javascript - D3.js: "On the fly"添加到数组的元素不刷新 svg 图形

Question

我有一个气泡行，在任何给定时间我都有 6 个气泡。该数组有 6 个 json 对象。该代码仅显示加载时首次添加的圆圈。但是当我修改数组时，我想删除第一个气泡并在行的右端添加一个气泡。我正在使用 setInterval 将一个元素插入数组以对其进行测试。由于我正在记录数组的状态，因此数组正在正确更改，但 svg 图形未刷新。我只是不知道问题是否出在重新利用 createElementGroup() 或如何在这种情况下删除节点(我看到常见的情况是使用 exit() d3 方法，但我不确定在哪里实现它这个特殊情况)。

另外，当我删除和添加一个元素时，我应该把过渡放在哪里才能使其平滑？现场演示在这里:

http://codepen.io/juanf03/pen/BQyYBq (您可以单击气泡以查看它展开并显示数据，这样我会检查是否是正确的节点)

代码:

//listener that will be executed on setIntervalCheck to update the graphic   
setInterval(function(){
  moveForwardOnBubbleList();
  createElementGroup();
  }, 100000);



var profile_pic_url="https://scontent.fsst1-2.fna.fbcdn.net/v/t1.0-9/13680856_103268503450198_1479797031996897052_n.jpg?oh=f43bced91822fb210c8be8a410825da9&oe=58D46460";

var dataset = [{unique_followers: 5, profile_pic:profile_pic_url}, {unique_followers: 10, profile_pic:profile_pic_url},{ unique_followers: 15, profile_pic:profile_pic_url}, { unique_followers: 20, profile_pic:profile_pic_url}, { unique_followers: 25, profile_pic:profile_pic_url}, {unique_followers: 40, profile_pic:profile_pic_url} ];

var w=600,h=600;

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

//1st level:All circles group
var circlesGroup = svg.append("g").classed("general-group",true);
//2nd level: Group of circle and text
var elementGroup;

var circle;

var circleAttributes;
//create g's of existing data
createElementGroup();

elementGroup.on('click', function(d,i){
  var that=this;

  d3.selectAll('.element-group').each(function(d,i) {
    if(this.id!==that.id){
      d3.select(this).classed("selected",false);
    }
  });

  d3.select(this).classed("selected", !d3.select(this).classed("selected"));

  });

//adding circular background image to the circles
//var circlesSelection=svg.selectAll('circle');


function createElementGroup(){
  elementGroup = circlesGroup
  .selectAll('circle')
  .data(dataset)
  .enter()
  .append("g").classed("element-group",true);

  circle=elementGroup.append('circle');

  circleAttributes = circle
  .attr("r", 20)
  .attr("stroke","black")
  .attr("fill", "white")
  .classed("circle",true);

  //text to show
   elementGroup.append("text")
      .attr("text-anchor", "middle")
   .text(function(d) {
     return parseInt(d.unique_followers);
   })
     .style("pointer-events","none")
     .classed('tweet-number', true);

     //image to show as background

  //element group positioning for the text to be inside circle
  elementGroup.attr("transform", function(d,i){
    return "translate(" + (i*80+45) + "," + h/2 + ")"; 
});

  elementGroup.attr( "fill-opacity", 0 ).transition().duration(500).attr( "fill-opacity", 1 );
  elementGroup.attr("id", function(d, i) { return "c"+i; });


}

function addBubbleLast(){
    dataset.push({unique_followers: 40, profile_pic:profile_pic_url});
}

function removeFirstBubble(){
  dataset.shift();

}

function moveForwardOnBubbleList(){
  addBubbleLast();
  removeFirstBubble();
}



/*CSS*/
 body
        {
          /*padding-top: 50px;*/
          padding-left: 100px;
        }

        .tweet-number{
         opacity:0.25;
        }

        .circle{

        }


        .selected *{
          transform: scale(2);
          transition: all 0.5s ease, opacity 0.5s ease;
          opacity:1.0;
    }

编辑:根据 Gerardo Furtado 的重要建议修复了代码。我发布它以防有人遇到类似问题:

