How to draw grid lines only inside area - d3.js

Question

I need to draw axis grid lines only inside areas in Area Chart, written in D3 (version 4) .
Have any solutionss of this issue?

Answer 1

Use negative width and height for the axis tick length
And then use a CSS style to stroke the grid.
g.append("g")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(x));
g.append("g")
.call(d3.axisLeft(y));
g.append("g")
.attr("class", "grid")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(x)
.tickSize(-height)
.tickFormat("")
);
g.append("g")
.attr("class", "grid")
.call(d3.axisLeft(y)
.tickSize(-width)
.tickFormat("")
);
Edit
If it is inside the Area define a clipping path that equals the area and group the grid lines to this clipping path.
Using the example from https://www.mattlayman.com/blog/2015/d3js-area-chart/
var data = [
{ x: 0, y: 10, },
{ x: 1, y: 15, },
{ x: 2, y: 35, },
{ x: 3, y: 20, },
];
var margin = {top: 20, right: 20, bottom: 30, left: 50},
width = 575 - margin.left - margin.right,
height = 350 - margin.top - margin.bottom;
var x = d3.scaleLinear()
.domain([0, d3.max(data, function(d) { return d.x; })])
.range([0, width]);
var y = d3.scaleLinear()
.domain([0, d3.max(data, function(d) { return d.y; })])
.range([height, 0]);
var xAxis = d3.axisBottom()
.scale(x);
var yAxis = d3.axisLeft()
.scale(y);
var area = d3.area()
.x(function(d) { return x(d.x); })
.y0(height)
.y1(function(d) { return y(d.y); });
var svg = d3.select("svg#area")
.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("path")
.datum(data)
.attr("class", "area")
.attr("d", area);
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
svg.append("g")
.attr("class", "y axis")
.call(yAxis);
svg.append("clipPath")
.attr("id", "area-clip")
.append("path")
.attr("d", area(data));
var grid = svg.append("g")
.attr("clip-path","url(#area-clip)");
grid.append("g")
.attr("class", "grid")
.attr("transform", "translate(0," + height + ")")
.call(xAxis.tickSize(-height).tickFormat(""));
grid.append("g")
.attr("class", "grid")
.call(yAxis.tickSize(-width).tickFormat(""));
.area {fill:steelblue;}
.grid line {fill:none; stroke:red; stroke-width:1;}
<script src="https://d3js.org/d3.v5.min.js"></script>
<svg id="area"></svg>