textra

A package designed to extract and work with go structs as values. Types & Tags export

Programming language: Go

License: BSD 3-clause "New" or "Revised" License

Tags: Go Tools    

README

Textra

Textra is a simple and fast tag extractor package that helps to work with structs tags. It also has json tags for all structs, in case of JSON output.

Initially I built it for another private project, but decided to try to open-source it, since it could be useful in some use-cases. Because of that it has some features that feels redundant, like having field type as a part of returned data

Documentation

Installation

go get github.com/Ravcii/textra

Examples

Basic usage:

type Tester struct {
    NoTags   bool
    WithTag  string `json:"with_tag,omitempty"`
    WithTags string `json:"with_tags"          sql:"with_tag"`
    SqlOnly  string `sql:"sql_only"`
}

func main() {
    fields := textra.Extract((*Tester)(nil))
    for _, field := range fields {
        fmt.Println(field)
    }
}

NoTags(bool):[]
WithTag(string):[json:"with_tag,omitempty"]
WithTags(string):[json:"with_tags" sql:"with_tag"]
SqlOnly(string):[sql:"sql_only"]

You can look at return types at go.doc, basically it returns a slice of fields with its types (as strings) and a slice of Tags for each field.

Now let's apply some functions:

fields := textra.Extract((*Tester)(nil)).RemoveEmpty()

WithTag(string):[json:"with_tag,omitempty"]
WithTags(string):[json:"with_tags" sql:"with_tag"]
SqlOnly(string):[sql:"sql_only"]

What if we care only about SQL tags?

fields := textra.Extract((*Tester)(nil)).RemoveEmpty().Only("sql")

{WithTags string sql:"with_tag"}
{SqlOnly string sql:"sql_only"}

Only() is a bit special as it returns a Field of a different type, with Tag rather than Tags

Although it may be redundant, it also parses types a their string representation (for easier comparsion or output, if you need it)

type Types struct {
    intType         int
    byteType        byte
    runeType        rune
    stringType      string
    booleanType     bool
    sliceStringType []string
    mapType         map[string]string
    chanType        chan int
    funcType        func() error
    importType      time.Time
    pointerType     *string
}

func main() {
    fields := textra.Extract((*Types)(nil))
    for _, field := range fields {
        fmt.Println(field.Name, field.Type)
    }
}

intType int
byteType uint8
runeType int32
stringType string
booleanType bool
sliceStringType slice
mapType map
chanType chan
funcType func
importType time.Time
pointerType *string

TODO

• [x] Better README.md (i hope)
• [x] Add blacklisting (RemoveFields)
• [ ] Examples for go.dev
• [x] Some sugar for common tags
  • [x] ByName to get tag for each field
  • [x] Omitempty for "*,omitempty"
  • [x] Ignored for "-"
• [x] Better string representation
• [ ] ...?