Create IF to change chart.js bar color

Question

I'm new to JavaScript and i'm using chart.js to create some data visualizations, and i need to change the color of the entire bar for different values, the code i have so far is what follows, but i can't make it work, this isn't giving me any errors, so i don't know were to go.

var dData1 = 90; ///////CARREGAR DADOS  DE FACTURAÇÃO (for developer)
var dData2 = 70; ///////CARREGAR DADOS  DE FACTURAÇÃO (for developer)

    var barChartData = {
            labels: ["MÊS", "ANO"],
            datasets: [{
                fillColor: "#f37c8a",
                strokeColor: "none",
                data: [dData1, dData2]
                }]
        }

    if (dData1 < 75)
        {
            barChartData.datasets[0].fillColor = "#f37c8a";
        }
         else if (dData1 > 76 && dData1 < 85) 
        {
            barChartData.datasets[0].fillColor = "#f3e97c";
        } 
        else if (dData1 > 86)
        {
            barChartData.datasets[0].fillColor = "#9ae27d";
        } else 
        {
            barChartData.datasets[0].fillColor = "#fff";
        };  

    if (dData2 < 75)
        {
            barChartData.datasets[0].fillColor = "#f37c8a";
        }
         else if (dData2 > 76 && dData1 < 85) 
        {
            barChartData.datasets[0].fillColor = "#f3e97c";
        } 
        else if (dData2 > 86)
        {
            barChartData.datasets[0].fillColor = "#9ae27d";
        } else 
        {
            barChartData.datasets[0].fillColor = "#fff";
        };

Answer 1

You need to set the colors for the bars after generating the chart. You'll need to set the fillColor, the highlightFill and _saved.fillColor (which Chart.js uses to restore the bar color after a tooltip hover)

So you need something like

if (dData1 < 75)
{
    barChart.datasets[0].bars[0].fillColor = barChart.datasets[0].bars[0].highlightFill = barChart.datasets[0].bars[0]._saved.fillColor = "#f37c8a";
}
else if (dData1 > 76 && dData1 < 85) 
{
    barChart.datasets[0].bars[0].fillColor = barChart.datasets[0].bars[0].highlightFill = barChart.datasets[0].bars[0]._saved.fillColor = "#f3e97c";
} 
else if (dData1 > 86)
{
    barChart.datasets[0].bars[0].fillColor = barChart.datasets[0].bars[0].highlightFill = barChart.datasets[0].bars[0]._saved.fillColor = "#9ae27d";
} else 
{
    barChart.datasets[0].bars[0].fillColor = barChart.datasets[0].bars[0].highlightFill = barChart.datasets[0].bars[0]._saved.fillColor = "#fff";
};  

for the 1st block, where barChart is your chart object. Note that the above code assumes a single series of 2 elements.

---

Fiddle - https://jsfiddle.net/2a86gqsa/

Note that you had dData1 < 85 in the second block - I changed it to dData2 < 85. Seeing that much of the code for the 2 blocks are common you might want to move it to a function.

Answer 2

Solved, i was calling the items inside the library wrong.

    var dData1 = 90; ///////CARREGAR DADOS  DE FACTURAÇÃO
    var dData2 = 70; ///////CARREGAR DADOS  DE FACTURAÇÃO

    var barChartData = {
            labels: ["MÊS", "ANO"],
            datasets: 

                 [{
                fillColor: "rgba(220,220,220,1)",
                strokeColor: "rgba(220,220,220,0.0)",
                highlightFill: "rgba(220,220,220,0.0)",
                highlightStroke: "rgba(220,220,220,0)",
                data: [dData1, dData2]
                }]
        }

    var ctx = document.getElementById("myChart").getContext("2d");
    var myChart = new Chart(ctx).Bar(barChartData, {
      responsive: true,
      barValueSpacing: 10
    });

    if (barChartData.datasets[0].data=[dData1] < 75)
        { 
            console.log("vermelho");
            myChart.datasets[0].bars[0].fillColor = "rgba(243,124,138,1.00)";
            myChart.update();
        }
         else if (dData1 > 76 && dData1 < 85) 
        {
            console.log("amarelo");
            myChart.datasets[0].bars[0].fillColor = "rgba(243,233,7,1.00)";
            myChart.update();
        } 
        else if (dData1 > 86)
        {
            console.log("verde");
            myChart.datasets[0].bars[0].fillColor = "rgba(154,226,125,1.00)";
            myChart.update();
        } else 
        {
            console.log("branco");
            myChart.datasets[0].bars[0].fillColor = "rgba(255,255,255,1)";
            myChart.update();
        };  



    if (barChartData.datasets[0].data=[dData2] < 75)
        { 
            console.log("vermelho2");
            myChart.datasets[0].bars[1].fillColor = "rgba(243,124,138,1.00)";
            myChart.update();
        }
         else if (dData2 > 76 && dData2 < 85) 
        {
            console.log("amarelo2");
            myChart.datasets[0].bars[1].fillColor = "rgba(243,233,7,1.00)";
            myChart.update();
        } 
        else if (dData2 > 86)
        {
            console.log("verde2");
            myChart.datasets[0].bars[1].fillColor = "rgba(154,226,125,1.00)";
            myChart.update();
        } else 
        {
            console.log("branco2");
            myChart.datasets[0].bars[1].fillColor = "rgba(255,255,255,1)";
            myChart.update();
        };