Handle tax details and new tax forms with structs and validation

I implemented the Valuer and Scanner interfaces to InputField and
SelectField for better passing values between the database and Go.  I
had a conflict with the Value name and renamed the struct member to Val.

I also had to change the attributes array to be of type
template.HTMLAttr or html/template would replace `form="newtax"`
attribute to `zgotmplz="newtax"` because it deems it “unsafe”.  I do
not like having to use template.HTMLAttr when assigning values, but
i do not know what else i can do now.

pkg/company.go

@@ -3,6 +3,7 @@ package pkg
 import (
 	"context"
 	"errors"
+	"html/template"
 	"net/http"
 	"net/url"
 	"strconv"
@@ -82,54 +83,202 @@ type Tax struct {
 	Rate int
 }
 
+type taxDetailsForm struct {
+	locale       *Locale
+	BusinessName *InputField
+	VATIN        *InputField
+	TradeName    *InputField
+	Phone        *InputField
+	Email        *InputField
+	Web          *InputField
+	Address      *InputField
+	City         *InputField
+	Province     *InputField
+	PostalCode   *InputField
+	Country      *SelectField
+	Currency     *SelectField
+}
+
+func newTaxDetailsForm(ctx context.Context, conn *Conn, locale *Locale) *taxDetailsForm {
+	return &taxDetailsForm{
+		locale: locale,
+		BusinessName: &InputField{
+			Name:     "business_name",
+			Label:    pgettext("input", "Business name", locale),
+			Type:     "text",
+			Required: true,
+			Attributes: []template.HTMLAttr{
+				`autocomplete="organization"`,
+			},
+		},
+		VATIN: &InputField{
+			Name:     "vatin",
+			Label:    pgettext("input", "VAT number", locale),
+			Type:     "text",
+			Required: true,
+		},
+		TradeName: &InputField{
+			Name:  "trade_name",
+			Label: pgettext("input", "Trade name", locale),
+			Type:  "text",
+		},
+		Phone: &InputField{
+			Name:     "phone",
+			Label:    pgettext("input", "Phone", locale),
+			Type:     "tel",
+			Required: true,
+			Attributes: []template.HTMLAttr{
+				`autocomplete="tel"`,
+			},
+		},
+		Email: &InputField{
+			Name:     "email",
+			Label:    pgettext("input", "Email", locale),
+			Type:     "email",
+			Required: true,
+			Attributes: []template.HTMLAttr{
+				`autocomplete="email"`,
+			},
+		},
+		Web: &InputField{
+			Name:  "web",
+			Label: pgettext("input", "Web", locale),
+			Type:  "url",
+			Attributes: []template.HTMLAttr{
+				`autocomplete="url"`,
+			},
+		},
+		Address: &InputField{
+			Name:     "address",
+			Label:    pgettext("input", "Address", locale),
+			Type:     "text",
+			Required: true,
+			Attributes: []template.HTMLAttr{
+				`autocomplete="address-line1"`,
+			},
+		},
+		City: &InputField{
+			Name:     "city",
+			Label:    pgettext("input", "City", locale),
+			Type:     "text",
+			Required: true,
+		},
+		Province: &InputField{
+			Name:     "province",
+			Label:    pgettext("input", "Province", locale),
+			Type:     "text",
+			Required: true,
+		},
+		PostalCode: &InputField{
+			Name:     "postal_code",
+			Label:    pgettext("input", "Postal code", locale),
+			Type:     "text",
+			Required: true,
+			Attributes: []template.HTMLAttr{
+				`autocomplete="postal-code"`,
+			},
+		},
+		Country: &SelectField{
+			Name:     "country",
+			Label:    pgettext("input", "Country", locale),
+			Options:  mustGetCountryOptions(ctx, conn, locale),
+			Selected: "ES",
+			Attributes: []template.HTMLAttr{
+				`autocomplete="country"`,
+			},
+		},
+		Currency: &SelectField{
+			Name:     "currency",
+			Label:    pgettext("input", "Currency", locale),
