React Native

Check if a MIME Part is Application Data

Demonstrates the Chilkat Mime.IsApplicationData method, which returns whether the Content-Type begins with application/. It takes no arguments and applies to the current part.

Note: The file path is relative to the application's current working directory. Absolute paths may also be used. Supply the path to your own file.

Background: The application/ family covers everything that is not plain media or text — PDFs, Office documents, ZIP archives, JSON, and the S/MIME application/pkcs7-* types. This broad check is a quick way to flag "binary document" parts, though you will usually look at the specific subtype to decide how to handle each.

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React Native

import { Mime } from '@chilkat/react-native'

function chilkatExample() {
  // Demonstrates the Mime.IsApplicationData method, which returns whether the Content-Type begins with application/.  It takes no arguments and applies to the current
  // part.  This example iterates the parts of a multipart message and reports which ones match.

  const mime = new Mime();
  try {
    mime.loadMimeFile('qa_data/multipart_message.eml');
  } catch {
    console.log(mime.lastErrorText);
    return;
  }

  const n = mime.numParts;
  const part = new Mime();
  for (let i = 0; i < n; i++) {
    try {
      mime.partAt(i, part);
    } catch {
      console.log(mime.lastErrorText);
      return;
    }

    if (part.isApplicationData()) {
      console.log(`Part ${i} (${part.contentType}) is application data.`);
    }
  }
}