Refactor loading

load.go

@@ -16,21 +16,157 @@ import (
 type Encoding uint
 
 const (
+	// utf8Default is a private placeholder for the zero value of Encoding to
+	// ensure that it has the correct meaning. UTF8 is the default encoding but
+	// was assigned a non-zero value which cannot be changed without breaking
+	// existing code. Clients should continue to use the public constants.
+	utf8Default Encoding = iota
+
 	// UTF8 interprets the input data as UTF-8.
-	UTF8 Encoding = 1 << iota
+	UTF8
 
 	// ISO_8859_1 interprets the input data as ISO-8859-1.
 	ISO_8859_1
 )
 
+type Loader struct {
+	// Encoding determines how the data from files and byte buffers
+	// is interpreted. For URLs the Content-Type header is used
+	// to determine the encoding of the data.
+	Encoding Encoding
+
+	// DisableExpansion configures the property expansion of the
+	// returned property object. When set to true, the property values
+	// will not be expanded and the Property object will not be checked
+	// for invalid expansion expressions.
+	DisableExpansion bool
+
+	// IgnoreMissing configures whether missing files or URLs which return
+	// 404 are reported as errors. When set to true, missing files and 404
+	// status codes are not reported as errors.
+	IgnoreMissing bool
+}
+
+// Load reads a buffer into a Properties struct.
+func (l *Loader) LoadBytes(buf []byte) (*Properties, error) {
+	return l.loadBytes(buf, l.Encoding)
+}
+
+// LoadAll reads the content of multiple URLs or files in the given order into
+// a Properties struct. If IgnoreMissing is true then a 404 status code or
+// missing file will not be reported as error. Encoding sets the encoding for
+// files. For the URLs see LoadURL for the Content-Type header and the
+// encoding.
+func (l *Loader) LoadAll(names []string) (*Properties, error) {
+	all := NewProperties()
+	for _, name := range names {
+		n, err := expandName(name)
+		if err != nil {
+			return nil, err
+		}
+
+		var p *Properties
+		switch {
+		case strings.HasPrefix(n, "http://"):
+			p, err = l.LoadURL(n)
+		case strings.HasPrefix(n, "https://"):
+			p, err = l.LoadURL(n)
+		default:
+			p, err = l.LoadFile(n)
+		}
+		if err != nil {
+			return nil, err
+		}
+		all.Merge(p)
+	}
+
+	all.DisableExpansion = l.DisableExpansion
+	if all.DisableExpansion {
+		return all, nil
+	}
+	return all, all.check()
+}
+
+// LoadFile reads a file into a Properties struct.
+// If IgnoreMissing is true then a missing file will not be
+// reported as error.
+func (l *Loader) LoadFile(filename string) (*Properties, error) {
+	data, err := ioutil.ReadFile(filename)
+	if err != nil {
+		if l.IgnoreMissing && os.IsNotExist(err) {
+			LogPrintf("properties: %s not found. skipping", filename)
+			return NewProperties(), nil
+		}
+		return nil, err
+	}
+	return l.loadBytes(data, l.Encoding)
+}
+
+// LoadURL reads the content of the URL into a Properties struct.
+//
+// The encoding is determined via the Content-Type header which
+// should be set to 'text/plain'. If the 'charset' parameter is
+// missing, 'iso-8859-1' or 'latin1' the encoding is set to
+// ISO-8859-1. If the 'charset' parameter is set to 'utf-8' the
+// encoding is set to UTF-8. A missing content type header is
+// interpreted as 'text/plain; charset=utf-8'.
+func (l *Loader) LoadURL(url string) (*Properties, error) {
+	resp, err := http.Get(url)
+	if err != nil {
+		return nil, fmt.Errorf("properties: error fetching %q. %s", url, err)
+	}
+
+	if resp.StatusCode == 404 && l.IgnoreMissing {
+		LogPrintf("properties: %s returned %d. skipping", url, resp.StatusCode)
+		return NewProperties(), nil
+	}
+
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("properties: %s returned %d", url, resp.StatusCode)
+	}
+
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("properties: %s error reading response. %s", url, err)
+	}
+	defer resp.Body.Close()
+
+	ct := resp.Header.Get("Content-Type")
+	var enc Encoding
+	switch strings.ToLower(ct) {
+	case "text/plain", "text/plain; charset=iso-8859-1", "text/plain; charset=latin1":
+		enc = ISO_8859_1
+	case "", "text/plain; charset=utf-8":
+		enc = UTF8
+	default:
+		return nil, fmt.Errorf("properties: invalid content type %s", ct)
+	}
+
+	return l.loadBytes(body, enc)
+}
+
+func (l *Loader) loadBytes(buf []byte, enc Encoding) (*Properties, error) {
+	p, err := parse(convert(buf, enc))
+	if err != nil {
+		return nil, err
+	}
+	p.DisableExpansion = l.DisableExpansion
+	if p.DisableExpansion {
+		return p, nil
+	}
+	return p, p.check()
+}
+
 // Load reads a buffer into a Properties struct.
 func Load(buf []byte, enc Encoding) (*Properties, error) {
-	return loadBuf(buf, enc, false)
+	l := &Loader{Encoding: enc}
+	return l.LoadBytes(buf)
 }
 
