Blazorise Chart Streaming

Chart plugin for live streaming data.

Live streaming is made possible with the help of chartjs-plugin-streaming.

Installation

NuGet

Install chart streaming extension from NuGet. 
Install-Package Blazorise.Charts.Streaming

Static Files

Include the necessary files into your index.html or _Layout.cshtml / _Host.cshtml file, depending if you’re using a Blazor WebAssembly or Blazor Server side project. 
<script src="https://cdn.jsdelivr.net/npm/luxon@1.28.1"></script>
<script src="https://cdn.jsdelivr.net/npm/chartjs-adapter-luxon@1.0.0"></script>
<script src="https://cdn.jsdelivr.net/npm/chartjs-plugin-streaming@2.0.0"></script>

Examples

Basic Example

<LineChart @ref="horizontalLineChart" TItem="LiveDataPoint" OptionsObject="@horizontalLineChartOptions">
    <ChartStreaming TItem="LiveDataPoint"
                    Options="new ChartStreamingOptions { Delay = 2000 }"
                    Refreshed="@OnHorizontalLineRefreshed" />
</LineChart>

@code{
    LineChart<LiveDataPoint> horizontalLineChart;
    Random random = new Random( DateTime.Now.Millisecond );

    string[] Labels = { "Red", "Blue", "Yellow", "Green", "Purple", "Orange" };
    List<string> backgroundColors = new List<string> { ChartColor.FromRgba( 255, 99, 132, 0.2f ), ChartColor.FromRgba( 54, 162, 235, 0.2f ), ChartColor.FromRgba( 255, 206, 86, 0.2f ), ChartColor.FromRgba( 75, 192, 192, 0.2f ), ChartColor.FromRgba( 153, 102, 255, 0.2f ), ChartColor.FromRgba( 255, 159, 64, 0.2f ) };
    List<string> borderColors = new List<string> { ChartColor.FromRgba( 255, 99, 132, 1f ), ChartColor.FromRgba( 54, 162, 235, 1f ), ChartColor.FromRgba( 255, 206, 86, 1f ), ChartColor.FromRgba( 75, 192, 192, 1f ), ChartColor.FromRgba( 153, 102, 255, 1f ), ChartColor.FromRgba( 255, 159, 64, 1f ) };

    public struct LiveDataPoint
    {
        public object X { get; set; }

        public object Y { get; set; }
    }

    object horizontalLineChartOptions = new
    {
        Scales = new
        {
            Y = new
            {
                Title = new
                {
                    Display = true,
                    Text = "Value"
                }
            }
        },
        Interaction = new
        {
            intersect = false
        }
    };

    protected override async Task OnAfterRenderAsync( bool firstRender )
    {
        if ( firstRender )
        {
            await Task.WhenAll(
                HandleRedraw( horizontalLineChart, GetLineChartDataset1 ) );
        }
    }

    async Task HandleRedraw<TDataSet, TItem, TOptions, TModel>( BaseChart<TDataSet, TItem, TOptions, TModel> chart, params Func<TDataSet>[] getDataSets )
        where TDataSet : ChartDataset<TItem>
        where TOptions : ChartOptions
        where TModel : ChartModel
    {
        await chart.Clear();

        await chart.AddLabelsDatasetsAndUpdate( Labels, getDataSets.Select( x => x.Invoke() ).ToArray() );
    }

    LineChartDataset<LiveDataPoint> GetLineChartDataset1()
    {
        return new LineChartDataset<LiveDataPoint>
        {
            Data = new List<LiveDataPoint>(),
            Label = "Dataset 1 (linear interpolation)",
            BackgroundColor = backgroundColors[0],
            BorderColor = borderColors[0],
            Fill = false,
            Tension = 0,
            BorderDash = new List<int> { 8, 4 },
        };
    }

    Task OnHorizontalLineRefreshed( ChartStreamingData<LiveDataPoint> data )
    {
        data.Value = new LiveDataPoint
        {
            X = DateTime.Now,
            Y = RandomScalingFactor(),
        };

        return Task.CompletedTask;
    }

    double RandomScalingFactor()
    {
        return ( random.NextDouble() > 0.5 ? 1.0 : -1.0 ) * Math.Round( random.NextDouble() * 100 );
    }
}

