How can you access the HTTP response from a server using client-side JavaScript?

Question

I'm trying to do client-side processing of some data sent in a server's HTTP response.

Here's what I'm working with: I have a web application that sends commands to a backend simulation engine, which then sends back a bunch of data/results in the response body. I want to be able to access this response using JavaScript (note..not making a new response, but simply accessing the data already sent from the server).

Right now, I am able to do this via a kludgy hack of sorts:

var responseText = "{{response}}";

This is using Django's template system, where I have already pre-formatted the template context variable "response" to contain a pre-formatted string representation of a csv file (ie, proper unicode separators, etc).

This results in a huge string being transmitted to the page. Right now, this supports my immediate goal of making this data available for download as a csv, but it doesn't really support more sophisticated tasks. Also, I'm not sure if it will scale well when my string is, say, 2 MB as opposed to less than 1 KB.

I'd like to have this response data stored more elegantly, perhaps as part of the DOM or maybe in a cache (?) [not familiar with this].

Answer 1

The ideal way to do this is to not load the csv on document load, either as a javascript variable or as part of the DOM. Why would you want to load a 2MB data every time to the user when his intention may not be to download the csv everytime?

I suggest creating a controller/action for downloading the csv and get it on click of the download button.