/// <summary>
/// Get a sequence of datapoints corresponding to a specific category, ensuring there is a value for each of the categories.
/// </summary>
/// <param name="dataset"></param>
/// <param name="categoryNames"></param>
/// <returns></returns>
private List <decimal> GetDataPointsForAllCategories(ChartJsCategoryValuesDataset dataset, List <string> categoryNames)
{
var dataValues = new List <decimal>();
foreach (var categoryName in categoryNames)
{
var datapoint = dataset.DataPoints.FirstOrDefault(x => x.Category == categoryName);
if (datapoint == null)
{
dataValues.Add(0);
}
else
{
dataValues.Add(datapoint.Value);
}
}
return(dataValues);
}
/// <summary>
/// Convert a collection of time series datasets to category-value datasets, where the categories represent discrete periods in the specified time scale.
/// </summary>
/// <remarks>
/// Quantizing the data points in this way will substantially improve the performance of Chart.js for large data sets.
/// </remarks>
private List <ChartJsCategoryValuesDataset> GetCategoryDatasets(ChartJsTimeSeriesTimeScaleSpecifier timeScale)
{
var quantizedDatasets = new List <ChartJsCategoryValuesDataset>();
foreach (var dataset in this.Datasets)
{
var datapoints = dataset.DataPoints;
var datasetQuantized = new ChartJsCategoryValuesDataset();
datasetQuantized.Name = dataset.Name;
datasetQuantized.BorderColor = dataset.BorderColor;
datasetQuantized.FillColor = dataset.FillColor;
if (timeScale == ChartJsTimeSeriesTimeScaleSpecifier.Day)
{
var quantizedDataPoints = datapoints
.GroupBy(x => new { Day = x.DateTime })
.Select(x => new ChartJsCategoryValuesDataPoint
{
Category = x.Key.Day.ToString(DateFormatStringDayMonthYear),
Value = x.Sum(y => y.Value),
SortKey = x.Key.Day.ToString("yyyyMMdd"),
})
.OrderBy(x => x.SortKey)
.ToList();
datasetQuantized.DataPoints = quantizedDataPoints.Cast <IChartJsCategoryValuesDataPoint>().ToList();
}
else if (timeScale == ChartJsTimeSeriesTimeScaleSpecifier.Month)
{
var quantizedDataPoints = datapoints
.GroupBy(x => new { Month = new DateTime(x.DateTime.Year, x.DateTime.Month, 1) })
.Select(x => new ChartJsCategoryValuesDataPoint
{
Category = x.Key.Month.ToString(DateFormatStringMonthYear),
Value = x.Sum(y => y.Value),
SortKey = x.Key.Month.ToString("yyyyMM"),
})
.OrderBy(x => x.SortKey)
.ToList();
datasetQuantized.DataPoints = quantizedDataPoints.Cast <IChartJsCategoryValuesDataPoint>().ToList();
}
else if (timeScale == ChartJsTimeSeriesTimeScaleSpecifier.Year)
{
var quantizedDataPoints = datapoints
.GroupBy(x => new { Year = new DateTime(x.DateTime.Year, 1, 1) })
.Select(x => new ChartJsCategoryValuesDataPoint
{
Category = x.Key.Year.ToString("yyyy"),
Value = x.Sum(y => y.Value),
SortKey = x.Key.Year.ToString("yyyy"),
})
.OrderBy(x => x.SortKey)
.ToList();
datasetQuantized.DataPoints = quantizedDataPoints.Cast <IChartJsCategoryValuesDataPoint>().ToList();
}
else
{
throw new NotImplementedException("Timescale is not implemented");
}
quantizedDatasets.Add(datasetQuantized);
}
return(quantizedDatasets);
}
