update_svg_enter_append = {
var rectWidth = 10;
var height = 100;
var data = [10, 50, 10, 70, 100, 100, 50, 10, 70, 100];
var svg = d3.select('#svg_enter_append');
var enter = svg.selectAll('rect')
.data(data)
.enter()
.append('rect')
.attr('x', (d,i) => i * rectWidth)
.attr('y', d => height - d)
.attr('width', rectWidth)
.attr('height', d => d)
.attr('fill', d => {
if (d>50) return 'green'
return 'blue'
})
.attr('stroke', '#fff')
return md`d3 code to enter then append new rectangles`
}