+			Options:  MustGetOptions(ctx, conn, "select currency_code, currency_symbol from currency order by currency_code"),
+			Selected: "EUR",
+		},
+	}
+}
+
+func (form *taxDetailsForm) Parse(r *http.Request) error {
+	if err := r.ParseForm(); err != nil {
+		return err
+	}
+	form.BusinessName.FillValue(r)
+	form.VATIN.FillValue(r)
+	form.TradeName.FillValue(r)
+	form.Phone.FillValue(r)
+	form.Email.FillValue(r)
+	form.Web.FillValue(r)
+	form.Address.FillValue(r)
+	form.City.FillValue(r)
+	form.Province.FillValue(r)
+	form.PostalCode.FillValue(r)
+	form.Country.FillValue(r)
+	form.Currency.FillValue(r)
+	return nil
+}
+
+func (form *taxDetailsForm) Validate(ctx context.Context, conn *Conn) bool {
+	validator := newFormValidator()
+	validator.CheckRequiredInput(form.BusinessName, gettext("Business name can not be empty.", form.locale))
+	if validator.CheckRequiredInput(form.VATIN, gettext("VAT number can not be empty.", form.locale)) {
+		validator.CheckValidVATINInput(form.VATIN, form.Country.Selected, gettext("This value is not a valid VAT number.", form.locale))
+	}
+	if validator.CheckRequiredInput(form.Phone, gettext("Phone can not be empty.", form.locale)) {
+		validator.CheckValidPhoneInput(form.Phone, form.Country.Selected, gettext("This value is not a valid phone number.", form.locale))
+	}
+	if validator.CheckRequiredInput(form.Email, gettext("Email can not be empty.", form.locale)) {
+		validator.CheckValidEmailInput(form.Email, gettext("This value is not a valid email. It should be like name@domain.com.", form.locale))
+	}
+	if form.Web.Val != "" {
+		validator.checkValidURL(form.Web, gettext("This value is not a valid web address. It should be like https://domain.com/.", form.locale))
+	}
+	validator.CheckRequiredInput(form.Address, gettext("Address can not be empty.", form.locale))
+	validator.CheckRequiredInput(form.City, gettext("City can not be empty.", form.locale))
+	validator.CheckRequiredInput(form.Province, gettext("Province can not be empty.", form.locale))
+	if validator.CheckRequiredInput(form.PostalCode, gettext("Postal code can not be empty.", form.locale)) {
+		validator.CheckValidPostalCode(ctx, conn, form.PostalCode, form.Country.Selected, gettext("This value is not a valid postal code.", form.locale))
+	}
+	validator.CheckValidSelectOption(form.Country, gettext("Selected country is not valid.", form.locale))
+	validator.CheckValidSelectOption(form.Currency, gettext("Selected currency is not valid.", form.locale))
+	return validator.AllOK()
+}
+
+func (form *taxDetailsForm) mustFillFromDatabase(ctx context.Context, conn *Conn, company *Company) *taxDetailsForm {
+	err := conn.QueryRow(ctx, "select business_name, substr(vatin::text, 3), trade_name, phone, email, web, address, city, province, postal_code, country_code, currency_code from company where company_id = $1", company.Id).Scan(form.BusinessName, form.VATIN, form.TradeName, form.Phone, form.Email, form.Web, form.Address, form.City, form.Province, form.PostalCode, form.Country, form.Currency)
+	if err != nil {
+		panic(err)
+	}
+	return form
+}
+
 type TaxDetailsPage struct {
-	BusinessName string
+	DetailsForm *taxDetailsForm
-	VATIN        string
+	NewTaxForm  *newTaxForm
-	TradeName    string
+	Taxes       []*Tax
-	Phone        string
-	Email        string
-	Web          string
-	Address      string
-	City         string
-	Province     string
-	PostalCode   string
-	CountryCode  string
-	Countries    []CountryOption
-	CurrencyCode string
-	Currencies   []CurrencyOption
-	Taxes        []Tax
 }
 
