Gmail API decoding messages in Javascript

Question

I am having serious problems decoding the message body of the emails I get using the Gmail API. I want to grab the message content and put the content in a div. I am using a

Answer 1

Use atob to decode the messages in JavaScript (see ref). For accessing your message payload, you can write a function:

var extractField = function(json, fieldName) {
  return json.payload.headers.filter(function(header) {
    return header.name === fieldName;
  })[0].value;
};
var date = extractField(response, "Date");
var subject = extractField(response, "Subject");

referenced from my previous SO Question and

var part = message.parts.filter(function(part) {
  return part.mimeType == 'text/html';
});
var html = atob(part.body.data);

If the above does not decode 100% properly, the comments by @cgenco on this answer below may apply to you. In that case, do

var html = atob(part.body.data.replace(/-/g, '+').replace(/_/g, '/'));