Chart.js - Writing Labels Inside of Horizontal Bar

问题:

In Chart.js, is there any way to write the labels inside of the horizontal bars in a "horizontalBar" chart? As in something like:

Is anything similar to this possible in Chart.js?

Thanks!

回答1:

There is now on option "mirror" to make the label appear inside the bar.

Example of "options" config for a horizontalBar chart :

options: {
    scales: {
        yAxes: [{ticks: {mirror: true}}]
    }
}

Doc : http://www.chartjs.org/docs/latest/axes/cartesian/#common-configuration

回答2:

With reference to the original solution to displaying data value by using HTML5 Canvas fillText() method in the animation's onComplete, the code below will get you what you need:

The key to custom-displaying any chart related data is inspecting the chart's dataset as in this.data.datasets below. I did this by inspecting where the different values are in this dataset, as well as the position to place them for the fillText method.

Inspecting the chart's dataset: Image

Script (Chart.js 2.0 & up):

var barOptions = {
      events: false,
        showTooltips: false,
      legend: {
        display: false
      },
      scales:{
        yAxes: [{
          display: false
        }]
      },
        animation: {
        onComplete: function () {
          var ctx = this.chart.ctx;
          ctx.font = Chart.helpers.fontString(Chart.defaults.global.defaultFontFamily, 'normal', Chart.defaults.global.defaultFontFamily);
          ctx.textAlign = 'left';
          ctx.textBaseline = 'bottom';

          this.data.datasets.forEach(function (dataset) {
            for (var i = 0; i < dataset.data.length; i++) {
              var model = dataset._meta[Object.keys(dataset._meta)[0]].data[i]._model,
                  left = dataset._meta[Object.keys(dataset._meta)[0]].data[i]._xScale.left;
              ctx.fillStyle = '#444'; // label color
              var label = model.label;
              ctx.fillText(label, left + 15, model.y + 8);
            }
          });               
        }
        }
    };

jsFiddle: http://jsfiddle.net/jfvy12h9/

回答3:

You can achieve this effect in chartjs 2.0 + by rotating the labels 90 degrees and applying negative padding, so that the label moves up inside the 'bar'. Something like this:

new Chart(document.getElementById(id), {
  type: 'bar',
  data: data,
  options: {
    scales: {
      xAxes: [
        {
          ticks: {
            autoSkip: false,
            maxRotation: 90,
            minRotation: 90,
            padding: -110
          }
        }
      ]
    }
  }
});

See the tick configuration documentation for more information.

回答4:

It seems like there is no direct option for this right now. A possible implementation is iterating over bars/columns by using onAnimationComplete hook. You can view this question for detailed explanations how to display data values on Chart.js

I would like you remind that this has a drawback. Since it uses onAnimationComplete, whenever an animation happens on chart, values will be disappear for a second and appear again.