Where to find body of email depending of mimeType

Question

I am making a request to the User.messages endpoint. All objects returned (the emails) have a mimeType property which I\'m struggling to understand.

More specificall

Answer 1

Based on the Tholle idea, I've completed his script to extract Gmail body and attachments.

First of all, you should fetch any gmail-message object and then parse it. You can fetch any gmail-message with this code:

const {google} = require('googleapis')
// do your authenticatoin here
const oAuth2Client = new google.auth.OAuth2(client_id, client_secret, redirectTo)
const gmail = google.gmail({ version: 'v1', auth: oAuth2Client })

const response = await this.gmail.users.messages.get({
  auth: oAuth2Client,
  userId: 'me',
  id: messageId,
  format: 'full'
})

const message_obj = response.data

Main Script:

function parser(response) {

  function decode(input) {
    const text = new Buffer.from(input, 'base64').toString('ascii')
    return decodeURIComponent(escape(text))
  }

  function decode_alternative(input) {
    // this way does not escape special "B" characters
    // const text = Buffer.from(input, 'base64').toString('ascii')
    // return decodeURIComponent(escape(text))

    return base64.decode(input.replace(/-/g, '+').replace(/_/g, '/'))
  }

  const result = {
   text: '',
   html: '',
   attachments: []
  }

  let parts = [response.payload]

  while (parts.length) {
    let part = parts.shift()

    if (part.parts)
      parts = parts.concat(part.parts)

    if (part.mimeType === 'text/plain')
      result.text = decode(part.body.data)

    if (part.mimeType === 'text/html')
      result.html = decode(part.body.data)


    if (part.body.attachmentId) {
      result.attachments.push({
        'partId': part.partId,
        'mimeType': part.mimeType,
        'filename': part.filename,
        'body': part.body
      })
    }
  }

  return result
}

Sample Data and response:

const with_multi_type_attachments = {
  "id": "16c624e85dfd9883",
  "threadId": "16c62397458f34b1",
  "labelIds": [],
  "snippet": "This is body. Inline-attachments my-custom-link my-custom-email-address Emoji: