spreadsheet: fix for sheet ordering bug

Need to test this more, may be working by chance...

Updates unidoc#154

algo/naturalsort.go

@@ -0,0 +1,63 @@
+// Copyright 2017 Baliance. All rights reserved.
+//
+// Use of this source code is governed by the terms of the Affero GNU General
+// Public License version 3.0 as published by the Free Software Foundation and
+// appearing in the file LICENSE included in the packaging of this file. A
+// commercial license can be purchased by contacting [email protected].
+
+package algo
+
+import (
+	"strconv"
+)
+
+func isdigit(c byte) bool {
+	return c >= '0' && c <= '9'
+}
+
+// NaturalLess compares two strings in a human manner so rId2 sorts less than rId10
+func NaturalLess(lhs, rhs string) bool {
+	lidx, ridx := 0, 0
+	for lidx < len(lhs) && ridx < len(rhs) {
+		lc := lhs[lidx]
+		rc := rhs[ridx]
+		ldigit := isdigit(lc)
+		rdigit := isdigit(rc)
+		switch {
+		// digits sort before characters
+		case ldigit && !rdigit:
+			return true
+		// characters after digits
+		case !ldigit && rdigit:
+			return false
+		// no digits, so compare the characters
+		case !ldigit && !rdigit:
+			if lc != rc {
+				return lc < rc
+			}
+			lidx++
+			ridx++
+		// both digits, so parse and compare
+		default:
+			lend := lidx + 1
+			rend := ridx + 1
+
+			for lend < len(lhs) && isdigit(lhs[lend]) {
+				lend++
+			}
+			for rend < len(rhs) && isdigit(rhs[rend]) {
+				rend++
+			}
+			lv, _ := strconv.ParseUint(lhs[lidx:lend], 10, 64)
+			rv, _ := strconv.ParseUint(rhs[lidx:rend], 10, 64)
+			if lv != rv {
+				return lv < rv
+			}
+			// digits are equal, so keep looking
+			lidx = lend
+			ridx = rend
+		}
+	}
+	// fall back to comparing length
+	return len(lhs) < len(rhs)
+}

algo/naturalsort_test.go

@@ -0,0 +1,41 @@
+// Copyright 2017 Baliance. All rights reserved.
+//
+// Use of this source code is governed by the terms of the Affero GNU General
+// Public License version 3.0 as published by the Free Software Foundation and
+// appearing in the file LICENSE included in the packaging of this file. A
+// commercial license can be purchased by contacting [email protected].
+
+package algo_test
+
+import (
+	"testing"
+
+	"baliance.com/gooxml/algo"
+)
+
+func TestSort(t *testing.T) {
+
+	tests := []struct {
+		a, b string
+	}{
+		{"rId1", "rId2"},
+		{"rId1", "rId10"},
+		{"rId2", "rId10"},
+		{"rId5", "rId10"},
+		{"rId5", "rId15"},
+		{"rId5", "rId51"},
+		{"rId1a", "rId1b"},
+	}
+
+	for _, tc := range tests {
+		if !algo.NaturalLess(tc.a, tc.b) {
+			t.Errorf("bad sort, expected %s < %s", tc.a, tc.b)
+		} else {
+			// no need to check if it failed the first time
+			if algo.NaturalLess(tc.b, tc.a) {
+				t.Errorf("bad sort, expected %s > %s", tc.b, tc.a)
+			}
+		}
+	}
+
+}

spreadsheet/workbook_test.go

@@ -269,3 +269,24 @@ func TestSheetGetName(t *testing.T) {
 		t.Errorf("expected no error")
 	}
 }
+
+// TestOpenOrderedSheets test for issue #154 where sheet title didn't match sheet content.
+func TestOpenOrderedSheets(t *testing.T) {
+	wb, err := spreadsheet.Open("./testdata/ordered-sheets.xlsx")
+	defer wb.Close()
+	if err != nil {
+		t.Fatalf("error opening workbook: %s", err)
+	}
+
+	for i, sheet := range wb.Sheets() {
+		expContent := fmt.Sprintf("%d", i+1)
+		if sheet.Name() != expContent {
+			t.Errorf("expected sheet %d name = %s, got %s", i, expContent, sheet.Name())
+		}
+		got := sheet.Cell("A1").GetFormattedValue()
+		if got != expContent {
+			t.Errorf("expected sheet %d cell A1 = %s, got %s", i, expContent, got)
+		}
+	}
+
+}

zippkg/helpers.go

@@ -14,7 +14,11 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"sort"
 	"strings"
+
+	"baliance.com/gooxml/algo"
+	"baliance.com/gooxml/schema/soo/pkg/relationships"
 )
 
 // RelationsPathFor returns the relations path for a given filename.
@@ -38,6 +42,16 @@ func Decode(f *zip.File, dest interface{}) error {
 	if err := dec.Decode(dest); err != nil {
 		return fmt.Errorf("error decoding %s: %s", f.Name, err)
 	}
+
+	// this ensures that relationship ID is increasing, which we apparently rely
+	// on....
+	if ds, ok := dest.(*relationships.Relationships); ok {
+		sort.Slice(ds.Relationship, func(i, j int) bool {
+			lhs := ds.Relationship[i]
+			rhs := ds.Relationship[j]
+			return algo.NaturalLess(lhs.IdAttr, rhs.IdAttr)
+		})
+	}
 	return nil
 }