How to send ArrayBuffer

[pranavwani]

Description: How to send binary data, as Curl.option.POSTFIELDSonly allow sendingstringandCurl.option.HTTPPOST` allow to sending the form data

Request Payload:

{
  uuid: '7d0ce53d-a614-49e6-96d5-0d9054e82f46',
  method: 'post',
  url: 'http://localhost:3100/api/protobuf',
  params: {},
  headers: { 'Content-Type': 'application/octet-stream' },
  withCredentials: true,
  crossDomain: true,
  extra_config: {
    ignore_response_content_length: false,
    user_agent: '',
    request_timeout: '',
    ssl: { disable_ssl_validation: false },
    proxy: {},
    origin: '',
    follow_location: true,
    max_redirects: -1
  },
  data: Uint8Array [
    10,   6, 112, 114,
    97, 110,  97, 118
  ]
}

[JCMais]

Hi, you want to use the READFUNCTION function, an example with streams is available at https://github.com/JCMais/node-libcurl/blob/6695c91987c6d8a0782cb5a769fb208bf00fea8d/examples/08-file-upload-stream.js

The caveat is that by using this option you cannot use POSTFIELDS or HTTPPOST. So if you also want to send additional data you must build the post payload yourself.

One feature that would allow submitting buffers directly in the POST upload would be to add support for CURLFORM_BUFFERPTR as mentioned in the libcurl docs for curl_formadd (which is the function used internally to add each field): https://curl.haxx.se/libcurl/c/curl_formadd.html

However, currently there is no support for this param, as can be seen here:

node-libcurl/src/CurlHttpPost.cc

Lines 23 to 50 in 6695c91

	CURLFORMcode CurlHttpPost::AddFile(char* fieldName, long fieldNameLength, // NOLINT(runtime/int)
	char* fileName) {
	return curl_formadd(&this->first, &this->last, CURLFORM_COPYNAME, fieldName, CURLFORM_NAMELENGTH,
	fieldNameLength, CURLFORM_FILE, fileName, CURLFORM_END);
	}
	CURLFORMcode CurlHttpPost::AddFile(char* fieldName, long fieldNameLength, // NOLINT(runtime/int)
	char* fileName, char* contentType) {
	return curl_formadd(&this->first, &this->last, CURLFORM_COPYNAME, fieldName, CURLFORM_NAMELENGTH,
	fieldNameLength, CURLFORM_FILE, fileName, CURLFORM_CONTENTTYPE, contentType,
	CURLFORM_END);
	}
	CURLFORMcode CurlHttpPost::AddFile(char* fieldName, long fieldNameLength, // NOLINT(runtime/int)
	char* fileName, char* contentType, char* newFileName) {
	return curl_formadd(&this->first, &this->last, CURLFORM_COPYNAME, fieldName, CURLFORM_NAMELENGTH,
	fieldNameLength, CURLFORM_FILE, fileName, CURLFORM_CONTENTTYPE, contentType,
	CURLFORM_FILENAME, newFileName, CURLFORM_END);
	}
	CURLFORMcode CurlHttpPost::AddField(char* fieldName, long fieldNameLength, // NOLINT(runtime/int)
	char* fieldValue,
	long fieldValueLength) { // NOLINT(runtime/int)
	return curl_formadd(&this->first, &this->last, CURLFORM_COPYNAME, fieldName, CURLFORM_NAMELENGTH,
	fieldNameLength, CURLFORM_COPYCONTENTS, fieldValue, CURLFORM_CONTENTSLENGTH,
	fieldValueLength, CURLFORM_END);
	}
	} // namespace NodeLibcurl

Adding support for that is not something I think I will do, as the HTTPPOST libcurl option was deprecated, instead we should add support for the MIMEPOST option and their related functions: #112

[pranavwani]

Thanks, @JCMais for put attention on this query. I will try to implement as you suggested.

Specific reason to sending buffer over HTTP API is: request payload is encoded via protobuf. To keep the benefits of protobuf to sending binary data over HTTP API raised the query.

[JCMais]

No problem, please let me know if you have any issues

[JCMais]

@pranavwani I've added an example showing how to send binary data, like in your specific scenario, sending protobuf encoded data: https://github.com/JCMais/node-libcurl/blob/develop/examples/19-binary-data-protobuf.js

[pranavwani]

Thanks Jonathan for help.