TagX

Extract tag values from any Go struct fields

Install

go get github.com/dergus/tagx

Features

Extract tag values by a tag key as a hierarchical data structure
Extract tag values by a tag key as a flat array of strings concatenated by a given delimiter

Usage

Extract

type S struct {
    FieldA       int `json:"field_a"`
    NestedStruct struct {
    NestedFieldA        string `json:"nested_field_a"`
        AnotherNestedStruct struct {
        AnotherNestedField int `json:"another_nested_field"`
        } `json:"another_nested_struct"`
    } `json:"nested_struct"`
}

tags := tagx.Extract(S{}, "json")

// tags
[]tagx.Tag{
	{
		Value:"field_a",
	},
	{
		Value:"nested_struct",
		Children: []tagx.Tag{
			{
				Value: "nested_field_a",
			},
			{
				Value: "another_nested_struct",
				Children: []tagx.Tag{
					{
						Value:"another_nested_field",
					}
                }
            }
        }
	}
}

ExtractFlat

type S struct {
    FieldA       int `json:"field_a"`
    NestedStruct struct {
    NestedFieldA        string `json:"nested_field_a"`
        AnotherNestedStruct struct {
        AnotherNestedField int `json:"another_nested_field"`
        } `json:"another_nested_struct"`
    } `json:"nested_struct"`
}

tags := tagx.ExtractFlat(S{}, "json", ".")

// tags
[]string{
    "field_a",
    "nested_struct.nested_field_a",
    "nested_struct.another_nested_struct.another_nested_field",
}

Caveats

Only tag value is returned, options(e.g. omitempty for the json tag) are omitted
Private Fields (with tag value -) are ignored and not returned
Empty tag values or just whitespace values are ignored and not returned
Fields of recursive structs aren't explored

License

This project is MIT licensed.