colorLegend.js
export const colorLegend = (selection, props) => {
const {
colorScale,
circleRadius,
spacing,
textOffset
} = props;
const groups = selection.selectAll('g')
.data(colorScale.domain());
const groupsEnter = groups
.enter().append('g')
.attr('class', 'tick');
groupsEnter
.merge(groups)
.attr('transform', (d, i) =>
`translate(0, ${i * spacing})`
);
groups.exit().remove();
groupsEnter.append('circle')
.merge(groups.select('circle'))
.attr('r', circleRadius)
.attr('fill', colorScale);
groupsEnter.append('text')
.merge(groups.select('text'))
.text(d => d)
.attr('dy', '0.32em')
.attr('x', textOffset);
}
