[Solved]-Is there a way to zoom into a D3 force layout graph?-d3.js

I got a solution for D3 force directed graph with zooming option.

    var m = [40, 240, 40, 240],
    width = 960,
    height = 700,
    root;
var svg = d3.select("body").append("svg")
    .attr("class", "svg_container")
    .attr("width", width)
    .attr("height", height)
    .style("overflow", "scroll")
    .style("background-color", "#EEEEEE")
    .append("svg:g")
    .attr("class", "drawarea")
    .append("svg:g")
    .attr("transform", "translate(" + m[3] + "," + m[0] + ")");

//applying zoom in&out for svg
d3.select("svg") 
.call(d3.behavior.zoom()
    .scaleExtent([0.5, 5])
    .on("zoom", zoom));

//zooming 
function zoom() { //zoom in&out function 
    var scale = d3.event.scale,
        translation = d3.event.translate,
        tbound = -height * scale,
        bbound = height * scale,
        lbound = (-width + m[1]) * scale,
        rbound = (width - m[3]) * scale;
    // limit translation to thresholds
    translation = [
        Math.max(Math.min(translation[0], rbound), lbound),
        Math.max(Math.min(translation[1], bbound), tbound)
    ];
    d3.select(".drawarea")
        .attr("transform", "translate(" + translation + ")" +
            " scale(" + scale + ")");
}

If you want to zoom and pan force layout without changing node-size, try below. You can also drag nodes without trembling. This code is based on original force layout example. As for nodes and links data, please refer to original sample data. http://bl.ocks.org/mbostock/4062045

Plz note the variables xScale and yScale, the functions dragstarted(), dragged(), and dragended(). Function tick() was changed as well.

You can see the result at http://steelblue.tistory.com/9 The language on the site is Korean. However you can easily find the result at the third example on the page.

var graph = {
    "nodes": [
      { "name": "Myriel", "group": 1 },
      { "name": "Napoleon", "group": 1 },
      // ......
      { "name": "Mme.Hucheloup", "group": 8 }
    ],
    "links": [
      { "source": 1, "target": 0, "value": 1 },
      { "source": 2, "target": 0, "value": 8 },
    // .......
      { "source": 76, "target": 58, "value": 1 }
    ]
};
var width = 640,
    height = 400;
 var color = d3.scale.category20();



var xScale = d3.scale.linear()
        .domain([0, width])
         .range([0, width]);

var yScale = d3.scale.linear()
    .domain([0, height])
   .range([0, height]);
var zoomer = d3.behavior.zoom().x(xScale).y(yScale).scaleExtent([0.1, 8]).on("zoom", zoom);
function zoom() {

    tick(); 
};

var drag = d3.behavior.drag()
        .origin(function (d) { return d; })
         .on("dragstart", dragstarted)
        .on("drag", dragged)
        .on("dragend", dragended);

function dragstarted(d) {
    d3.event.sourceEvent.stopPropagation();

    d.fixed |= 2;         
}
function dragged(d) {

    var mouse = d3.mouse(svg.node());
    d.x = xScale.invert(mouse[0]);
    d.y = yScale.invert(mouse[1]);
    d.px = d.x;         
    d.py = d.y;
    force.resume();
}

function dragended(d) {

    d.fixed &= ~6;           }

var force = d3.layout.force()
    .charge(-120)
    .linkDistance(30)
    .size([width, height]);

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);

svg.call(zoomer);

    force
        .nodes(graph.nodes)
        .links(graph.links)
        .start();

    var link = svg.selectAll(".link")
        .data(graph.links)
      .enter().append("line")
        .attr("class", "link")
        .style("stroke-width", function (d) { return Math.sqrt(d.value); });

    var node = svg.selectAll(".node")
        .data(graph.nodes)
      .enter().append("circle")
        .attr("class", "node")
        .attr("r", 5)
        .style("fill", function (d) { return color(d.group); })
        .call(drag);

    node.append("title")
        .text(function (d) { return d.name; });

    force.on("tick",tick);

function tick(){            
        link.attr("x1", function (d) { return  xScale(d.source.x); })
            .attr("y1", function (d) { return yScale(d.source.y);  })
            .attr("x2", function (d) { return xScale(d.target.x); })
            .attr("y2", function (d) { return yScale(d.target.y); });

        node.attr("transform", function (d) {
            return "translate(" + xScale(d.x) + "," + yScale(d.y) + ")";
        });


    };

I got my graph to work without the second "svg:g" append.

[...].attr("pointer-events", "all")
     .attr("width", width2)
     .attr("height", height2)
     .append('svg:g')
     .call(d3.behavior.zoom().on("zoom", redraw));

The rest is the same.

The provided answers work in D3 v2 but not in v3. I've synthesized the responses into a clean solution and resolved the v3 issue using the answer provided here: Why does d3.js v3 break my force graph when implementing zooming when v2 doesn't?

First the main code. This is a cleaned up version of @ahaarnos' answer:

    var svg = d3.select("body")
        .append("svg")
        .attr("width", width)
        .attr("height", height)
            .call(d3.behavior.zoom().on("zoom", redraw))
        .append('g');

    function redraw() {
      svg.attr("transform",
          "translate(" + d3.event.translate + ")"
          + " scale(" + d3.event.scale + ")");
    }   

Now you have pan and zoom, but you won't be able to drag nodes because the pan functionality will override the drag functionality. So we need to do this:

var drag = force.stop().drag()
.on("dragstart", function(d) {
    d3.event.sourceEvent.stopPropagation(); // to prevent pan functionality from 
                                            //overriding node drag functionality.
    // put any other 'dragstart' actions here
});

Here's @nrabinowitz' fiddle modified to use this cleaner zoom implementation, but illustrating how D3v3 breaks node drag: http://jsfiddle.net/QMKm3/718/

And here's the same fiddle modified to work with D3v3: http://jsfiddle.net/QMKm3/719/

Why the nested <g>'s?

This code below worked well for me (only one <g>, with no random large white <rect>:

var svg = d3.select("body")
    .append("svg")
      .attr({
        "width": "100%",
        "height": "100%"
      })
      .attr("viewBox", "0 0 " + width + " " + height )
      .attr("preserveAspectRatio", "xMidYMid meet")
      .attr("pointer-events", "all")
    .call(d3.behavior.zoom().on("zoom", redraw));

var vis = svg
    .append('svg:g');

function redraw() {
  vis.attr("transform",
      "translate(" + d3.event.translate + ")"
      + " scale(" + d3.event.scale + ")");
}

Where all the elements in your svg are then appended to the vis element.