 func CompanyTaxDetailsHandler() http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		locale := getLocale(r)
-		page := &TaxDetailsPage{}
-		company := mustGetCompany(r)
 		conn := getConn(r)
-		if r.Method == "POST" {
+		page := &TaxDetailsPage{
-			r.ParseForm()
+			DetailsForm: newTaxDetailsForm(r.Context(), conn, locale),
-			page.BusinessName = r.FormValue("business_name")
+			NewTaxForm:  newNewTaxForm(locale),
-			page.CountryCode = r.FormValue("country")
+		}
-			page.VATIN = page.CountryCode + r.FormValue("vatin")
+		company := mustGetCompany(r)
-			page.TradeName = r.FormValue("trade_name")
+		if r.Method == "POST" {
-			page.Phone = r.FormValue("phone")
+			if err := page.DetailsForm.Parse(r); err != nil {
-			page.Email = r.FormValue("email")
+				http.Error(w, err.Error(), http.StatusBadRequest)
-			page.Web = r.FormValue("web")
+				return
-			page.Address = r.FormValue("address")
+			}
-			page.City = r.FormValue("city")
+			if ok := page.DetailsForm.Validate(r.Context(), conn); ok {
-			page.Province = r.FormValue("province")
+				form := page.DetailsForm
-			page.PostalCode = r.FormValue("postal_code")
+				conn.MustExec(r.Context(), "update company set business_name = $1, vatin = ($11 || $2)::vatin, trade_name = $3, phone = parse_packed_phone_number($4, $11), email = $5, web = $6, address = $7, city = $8, province = $9, postal_code = $10, country_code = $11, currency_code = $12 where company_id = $13", form.BusinessName, form.VATIN, form.TradeName, form.Phone, form.Email, form.Web, form.Address, form.City, form.Province, form.PostalCode, form.Country, form.Currency, company.Id)
-			page.CurrencyCode = r.FormValue("currency")
+				http.Redirect(w, r, "/company/"+company.Slug+"/tax-details", http.StatusSeeOther)
-			conn.MustExec(r.Context(), "update company set business_name = $1, vatin = $2, trade_name = $3, phone = parse_packed_phone_number($4, $11), email = $5, web = $6, address = $7, city = $8, province = $9, postal_code = $10, country_code = $11, currency_code = $12 where company_id = $13", page.BusinessName, page.VATIN, page.TradeName, page.Phone, page.Email, page.Web, page.Address, page.City, page.Province, page.PostalCode, page.CountryCode, page.CurrencyCode, company.Id)
+				return
-			http.Redirect(w, r, "/company/"+company.Slug+"/tax-details", http.StatusSeeOther)
+			}
-		} else {
+			w.WriteHeader(http.StatusUnprocessableEntity)
-			err := conn.QueryRow(r.Context(), "select business_name, substr(vatin::text, 3), trade_name, phone, email, web, address, city, province, postal_code, country_code, currency_code from company where company_id = $1", company.Id).Scan(&page.BusinessName, &page.VATIN, &page.TradeName, &page.Phone, &page.Email, &page.Web, &page.Address, &page.City, &page.Province, &page.PostalCode, &page.CountryCode, &page.CurrencyCode)
+		} else {
-			if err != nil {
+			page.DetailsForm.mustFillFromDatabase(r.Context(), conn, company)
-				panic(err)
-			}
 		}
-		page.Countries = mustGetCountryOptions(r.Context(), conn, locale)
-		page.Currencies = mustGetCurrencyOptions(r.Context(), conn)
 		page.Taxes = mustGetTaxes(r.Context(), conn, company)
 		mustRenderAppTemplate(w, r, "tax-details.gohtml", page)
 	})
@@ -143,62 +292,16 @@ func mustGetCompany(r *http.Request) *Company {
 	return company
 }
 
