javascript - d3js - force: nodes and links from json file not loaded in my svg during redrawing -

i'm still trying load nodes , links extern json file. works when outside redraw() function. goal load them , add additional nodes , link svg. thats why created redraw() function make great part of job. inspired force example , other example. nothing appears (i have no error). have ?

my code :

var width = 960,     height = 500;  var selected_node = null,     selected_link = null;  var svg = d3.select("body")     .append("svg")     .attr("width", width)     .attr("height", height)     .attr("pointer-events", "all");  var visual = svg    .append('svg:g')    .append('svg:g')       .on("mousemove", mousemove)       .on("click", click);  visual.append('svg:rect')     .attr('width', width)     .attr('height', height)     .attr('fill', 'white');  var force = d3.layout.force()     .size([width, height])     .charge(-400)     .on("tick", tick);  // future link var drag_line = visual.append("line")     .attr("class", "drag_line")     .attr("x1", 0)     .attr("y1", 0)     .attr("x2", 0)     .attr("y2", 0);  var nodes = force.nodes(),     links = force.links(); var node = visual.selectall(".node"),     link = visual.selectall(".link");  // allows drag actions  var drag = force.drag()   .on("dragstart", dragstart);  d3.json("graph.json", function(error, graph) {     if (error) console.log("error: " + error);         nodes = graph.nodes;     links = graph.links; });   // add properties links , nodes function tick() {     link.attr("x1", function (d) {         return d.source.x;     })         .attr("y1", function (d) {         return d.source.y;     })         .attr("x2", function (d) {         return d.target.x;     })         .attr("y2", function (d) {         return d.target.y;     });      node.attr("cx", function (d) {         return d.x;     })         .attr("cy", function (d) {         return d.y;     }); }  function dragstart(d) {   d3.select(this).classed("selected", "selected"); }   function redraw() {   console.log("redraw start");    force       .nodes(nodes)       .links(links)    link = link.data(links);    link.enter().append("line")     .attr("class", "link");    link.exit().remove();    node = node.data(nodes);    node.enter().append("circle")     .attr("class", "node")     .attr("r", 6)     .attr("fixed", true)     .call(drag);    node.exit().transition()       .attr("r", 0)       .remove();    force.start(); }  redraw(); 

as user3714582 proposed, solution call redraw() (the second function call) @ end of first function. if has add, he/she's welcome.