1 files changed, 299 insertions, 0 deletions
diff --git a/vendor/github.com/gorilla/schema/decoder.go b/vendor/github.com/gorilla/schema/decoder.go
new file mode 100644
index 00000000..53b0337f
--- /dev/null
+++ b/vendor/github.com/gorilla/schema/decoder.go
@@ -0,0 +1,299 @@
+// Copyright 2012 The Gorilla Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package schema
+
+import (
+	"encoding"
+	"errors"
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+// NewDecoder returns a new Decoder.
+func NewDecoder() *Decoder {
+	return &Decoder{cache: newCache()}
+}
+
+// Decoder decodes values from a map[string][]string to a struct.
+type Decoder struct {
+	cache             *cache
+	zeroEmpty         bool
+	ignoreUnknownKeys bool
+}
+
+// SetAliasTag changes the tag used to locate custom field aliases.
+// The default tag is "schema".
+func (d *Decoder) SetAliasTag(tag string) {
+	d.cache.tag = tag
+}
+
+// ZeroEmpty controls the behaviour when the decoder encounters empty values
+// in a map.
+// If z is true and a key in the map has the empty string as a value
+// then the corresponding struct field is set to the zero value.
+// If z is false then empty strings are ignored.
+//
+// The default value is false, that is empty values do not change
+// the value of the struct field.
+func (d *Decoder) ZeroEmpty(z bool) {
+	d.zeroEmpty = z
+}
+
+// IgnoreUnknownKeys controls the behaviour when the decoder encounters unknown
+// keys in the map.
+// If i is true and an unknown field is encountered, it is ignored. This is
+// similar to how unknown keys are handled by encoding/json.
+// If i is false then Decode will return an error. Note that any valid keys
+// will still be decoded in to the target struct.
+//
+// To preserve backwards compatibility, the default value is false.
+func (d *Decoder) IgnoreUnknownKeys(i bool) {
+	d.ignoreUnknownKeys = i
+}
+
+// RegisterConverter registers a converter function for a custom type.
+func (d *Decoder) RegisterConverter(value interface{}, converterFunc Converter) {
+	d.cache.regconv[reflect.TypeOf(value)] = converterFunc
+}
+
+// Decode decodes a map[string][]string to a struct.
+//
+// The first parameter must be a pointer to a struct.
+//
+// The second parameter is a map, typically url.Values from an HTTP request.
+// Keys are "paths" in dotted notation to the struct fields and nested structs.
+//
+// See the package documentation for a full explanation of the mechanics.
+func (d *Decoder) Decode(dst interface{}, src map[string][]string) error {
+	v := reflect.ValueOf(dst)
+	if v.Kind() != reflect.Ptr || v.Elem().Kind() != reflect.Struct {
+		return errors.New("schema: interface must be a pointer to struct")
+	}
+	v = v.Elem()
+	t := v.Type()
+	errors := MultiError{}
+	for path, values := range src {
+		if parts, err := d.cache.parsePath(path, t); err == nil {
+			if err = d.decode(v, path, parts, values); err != nil {
+				errors[path] = err
+			}
+		} else if !d.ignoreUnknownKeys {
+			errors[path] = fmt.Errorf("schema: invalid path %q", path)
+		}
+	}
+	if len(errors) > 0 {
+		return errors
+	}
+	return nil
+}
+
+// decode fills a struct field using a parsed path.
+func (d *Decoder) decode(v reflect.Value, path string, parts []pathPart, values []string) error {
+	// Get the field walking the struct fields by index.
+	for _, name := range parts[0].path {
+		if v.Type().Kind() == reflect.Ptr {
+			if v.IsNil() {
+				v.Set(reflect.New(v.Type().Elem()))
+			}
+			v = v.Elem()
+		}
+		v = v.FieldByName(name)
+	}
+
+	// Don't even bother for unexported fields.
+	if !v.CanSet() {
+		return nil
+	}
+
+	// Dereference if needed.
+	t := v.Type()
+	if t.Kind() == reflect.Ptr {
+		t = t.Elem()
+		if v.IsNil() {
+			v.Set(reflect.New(t))
+		}
+		v = v.Elem()
+	}
+
+	// Slice of structs. Let's go recursive.
+	if len(parts) > 1 {
+		idx := parts[0].index
+		if v.IsNil() || v.Len() < idx+1 {
+			value := reflect.MakeSlice(t, idx+1, idx+1)
+			if v.Len() < idx+1 {
+				// Resize it.
+				reflect.Copy(value, v)
+			}
+			v.Set(value)
+		}
+		return d.decode(v.Index(idx), path, parts[1:], values)
+	}
+
+	// Get the converter early in case there is one for a slice type.
