React Native

Debug REST HTTP Request

See more REST Examples

Demonstrates how to generate the HTTP Request (with all headers intact) without actually sending the request.

Note: This example requires Chilkat v9.5.0.77 or later.

React Native

import { BinData, JsonObject, Rest, StringBuilder } from '@chilkat/react-native'

async function chilkatExample() {
  // This example requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  // This example will connect to the web server, but does not actually send a request.
  // When in DebugMode, the request is composed in memory and can be retrieved by calling
  // GetLastDebugRequest.

  const rest = new Rest();

  // Connect Code...
  // URL: https://test-api.service.hmrc.gov.uk/organisations/vat/MY_HMRC_VRN/returns
  const bTls = true;
  const port = 443;
  const bAutoReconnect = true;
  try {
    await rest.connectAsync('test-api.service.hmrc.gov.uk', port, bTls, bAutoReconnect);
  } catch {
    console.log(`ConnectFailReason: ${rest.connectFailReason}`);
    console.log(rest.lastErrorText);
    return;
  }

  // Build the request body...
  const json = new JsonObject();
  json.updateString('periodKey', 'A001');
  json.updateNumber('vatDueSales', '105.50');
  json.updateNumber('vatDueAcquisitions', '-100.45');
  json.updateNumber('totalVatDue', '5.05');
  json.updateNumber('vatReclaimedCurrPeriod', '105.15');
  json.updateNumber('netVatDue', '100.10');
  json.updateInt('totalValueSalesExVAT', 300);
  json.updateInt('totalValuePurchasesExVAT', 300);
  json.updateInt('totalValueGoodsSuppliedExVAT', 3000);
  json.updateInt('totalAcquisitionsExVAT', 3000);
  json.updateBool('finalised', true);

  // Add Headers...
  rest.addHeader('Accept', 'application/vnd.hmrc.1.0+json');
  rest.addHeader('Authorization', 'Bearer HMRC_ACCESS_TOKEN');
  rest.addHeader('Content-Type', 'application/json');

  const sbRequestBody = new StringBuilder();
  json.emitSb(sbRequestBody);

  // Set DebugMode so that no request is actually sent.
  rest.debugMode = true;

  const sbResponseBody = new StringBuilder();
  try {
    await rest.fullRequestSbAsync('POST', '/organisations/vat/MY_HMRC_VRN/returns', sbRequestBody, sbResponseBody);
  } catch {
    console.log(rest.lastErrorText);
    return;
  }

  // Get the exact contents of what would've been sent.
  // This includes the HTTP start line, the HTTP request headers, and the request body.
  // Given that it's possible for the request body to contain binary data,
  // the GetLastDebugRequest fetches into a BinData object.
  // In this case, however, our request body contained JSON, so we can
  // examine it as a string..
  const bdRequest = new BinData();
  rest.getLastDebugRequest(bdRequest);

  console.log('----');
  console.log(bdRequest.getString('utf-8'));
  console.log('----');

  // The output for the above case:

  // POST /organisations/vat/MY_HMRC_VRN/returns HTTP/1.1
  // Accept: application/vnd.hmrc.1.0+json
  // Host: test-api.service.hmrc.gov.uk
  // Authorization: Bearer HMRC_ACCESS_TOKEN
  // Content-Type: application/json
  // Content-Length: 281
  // 
  // {"periodKey":"A001","vatDueSales":105.50, ... ,"finalised":true}
  // 
  // 
}