Pause/Play

Making the stream pause and play is very simple. You only need to add a @ref to the ChartStreaming and the call .Pause() or .Play() methods. 
<LineChart @ref="@horizontalLineChart" TItem="LiveDataPoint" OptionsObject="@horizontalLineChartOptions">
    <ChartStreaming @ref="@chartStreaming"
                    TItem="LiveDataPoint"
                    Options="new ChartStreamingOptions { Delay = 2000 }"
                    Refreshed="@OnHorizontalLineRefreshed" />
</LineChart>

<Row>
    <Column>
        <Button Color="Color.Primary" Clicked="@(()=>chartStreaming.Pause())">Pause</Button>
        <Button Color="Color.Primary" Clicked="@(()=>chartStreaming.Play())">Play</Button>
    </Column>
</Row>

@code{
    LineChart<LiveDataPoint> horizontalLineChart;
    ChartStreaming<LiveDataPoint>  chartStreaming;
    Random random = new Random( DateTime.Now.Millisecond );

    string[] Labels = { "Red", "Blue", "Yellow", "Green", "Purple", "Orange" };
    List<string> backgroundColors = new List<string> { ChartColor.FromRgba( 255, 99, 132, 0.2f ), ChartColor.FromRgba( 54, 162, 235, 0.2f ), ChartColor.FromRgba( 255, 206, 86, 0.2f ), ChartColor.FromRgba( 75, 192, 192, 0.2f ), ChartColor.FromRgba( 153, 102, 255, 0.2f ), ChartColor.FromRgba( 255, 159, 64, 0.2f ) };
    List<string> borderColors = new List<string> { ChartColor.FromRgba( 255, 99, 132, 1f ), ChartColor.FromRgba( 54, 162, 235, 1f ), ChartColor.FromRgba( 255, 206, 86, 1f ), ChartColor.FromRgba( 75, 192, 192, 1f ), ChartColor.FromRgba( 153, 102, 255, 1f ), ChartColor.FromRgba( 255, 159, 64, 1f ) };

    public struct LiveDataPoint
    {
        public object X { get; set; }

        public object Y { get; set; }
    }

    object horizontalLineChartOptions = new
    {
        Scales = new
        {
            Y = new
            {
                Title = new
                {
                    Display = true,
                    Text = "Value"
                }
            }
        },
        Interaction = new
        {
            intersect = false
        }
    };

    protected override async Task OnAfterRenderAsync( bool firstRender )
    {
        if ( firstRender )
        {
            await Task.WhenAll(
                HandleRedraw( horizontalLineChart, GetLineChartDataset1 ) );
        }
    }

    async Task HandleRedraw<TDataSet, TItem, TOptions, TModel>( BaseChart<TDataSet, TItem, TOptions, TModel> chart, params Func<TDataSet>[] getDataSets )
        where TDataSet : ChartDataset<TItem>
        where TOptions : ChartOptions
        where TModel : ChartModel
    {
        await chart.Clear();

        await chart.AddLabelsDatasetsAndUpdate( Labels, getDataSets.Select( x => x.Invoke() ).ToArray() );
    }

    LineChartDataset<LiveDataPoint> GetLineChartDataset1()
    {
        return new LineChartDataset<LiveDataPoint>
        {
            Data = new List<LiveDataPoint>(),
            Label = "Dataset 1 (linear interpolation)",
            BackgroundColor = backgroundColors[0],
            BorderColor = borderColors[0],
            Fill = false,
            Tension = 0,
            BorderDash = new List<int> { 8, 4 },
        };
    }

    Task OnHorizontalLineRefreshed( ChartStreamingData<LiveDataPoint> data )
    {
        data.Value = new LiveDataPoint
        {
            X = DateTime.Now,
            Y = RandomScalingFactor(),
        };

        return Task.CompletedTask;
    }

    double RandomScalingFactor()
    {
        return ( random.NextDouble() > 0.5 ? 1.0 : -1.0 ) * Math.Round( random.NextDouble() * 100 );
    }
}

API

Methods

Name Description
Pause() Pauses the current chart streaming.
Play() Plays the current chart streaming.
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