structtags

README

structtags

A go package for parsing struct tags based on the pattern used in the encoding packages of the go stdlib.

Usage

See the example in the Go Docs.

Documentation

Overview

Package structtags parses struct tags based on the pattern used in the encoding packages of the go stdlib.

Index

• type Tag
  • func Parse(tag string) Tag
• type TagOptions
  • func (o TagOptions) Contains(option string) bool

Examples

• Parse

Types

type Tag

type Tag struct {
	Value   string
	Options TagOptions
}

Tag contains a tag value and options.

func Parse

func Parse(tag string) Tag

Parse parses a string tag into a Tag struct. A tag defined as `myTag:"value,abc,def"` will be parsed as:

Tag {
  Value: "value",
  Options: ["abc", "def"],
}

Example

package main

import (
	"fmt"
	"reflect"

	"4d63.com/structtags"
)

func main() {
	s := struct {
		A string `myTag:"a,omitempty,flatten"`
		B string `myTag:",omitempty"`
		C int
	}{}

	t := reflect.TypeOf(s)

	for i := 0; i < t.NumField(); i++ {
		f := t.Field(i)

		if tagStr, ok := f.Tag.Lookup("myTag"); ok {
			tag := structtags.Parse(tagStr)

			fmt.Printf("Tag: %#v\n", tag.Value)
			fmt.Println("  Omit Empty:", tag.Options.Contains("omitempty"))
			fmt.Println("  Flatten:", tag.Options.Contains("flatten"))
		}
	}

}

Output:

Tag: "a"
  Omit Empty: true
  Flatten: true
Tag: ""
  Omit Empty: true
  Flatten: false

type TagOptions

type TagOptions []string

TagOptions contains the options for a tag.

func (TagOptions) Contains

func (o TagOptions) Contains(option string) bool

Contains checks if the option is contained in the TagOptions.