Read Uint8Array buffer from Collection and download as pdf - mongodb

Question

I saved a pdf file in a collection using this function:
/*** client.js ***/
// asign a change event into input tag
'change input' : function(event,template){
var file = event.target.files[0]; //assuming 1 file only
if (!file) return;
var reader = new FileReader(); //create a reader according to HTML5 File API
reader.onload = function(event){
var buffer = new Uint8Array(reader.result) // convert to binary
Meteor.call('saveFile', buffer);
}
reader.readAsArrayBuffer(file); //read the file as arraybuffer
}
/*** server.js ***/
Files = new Mongo.Collection('files');
Meteor.methods({
'saveFile': function(buffer){
Files.insert({data:buffer})
}
});
How can I read it again from the collection and provide a download link that the user can download the file as a pdf and save it on the local computer?

Answer 1

It depends on what the data type ends up to be on the front-end when you see that document record in your MiniMongo collection. What you want to do is to convert that Uint8Array data to a base64-encoded data URL and provide a Download PDF link after you get the data in the browser.
Meteor does not support serving files from the server out of the box, so you'll likely have to publish that file's blob via mongo->minimongo publication/subscription mechanism and then use the HTML data-uri API to get it like I've just described.