使用Angular 2拖动和缩放D3 V4图表

Question

I am working with d3 4.2.2 to create charts with Angular2. I created a multi series line chart and now I am trying to add more features. My data source has data for 90 days and the chart displays all the data but it doesn't looks good. So I trued to add zoom and pan features to the chart. But outcome is not what I really expected. X-axis label are overlapping. Axis names are displaying half. Here is what I tried.

Data Source

 var data = [{
  "date": "2016-10-01",
  "sales": 110,
  "searches": 67
}, 
....
{
  "date": "2016-12-31",
  "sales": 110,
  "searches": 45
}];

To add zoom & pan

var svg = d3.select(this.htmlElement).append("svg")
  .attr("class", "bar-graph")
  .attr("width", width + margin.left + margin.right)
  .attr("height", height + margin.top + margin.bottom)
  .call(d3.zoom().scaleExtent([1, 10]).on("zoom", function () {
        svg.attr("transform", d3.event.transform)
    }))
  .append("g")
  .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

Adding ticks

// Add the X Axis
svg.append("g")
  .style("font", "14px open-sans")
  .attr("transform", "translate(0," + height + ")")
  .call(d3.axisBottom(x).ticks(d3.timeDay.every(1)).tickFormat(d3.timeFormat("%d/%m")));


// Add the Y Axis
svg.append("g")
  .style("font", "14px open-sans")
  //.tickSize(-height)
  .call(d3.axisLeft(y).ticks(5));

At the end My chart looks like below.

Now the chart is able to zoom & drag as the whole chart. Is there a way to limit number of ticks of x-axis to display then user will be able to drag and see the rest of the chart?

I would be much obliged if anyone could be so kind enough to help me to make my chart good looking

Thank you

Answer 1

You need to recalculate the x and y axis with the zoom transform on zoom callback function.

function zoomed() {
    var t = d3.event.transform,
        xt = t.rescaleX(x);
        yt = t.rescaleY(y);
    svg.attr("transform", t)
    var line = d3.line()
        .x(function(d) {
            return xt(d.date);
        })
        .y(function(d) {
            return yt(d.scales);
        });
    g.select("path").attr("d", line);
    svg.select(".axis--x").call(xAxis.scale(xt));
}