Javascript: How To "cache" A File To Download, Then Trigger Download Upon Request?

I have a web app that allows a user to 'generate' an HTML email that they can download. When the user clicks the 'preview' button, the form is submitted to a new window, which actu

Solution 1:

Based on Mikko Ohtamaa's comment above, it seems that there is no way to achieve this with JavaScript. I have decided to save the file to a temp directory as a workaround. I'm still interested to hear if there is a way to do something like this without saving the file to the server.