Gmail API - Parse message content (Base64 decoding?) with Javascript

Question

I\'m trying to use the Gmail API to get a user\'s email, grab the message subject and body, and then display it on a webpage. I\'ll be doing other stuff with it, but this is

Answer 1

You need to search where the body for a given mime type is, I have written a recursive function for that:

function searchBodyRec(payload, mimeType){
    if (payload.body && payload.body.size && payload.mimeType === mimeType) {
        return payload.body.data;
    } else if (payload.parts && payload.parts.length) {
        return payload.parts.flatMap(function(part){
            return searchBodyRec(part, mimeType);
        }).filter(function(body){
            return body;
        });
    }
}

So now you can call

var encodedBody = searchBodyRec(this.message.payload, 'text/plain');

See the flatMap method up there? Classic FP method missing in js, here is how to add it (or you can use lodash.js, or underscore.js if you don't want to mess with the native objects)

Array.prototype.flatMap = function(lambda) { 
    return Array.prototype.concat.apply([], this.map(lambda)); 
};