React Native

Save All MIME Attachments to Files

Demonstrates the Chilkat Mime.PartsToFiles method, which recursively traverses the MIME tree and saves each part having a nonempty filename parameter to a directory. The first argument is the destination directory and the second is a StringTable that receives the saved filenames.

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 extracts every named attachment from a message in one call, walking the whole tree so it finds attachments nested inside multipart containers. It saves only parts that declare a filename — inline body parts without one are skipped — and reports what it wrote via the StringTable, which is handy for logging or follow-up processing. The destination directory must already exist.

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React Native

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

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

  // Recursively traverse the MIME tree and save each part that has a nonempty "filename" parameter
  // to a directory.  The 1st argument is the destination directory and the 2nd is a StringTable
  // that receives the saved filenames.
  const savedFiles = new StringTable();
  try {
    mime.partsToFiles('qa_output/attachments', savedFiles);
  } catch {
    console.log(mime.lastErrorText);
    return;
  }

  const n = savedFiles.count;
  console.log(`Saved ${n} files:`);
  for (let i = 0; i < n; i++) {
    let name: string;
    try {
      name = savedFiles.stringAt(i);
    } catch {
      console.log(savedFiles.lastErrorText);
      return;
    }

    console.log(name);
  }
}