A reusable chart combinator for D3.

chart.js

var chart = (function() {
  function copy(o) {
    return Object.keys(o).reduce(function(no, k) {
      no[k] = o[k];
      return no;
    }, {});
  }

  return function(defaults, _cstr) {
    return function() {
      var attrs = {};

      var my = function(selection) {
        return _cstr(selection, copy(attrs));
      };

      d3.entries(defaults).forEach(function(e) {
        my[e.key] = function(value) {
          if (arguments.length == 0) { return attrs[e.key]; }
          attrs[e.key] = value;
          return my;
        }

        attrs[e.key] = e.value;
      });

      return my;
    };
  };
})();