-func mustGetCountryOptions(ctx context.Context, conn *Conn, locale *Locale) []CountryOption {
+func mustGetTaxes(ctx context.Context, conn *Conn, company *Company) []*Tax {
-	rows, err := conn.Query(ctx, "select country.country_code, coalesce(i18n.name, country.name) as l10n_name from country left join country_i18n as i18n on country.country_code = i18n.country_code and i18n.lang_tag = $1 order by l10n_name", locale.Language)
-	if err != nil {
-		panic(err)
-	}
-	defer rows.Close()
-
-	var countries []CountryOption
-	for rows.Next() {
-		var country CountryOption
-		err = rows.Scan(&country.Code, &country.Name)
-		if err != nil {
-			panic(err)
-		}
-		countries = append(countries, country)
-	}
-	if rows.Err() != nil {
-		panic(rows.Err())
-	}
-
-	return countries
-}
-
-func mustGetCurrencyOptions(ctx context.Context, conn *Conn) []CurrencyOption {
-	rows, err := conn.Query(ctx, "select currency_code, currency_symbol from currency order by currency_code")
-	if err != nil {
-		panic(err)
-	}
-	defer rows.Close()
-
-	var currencies []CurrencyOption
-	for rows.Next() {
-		var currency CurrencyOption
-		err = rows.Scan(&currency.Code, &currency.Symbol)
-		if err != nil {
-			panic(err)
-		}
-		currencies = append(currencies, currency)
-	}
-	if rows.Err() != nil {
-		panic(rows.Err())
-	}
-
-	return currencies
-}
-
-func mustGetTaxes(ctx context.Context, conn *Conn, company *Company) []Tax {
 	rows, err := conn.Query(ctx, "select tax_id, name, (rate * 100)::integer from tax where company_id = $1 order by rate, name", company.Id)
 	if err != nil {
 		panic(err)
 	}
 	defer rows.Close()
 
-	var taxes []Tax
+	var taxes []*Tax
 	for rows.Next() {
-		var tax Tax
+		tax := &Tax{}
 		err = rows.Scan(&tax.Id, &tax.Name, &tax.Rate)
 		if err != nil {
 			panic(err)
@@ -212,6 +315,52 @@ func mustGetTaxes(ctx context.Context, conn *Conn, company *Company) []Tax {
 	return taxes
 }
 
+type newTaxForm struct {
+	locale *Locale
+	Name   *InputField
+	Rate   *InputField
+}
+
+func newNewTaxForm(locale *Locale) *newTaxForm {
+	return &newTaxForm{
+		locale: locale,
+		Name: &InputField{
+			Name:     "tax_name",
+			Label:    pgettext("input", "Tax name", locale),
+			Type:     "text",
+			Required: true,
+		},
+		Rate: &InputField{
+			Name:     "tax_rate",
+			Label:    pgettext("input", "Rate (%)", locale),
+			Type:     "number",
+			Required: true,
+			Attributes: []template.HTMLAttr{
+				"min=-99",
+				"max=99",
+			},
+		},
+	}
+}
+
+func (form *newTaxForm) Parse(r *http.Request) error {
+	if err := r.ParseForm(); err != nil {
+		return err
+	}
+	form.Name.FillValue(r)
+	form.Rate.FillValue(r)
+	return nil
+}
+
+func (form *newTaxForm) Validate() bool {
+	validator := newFormValidator()
+	validator.CheckRequiredInput(form.Name, gettext("Tax name can not be empty.", form.locale))
+	if validator.CheckRequiredInput(form.Rate, gettext("Tax rate can not be empty.", form.locale)) {
+		validator.CheckValidInteger(form.Rate, -99, 99, gettext("Tax rate must be an integer between -99 and 99.", form.locale))
+	}
+	return validator.AllOK()
+}
+
 func CompanyTaxHandler() http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		param := r.URL.Path
@@ -222,12 +371,26 @@ func CompanyTaxHandler() http.Handler {
 		company := mustGetCompany(r)
 		if taxId, err := strconv.Atoi(param); err == nil {
 			conn.MustExec(r.Context(), "delete from tax where tax_id = $1", taxId)
+			http.Redirect(w, r, "/company/"+company.Slug+"/tax-details", http.StatusSeeOther)
 		} else {
-			r.ParseForm()
+			locale := getLocale(r)
-			name := r.FormValue("name")
+			form := newNewTaxForm(locale)
-			rate, _ := strconv.Atoi(r.FormValue("rate"))
+			if err := form.Parse(r); err != nil {
-			conn.MustExec(r.Context(), "insert into tax (company_id, name, rate) values ($1, $2, $3 / 100::decimal)", company.Id, name, rate)
+				http.Error(w, err.Error(), http.StatusBadRequest)
+				return
+			}
+			if form.Validate() {
+				conn.MustExec(r.Context(), "insert into tax (company_id, name, rate) values ($1, $2, $3 / 100::decimal)", company.Id, form.Name, form.Rate.Integer())
+				http.Redirect(w, r, "/company/"+company.Slug+"/tax-details", http.StatusSeeOther)
+			} else {
+				w.WriteHeader(http.StatusUnprocessableEntity)
+			}
+			page := &TaxDetailsPage{
+				DetailsForm: newTaxDetailsForm(r.Context(), conn, locale).mustFillFromDatabase(r.Context(), conn, company),
+				NewTaxForm:  form,
+				Taxes:       mustGetTaxes(r.Context(), conn, company),
+			}
+			mustRenderAppTemplate(w, r, "tax-details.gohtml", page)
 		}
-		http.Redirect(w, r, "/company/"+company.Slug+"/tax-details", http.StatusSeeOther)
 	})
 }

