React Native

Access a Part in a Multipart MIME Entity

Demonstrates the Chilkat Mime.PartAt method, which provides live access to the direct child at a zero-based index. The first argument is the index and the second is a Mime object that will reference the child. Modifying it modifies the child stored in the parent tree.

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

Background: This is how you reach into a multipart message to inspect or edit an individual part — read a part's Content-Type, extract an attachment's body, or change a part in place. The key point is that the returned Mime is a live reference, not a copy, so edits to it flow back into the parent tree. Loop from 0 to NumParts - 1 to visit every direct child.

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React Native

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

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

  // PartAt provides LIVE access to a direct child part.  The 1st argument is the zero-based index
  // and the 2nd is a Mime object that will reference the child.  Modifying it modifies the child in
  // the parent tree.
  const n = mime.numParts;
  console.log(`Number of parts: ${n}`);

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

    console.log(`Part ${i} Content-Type: ${part.contentType}`);
  }
}