structs

Documentation

Overview

Package structs provides functions for struct information retrieving and struct conversion.

Inspired and improved from: https://github.com/fatih/structs

Index

• Constants
• func FieldMap(input FieldMapInput) (map[string]*Field, error)
• func ParseTag(tag string) map[string]string
• func TagMapField(object interface{}, priority []string) (map[string]*Field, error)
• func TagMapName(pointer interface{}, priority []string) (map[string]string, error)
• type Field
  • func TagFields(pointer interface{}, priority []string) ([]*Field, error)
  • func (f *Field) IsEmbedded() bool
  • func (f *Field) IsExported() bool
  • func (f *Field) Kind() reflect.Kind
  • func (f *Field) Name() string
  • func (f *Field) OriginalKind() reflect.Kind
  • func (f *Field) Tag(key string) string
  • func (f *Field) TagLookup(key string) (value string, ok bool)
  • func (f *Field) TagStr() string
  • func (f *Field) Type() Type
• type FieldMapInput
• type Type
  • func StructType(object interface{}) (*Type, error)
  • func (t Type) FieldKeys() []string
  • func (t Type) Signature() string

Constants

const (
	RecursiveOptionNone          = 0 // No recursively retrieving fields as map if the field is an embedded struct.
	RecursiveOptionEmbedded      = 1 // Recursively retrieving fields as map if the field is an embedded struct.
	RecursiveOptionEmbeddedNoTag = 2 // Recursively retrieving fields as map if the field is an embedded struct and the field has no tag.
)

Functions

func FieldMap

func FieldMap(input FieldMapInput) (map[string]*Field, error)

FieldMap retrieves and returns struct field as map[name/tag]*Field from `pointer`.

The parameter `pointer` should be type of struct/*struct.

The parameter `priority` specifies the priority tag array for retrieving from high to low. If it's given `nil`, it returns map[name]*Field, of which the `name` is attribute name.

The parameter `recursive` specifies the whether retrieving the fields recursively if the attribute is an embedded struct.

Note that it only retrieves the exported attributes with first letter up-case from struct.

func ParseTag

func ParseTag(tag string) map[string]string

ParseTag parses tag string into map.

func TagMapField

func TagMapField(object interface{}, priority []string) (map[string]*Field, error)

TagMapField retrieves struct tags as map[tag]*Field from `pointer`, and returns it. The parameter `object` should be either type of struct/*struct/[]struct/[]*struct.

Note that it only retrieves the exported attributes with first letter up-case from struct.

func TagMapName

func TagMapName(pointer interface{}, priority []string) (map[string]string, error)

TagMapName retrieves and returns struct tags as map[tag]attribute from `pointer`.

The parameter `pointer` should be type of struct/*struct.

Note that it only retrieves the exported attributes with first letter up-case from struct.

Types

type Field

type Field struct {
	Value    reflect.Value       // The underlying value of the field.
	Field    reflect.StructField // The underlying field of the field.
	TagValue string              // Retrieved tag value. There might be more than one tags in the field, but only one can be retrieved according to calling function rules.
}

Field contains information of a struct field .

func TagFields

func TagFields(pointer interface{}, priority []string) ([]*Field, error)

TagFields retrieves and returns struct tags as []*Field from `pointer`.

The parameter `pointer` should be type of struct/*struct.

Note that it only retrieves the exported attributes with first letter up-case from struct.

func (*Field) IsEmbedded

func (f *Field) IsEmbedded() bool

IsEmbedded returns true if the given field is an anonymous field (embedded)

func (*Field) IsExported

func (f *Field) IsExported() bool

IsExported returns true if the given field is exported.

func (*Field) Kind

func (f *Field) Kind() reflect.Kind

Kind returns the reflect.Kind for Value of Field `f`.

func (*Field) Name

func (f *Field) Name() string

Name returns the name of the given field

func (*Field) OriginalKind

func (f *Field) OriginalKind() reflect.Kind

OriginalKind retrieves and returns the original reflect.Kind for Value of Field `f`.

func (*Field) Tag

func (f *Field) Tag(key string) string

Tag returns the value associated with key in the tag string. If there is no such key in the tag, Tag returns the empty string.

func (*Field) TagLookup

func (f *Field) TagLookup(key string) (value string, ok bool)

TagLookup returns the value associated with key in the tag string. If the key is present in the tag the value (which may be empty) is returned. Otherwise, the returned value will be the empty string. The ok return value reports whether the value was explicitly set in the tag string. If the tag does not have the conventional format, the value returned by Lookup is unspecified.

func (*Field) TagStr

func (f *Field) TagStr() string

TagStr returns the tag string of the field.

func (*Field) Type

func (f *Field) Type() Type

Type returns the type of the given field

type FieldMapInput

type FieldMapInput struct {
	// Pointer should be type of struct/*struct.
	Pointer interface{}

	// PriorityTagArray specifies the priority tag array for retrieving from high to low.
	// If it's given `nil`, it returns map[name]*Field, of which the `name` is attribute name.
	PriorityTagArray []string

	// RecursiveOption specifies the way retrieving the fields recursively if the attribute
	// is an embedded struct. It is RecursiveOptionNone in default.
	RecursiveOption int
}

type Type

type Type struct {
	reflect.Type
}

Type wraps reflect.Type for additional features.

func StructType

func StructType(object interface{}) (*Type, error)

StructType retrieves and returns the struct Type of specified struct/*struct. The parameter `object` should be either type of struct/*struct/[]struct/[]*struct.

func (Type) FieldKeys

func (t Type) FieldKeys() []string

FieldKeys returns the keys of current struct/map.

func (Type) Signature

func (t Type) Signature() string

Signature returns a unique string as this type.