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Diffstat (limited to 'vendor/github.com/fatih/structs/structs.go')
| -rw-r--r-- | vendor/github.com/fatih/structs/structs.go | 579 |
1 files changed, 579 insertions, 0 deletions
diff --git a/vendor/github.com/fatih/structs/structs.go b/vendor/github.com/fatih/structs/structs.go new file mode 100644 index 0000000..06da620 --- /dev/null +++ b/vendor/github.com/fatih/structs/structs.go @@ -0,0 +1,579 @@ +// Package structs contains various utilities functions to work with structs. +package structs + +import ( + "fmt" + + "reflect" +) + +var ( + // DefaultTagName is the default tag name for struct fields which provides + // a more granular to tweak certain structs. Lookup the necessary functions + // for more info. + DefaultTagName = "structs" // struct's field default tag name +) + +// Struct encapsulates a struct type to provide several high level functions +// around the struct. +type Struct struct { + raw interface{} + value reflect.Value + TagName string +} + +// New returns a new *Struct with the struct s. It panics if the s's kind is +// not struct. +func New(s interface{}) *Struct { + return &Struct{ + raw: s, + value: strctVal(s), + TagName: DefaultTagName, + } +} + +// Map converts the given struct to a map[string]interface{}, where the keys +// of the map are the field names and the values of the map the associated +// values of the fields. The default key string is the struct field name but +// can be changed in the struct field's tag value. The "structs" key in the +// struct's field tag value is the key name. Example: +// +// // Field appears in map as key "myName". +// Name string `structs:"myName"` +// +// A tag value with the content of "-" ignores that particular field. Example: +// +// // Field is ignored by this package. +// Field bool `structs:"-"` +// +// A tag value with the content of "string" uses the stringer to get the value. Example: +// +// // The value will be output of Animal's String() func. +// // Map will panic if Animal does not implement String(). +// Field *Animal `structs:"field,string"` +// +// A tag value with the option of "flatten" used in a struct field is to flatten its fields +// in the output map. Example: +// +// // The FieldStruct's fields will be flattened into the output map. +// FieldStruct time.Time `structs:",flatten"` +// +// A tag value with the option of "omitnested" stops iterating further if the type +// is a struct. Example: +// +// // Field is not processed further by this package. +// Field time.Time `structs:"myName,omitnested"` +// Field *http.Request `structs:",omitnested"` +// +// A tag value with the option of "omitempty" ignores that particular field if +// the field value is empty. Example: +// +// // Field appears in map as key "myName", but the field is +// // skipped if empty. +// Field string `structs:"myName,omitempty"` +// +// // Field appears in map as key "Field" (the default), but +// // the field is skipped if empty. +// Field string `structs:",omitempty"` +// +// Note that only exported fields of a struct can be accessed, non exported +// fields will be neglected. +func (s *Struct) Map() map[string]interface{} { + out := make(map[string]interface{}) + s.FillMap(out) + return out +} + +// FillMap is the same as Map. Instead of returning the output, it fills the +// given map. +func (s *Struct) FillMap(out map[string]interface{}) { + if out == nil { + return + } + + fields := s.structFields() + + for _, field := range fields { + name := field.Name + val := s.value.FieldByName(name) + isSubStruct := false + var finalVal interface{} + + tagName, tagOpts := parseTag(field.Tag.Get(s.TagName)) + if tagName != "" { + name = tagName + } + + // if the value is a zero value and the field is marked as omitempty do + // not include + if tagOpts.Has("omitempty") { + zero := reflect.Zero(val.Type()).Interface() + current := val.Interface() + + if reflect.DeepEqual(current, zero) { + continue + } + } + + if !tagOpts.Has("omitnested") { + finalVal = s.nested(val) + + v := reflect.ValueOf(val.Interface()) + if v.Kind() == reflect.Ptr { + v = v.Elem() + } + + switch v.Kind() { + case reflect.Map, reflect.Struct: + isSubStruct = true + } + } else { + finalVal = val.Interface() + } + + if tagOpts.Has("string") { + s, ok := val.Interface().(fmt.Stringer) + if ok { + out[name] = s.String() + } + continue + } + + if isSubStruct && (tagOpts.Has("flatten")) { + for k := range finalVal.(map[string]interface{}) { + out[k] = finalVal.(map[string]interface{})[k] + } + } else { + out[name] = finalVal + } + } +} + +// Values converts the given s struct's field values to a []interface{}. A +// struct tag with the content of "-" ignores the that particular field. +// Example: +// +// // Field is ignored by this package. +// Field int `structs:"-"` +// +// A value with the option of "omitnested" stops iterating further if the type +// is a struct. Example: +// +// // Fields is not processed further by this package. +// Field time.Time `structs:",omitnested"` +// Field *http.Request `structs:",omitnested"` +// +// A tag value with the option of "omitempty" ignores that particular field and +// is not added to the values if the field value is empty. Example: +// +// // Field is skipped if empty +// Field string `structs:",omitempty"` +// +// Note that only exported fields of a struct can be accessed, non exported +// fields will be neglected. +func (s *Struct) Values() []interface{} { + fields := s.structFields() + + var t []interface{} + + for _, field := range fields { + val := s.value.FieldByName(field.Name) + + _, tagOpts := parseTag(field.Tag.Get(s.TagName)) + + // if the value is a zero value and the field is marked as omitempty do + // not include + if tagOpts.Has("omitempty") { + zero := reflect.Zero(val.Type()).Interface() + current := val.Interface() + + if reflect.DeepEqual(current, zero) { + continue + } + } + + if tagOpts.Has("string") { + s, ok := val.Interface().