Question

我的json文件是这样的。

[
  {
    "ArtistID": 1,
    "FollowerID": 1,
    "Name": "JAYAH-Paradiso",
    "Location": "UK",
    "Latitude": "51.5",
    "Longitude": "0.1167",
    "Date": "22/03/2014"
  },
  {
    "ArtistID": 1,
    "FollowerID": 2,
    "Name": "Yasmin Dan",
    "Location": "London",
    "Latitude": "51.5072",
    "Longitude": "0.1275",
    "Date": "22/03/2014"
  },
  {
    "ArtistID": 2,
    "FollowerID": 1,
    "Name": "Daniel Sutka",
    "Location": "London",
    "Latitude": "51.5072",
    "Longitude": "0.1275",
    "Date": "22/03/2014"
  },
  {
    "ArtistID": 2,
    "FollowerID": 2,
    "Name": "Colton Brown",
    "Location": "Moore Haven, Florida",
    "Latitude": "26.8333",
    "Longitude": "81.1",
    "Date": "22/03/2014"
  }
]

我想在地图中显示艺术家1和艺术家2的追随者。我想分别显示这些数据，如红圈中艺术家1的追随者位置和蓝圈中艺术家2的追随者位置。

艺术家1和艺术家2有2个按钮。当我点击艺术家1按钮时，它应该只显示红色圆圈。

有人可以告诉我一种使用ArtistID对这些数据进行分组的方法，以便我可以在那些按钮点击中使用它吗？

或

我在地图上有这些圆圈，如10个红色圆圈（Artist1），10个蓝色圆圈（Artist2），10个绿色圆圈（Artist3）。如何使用d3 selectAll仅选择红色圆圈或选择？

或者还有其他方法吗？

这样的颜色（作为＆＃34的值;填充＆＃34;＆＃34;样式＆＃34;属性，

feature = g.selectAll("circle")
                    .data(data)
                    .enter().append("circle")
                    .attr("id", function (d) { return d.ArtistID + d.FollowerID; })
                    .style("stroke", "black")
                    .style("opacity", .6)
                    .style("fill", function (d) {
                        if (d.ArtistID == 1) { return "red" }
                        else if (d.ArtistID == 2) { return "blue" }
                        else { return "green" }
                        ;
                    })
                    .attr("r", 10);

所以，圆圈会像这样绘制，

<circle id="10" r="10" transform="translate(695,236)" style="stroke: rgb(0, 0, 0); opacity: 0.6; fill: rgb(255, 255, 0);"></circle>

我想选择红色圆圈。

过滤json文件的数据，或只选择一种颜色的圆圈会有所帮助。

先谢谢。

Answer 1

您可以使用以下代码过滤数据并获取Artist 2的关注者数组：

<html>
 <head>     
 <script src="http://code.jquery.com/jquery-1.11.1.js"></script>
 <script>
$(function() {
        var json =  '[{"ArtistID":1,"FollowerID":1,"Name":"JAYAH-Paradiso","Location":"UK","Latitude":"51.5","Longitude":"0.1167","Date":"22/03/2014"},{"ArtistID":1,"FollowerID":2,"Name":"Yasmin Dan","Location":"London","Latitude":"51.5072","Longitude":"0.1275","Date":"22/03/2014"},{"ArtistID":1,"FollowerID":3,"Name":"Aaron Senior","Location":"London,UK","Latitude":"51.5072","Longitude":"0.1275","Date":"22/03/2014"},{"ArtistID":2,"FollowerID":1,"Name":"Daniel Sutka","Location":"London","Latitude":"51.5072","Longitude":"0.1275","Date":"22/03/2014"},{"ArtistID":2,"FollowerID":2,"Name":"Colton Brown","Location":"Moore Haven, Florida","Latitude":"26.8333","Longitude":"81.1","Date":"22/03/2014"},{"ArtistID":2,"FollowerID":3,"Name":"Thia Kirby","Location":"England","Latitude":"51.5","Longitude":"0.1167","Date":"22/03/2014"}]';

        var obj = jQuery.parseJSON(json);

        console.log(obj);

        var newArray = obj.filter( function (el) { return el.ArtistID == 2 } );

        console.log(newArray);
});
 </script>
 </head>
 <body>

 </body>
</html>

Answer 2

尝试使用以下方法获取必填字段：

<script>
var json = [
 {
   "ArtistID": 1,
   "FollowerID": 1,
   "Name": "JAYAH-Paradiso",
   "Location": "UK",
   "Latitude": "51.5",
   "Longitude": "0.1167",
   "Date": "22/03/2014"
 },
 {
   "ArtistID": 1,
   "FollowerID": 2,
   "Name": "Yasmin Dan",
   "Location": "London",
   "Latitude": "51.5072",
   "Longitude": "0.1275",
   "Date": "22/03/2014"
 },
 {
   "ArtistID": 2,
   "FollowerID": 1,
   "Name": "Daniel Sutka",
   "Location": "London",
   "Latitude": "51.5072",
   "Longitude": "0.1275",
   "Date": "22/03/2014"
 },
 {
   "ArtistID": 2,
   "FollowerID": 2,
   "Name": "Colton Brown",
   "Location": "Moore Haven, Florida",
   "Latitude": "26.8333",
   "Longitude": "81.1",
   "Date": "22/03/2014"
 }
];
var data = eval(json);
for(x in data){
    alert(data[x].ArtistID);
if(){//check condition on ArtistID and use the data
}
}
</script>

Answer 3

您可能需要考虑使用下划线。（特别是如果你正在做更多这样的操作。）where函数描述了你要找的东西。

_.where(array, {ArtistID: X});

http://underscorejs.org

编辑：在这种情况下，groupBy方法也可能对您有用。

根据一个属性过滤JavaScript对象

3 个答案: