crgimenes/goConfig

package validate

import (
    "fmt"
    "reflect"
    "strconv"
    "strings"

    "crg.eti.br/go/config/structtag"
)

// Prefix is a string that would be placed at the beginning of the generated tags.
var Prefix string

// Usage is the function that is called when an error occurs.
var Usage func()

// Setup maps and variables.
func Setup(tag string, tagDefault string) {
    structtag.Setup()
    structtag.Prefix = Prefix
    SetTag(tag)
    SetTagDefault(tagDefault)

    structtag.ParseMap[reflect.Int64] = reflectInt
    structtag.ParseMap[reflect.Int] = reflectInt
    structtag.ParseMap[reflect.Float64] = reflectFloat
    structtag.ParseMap[reflect.String] = reflectString
    structtag.ParseMap[reflect.Bool] = reflectBool
}

// SetTag set a new tag.
func SetTag(tag string) {
    structtag.Tag = tag
}

// SetTagDefault set a new TagDefault to retorn default values.
func SetTagDefault(tag string) {
    structtag.TagDefault = tag
}

// Parse configuration.
func Parse(config interface{}) (err error) {
    err = structtag.Parse(config, "")
    return
}

// PrintDefaultsOutput changes the default output help string.
var PrintDefaultsOutput string

func getValue(value *reflect.Value, datatype string) (ret string) {
    switch datatype {
    case "bool":
        if value.Bool() {
            ret = "true"
            return
        }
    case "string":
        ret = value.String()
        return
    case "int":
        ret = strconv.FormatInt(value.Int(), 10)
        return
    case "float64":
        f := value.Float()
        ret = strconv.FormatFloat(f, 'f', -1, 64)
        return
    }
    return
}

func reflectInt(field *reflect.StructField, value *reflect.Value, tag string) (err error) {
    req := field.Tag.Get("cfgRequired")
    valueStr := getValue(value, "int")
    if req == "true" && valueStr == "0" {
        err = fmt.Errorf("-%v is required", tag)
    }
    return
}

func reflectFloat(field *reflect.StructField, value *reflect.Value, tag string) (err error) {
    req := field.Tag.Get("cfgRequired")
    valueStr := getValue(value, "float64")
    if req == "true" && valueStr == "0" {
        err = fmt.Errorf("-%v is required", tag)
    }
    return
}

func reflectString(field *reflect.StructField, value *reflect.Value, tag string) (err error) {
    req := field.Tag.Get("cfgRequired")
    valueStr := getValue(value, "string")
    if req == "true" && valueStr == "" {
        err = fmt.Errorf("-%v is required", strings.ToLower(tag))
    }
    return
}

func reflectBool(field *reflect.StructField, value *reflect.Value, tag string) (err error) {
    return
}