(fmt.Stringer) + if ok { + t = append(t, s.String()) + } + continue + } + + if IsStruct(val.Interface()) && !tagOpts.Has("omitnested") { + // look out for embedded structs, and convert them to a + // []interface{} to be added to the final values slice + for _, embeddedVal := range Values(val.Interface()) { + t = append(t, embeddedVal) + } + } else { + t = append(t, val.Interface()) + } + } + + return t +} + +// Fields returns a slice of Fields. A struct tag with the content of "-" +// ignores the checking of that particular field. Example: +// +// // Field is ignored by this package. +// Field bool `structs:"-"` +// +// It panics if s's kind is not struct. +func (s *Struct) Fields() []*Field { + return getFields(s.value, s.TagName) +} + +// Names returns a slice of field names. A struct tag with the content of "-" +// ignores the checking of that particular field. Example: +// +// // Field is ignored by this package. +// Field bool `structs:"-"` +// +// It panics if s's kind is not struct. +func (s *Struct) Names() []string { + fields := getFields(s.value, s.TagName) + + names := make([]string, len(fields)) + + for i, field := range fields { + names[i] = field.Name() + } + + return names +} + +func getFields(v reflect.Value, tagName string) []*Field { + if v.Kind() == reflect.Ptr { + v = v.Elem() + } + + t := v.Type() + + var fields []*Field + + for i := 0; i < t.NumField(); i++ { + field := t.Field(i) + + if tag := field.Tag.Get(tagName); tag == "-" { + continue + } + + f := &Field{ + field: field, + value: v.FieldByName(field.Name), + } + + fields = append(fields, f) + + } + + return fields +} + +// Field returns a new Field struct that provides several high level functions +// around a single struct field entity. It panics if the field is not found. +func (s *Struct) Field(name string) *Field { + f, ok := s.FieldOk(name) + if !ok { + panic("field not found") + } + + return f +} + +// FieldOk returns a new Field struct that provides several high level functions +// around a single struct field entity. The boolean returns true if the field +// was found. +func (s *Struct) FieldOk(name string) (*Field, bool) { + t := s.value.Type() + + field, ok := t.FieldByName(name) + if !ok { + return nil, false + } + + return &Field{ + field: field, + value: s.value.FieldByName(name), + defaultTag: s.TagName, + }, true +} + +// IsZero returns true if all fields in a struct is a zero value (not +// initialized) A struct tag with the content of "-" ignores the checking of +// that particular field. Example: +// +// // Field is ignored by this package. +// Field bool `structs:"-"` +// +// A value with the option of "omitnested" stops iterating further if the type +// is a struct. Example: +// +// // Field is not processed further by this package. +// Field time.Time `structs:"myName,omitnested"` +// Field *http.Request `structs:",omitnested"` +// +// Note that only exported fields of a struct can be accessed, non exported +// fields will be neglected. It panics if s's kind is not struct. +func (s *Struct) IsZero() bool { + fields := s.structFields() + + for _, field := range fields { + val := s.value.FieldByName(field.Name) + + _, tagOpts := parseTag(field.Tag.Get(s.TagName)) + + if IsStruct(val.Interface()) && !tagOpts.Has("omitnested") { + ok := IsZero(val.Interface()) + if !ok { + return false + } + + continue + } + + // zero value of the given field, such as "" for string, 0 for int + zero := reflect.Zero(val.Type()).Interface() + + // current value of the given field + current := val.Interface() + + if !reflect.DeepEqual(current, zero) { + return false + } + } + + return true +} + +// HasZero returns true if a field in a struct is not initialized (zero value). +// A struct tag with the content of "-" ignores the checking of that particular +// field. Example: +// +// // Field is ignored by this package. +// Field bool `structs:"-"` +// +// A value with the option of "omitnested" stops iterating further if the type +// is a struct. Example: +// +// // Field is not processed further by this package. +// Field time.Time `structs:"myName,omitnested"` +// Field *http.Request `structs:",omitnested"` +// +// Note that only exported fields of a struct can be accessed, non exported +// fields will be neglected. It panics if s's kind is not struct. +func (s *Struct) HasZero() bool { + fields := s.structFields() + + for _, field := range fields { + val := s.value.FieldByName(field.Name) + + _, tagOpts := parseTag(field.Tag.Get(s.TagName)) + + if