Making events not trigger so often on a datatable with dc.js

Question

I used this answer to make a table with datatables.net and dc.js. However, I detected a performance issue in this loop:

function RefreshTable() {
 dc.events.trigger(function () {
 datatable.api()
 .clear()
 .rows.add( YearDimension.top(Infinity) )
 .draw() ;
 });
}
count = dc.chartRegistry.list().length
for (var i=count; i--;) {
 dc.chartRegistry.list()[i].on("filtered", RefreshTable);
}
RefreshTable() ;

Because when resetting all the filters with

dc.filterAll();dc.redrawAll();

RefreshTable() is executed once for every dc chart (or dimension?). In my case it's 5 loops at ~500ms each, thus more than 2s for 4 charts and 10k records.

Has someone any idea on how to make it faster? The table should be refreshed only once.

• user456789123: Why is this not allowed ? >2 seconds is more a bug than a performance issue to me. And this could be usefull to others.
• Gordon: I think this is a problem with the way the question was phrased. It turns out to be a question about the API but indeed the title makes it look like a code review question.
• Gordon: Okay I read this wrong. Indeed it is a code review question.

Answer 1

What is ineficient here is always running RefreshTable 5 times. Even if no filters where applied to any charts.

Make a new function that only resets filters from charts that have a filter.

function filterAll_performance(){
 var chartlist=[chart_year, chart_genre, chart_runtime, chart_globalscore]
 count=chartlist.length;
 for (var i=count; i--;) {
 if(chartlist[i].filters()!=0) {
 chartlist[i].filterAll();
 }
 }
}

and replace

dc.filterAll();

with

filterAll_performance();

This will still refresh the datatable more than once sometimes but it's still better.

• janos: Congratulations, a very rare piece of well-written selfie answer :-)