Add examples of rendering each chart type using the Painter API

In addition two bugs were discovered using this API:
* Bar chart series type and filtering was not handled correctly (used line chart and default of line chart is confusing).  Fixed in this commit.
* Using the Painter API means defaults are not filled out.  I will fill this as an issue to fix.

Additional TODO notes are added for future investigation before v0.4.0 is tagged

Author: jentfoo

bar_chart.go

@@ -211,6 +211,6 @@ func (b *barChart) Render() (Box, error) {
 	if err != nil {
 		return BoxZero, err
 	}
-	seriesList := opt.SeriesList.Filter(ChartTypeLine)
+	seriesList := opt.SeriesList.Filter(ChartTypeBar)
 	return b.render(renderResult, seriesList)
 }

chart_option.go

@@ -50,6 +50,7 @@ type ChartOption struct {
 	// Children are child charts to render together.
 	Children []ChartOption
 	parent   *Painter
+	// TODO - review how this is set on other Option structs
 	// ValueFormatter to format numeric values into labels.
 	ValueFormatter ValueFormatter
 }

examples/README.md

@@ -5,17 +5,23 @@ Examples are our primary method for demonstrating the starting point our use and
 ## Example List
 
 * [bar_chart-1](./bar_chart-1) - Bar chart with included mark points and mark lines.
+* [bar_chart-2](./bar_chart-2) - The above example bar chart re-demonstrated using the Painter API.
 * [chinese](./chinese) - Line chart with chinese characters that uses a custom font (must be downloaded by user, see comment in code).
 * [funnel_chart-1](./funnel_chart-1) - Basic funnel chart.
+* [funnel_chart-2](./funnel_chart-2) - The above example funnel chart re-demonstrated using the Painter API.
 * [horizontal_bar_chart-1](./horizontal_bar_chart-1) - Basic horizontal bar chart.
+* [horizontal_bar_chart-2](./horizontal_bar_chart-2) - The above example bar chart re-demonstrated using the Painter API.
 * [line_chart-1](./line_chart-1) - Basic line chart with some simple styling changes and a demonstration of `null` values.
-* [line_chart-2](./line_chart-2) - Line chart with dense data and more custom styling configured.
+* [line_chart-2](./line_chart-2) - The above example line chart re-demonstrated using the Painter API.
+* [line_chart-3](./line_chart-3) - Line chart with dense data and more custom styling configured.
 * [line_chart-area](./line_chart-area) - Example line chart with the area below the line shaded.
 * [multiple_charts-1](./multiple_charts-1) - Example of manually building a painter so that you can render 4 charts on the same image.
 * [multiple_charts-2](./multiple_charts-2) - Combining two charts together by writting one chart over the other.
 * [multiple_charts-3](./multiple_charts-3) - An alternative API for overlaying two charts together in the same image.
 * [pie_chart-1](./pie_chart-1) - Pie chart with a variety of customization demonstrated including positioning the legend in the bottom right corner.
+* [pie_chart-2](./pie_chart-2) - The above example pie chart re-demonstrated using the Painter API.
 * [radar_chart-1](./radar_chart-1) - Basic radar chart.
+* [radar_chart-2](./radar_chart-2) - The above example radar chart re-demonstrated using the Painter API.
 * [table-1](./table-1) - Table with a variety of table specific configuration and styling demonstrated.
 * [web-1](./web-1) - Hosts an example http server which will render the charts to the web page.
 

examples/bar_chart-1/main.go

@@ -17,61 +17,23 @@ func writeFile(buf []byte) error {
 		return err
 	}
 
-	file := filepath.Join(tmpPath, "bar-chart.png")
+	file := filepath.Join(tmpPath, "bar-chart-1.png")
 	return os.WriteFile(file, buf, 0600)
 }
 
 func main() {
 	values := [][]float64{
-		{
-			2.0,
-			4.9,
-			7.0,
-			23.2,
-			25.6,
-			76.7,
-			135.6,
-			162.2,
-			32.6,
-			20.0,
-			6.4,
-			3.3,
-		},
-		{
-			2.6,
-			5.9,
-			9.0,
-			26.4,
-			28.7,
-			70.7,
-			175.6,
-			182.2,
-			48.7,
-			18.8,
-			6.0,
-			2.3,
-		},
+		{2.0, 4.9, 7.0, 23.2, 25.6, 76.7, 135.6, 162.2, 32.6, 20.0, 6.4, 3.3},
+		{2.6, 5.9, 9.0, 26.4, 28.7, 70.7, 175.6, 182.2, 48.7, 18.8, 6.0, 2.3},
 	}
 	p, err := charts.BarRender(
 		values,
 		charts.XAxisDataOptionFunc([]string{
-			"Jan",
-			"Feb",
-			"Mar",
-			"Apr",
-			"May",
-			"Jun",
-			"Jul",
-			"Aug",
-			"Sep",
-			"Oct",
-			"Nov",
-			"Dec",
+			"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
 		}),
 		charts.LegendOptionFunc(charts.LegendOption{
 			Data: []string{
-				"Rainfall",
-				"Evaporation",
+				"Rainfall", "Evaporation",
 			},
 			Offset:       charts.OffsetRight,
 			OverlayChart: charts.True(),