//listener that will be executed on setIntervalCheck to update the graphic   
setInterval(function(){
  moveForwardOnBubbleList();
  createElementGroup();
  }, 6000);



var profile_pic_url="https://scontent.fsst1-2.fna.fbcdn.net/v/t1.0-9/13680856_103268503450198_1479797031996897052_n.jpg?oh=f43bced91822fb210c8be8a410825da9&oe=58D46460";

var dataset = [{unique_followers: 5, profile_pic:profile_pic_url}, {unique_followers: 10, profile_pic:profile_pic_url},{ unique_followers: 15, profile_pic:profile_pic_url}, { unique_followers: 20, profile_pic:profile_pic_url}, { unique_followers: 25, profile_pic:profile_pic_url}, {unique_followers: 40, profile_pic:profile_pic_url} ];

var w=900,h=600;

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

//1st level:All circles group
var circlesGroup = svg.append("g").classed("general-group",true);
//2nd level: Group of circle and text
var elementGroup;

var circle;

var circleAttributes;
//create g's of existing data
createElementGroup();



//adding circular background image to the circles
//var circlesSelection=svg.selectAll('circle');


function createElementGroup(){
  elementGroup = circlesGroup
  .selectAll('.element-group')
  .data(dataset, function(d){ return d.unique_followers});
 //doesn't work the exit transition 
   var elementExit = elementGroup.exit().transition().duration(1000).style("opacity", 0).remove();

  var elementEnter = elementGroup.enter()
  .append("g").classed("element-group",true).style("opacity",0);

    elementEnter.merge(elementGroup).attr("transform", function(d,i){

   //option 1 generation by mod   
   if(i%2===0){   
    return "translate(" + (i*80+45) + "," + h/1.55 + ")"; 
   }else{
    return "translate(" + (i*80+45) + "," + h/1.45 + ")"; 

   }

  /*   
  //option 2 random
  var random= (Math.random() * (1.6 - 1.45) + 1.45).toFixed(4);

         return "translate(" + (i*80+45) + "," + h/random + ")";*/ 


}).transition().duration(2000).style("opacity", 1.0);

    circle=elementEnter.append('circle');



  circleAttributes = circle
  .attr("r", 20)
  .attr("stroke","black")
  .attr("fill", "white")
  .classed("circle",true);

  d3.selectAll('.element-group').on('click', function(d,i){
  var that=this;
  d3.selectAll('.element-group').each(function(d,i) {
    if(this.id!==that.id){
      d3.select(this).classed("selected",false);
    }
  });

  d3.select(this).classed("selected", !d3.select(this).classed("selected"));

  });

  //text to show
   var texts = elementEnter.append("text")
      .attr("text-anchor", "middle")
   .text(function(d) {
     return parseInt(d.unique_followers);
   })
     .style("pointer-events","none")
     .classed('tweet-number', true);

     //image to show as background

  //element group positioning for the text to be inside circle



}

function addBubbleLast(){

  var random=Math.floor(Math.random() * (40)) + 1;


    dataset.push({unique_followers: random, profile_pic:profile_pic_url});
}

function removeFirstBubble(){
  dataset.shift();

}

function moveForwardOnBubbleList(){
  addBubbleLast();
  removeFirstBubble();
}

//CSS

    body
    {
      /*padding-top: 50px;*/
      padding-left: 100px;
    }

    .tweet-number{
     opacity:0.25;
    }

    .circle{

    }

 .selected *{
      transform: scale(2);
      transition: all 0.5s ease;
      opacity:1.0;
}

.element-group *{
  transition: all 0.5s ease;
}

circle + text{
}

Answer 1

您需要“进入”、“退出”和“更新”选项。

首先，我们绑定(bind)数据(使用键函数):

elementGroup = circlesGroup
    .selectAll('.element-group')
    .data(dataset, function(d){ return d.unique_followers});

然后，我们设置输入选择:

var elementEnter = elementGroup.enter()
    .append("g").classed("element-group",true);

现在重要说明:由于这是 D3 v4.x，您需要 merge具有工作更新选择的选择:

elementEnter.merge(elementGroup).attr("transform", function(d,i){
    return "translate(" + (i*80+45) + "," + h/2 + ")"; 
});

最后是退出选择:

var elementExit = elementGroup.exit().remove();

这是您的 CodePen:http://codepen.io/anon/pen/Wobyem