chart.coffee

class BaseChart

  accessors:
    width: 100
    height: 100

  _margin: {}
  @margin: top: 0, right: 0, bottom: 0, left: 0

  # http://bost.ocks.org/mike/chart/
  @chart: ->
    instance = new this

    chart = (selection) ->
      selection.each (d, i) -> instance.draw(this, d, i)

    mixedChart = _.extend chart,
      instance, _.cloneDeep instance.__proto__

    mixedChart

  constructor: ->
    @buildAccessors()
    Object.keys(Vis.margin).forEach (k) =>
      @_margin[k] = Vis.margin[k]

  draw: (el, d, i) ->
    throw new Error 'You must declare a #draw function.'

  margin: (margin) ->
    return @_margin unless arguments.length
    for k,v of margin
      @_margin[k] = v

    this

  # Generate the getters/setters in the accessors property.
  buildAccessors: ->
    for name, accessor of @accessors
      continue if this[name]?

      do (name, accessor) =>
        this[name] = (_) ->
          return accessor unless arguments.length
          accessor = _

          this


class MyChart extends BaseChart

  draw: (elem, d, i) ->
    # generate chart here; `d` is the data and `elem` is the element


chart = MyChart.chart()
chart.width(800).height(120)
d3.select('body').datum(data).call(chart)