d3js v4 can't remove old data chart after update - d3.js

Question

I've modified nice AlainRo’s Block for my needs (unfortunately can't link to it, because have not enough reputation), and I can't remove old data chart after entering new data. There is my codepen. In another example I've added merge(), and the chart is well aligned but the old one is still visible and text values are missed.
I spent a lot of time on it, and I run out of ideas.
There's code
barData = [
{ index: _.uniqueId(), value: _.random(1, 20) },
{ index: _.uniqueId(), value: _.random(1, 20) },
{ index: _.uniqueId(), value: _.random(1, 20) }
];
var margin = {top: 20, right: 20, bottom: 50, left: 70},
width = 400 - margin.left - margin.right,
height = 400 - margin.top - margin.bottom,
delim = 4;
var scale = d3.scaleLinear()
.domain([0, 21])
.rangeRound([height, 0]);
var x = d3.scaleLinear()
.domain([0, barData.length])
.rangeRound([0, width]);
var y = d3.scaleLinear()
.domain([0, 21])
.rangeRound([height, 0]);
var svg = d3.select('#chart')
.append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append('g')
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
svg.append("g")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(x));
svg.append("g")
.call(d3.axisLeft(y));
function draw() {
x.domain([0, barData.length]);
var brush = d3.brushY()
.extent(function (d, i) {
return [[x(i)+ delim/2, 0],
[x(i) + x(1) - delim/2, height]];})
.on("brush", brushmove);
var svgbrush = svg.selectAll('.brush')
.data(barData)
.enter()
.append('g')
.attr('class', 'brush')
.append('g')
.call(brush)
.call(brush.move, function (d){return [d.value, 0].map(scale);});
svgbrush
.append('text')
.attr('y', function (d){return scale(d.value) + 25;})
.attr('x', function (d, i){return x(i) + x(0.5);})
.attr('dx', '-.60em')
.attr('dy', -5)
.style('fill', 'white')
.text(function (d) {return d3.format('.2')(d.value);});
svgbrush
.exit()
.append('g')
.attr('class', 'brush')
.remove();
function brushmove() {
if (!d3.event.sourceEvent) return; // Only transition after input.
if (!d3.event.selection) return; // Ignore empty selections.
if (d3.event.sourceEvent.type === "brush") return;
var d0 = d3.event.selection.map(scale.invert);
var d = d3.select(this).select('.selection');;
var d1 =[d0[0], 0];
d.datum().value = d0[0]; // Change the value of the original data
d3.select(this).call(d3.event.target.move, d1.map(scale));
svgbrush
.selectAll('text')
.attr('y', function (d){return scale(d.value) + 25;})
.text(function (d) {return d3.format('.2')(d.value);});
}
}
draw();
function upadateChartData() {
var newBarsToAdd = document.getElementById('charBarsCount').value;
var newBarData = function() {
return { index: _.uniqueId(), value: _.random(1, 20) }
};
newBarData = _.times(newBarsToAdd, newBarData);
barData = _.concat(barData, newBarData)
draw();
};
Is it also possible to remove cross pointer and leave only resize, when I'm dragging top bar border?

Answer 1

You're appending g elements twice. This:
svgbrush.enter()
.append('g')
.attr('class', 'brush')
.merge(svgbrush)
.append('g')
.call(brush)
.call(brush.move, function (d){return [d.value, 0].map(scale);});
Should be:
svgbrush.enter()
.append('g')
.attr('class', 'brush')
.merge(svgbrush)
.call(brush)
.call(brush.move, function (d){return [d.value, 0].map(scale);});
Here is your updated Pen: http://codepen.io/anon/pen/VmavyX
PS: I also made other changes, declaring some new variables, just to organize your enter and update selections and solving the texts problem.