refactoring csv package

tpl-ex3/main.go

@@ -1,31 +1,24 @@
 package main
 
 import (
-	"encoding/csv"
 	"html/template"
 	"io"
 	"log"
 	"net/http"
 	"os"
-	"strconv"
+
+	"meutel.net/meutel/go-examples/tpl-ex3/records"
 )
 
-var COLUMNS []string
-
-type FinancialData struct {
-	Date                                      string
-	Open, High, Low, Close, Adj_Close, Volume float64
-}
-
 type TplData struct {
 	Columns []string
-	Rows    []FinancialData
+	Rows    []records.FinancialData
 }
 
-func printHTML(tpl *template.Template, data []FinancialData, out io.Writer) {
+func printHTML(tpl *template.Template, cols []string, rows []records.FinancialData, out io.Writer) {
 	tplData := TplData{
-		COLUMNS,
+		cols,
-		data,
+		rows,
 	}
 	err := tpl.ExecuteTemplate(out, "tpl.html", tplData)
 	if err != nil {
@@ -33,62 +26,6 @@ func printHTML(tpl *template.Template, data []FinancialData, out io.Writer) {
 	}
 }
 
-func readCsvLine(line []string) *FinancialData {
-	data := new(FinancialData)
-	for i, col := range line {
-		switch COLUMNS[i] {
-		case "Date":
-			data.Date = col
-		case "Open":
-			data.Open = toFloat(col)
-		case "High":
-			data.High = toFloat(col)
-		case "Low":
-			data.Low = toFloat(col)
-		case "Close":
-			data.Close = toFloat(col)
-		case "Adj Close":
-			data.Adj_Close = toFloat(col)
-		case "Volume":
-			data.Volume = toFloat(col)
-		}
-	}
-	return data
-}
-
-func toFloat(v string) float64 {
-	f, err := strconv.ParseFloat(v, 64)
-	if err != nil {
-		log.Fatalln(err)
-	}
-	return f
-}
-
-func readCsvHeader(line []string) {
-	for _, col := range line {
-		COLUMNS = append(COLUMNS, col)
-	}
-}
-
-func readCsv(in io.Reader) []FinancialData {
-	data := []FinancialData{}
-	csvReader := csv.NewReader(in)
-	for {
-		line, err := csvReader.Read()
-		if err == io.EOF {
-			break
-		} else if err != nil {
-			log.Fatal(err)
-		}
-		if len(COLUMNS) == 0 {
-			readCsvHeader(line)
-		} else {
-			data = append(data, *readCsvLine(line))
-		}
-	}
-	return data
-}
-
 func main() {
 	if len(os.Args) < 2 {
 		log.Fatalln("Usage go-financial <file>")
@@ -102,7 +39,7 @@ func main() {
 	defer csv.Close()
 
 	// parse data
-	data := readCsv(csv)
+	cols, rows := records.ReadCsv(csv)
 
 	tpl, err := template.New("").Funcs(template.FuncMap{
 		"class": func(index int) string {
@@ -116,7 +53,7 @@ func main() {
 		panic(err)
 	}
 	http.HandleFunc("/", func(res http.ResponseWriter, req *http.Request) {
-		printHTML(tpl, data, res)
+		printHTML(tpl, cols, rows, res)
 	})
 	http.ListenAndServe(":9000", nil)
 }

tpl-ex3/records/records.go

@@ -0,0 +1,72 @@
+package records
+
+import (
+	"encoding/csv"
+	"io"
+	"log"
+	"strconv"
+)
+
+type FinancialData struct {
+	Date                                      string
+	Open, High, Low, Close, Adj_Close, Volume float64
+}
+
+func readCsvLine(cols []string, line []string) *FinancialData {
+	data := new(FinancialData)
+	for i, col := range line {
+		switch cols[i] {
+		case "Date":
+			data.Date = col
+		case "Open":
+			data.Open = toFloat(col)
+		case "High":
+			data.High = toFloat(col)
+		case "Low":
+			data.Low = toFloat(col)
+		case "Close":
+			data.Close = toFloat(col)
+		case "Adj Close":
+			data.Adj_Close = toFloat(col)
+		case "Volume":
+			data.Volume = toFloat(col)
+		}
+	}
+	return data
+}
+
+func toFloat(v string) float64 {
+	f, err := strconv.ParseFloat(v, 64)
+	if err != nil {
+		log.Fatalln(err)
+	}
+	return f
+}
+
+func readCsvHeader(line []string) []string {
+	cols := []string{}
+	for _, col := range line {
+		cols = append(cols, col)
+	}
+	return cols
+}
+
+func ReadCsv(in io.Reader) ([]string, []FinancialData) {
+	cols := []string{}
+	data := []FinancialData{}
+	csvReader := csv.NewReader(in)
+	for {
+		line, err := csvReader.Read()
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			log.Fatal(err)
+		}
+		if len(cols) == 0 {
+			cols = readCsvHeader(line)
+		} else {
+			data = append(data, *readCsvLine(cols, line))
+		}
+	}
+	return cols, data
+}