
  }
})
  .then(response => response.json())
  .catch(error => {
    console.log("ERROR ", error);
  })
  .then(responseData => {
    console.log("Success", responseData);
  })
  .done();