SaveAs tool and example

[swederik]

Small function for saving PNG files from the canvases. Addresses #31.

Seems it can't be automatically merged because of changes to dist/cornerstoneTools... How should we approach this? I assume I stop using grunt before commits? But then the rawgit examples won't work...

Update: Rebased and fixed

[cancan101]

Is it possible to use any of this code for send the binary image over HTTP, for example using window.fetch?

[swederik]

Yeah, sure, but what for? You want to save the canvas as an image on your server?

I think you can just use canvas.toDataURL(); and then POST that data to the server. Then you just decode the base64 string to produce an image on the server.

[cancan101]

Yes, exactly. I want to save the save the canvas (which has all of the user's modifications, transforms and annotations) to the server. This along with #30 so that I have both the steps to re-create the modifications and the image of the canvas.

[swederik]

Ok so you want to use the image to show the saved-state then. Seems easy enough to do, but I don't know if it's worth having extra code for it in cornerstone itself.

// Get the canavas
var canvas = $(element).find("canvas").get(0);
var imageData = canvas.toDataURL();
$.ajax({
  method: "POST",
  url: "/your/server/",
  data: {"image": imageData}
})

Then on the server (at least in Python):

import base64

# Assuming you have a request like in Django
data = request.POST["image"]

filename = "MyNewImage.png"
out_file = open(filename, "w")
out_file.write(base64.decodestring(data))
out_file.close()

Hope that helps

[cancan101]

Sure that seems simple enough. I do think though that a save as tool for in browser saves still stands on its own as a useful feature.

[cancan101]

Does it make sense to extract $(element).find("canvas").get(0); as a helper method?

[swederik]

Probably not, it's boilerplate jQuery.