Per the docs, "The call operator always returns the current selection, regardless of the return value of the specified function." I'd like to know if there is a variant of call or reasonable workaround for getting call-behavior that returns values other than the selection.
Motivation:
I've got a chart and a datebrush, each encapsulated in a function
function trends_datebrush() {
// Setup
function chart(_selection) {
_selection.each(function(_data) {
// Do things
...});
}
return chart;
};
(The chart follows a similar format but isn't called datebrush).
These are instantiated with:
d3.select("someDiv")
.datum("data")
.call(trends_datebrush());
// And then we call the chart
I'd like to return a subselection from brush to be used as the data variable in the chart call. As is I need to make them both aware of some higher order global state, which gets messy especially since I want other control functions to drill down on the data. If I could override call, then I could do something like
d3.select("someDiv")
.datum("data")
.call(trends_datebrush())
.call(trends_chart());
And then if I were to implement some new filter I could throw it into the chain with another call statement.
tl;DR: Looking for ways to get chain chart calls s.t. they can pass transformed data to each other. I want monadic D3 charts! Except I don't really know monads so I might be misusing the word.
