GitHub - tiendc/go-validator: Intuitive validation library for Golang (original) (raw)

Fast and intuitive validation library for Go

This lib uses the Is... validation functions from the govalidator project.

Installation

go get github.com/tiendc/go-validator

Usage

General usage

import (
    vld "github.com/tiendc/go-validator"
)

type Person struct {
    FirstName string
    LastName  string
    Birthdate time.Time

    Unemployed bool
    Salary     uint
    Rank       string
    WorkEmail  string
    Projects   []string
    TaskMap    map[string]Task
}
var p Person

errs := vld.Validate(
    // Validate first and last names separately
    vld.StrLen(&p.FirstName, 3, 30).OnError(
        vld.SetField("first_name", nil),
        vld.SetCustomKey("ERR_VLD_PERSON_FIRST_NAME_INVALID"),
    ),
    vld.StrLen(&p.FirstName, 3, 30).OnError(
        vld.SetField("last_name", nil),
        vld.SetCustomKey("ERR_VLD_PERSON_LAST_NAME_INVALID"),
    ),

    // OR use this to produce only one error when one of them fails
    vld.Group(
        vld.StrLen(&p.FirstName, 3, 30),
        vld.StrLen(&p.LastName, 3, 30),
    ).OnError(
        vld.SetField("name", nil),
        vld.SetCustomKey("ERR_VLD_PERSON_NAME_INVALID"),
    ),

    // Birthdate is optional, but when it's present, it must be within 1950 and now
    vld.When(!p.Birthdate.IsZero()).Then(
        vld.TimeRange(p.Birthdate, <1950-01-01>, time.Now()).OnError(...),
    )

    vld.When(!p.Unemployed).Then(
        vld.Required(&p.Salary),
        // Work email must be valid
        vld.StrIsEmail(&p.WorkEmail),

        // Rank must be one of the constants
        vld.StrIn(&p.Rank, "Employee", "Manager", "Director"),
        vld.Case(
            vld.When(p.Rank == "Manager").Then(vld.NumGT(&p.Salary, 10000)),
            vld.When(p.Rank == "Director").Then(vld.NumGT(&p.Salary, 30000)),
        ).Default(
            vld.NumLT(&p.Salary, 10000),
        ),

        // Projects are optional, but when they are present, they must be unique and sorted
        vld.When(len(p.Projects) > 0).Then(
            vld.SliceUnique(p.Projects).OnError(...),
            vld.SliceSorted(p.Projects).OnError(...),
        )
    ).Else(
        // When person is unemployed
        vld.NumEQ(&p.Salary, 0),
        vld.StrEQ(&p.WorkEmail, ""),
    ),

    // Validate slice elements
    vld.Slice(p.Projects).ForEach(func(elem int, index int, validator ItemValidator) {
        validator.Validate(
            vld.StrLen(&elem, 10, 30).OnError(
                vld.SetField(fmt.Sprintf("projects[%d]", index), nil),
                vld.SetCustomKey("ERR_VLD_PROJECT_NAME_INVALID"),
            ),
        )
    }),

    // Validate map entries
    vld.Map(p.TaskMap).ForEach(func(k string, v Task, validator ItemValidator) {
        validator.Validate(
            vld.StrLen(&v.Name, 10, 30).OnError(
                vld.SetField(fmt.Sprintf("taskMap[%s].name", k), nil),
                vld.SetCustomKey("ERR_VLD_TASK_NAME_INVALID"),
            ),
        )
    }),

    // OTHER FUNCTIONS
    // Pass if at least one of the validations passes
    vld.OneOf(
        // List of validations
    ),

    // Pass if exact one of the validations passes
    vld.ExactOneOf(
        // List of validations
    ),

    // Pass if none of the validations passes
    vld.NotOf(
        // List of validations
    ),
)

for _, e := range errs {
    detail, warnErr := e.BuildDetail()
    fmt.Printf("%+v\n", detail)
}

Error message localization

• Method 1: inline localization (not recommended)

  errs := Validate( NumLTE(&p.Age, 40).OnError( // Override the default template in english SetTemplate("Tuổi nhân viên phải nhỏ hơn hoặc bằng {{.Max}}"), ), )

  for _, e := range errs { detail, warnErr := e.BuildDetail() fmt.Printf("%+v\n", detail) }

• Method 2: using another localization lib (recommended)

  // Supposed you have 2 files defining error messages // In error_messages.en: // ERR_VLD_EMPLOYEE_AGE_TOO_BIG = "Employee {{.EmployeeName}} has age bigger than {{.Max}}" // In error_messages.vi: // ERR_VLD_EMPLOYEE_AGE_TOO_BIG = "Nhân viên {{.EmployeeName}} có tuổi lớn hơn {{.Max}}"

  errs := Validate( NumLTE(&p.Age, 40).OnError( // Custom param (the default template doesn't have this one) SetParam("EmployeeName", p.Name), // Custom key to define custom template to use SetCustomKey("ERR_VLD_EMPLOYEE_AGE_TOO_BIG"), ), )

  for _, e := range errs { errKey := e.CustomKey() errParams : = e.Params() // or e.ParamsWithFormatter() errorMsg := translationFunction(errKey, errParams) // You need to provide this function fmt.Printf("%+v\n", errorMsg) }

Custom error param formatter

errs := Validate(
    NumLT(&budget, 1000000).OnError(
        SetField("Budget", nil),
    ),
)

// e.BuildDetail() may produce message `Budget must be less than 1000000`,
// but you may want a message like: `Budget must be less than 1,000,000`.
// Let's use a custom formatter

errs := Validate(
    NumLT(&budget, 1000000).OnError(
        SetField("Budget", nil),
        SetNumParamFormatter(NewDecimalFormatFunc('.', ',', "%f")),
    ),
)

Contributing

• You are welcome to make pull requests for new functions and bug fixes.

License

• MIT License