 // LoadString reads an UTF8 string into a properties struct.
 func LoadString(s string) (*Properties, error) {
-	return loadBuf([]byte(s), UTF8, false)
+	l := &Loader{Encoding: UTF8}
+	return l.LoadBytes([]byte(s))
 }
 
 // LoadMap creates a new Properties struct from a string map.
@@ -44,42 +180,41 @@ func LoadMap(m map[string]string) *Properties {
 
 // LoadFile reads a file into a Properties struct.
 func LoadFile(filename string, enc Encoding) (*Properties, error) {
-	return loadAll([]string{filename}, enc, false, false)
+	l := &Loader{Encoding: enc}
+	return l.LoadAll([]string{filename})
 }
 
 // LoadFiles reads multiple files in the given order into
 // a Properties struct. If 'ignoreMissing' is true then
 // non-existent files will not be reported as error.
 func LoadFiles(filenames []string, enc Encoding, ignoreMissing bool) (*Properties, error) {
-	return loadAll(filenames, enc, ignoreMissing, false)
+	l := &Loader{Encoding: enc, IgnoreMissing: ignoreMissing}
+	return l.LoadAll(filenames)
 }
 
 // LoadURL reads the content of the URL into a Properties struct.
-//
-// The encoding is determined via the Content-Type header which
-// should be set to 'text/plain'. If the 'charset' parameter is
-// missing, 'iso-8859-1' or 'latin1' the encoding is set to
-// ISO-8859-1. If the 'charset' parameter is set to 'utf-8' the
-// encoding is set to UTF-8. A missing content type header is
-// interpreted as 'text/plain; charset=utf-8'.
+// See Loader#LoadURL for details.
 func LoadURL(url string) (*Properties, error) {
-	return loadAll([]string{url}, UTF8, false, false)
+	l := &Loader{Encoding: UTF8}
+	return l.LoadAll([]string{url})
 }
 
 // LoadURLs reads the content of multiple URLs in the given order into a
-// Properties struct. If 'ignoreMissing' is true then a 404 status code will
-// not be reported as error. See LoadURL for the Content-Type header
+// Properties struct. If IgnoreMissing is true then a 404 status code will
+// not be reported as error. See Loader#LoadURL for the Content-Type header
 // and the encoding.
 func LoadURLs(urls []string, ignoreMissing bool) (*Properties, error) {
-	return loadAll(urls, UTF8, ignoreMissing, false)
+	l := &Loader{Encoding: UTF8, IgnoreMissing: ignoreMissing}
+	return l.LoadAll(urls)
 }
 
 // LoadAll reads the content of multiple URLs or files in the given order into a
 // Properties struct. If 'ignoreMissing' is true then a 404 status code or missing file will
 // not be reported as error. Encoding sets the encoding for files. For the URLs please see
 // LoadURL for the Content-Type header and the encoding.
 func LoadAll(names []string, enc Encoding, ignoreMissing bool) (*Properties, error) {
-	return loadAll(names, enc, ignoreMissing, false)
+	l := &Loader{Encoding: enc, IgnoreMissing: ignoreMissing}
+	return l.LoadAll(names)
 }
 
 // MustLoadString reads an UTF8 string into a Properties struct and
@@ -122,96 +257,6 @@ func MustLoadAll(names []string, enc Encoding, ignoreMissing bool) *Properties {
 	return must(LoadAll(names, enc, ignoreMissing))
 }
 
