角+ d3.js：数据与SVG的文本ATTR约束力？ [英] Angular + d3.js: Data binding with SVG text attr?

问题描述

我的工作，涉及更新的一个圆圈内出现一个文本元素的可视化。是这样的：

I'm working on a visualization that involves updating a text element that appear inside of a circle. Something like:

<g>
    <circle></circle>
    <text>My text that needs updating</text>
</g>

随着这个小小的视觉上被用作滑块D3刷。在刷/ brushend，我需要＆LT;文本＆gt;此处更新＆lt文本; /文本方式＆gt; 的基础上，用时间尺度沿着滑块的X轴相关的数据

Along with this small visual is a d3 brush being used as a slider. On brush/brushend, I need to <text>Update the text here</text>, based on data associated with a time scale along the slider's x-axis.

我有两个角指令。一个包含圆，另一个是滑块。在我的滑块指示我打电话：

I have two Angular directives. One that contains the circle, the other that is the slider. In my slider directive I'm calling:

$ rootScope $放出（'刷牙'）; 并设置根据我的数据rootScope变量， $ rootScope.myNewValue =为newValue; 如发生滑动

$rootScope.$emit('brushing'); and setting a rootScope variable according to my data, $rootScope.myNewValue = newValue; as sliding occurs

然后我在我的其他指令侦听此，和更新text.attr是rootScope VAR：

Then I'm listening for this in my other directive, and updating the text.attr to be the rootScope var:

$ rootScope。在（'刷牙'$，函数（）{
    myText.text（$ rootScope.myNewValue）;
}）;

其中：

var myText = svg.append('text')
    .text('I'm trying to update this text..');

...在code的D3部分

... in the d3 portion of the code

做事这种方式似乎工作，但我不知道是否有将数据直接绑定的方式会将myText初始化时：

Doing things this way seems to work, but I'm wondering if there is a way to bind the data directly when initializing myText:

var myText = svg.append('text)
    .text($rootScope.myNewValue);

这样的价值直接更新，而无需发出$和收听。我试过范围。$适用中的指令，但似乎没有任何效果。

So that the value updates directly without having to $emit and listen. I've tried scope.$apply in the directive but that seems to have no effect.

有没有人遇到过类似的情况？

Has anyone encountered a similar scenario when using d3 with Angular?

推荐答案

您可以包裹在一个指令中D3JS code，则使用在传递一个属性，看着它，看它是否改变了更新D3JS code相应（您保存到文本SVG的引用可能仍然是最好的选择）。举一个例子见下面，我用VAL更新条形图显示使用的数据我的指令（注意我没有过渡处理现在还没有到，而codeS有点乱，但是希望你看到一般点）

You can wrap up the D3JS code in a directive then use a property that is passed in and watch it to see if it changes to update the D3JS code accordingly (your saving a reference to the svg text is still probably the best bet). For an example see my directive below where I use val to update the data used in a bar chart display (note I didn't deal with transitions here yet, and the codes a bit of a mess but hopefully you see the general point)

directive('barChart', function ( /* dependencies */ ) {
  // define constants and helpers used for the directive

  var width = 600,
    height = 80;

  return {
    restrict: 'E', // the directive can be invoked only by using <bar-chart></bar-chart> tag in the template
    scope: { // attributes bound to the scope of the directive
      val: '='
    },
    link: function (scope, element, attrs) {
      // initialization, done once per my-directive tag in template. If my-directive is within an
      // ng-repeat-ed template then it will be called every time ngRepeat creates a new copy of the template.

      // set up initial svg object
      var vis = d3.select(element[0])
        .append("svg")
          .attr("class", "chart")
          .attr("width", width)
          .attr("height", height);


      // whenever the bound 'exp' expression changes, execute this 
      scope.$watch('val', function (newVal, oldVal) {

        // clear the elements inside of the directive
        vis.selectAll('*').remove();
        vis.attr("height", newVal.length*22);

        // if 'val' is undefined, exit
        if (!newVal) {
          return;
        }
        var totalDataSetSize = 0;

        for (var i = 0; i < newVal.length; i++) {
          totalDataSetSize += newVal[i].data.length
        };

        function calcBarWidth(d) {
          return (totalDataSetSize==0)?0:d.data.length/totalDataSetSize*420;
        }

        vis.selectAll("rect")
            .data(newVal)
          .enter().append("rect")
            .attr("y", function(d, i) { return i*20; })
            .attr("width", calcBarWidth)
            .attr("height", function(d) {return 20});

        vis.selectAll("text")
            .data(newVal)
          .enter().append("text")
            .attr("x", function(d) { return calcBarWidth(d)+10})
            .attr("y", function(d, i) { return (i+1)*20; })
            .attr("dy", "-.3em") // vertical-align: middle
            .style("font-size", ".7em")
            .attr("fill", "black")
            .attr("text-anchor", "beginning") // text-align: right
            .text(function(d,i){ return d.data.length.toString() + "  " + d.label})

      },true);
    }
  };
})

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