May 2013 – Greg Gigon's wEbLOG

I use Groovy a lot. It’s simple and easy to use, runs on JVM and saves me from Java verbosity. I also like the fact that it’s dynamic.

I use it with a simple Servlet to return data to JavaScript AJAX requests. I like to keep the server side very simple, so I don’t create a lot of POJOs and I’m using HashMaps instead. Groovy has few convenient methods that makes it easy to work with Maps.

I do convert the maps into JSON when returning results to a browser. I don’t use anything fancy, just a couple lines of Groovy code to do that.

	class JsonMap {
	def toJSON(elements, depth = 0) {
	def json = ""
	depth.times { json += "\t" }
	json += "{"
	elements.each { key, value ->
	json += "\"$key\":"
	json += jsonValue(value, depth)
	json += ", "
	}

	json = (elements.size() > 0) ? json.substring(0, json.length() - 2) : json
	json += "}"
	json
	}

	private def jsonValue(element, depth) {
	if (element instanceof Map) {
	return "\n" + toJSON(element, depth + 1)
	}
	if (element instanceof List) {
	def list = "["
	element.each { elementFromList ->
	list += jsonValue(elementFromList, depth)
	list += ", "
	}
	list = (element.size() > 0) ? list.substring(0, list.length() - 2) : list
	list += "]"
	return list
	}
	(element instanceof String) ? "\"$element\"": element?.toString()
	}
	}

view raw JsonMap.groovy hosted with ❤ by GitHub

	class MapToJsonTests extends GroovyTestCase {
	private final def mapper = new JsonMap()

	void test_convertMapWithListsOfMapsIntoJSON() {
	def map = ["a": "a", "b": [["b": "a"], 'd', [12, 12, "e"], ["r": 12]]]
	def expected = '''{"a":"a", "b":[
	\t{"b":"a"}, "d", ["12", "12", "e"],
	\t{"r":"12"}]}'''

	def result = mapper.toJSON(map)
	assert expected == result
	}
	}

view raw JsonMapTests.groovy hosted with ❤ by GitHub

With this code there is quite a bit of assumptions though:

it will only work for Map
it assumes Strings are used as Map Keys
it will convert Maps, Lists and Objects
when it meets Object it will call .toString() on it to get it’s value
it will try to format it with tabs and new lines a bit, so it’s more pleasant for the eye and human readable

Hope it would be useful for you. Greg

How to do it?

First of all, I’ve created a new Desktop using Mission Control and setup Desktop Background to my Custom “Kanban Board like” wallpaper.

Adding new desktop in the Mission Control

I’ve prepared two backgrounds, dark and bright, which you are more than welcome to use for free.

Kanban Board – Desktop background – Dark

Kanban Board – Desktop background – Light

My empty board is ready. All I need to do now is to add some Stickies onto it.

Background with Stickies

Voila. You can modify color of a sticky and make it transparent. I’m using colors to distinguish between different types of tasks. Stickies on the top are the one with top priority.

Once your Done column is full you can archive your Stickie by saving it and removing from the board.

Simple as that I hope you’ll find it helpful and easy to use. Greg

Month: May 2013

Groovy Map to Json String converter

Free Kanban board on Mac with no additional software

What you need?

How to do it?