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author | Christopher Speller <crspeller@gmail.com> | 2018-02-16 06:47:51 -0800 |
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committer | Joram Wilander <jwawilander@gmail.com> | 2018-02-16 09:47:51 -0500 |
commit | 6d8f122a5160f6d9e4c51579f2429dfaa62c7271 (patch) | |
tree | 6e0242cd6709260abd74060a7ec7dc1381efa36e /vendor/github.com/gorilla/schema/decoder.go | |
parent | b112747de76f9c11c4d8083207049fac6e435019 (diff) | |
download | chat-6d8f122a5160f6d9e4c51579f2429dfaa62c7271.tar.gz chat-6d8f122a5160f6d9e4c51579f2429dfaa62c7271.tar.bz2 chat-6d8f122a5160f6d9e4c51579f2429dfaa62c7271.zip |
Upgrading server dependancies (#8308)
Diffstat (limited to 'vendor/github.com/gorilla/schema/decoder.go')
-rw-r--r-- | vendor/github.com/gorilla/schema/decoder.go | 420 |
1 files changed, 420 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 000000000..e49b53c87 --- /dev/null +++ b/vendor/github.com/gorilla/schema/decoder.go @@ -0,0 +1,420 @@ +// 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.registerConverter(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 d.checkRequired(t, src, "") +} + +// checkRequired checks whether required fields are empty +// +// check type t recursively if t has struct fields, and prefix is same as parsePath: in dotted notation +// +// src is the source map for decoding, we use it here to see if those required fields are included in src +func (d *Decoder) checkRequired(t reflect.Type, src map[string][]string, prefix string) error { + struc := d.cache.get(t) + if struc == nil { + // unexpect, cache.get never return nil + return errors.New("cache fail") + } + + for _, f := range struc.fields { + if f.typ.Kind() == reflect.Struct { + err := d.checkRequired(f.typ, src, prefix+f.alias+".") + if err != nil { + if !f.anon { + return err + } + // check embedded parent field. + err2 := d.checkRequired(f.typ, src, prefix) + if err2 != nil { + return err + } + } + } + if f.required { + key := f.alias + if prefix != "" { + key = prefix + key + } + if isEmpty(f.typ, src[key]) { + return fmt.Errorf("%v is empty", key) + } + } + } + return nil +} + +// isEmpty returns true if value is empty for specific type +func isEmpty(t reflect.Type, value []string) bool { + if len(value) == 0 { + return true + } + switch t.Kind() { + case boolType, float32Type, float64Type, intType, int8Type, int32Type, int64Type, stringType, uint8Type, uint16Type, uint32Type, uint64Type: + return len(value[0]) == 0 + } + return false +} + +// 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) + m := isTextUnmarshaler(v) + if conv == nil && t.Kind() == reflect.Slice && m.IsSlice { + 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 { + conv = builtinConverters[elemT.Kind()] + 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 m.IsValid { + u := reflect.New(elemT) + if m.IsPtr { + u = reflect.New(reflect.PtrTo(elemT).Elem()) + } + if err := u.Interface().(encoding.TextUnmarshaler).UnmarshalText([]byte(value)); err != nil { + return ConversionError{ + Key: path, + Type: t, + Index: key, + Err: err, + } + } + if m.IsPtr { + items = append(items, u.Elem().Addr()) + } else if u.Kind() == reflect.Ptr { + items = append(items, u.Elem()) + } else { + items = append(items, u) + } + } 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 if m.IsValid { + // If the value implements the encoding.TextUnmarshaler interface + // apply UnmarshalText as the converter + if err := m.Unmarshaler.UnmarshalText([]byte(val)); err != nil { + return ConversionError{ + Key: path, + Type: t, + Index: -1, + Err: err, + } + } + } else if conv := builtinConverters[t.Kind()]; conv != nil { + if value := conv(val); value.IsValid() { + v.Set(value.Convert(t)) + } else { + return ConversionError{ + Key: path, + Type: t, + Index: -1, + } + } + } else { + return fmt.Errorf("schema: converter not found for %v", t) + } + } + return nil +} + +func isTextUnmarshaler(v reflect.Value) unmarshaler { + + // Create a new unmarshaller instance + m := unmarshaler{} + + // 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 m.Unmarshaler, m.IsValid = v.Interface().(encoding.TextUnmarshaler); m.IsValid { + return m + } + + // if v is []T or *[]T create new T + t := v.Type() + if t.Kind() == reflect.Ptr { + t = t.Elem() + } + if t.Kind() == reflect.Slice { + // if t is a pointer slice, check if it implements encoding.TextUnmarshaler + m.IsSlice = true + if t = t.Elem(); t.Kind() == reflect.Ptr { + t = reflect.PtrTo(t.Elem()) + v = reflect.Zero(t) + m.IsPtr = true + m.Unmarshaler, m.IsValid = v.Interface().(encoding.TextUnmarshaler) + return m + } + } + + v = reflect.New(t) + m.Unmarshaler, m.IsValid = v.Interface().(encoding.TextUnmarshaler) + return m +} + +// TextUnmarshaler helpers ---------------------------------------------------- +// unmarshaller contains information about a TextUnmarshaler type +type unmarshaler struct { + Unmarshaler encoding.TextUnmarshaler + IsSlice bool + IsPtr bool + IsValid bool +} + +// 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) +} |