Google Apps Script:
Sending an HTTP request with basic authentication

How to:

In Google Apps Script, to send an HTTP request with basic authentication, you utilize the UrlFetchApp service combined with a base64-encoded authorization header. Here’s a step-by-step guide:

1. Encode Credentials: First, encode your username and password in base64. Google Apps Script doesn’t have a native base64 encoding function for strings, so you’ll use Utilities.base64Encode for this purpose.

var username = 'YourUsername';
var password = 'YourPassword';
var encodedCredentials = Utilities.base64Encode(username + ':' + password);

2. Set Up Request Options: With the encoded credentials ready, prepare the options object for the HTTP request, including the method and headers.

var options = {
  method: 'get', // or 'post', 'put', depending on your needs
  headers: {
    'Authorization': 'Basic ' + encodedCredentials
  }
  // additional options like 'muteHttpExceptions' for error handling can be added here
};

3. Make the Request: Use the UrlFetchApp.fetch method with the target URL and the options object.

var url = 'https://example.com/api/resource';
var response = UrlFetchApp.fetch(url, options);
Logger.log(response.getContentText());

Sample output upon successful request will vary based on the API’s response. For a JSON-based API, you might see something like:

{"status":"Success","data":"Resource data here..."}

Ensure you handle possible HTTP errors by checking the response code or using muteHttpExceptions option for more controlled error management.

Deep Dive

Sending an HTTP request with basic authentication has been a standard method in many programming languages for accessing web-based resources that require authentication. In the context of Google Apps Script, UrlFetchApp provides a straightforward way to perform these HTTP requests, including those requiring authentication. The inclusion of basic credentials in the request headers is a simple yet effective method but comes with security caveats, primarily because the credentials are sent in plaintext, just base64-encoded, which can be easily decoded if intercepted.

For improved security, alternatives like OAuth 2.0 are recommended, especially when dealing with sensitive data or operations. Google Apps Script has built-in support for OAuth 2.0 with the OAuth2 library, streamlining the process of authenticating against services that support this protocol.

Despite its security limitations, basic authentication remains widely used for simple or internal applications not exposed to the broader internet. It’s straightforward to implement, as it requires only a single request with properly set headers, making it an appealing option for quick integrations or for APIs where higher security methods are not available. However, programmers are urged to consider the security implications and explore safer alternatives when available.