This is a proposal to move the chart registry out of dc.js into its own module, to create a standard for linked charts that's not bound to any one library.

I haven't started with making this a npm package/module, but the intention is for this to depend on d3-dispatch only, and even that is an implicit dependency.

If this succeeds it will be moved to the dc-js organization.

The chart registry contains "types" of "groups". A group is an instance of a type and usually an instance of d3.dispatch. The type specifies how to construct the group. For example, the underlying implementation for dc.chartRegistry can be instantiated like so:

var chartRegistry_store = chart_registry.create_type('dc-chart-registry', function() {
    return d3.dispatch('filterAll', 'focus', 'render', 'redraw');
});

Once a type is instantiated, groups can be added using create_group:

var chartgroup = chart_registry.create_group('dc-chart-registry', 'chartgroup1');

Registering the individual charts is now just subscribing to events:

chartgroup.on('filterAll', chart.filterAll.bind(chart))