examples/bar_chart-2/main.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/go-analyze/charts"
+)
+
+/*
+Example bar chart with a variety of basic configuration options shown using the Painter API.
+*/
+
+func writeFile(buf []byte) error {
+	tmpPath := "./tmp"
+	if err := os.MkdirAll(tmpPath, 0700); err != nil {
+		return err
+	}
+
+	file := filepath.Join(tmpPath, "bar-chart-2.png")
+	return os.WriteFile(file, buf, 0600)
+}
+
+func main() {
+	values := [][]float64{
+		{2.0, 4.9, 7.0, 23.2, 25.6, 76.7, 135.6, 162.2, 32.6, 20.0, 6.4, 3.3},
+		{2.6, 5.9, 9.0, 26.4, 28.7, 70.7, 175.6, 182.2, 48.7, 18.8, 6.0, 2.3},
+	}
+
+	opt := charts.BarChartOption{}
+	opt.SeriesList = charts.NewSeriesListDataFromValues(values, charts.ChartTypeBar)
+	opt.XAxis.Data = []string{
+		"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
+	}
+	opt.XAxis.LabelCount = 12 // force label count due to the labels being very close
+	opt.Legend = charts.LegendOption{
+		Data:         []string{"Rainfall", "Evaporation"},
+		Offset:       charts.OffsetRight,
+		OverlayChart: charts.True(),
+	}
+	opt.SeriesList[0].MarkLine = charts.NewMarkLine(charts.SeriesMarkDataTypeAverage)
+	opt.SeriesList[0].MarkPoint = charts.NewMarkPoint(
+		charts.SeriesMarkDataTypeMax,
+		charts.SeriesMarkDataTypeMin,
+	)
+	opt.SeriesList[1].MarkLine = charts.NewMarkLine(charts.SeriesMarkDataTypeAverage)
+	opt.SeriesList[1].MarkPoint = charts.NewMarkPoint(
+		charts.SeriesMarkDataTypeMax,
+		charts.SeriesMarkDataTypeMin,
+	)
+
+	p, err := charts.NewPainter(charts.PainterOptions{
+		OutputFormat: charts.ChartOutputPNG,
+		Width:        600,
+		Height:       400,
+	})
+	if err != nil {
+		panic(err)
+	}
+	if _, err = charts.NewBarChart(p, opt).Render(); err != nil {
+		panic(err)
+	}
+
+	if buf, err := p.Bytes(); err != nil {
+		panic(err)
+	} else if err = writeFile(buf); err != nil {
+		panic(err)
+	}
+}

examples/funnel_chart-1/main.go

@@ -17,31 +17,18 @@ func writeFile(buf []byte) error {
 		return err
 	}
 
-	file := filepath.Join(tmpPath, "funnel-chart.png")
+	file := filepath.Join(tmpPath, "funnel-chart-1.png")
 	return os.WriteFile(file, buf, 0600)
 }
 
 func main() {
-	values := []float64{
-		100,
-		80,
-		60,
-		40,
-		20,
-		10,
-		2,
-	}
+	values := []float64{100, 80, 60, 40, 20, 10, 2}
+
 	p, err := charts.FunnelRender(
 		values,
 		charts.TitleTextOptionFunc("Funnel"),
 		charts.LegendLabelsOptionFunc([]string{
-			"Show",
-			"Click",
-			"Visit",
-			"Inquiry",
-			"Order",
-			"Pay",
-			"Cancel",
+			"Show", "Click", "Visit", "Inquiry", "Order", "Pay", "Cancel",
 		}),
 		func(opt *charts.ChartOption) {
 			opt.Legend.Padding = charts.Box{Left: 100}