IsStruct(val.Interface()) && !tagOpts.Has("omitnested") { + ok := HasZero(val.Interface()) + if ok { + return true + } + + continue + } + + // zero value of the given field, such as "" for string, 0 for int + zero := reflect.Zero(val.Type()).Interface() + + // current value of the given field + current := val.Interface() + + if reflect.DeepEqual(current, zero) { + return true + } + } + + return false +} + +// Name returns the structs's type name within its package. For more info refer +// to Name() function. +func (s *Struct) Name() string { + return s.value.Type().Name() +} + +// structFields returns the exported struct fields for a given s struct. This +// is a convenient helper method to avoid duplicate code in some of the +// functions. +func (s *Struct) structFields() []reflect.StructField { + t := s.value.Type() + + var f []reflect.StructField + + for i := 0; i < t.NumField(); i++ { + field := t.Field(i) + // we can't access the value of unexported fields + if field.PkgPath != "" { + continue + } + + // don't check if it's omitted + if tag := field.Tag.Get(s.TagName); tag == "-" { + continue + } + + f = append(f, field) + } + + return f +} + +func strctVal(s interface{}) reflect.Value { + v := reflect.ValueOf(s) + + // if pointer get the underlying element≤ + for v.Kind() == reflect.Ptr { + v = v.Elem() + } + + if v.Kind() != reflect.Struct { + panic("not struct") + } + + return v +} + +// Map converts the given struct to a map[string]interface{}. For more info +// refer to Struct types Map() method. It panics if s's kind is not struct. +func Map(s interface{}) map[string]interface{} { + return New(s).Map() +} + +// FillMap is the same as Map. Instead of returning the output, it fills the +// given map. +func FillMap(s interface{}, out map[string]interface{}) { + New(s).FillMap(out) +} + +// Values converts the given struct to a []interface{}. For more info refer to +// Struct types Values() method. It panics if s's kind is not struct. +func Values(s interface{}) []interface{} { + return New(s).Values() +} + +// Fields returns a slice of *Field. For more info refer to Struct types +// Fields() method. It panics if s's kind is not struct. +func Fields(s interface{}) []*Field { + return New(s).Fields() +} + +// Names returns a slice of field names. For more info refer to Struct types +// Names() method. It panics if s's kind is not struct. +func Names(s interface{}) []string { + return New(s).Names() +} + +// IsZero returns true if all fields is equal to a zero value. For more info +// refer to Struct types IsZero() method. It panics if s's kind is not struct. +func IsZero(s interface{}) bool { + return New(s).IsZero() +} + +// HasZero returns true if any field is equal to a zero value. For more info +// refer to Struct types HasZero() method. It panics if s's kind is not struct. +func HasZero(s interface{}) bool { + return New(s).HasZero() +} + +// IsStruct returns true if the given variable is a struct or a pointer to +// struct. +func IsStruct(s interface{}) bool { + v := reflect.ValueOf(s) + if v.Kind() == reflect.Ptr { + v = v.Elem() + } + + // uninitialized zero value of a struct + if v.Kind() == reflect.Invalid { + return false + } + + return v.Kind() == reflect.Struct +} + +// Name returns the structs's type name within its package. It returns an +// empty string for unnamed types. It panics if s's kind is not struct. +func Name(s interface{}) string { + return New(s).Name() +} + +// nested retrieves recursively all types for the given value and returns the +// nested value. +func (s *Struct) nested(val reflect.Value) interface{} { + var finalVal interface{} + + v := reflect.ValueOf(val.Interface()) + if v.Kind() == reflect.Ptr { + v = v.Elem() + } + + switch v.Kind() { + case reflect.Struct: + n := New(val.Interface()) + n.TagName = s.TagName + m := n.Map() + + // do not add the converted value if there are no exported fields, ie: + // time.Time + if len(m) == 0 { + finalVal = val.Interface() + } else { + finalVal = m + } + case reflect.Map: + v := val.Type().Elem() + if v.Kind() == reflect.Ptr { + v = v.Elem() + } + + // only iterate over struct types, ie: map[string]StructType, + // map[string][]StructType, + if v.Kind() == reflect.Struct || + (v.Kind() == reflect.Slice && v.Elem().Kind() == reflect.Struct) { + m := make(map[string]interface{}, val.Len()) + for _, k := range val.MapKeys() { + m[k.String()] = s.nested(val.MapIndex(k)) + } + finalVal = m + break + } + + // TODO(arslan): should this be optional? + finalVal = val.Interface() + case reflect.Slice, reflect.Array: + if val.Type().Kind() == reflect.Interface { + finalVal = val.Interface() + break + } + + // TODO(arslan): should this be optional? + // do not iterate of non struct types, just pass the value. Ie: []int, + // []string, co... We only iterate further if it's a struct. + // i.e []foo or []*foo + if val.Type().Elem().Kind() != reflect.Struct && + !(val.Type().Elem().Kind() == reflect.Ptr && + val.Type().Elem().Elem().Kind() == reflect.Struct) { + finalVal = val.Interface() + break + } + + slices := make([]interface{}, val.Len(), val.Len()) + for x := 0; x < val.Len(); x++ { + slices[x] = s.nested(val.Index(x)) + } + finalVal = slices + default: + finalVal = val.Interface() + } + + return finalVal +} |