Histogram Chart

Installation

Examples

Props

Used by

Files installed (3)

• src/app/components/ui/charts/histogram-chart/histogram-chart.component.ts6.1 kB

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  import {
    AfterViewInit,
    Component,
    ElementRef,
    Input,
    OnChanges,
    OnDestroy,
    SimpleChanges,
    ViewChild,
    ChangeDetectionStrategy,
  } from '@angular/core'
  import type * as echarts from 'echarts/core'
  import { cn } from '@/lib/utils'
  import {
    getChartColors,
    getChartTextColor,
    getChartAxisColor,
    getChartSplitLineColor,
    getChartTooltipBg,
    getChartTooltipBorder,
    getChartTooltipText,
    mergeOptionBlock,
  } from '../use-chart-theme'
  
  /**
   * Angular port of the UIPKGE HistogramChart — auto-bins raw values or renders pre-binned counts. Standalone, theme-aware. Same inputs as the Vue `HistogramChart` (`values`, `data`, `bins`, `height`, `option`).
   */
  @Component({
    changeDetection: ChangeDetectionStrategy.Eager,
    selector: 'ui-histogram-chart, [ui-histogram-chart]',
    standalone: true,
    host: {
      '[attr.data-slot]': '"histogram-chart"',
      '[attr.data-uipkge]': '""',
      '[class]': 'hostClass',
      '[attr.role]': '"img"',
      '[attr.aria-label]': 'ariaLabel || "Chart"',
      '[attr.tabindex]': '0',
      '[style.height]': 'heightStyle',
    },
    template: `<div #chartEl class="size-full"></div>`,
  })
  export class UiHistogramChartComponent implements AfterViewInit, OnChanges, OnDestroy {
    /** Raw values to auto-bin. Ignored when data is provided. */
    @Input() values: number[] = []
    /** Pre-binned `{ bin, count }` rows. Takes precedence over values. */
    @Input() data: { bin: string; count: number }[] = []
    /** Bin count for auto-binning. Default 12. */
    @Input() bins = 12
    @Input() height: number | string = 300
    @Input() option?: Record<string, unknown>
    /** Accessible name announced for the chart image. Defaults to "Chart". */
    @Input() ariaLabel?: string
    @Input('class') className?: string
  
    @ViewChild('chartEl', { static: false }) chartEl?: ElementRef<HTMLDivElement>
  
    private chart: echarts.ECharts | null = null
    private unsubscribeTheme: (() => void) | null = null
  
    get hostClass(): string {
      return cn('block focus-visible:ring-ring w-full focus-visible:ring-2 focus-visible:outline-none', this.className)
    }
  
    get heightStyle(): string {
      return /^\d+$/.test(String(this.height)) ? `${this.height}px` : String(this.height)
    }
    /** Bin rows: pre-binned data wins, else equal-width bins over values. Pure. */
    binned(): { bin: string; count: number }[] {
      if (this.data?.length) return this.data
      const vals = this.values ?? []
      if (!vals.length) return []
      const min = Math.min(...vals)
      const max = Math.max(...vals)
      const span = max - min || 1
      const n = Math.max(1, this.bins)
      const counts = Array(n).fill(0)
      for (const v of vals) counts[Math.min(n - 1, Math.floor(((v - min) / span) * n))]++
      return counts.map((count: number, i: number) => ({
        bin: `${(min + (span * i) / n).toFixed(1)}–${(min + (span * (i + 1)) / n).toFixed(1)}`,
        count,
      }))
    }
  
    /** Build the merged ECharts option (pure — no DOM needed, unit-testable). */
    getOption(): Record<string, unknown> {
      const colors = getChartColors()
      const rows = this.binned()
      const peak = rows.reduce((m, d, i) => (d.count > (rows[m]?.count ?? -1) ? i : m), 0)
      const series = [
        {
          type: 'bar',
          data: rows.map((r) => r.count),
          barCategoryGap: '2%',
          itemStyle: {
            color: (p: { dataIndex: number }) => (p.dataIndex === peak ? colors[0] : colors[2]),
            borderRadius: [3, 3, 3, 3],
          },
        },
      ]
      const userOption: Record<string, any> = this.option ?? {}
      const {
        series: userSeries,
        xAxis: userXAxis,
        yAxis: userYAxis,
        grid: userGrid,
        tooltip: userTooltip,
        ...userRest
      } = userOption
      const mergedSeries = Array.isArray(userSeries) ? series.map((s, i) => ({ ...s, ...(userSeries[i] ?? {}) })) : series
      return {
        color: colors,
        grid: mergeOptionBlock(
          { left: 16, right: 16, top: 24, bottom: 24, outerBoundsMode: 'same', outerBoundsContain: 'axisLabel' },
          userGrid,
        ),
        tooltip: mergeOptionBlock(
          {
            trigger: 'axis',
            axisPointer: { type: 'shadow' },
            backgroundColor: getChartTooltipBg(),
            borderColor: getChartTooltipBorder(),
            textStyle: { color: getChartTooltipText(), fontSize: 12 },
          },
          userTooltip,
        ),
        xAxis: mergeOptionBlock(
          {
            type: 'category',
            data: rows.map((r) => r.bin),
            axisLine: { lineStyle: { color: getChartAxisColor() } },
            axisLabel: { color: getChartTextColor(), fontSize: 10, rotate: 30 },
            axisTick: { show: false },
          },
          userXAxis,
        ),
        yAxis: mergeOptionBlock(
          {
            type: 'value',
            splitLine: { lineStyle: { color: getChartSplitLineColor() } },
            axisLabel: { color: getChartTextColor(), fontSize: 11 },
          },
          userYAxis,
        ),
        series: mergedSeries,
        ...userRest,
      }
    }
  
    async ngAfterViewInit(): Promise<void> {
      if (typeof window === 'undefined' || !this.chartEl?.nativeElement) return
      const [{ use }, { CanvasRenderer }, { BarChart: EChartsBarChart }, comps] = await Promise.all([
        import('echarts/core'),
        import('echarts/renderers'),
        import('echarts/charts'),
        import('echarts/components'),
      ])
      use([CanvasRenderer, EChartsBarChart, comps.GridComponent, comps.TooltipComponent])
      const { init } = await import('echarts/core')
      this.chart = init(this.chartEl.nativeElement)
      this.chart.setOption(this.getOption())
      const { onChartThemeChange } = await import('../use-chart-theme')
      this.unsubscribeTheme = onChartThemeChange(() => this.chart?.setOption(this.getOption()))
      if (typeof ResizeObserver !== 'undefined') {
        new ResizeObserver(() => this.chart?.resize()).observe(this.chartEl.nativeElement)
      }
    }
  
    ngOnChanges(changes: SimpleChanges): void {
      if (this.chart && (changes['data'] || changes['option'] || changes['values'] || changes['bins'])) {
        this.chart.setOption(this.getOption())
      }
    }
  
    ngOnDestroy(): void {
      this.unsubscribeTheme?.()
      this.unsubscribeTheme = null
      try {
        this.chart?.dispose()
      } catch {
        /* already disposed */
      }
      this.chart = null
    }
  }
  

• src/app/components/ui/charts/histogram-chart/index.ts0.1 kB

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• src/app/components/ui/charts/use-chart-theme.ts7.4 kB

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Raw manifest:https://uipkge.dev/r/angular/histogram-chart.json

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