examples/funnel_chart-2/main.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/go-analyze/charts"
+)
+
+/*
+Example funnel chart with a variety of basic configuration options shown using the Painter API.
+*/
+
+func writeFile(buf []byte) error {
+	tmpPath := "./tmp"
+	if err := os.MkdirAll(tmpPath, 0700); err != nil {
+		return err
+	}
+
+	file := filepath.Join(tmpPath, "funnel-chart-2.png")
+	return os.WriteFile(file, buf, 0600)
+}
+
+func main() {
+	values := []float64{100, 80, 60, 40, 20, 10, 2}
+
+	opt := charts.FunnelChartOption{}
+	opt.SeriesList = charts.NewFunnelSeriesList(values)
+	opt.Title.Text = "Funnel"
+	opt.Legend.Data = []string{
+		"Show", "Click", "Visit", "Inquiry", "Order", "Pay", "Cancel",
+	}
+	opt.Legend.Padding = charts.Box{Left: 100}
+
+	p, err := charts.NewPainter(charts.PainterOptions{
+		OutputFormat: charts.ChartOutputPNG,
+		Width:        600,
+		Height:       400,
+	})
+	if err != nil {
+		panic(err)
+	}
+	if _, err = charts.NewFunnelChart(p, opt).Render(); err != nil {
+		panic(err)
+	}
+
+	if buf, err := p.Bytes(); err != nil {
+		panic(err)
+	} else if err = writeFile(buf); err != nil {
+		panic(err)
+	}
+}

examples/horizontal_bar_chart-1/main.go

@@ -17,30 +17,14 @@ func writeFile(buf []byte) error {
 		return err
 	}
 
-	file := filepath.Join(tmpPath, "horizontal-bar-chart.png")
+	file := filepath.Join(tmpPath, "horizontal-bar-chart-1.png")
 	return os.WriteFile(file, buf, 0600)
 }
 
 func main() {
 	values := [][]float64{
-		{
-			10,
-			30,
-			50,
-			70,
-			90,
-			110,
-			130,
-		},
-		{
-			20,
-			40,
-			60,
-			80,
-			100,
-			120,
-			140,
-		},
+		{10, 30, 50, 70, 90, 110, 130},
+		{20, 40, 60, 80, 100, 120, 140},
 	}
 	p, err := charts.HorizontalBarRender(
 		values,
@@ -52,17 +36,10 @@ func main() {
 			Left:   20,
 		}),
 		charts.LegendLabelsOptionFunc([]string{
-			"2011",
-			"2012",
+			"2011", "2012",
 		}),
 		charts.YAxisDataOptionFunc([]string{
-			"UN",
-			"Brazil",
-			"Indonesia",
-			"USA",
-			"India",
-			"China",
-			"World",
+			"UN", "Brazil", "Indonesia", "USA", "India", "China", "World",
 		}),
 	)
 	if err != nil {

examples/horizontal_bar_chart-2/main.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/go-analyze/charts"
+)
+
+/*
+Example horizontal bar chart with a variety of basic configuration options shown using the Painter API.
+*/
+
+func writeFile(buf []byte) error {
+	tmpPath := "./tmp"
+	if err := os.MkdirAll(tmpPath, 0700); err != nil {
+		return err
+	}
+
+	file := filepath.Join(tmpPath, "horizontal-bar-chart-2.png")
+	return os.WriteFile(file, buf, 0600)
+}
+
+func main() {
+	values := [][]float64{
+		{10, 30, 50, 70, 90, 110, 130},
+		{20, 40, 60, 80, 100, 120, 140},
+	}
+
+	opt := charts.HorizontalBarChartOption{}
+	opt.SeriesList = charts.NewSeriesListDataFromValues(values, charts.ChartTypeHorizontalBar)
+	opt.Title.Text = "World Population"
+	opt.Padding = charts.Box{
+		Top:    20,
+		Right:  40,
+		Bottom: 20,
+		Left:   20,
+	}
+	opt.Legend.Data = []string{
+		"2011", "2012",
+	}
+	opt.YAxis = []charts.YAxisOption{
+		{
+			Data: []string{
+				"UN", "Brazil", "Indonesia", "USA", "India", "China", "World",
+			},
+		},
+	}
+
+	p, err := charts.NewPainter(charts.PainterOptions{
+		OutputFormat: charts.ChartOutputPNG,
+		Width:        600,
+		Height:       400,
+	})
+	if err != nil {
+		panic(err)
+	}
+	if _, err = charts.NewHorizontalBarChart(p, opt).Render(); err != nil {
+		panic(err)
+	}
+
+	if buf, err := p.Bytes(); err != nil {
+		panic(err)
+	} else if err = writeFile(buf); err != nil {
+		panic(err)
+	}
+}