Accept GET/POST param for warpables json instead of a URL

[jywarren]

I want to move us closer to completing integration with MapKnitter, and we'll need this to be able to accept the JSON collection as follows:

$.post("http://34.74.118.242/api/v2/export/", {
    scale: 30,
    upload: true,
    collection: aJsonCollection // here is where we'll pass in the JSON
});

Just like in https://github.com/publiclab/mapknitter-exporter-sinatra#usage

Can we do that pretty easily, if URL isn't specified?

image-sequencer-app/src/api/v2/index.js

Lines 17 to 21 in 892c1ba

	let url = req.query.url || req.body;
	let scale = req.query.scale
	console.log("Export endpoint hit for url " + url);
	require("axios").get(url).then(function(data) {
	res.redirect(req.protocol + '://' + req.get('host') + "/api/v2/process" + `/?upload=${req.query.upload}&scale=${scale}&steps=${JSON.stringify(require('./util/converter-multiSequencer')(data.data, parseFloat(scale)))}`);

Thanks!

[jywarren]

Once we have this, we can show the above in the README as how to use this:

$.post("http://34.74.118.242/api/v2/export/", {
    scale: 30,
    upload: true,
    collection: aJsonCollection // here is where we'll pass in the JSON
}).success(function(response) {
  // here 'response' will include the URL to get status updates from
});

[jywarren]

I created a PR here - do you think this'll work, @tech4GT ? #33