udemy-go-web-1/internal/forms/forms.go

package forms

import (
	"fmt"
	"net/http"
	"net/url"
	"strings"

	"github.com/asaskevich/govalidator"
)

// Form creates a custom form struct, embeds a url.Values object
type Form struct {
	url.Values
	Errors errors
}

// New initializes a form struct
func New(data url.Values) *Form {
	return &Form{
		data,
		errors(map[string][]string{}),
	}
}

// Required checks required fields
func (f *Form) Required(fields ...string) {
    for _, field := range fields {
        value := f.Get(field)
        if strings.TrimSpace(value) == "" {
            f.Errors.Add(field, "This field cannot be blank")
        }
    }
}

// Has checks if form field is in post and not emtpy
func (f *Form) Has(field string, r *http.Request) bool {
	x := r.Form.Get(field)
    return x != ""
}

// Valid returns true if there are no errors, otherwise false
func (f *Form) Valid() bool {
	return len(f.Errors) == 0
}

// MinLength checks for string minimum length
func (f *Form) MinLength(field string, length int, r *http.Request) bool {
    value := r.Form.Get(field)
    if len(value) < length {
        f.Errors.Add(field, fmt.Sprintf("This field must have at least %d letters", length))
        return false
    }
    return true
}

// IsEmail checks the email address
func (f *Form) IsEmail(field string, r *http.Request) {
    value := r.Form.Get(field)
    if !govalidator.IsEmail(value) {
        f.Errors.Add(field, "Invalid email address")
    }
}