+	conv := d.cache.converter(t)
+	if conv == nil && t.Kind() == reflect.Slice {
+		var items []reflect.Value
+		elemT := t.Elem()
+		isPtrElem := elemT.Kind() == reflect.Ptr
+		if isPtrElem {
+			elemT = elemT.Elem()
+		}
+
+		// Try to get a converter for the element type.
+		conv := d.cache.converter(elemT)
+		if conv == nil {
+			// As we are not dealing with slice of structs here, we don't need to check if the type
+			// implements TextUnmarshaler interface
+			return fmt.Errorf("schema: converter not found for %v", elemT)
+		}
+
+		for key, value := range values {
+			if value == "" {
+				if d.zeroEmpty {
+					items = append(items, reflect.Zero(elemT))
+				}
+			} else if item := conv(value); item.IsValid() {
+				if isPtrElem {
+					ptr := reflect.New(elemT)
+					ptr.Elem().Set(item)
+					item = ptr
+				}
+				if item.Type() != elemT && !isPtrElem {
+					item = item.Convert(elemT)
+				}
+				items = append(items, item)
+			} else {
+				if strings.Contains(value, ",") {
+					values := strings.Split(value, ",")
+					for _, value := range values {
+						if value == "" {
+							if d.zeroEmpty {
+								items = append(items, reflect.Zero(elemT))
+							}
+						} else if item := conv(value); item.IsValid() {
+							if isPtrElem {
+								ptr := reflect.New(elemT)
+								ptr.Elem().Set(item)
+								item = ptr
+							}
+							if item.Type() != elemT && !isPtrElem {
+								item = item.Convert(elemT)
+							}
+							items = append(items, item)
+						} else {
+							return ConversionError{
+								Key:   path,
+								Type:  elemT,
+								Index: key,
+							}
+						}
+					}
+				} else {
+					return ConversionError{
+						Key:   path,
+						Type:  elemT,
+						Index: key,
+					}
+				}
+			}
+		}
+		value := reflect.Append(reflect.MakeSlice(t, 0, 0), items...)
+		v.Set(value)
+	} else {
+		val := ""
+		// Use the last value provided if any values were provided
+		if len(values) > 0 {
+			val = values[len(values)-1]
+		}
+
+		if val == "" {
+			if d.zeroEmpty {
+				v.Set(reflect.Zero(t))
+			}
+		} else if conv != nil {
+			if value := conv(val); value.IsValid() {
+				v.Set(value.Convert(t))
+			} else {
+				return ConversionError{
+					Key:   path,
+					Type:  t,
+					Index: -1,
+				}
+			}
+		} else {
+			// When there's no registered conversion for the custom type, we will check if the type
+			// implements the TextUnmarshaler interface. As the UnmarshalText function should be applied
+			// to the pointer of the type, we convert the value to pointer.
+			if v.CanAddr() {
+				v = v.Addr()
+			}
+
+			if u, ok := v.Interface().(encoding.TextUnmarshaler); ok {
+				if err := u.UnmarshalText([]byte(val)); err != nil {
+					return ConversionError{
+						Key:   path,
+						Type:  t,
+						Index: -1,
+						Err:   err,
+					}
+				}
+
+			} else {
+				return fmt.Errorf("schema: converter not found for %v", t)
+			}
+		}
+	}
+	return nil
+}
+
+// Errors ---------------------------------------------------------------------
+
+// ConversionError stores information about a failed conversion.
+type ConversionError struct {
+	Key   string       // key from the source map.
+	Type  reflect.Type // expected type of elem
+	Index int          // index for multi-value fields; -1 for single-value fields.
+	Err   error        // low-level error (when it exists)
+}
+
+func (e ConversionError) Error() string {
+	var output string
+
+	if e.Index < 0 {
+		output = fmt.Sprintf("schema: error converting value for %q", e.Key)
+	} else {
+		output = fmt.Sprintf("schema: error converting value for index %d of %q",
+			e.Index, e.Key)
+	}
+
+	if e.Err != nil {
+		output = fmt.Sprintf("%s. Details: %s", output, e.Err)
+	}
+
+	return output
+}
+
+// MultiError stores multiple decoding errors.
+//
+// Borrowed from the App Engine SDK.
+type MultiError map[string]error
+
+func (e MultiError) Error() string {
+	s := ""
+	for _, err := range e {
+		s = err.Error()
+		break
+	}
+	switch len(e) {
+	case 0:
+		return "(0 errors)"
+	case 1:
+		return s
+	case 2:
+		return s + " (and 1 other error)"
+	}
+	return fmt.Sprintf("%s (and %d other errors)", s, len(e)-1)
+}