Google Apps Script:
Reading a text file

How to:

To start reading a text file with Google Apps Script, you generally need to use the Google Drive API. Here’s a basic example demonstrating how to read a file from Google Drive:

function readFileContents(fileId) {
  // Obtains the Google Drive file by ID
  var file = DriveApp.getFileById(fileId);
  
  // Gets the blob data as text
  var text = file.getBlob().getDataAsString();
  
  // Logging the content to the Google Apps Script log
  Logger.log(text);
  return text;
}

Sample Output in the log:

Hello, world! This is a test text file.

In this example, fileId is the unique identifier of the file you wish to read. The DriveApp service fetches the file, and getDataAsString() reads its contents as a string. You can then manipulate or use this text as required.

Deep Dive

Historically, reading text files in web-based applications, like those built with Google Apps Script, presented challenges due to browser security restrictions and the asynchronous nature of JavaScript. Google Apps Script simplifies this with its abstracted services like DriveApp, providing a high-level API to interact with Google Drive files.

However, an important consideration is the performance and execution time limits imposed by Google Apps Script, especially when reading large files or performing complex operations with the data. In some cases, it might be more efficient to use Google Cloud services directly from a more powerful backend or to preprocess files into more manageable chunks.

For complex file processing or when real-time performance is critical, alternatives such as Google Cloud Functions, which supports Node.js, Python, and Go, might offer more flexibility and computational resources. Nonetheless, for straightforward tasks within the Google ecosystem, especially where simplicity and ease of integration with Google products are paramount, Google Apps Script provides a remarkably user-friendly approach.