-func loadBuf(buf []byte, enc Encoding, disableExpansion bool) (*Properties, error) {
-	p, err := parse(convert(buf, enc))
-	if err != nil {
-		return nil, err
-	}
-	if disableExpansion {
-		return p, nil
-	}
-	return p, p.check()
-}
-
-func loadAll(names []string, enc Encoding, ignoreMissing, disableExpansion bool) (*Properties, error) {
-	result := NewProperties()
-	for _, name := range names {
-		n, err := expandName(name)
-		if err != nil {
-			return nil, err
-		}
-		var p *Properties
-		if strings.HasPrefix(n, "http://") || strings.HasPrefix(n, "https://") {
-			p, err = loadURL(n, ignoreMissing)
-		} else {
-			p, err = loadFile(n, enc, ignoreMissing)
-		}
-		if err != nil {
-			return nil, err
-		}
-		result.Merge(p)
-
-	}
-	if disableExpansion {
-		return result, nil
-	}
-	return result, result.check()
-}
-
-func loadFile(filename string, enc Encoding, ignoreMissing bool) (*Properties, error) {
-	data, err := ioutil.ReadFile(filename)
-	if err != nil {
-		if ignoreMissing && os.IsNotExist(err) {
-			LogPrintf("properties: %s not found. skipping", filename)
-			return NewProperties(), nil
-		}
-		return nil, err
-	}
-	p, err := parse(convert(data, enc))
-	if err != nil {
-		return nil, err
-	}
-	return p, nil
-}
-
-func loadURL(url string, ignoreMissing bool) (*Properties, error) {
-	resp, err := http.Get(url)
-	if err != nil {
-		return nil, fmt.Errorf("properties: error fetching %q. %s", url, err)
-	}
-	if resp.StatusCode == 404 && ignoreMissing {
-		LogPrintf("properties: %s returned %d. skipping", url, resp.StatusCode)
-		return NewProperties(), nil
-	}
-	if resp.StatusCode != 200 {
-		return nil, fmt.Errorf("properties: %s returned %d", url, resp.StatusCode)
-	}
-	body, err := ioutil.ReadAll(resp.Body)
-	if err != nil {
-		return nil, fmt.Errorf("properties: %s error reading response. %s", url, err)
-	}
-	if err = resp.Body.Close(); err != nil {
-		return nil, fmt.Errorf("properties: %s error reading response. %s", url, err)
-	}
-
-	ct := resp.Header.Get("Content-Type")
-	var enc Encoding
-	switch strings.ToLower(ct) {
-	case "text/plain", "text/plain; charset=iso-8859-1", "text/plain; charset=latin1":
-		enc = ISO_8859_1
-	case "", "text/plain; charset=utf-8":
-		enc = UTF8
-	default:
-		return nil, fmt.Errorf("properties: invalid content type %s", ct)
-	}
-
-	p, err := parse(convert(body, enc))
-	if err != nil {
-		return nil, err
-	}
-	return p, nil
-}
-
 func must(p *Properties, err error) *Properties {
 	if err != nil {
 		ErrorHandler(err)
@@ -232,7 +277,7 @@ func expandName(name string) (string, error) {
 // first 256 unicode code points cover ISO-8859-1.
 func convert(buf []byte, enc Encoding) string {
 	switch enc {
-	case UTF8:
+	case utf8Default, UTF8:
 		return string(buf)
 	case ISO_8859_1:
 		runes := make([]rune, len(buf))

load_test.go

@@ -16,6 +16,18 @@ import (
 	"github.com/magiconair/properties/assert"
 )
 
+func TestEncoding(t *testing.T) {
+	if got, want := utf8Default, Encoding(0); got != want {
+		t.Fatalf("got encoding %d want %d", got, want)
+	}
+	if got, want := UTF8, Encoding(1); got != want {
+		t.Fatalf("got encoding %d want %d", got, want)
+	}
+	if got, want := ISO_8859_1, Encoding(2); got != want {
+		t.Fatalf("got encoding %d want %d", got, want)
+	}
+}
+
 func TestLoadFailsWithNotExistingFile(t *testing.T) {
 	_, err := LoadFile("doesnotexist.properties", ISO_8859_1)
 	assert.Equal(t, err != nil, true, "")

properties.go

@@ -85,7 +85,8 @@ func NewProperties() *Properties {
 
 // Load reads a buffer into the given Properties struct.
 func (p *Properties) Load(buf []byte, enc Encoding) error {
-	newProperties, err := loadBuf(buf, enc, p.DisableExpansion)
+	l := &Loader{Encoding: enc, DisableExpansion: p.DisableExpansion}
+	newProperties, err := l.LoadBytes(buf)
 	if err != nil {
 		return err
 	}