pkg/contacts.go

@@ -80,7 +80,7 @@ type NewContactPage struct {
 	Province     string
 	PostalCode   string
 	CountryCode  string
-	Countries    []CountryOption
+	Countries    []*SelectOption
 }
 
 func NewContactHandler() http.Handler {

pkg/form.go

@@ -2,9 +2,15 @@ package pkg
 
 import (
 	"context"
+	"database/sql/driver"
 	"errors"
+	"fmt"
+	"html/template"
 	"net/http"
 	"net/mail"
+	"net/url"
+	"regexp"
+	"strconv"
 	"strings"
 )
 
@@ -16,14 +22,32 @@ type InputField struct {
 	Name       string
 	Label      string
 	Type       string
-	Value      string
+	Val        string
 	Required   bool
-	Attributes []*Attribute
+	Attributes []template.HTMLAttr
 	Errors     []error
 }
 
+func (field *InputField) Scan(value interface{}) error {
+	if value == nil {
+		field.Val = ""
+		return nil
+	}
+	field.Val = fmt.Sprintf("%v", value)
+	return nil
+}
+
+func (field *InputField) Value() (driver.Value, error) {
+	return field.Val, nil
+}
+
 func (field *InputField) FillValue(r *http.Request) {
-	field.Value = strings.TrimSpace(r.FormValue(field.Name))
+	field.Val = strings.TrimSpace(r.FormValue(field.Name))
+}
+
+func (field *InputField) Integer() int {
+	value, _ := strconv.Atoi(field.Val)
+	return value
 }
 
 type SelectOption struct {
@@ -32,11 +56,25 @@ type SelectOption struct {
 }
 
 type SelectField struct {
-	Name     string
+	Name       string
-	Label    string
+	Label      string
-	Selected string
+	Selected   string
-	Options  []*SelectOption
+	Options    []*SelectOption
-	Errors   []error
+	Attributes []template.HTMLAttr
+	Errors     []error
+}
+
+func (field *SelectField) Scan(value interface{}) error {
+	if value == nil {
+		field.Selected = ""
+		return nil
+	}
+	field.Selected = fmt.Sprintf("%v", value)
+	return nil
+}
+
+func (field *SelectField) Value() (driver.Value, error) {
+	return field.Selected, nil
 }
 
 func (field *SelectField) FillValue(r *http.Request) {
@@ -75,6 +113,10 @@ func MustGetOptions(ctx context.Context, conn *Conn, sql string, args ...interfa
 	return options
 }
 
+func mustGetCountryOptions(ctx context.Context, conn *Conn, locale *Locale) []*SelectOption {
+	return MustGetOptions(ctx, conn, "select country.country_code, coalesce(i18n.name, country.name) as l10n_name from country left join country_i18n as i18n on country.country_code = i18n.country_code and i18n.lang_tag = $1 order by l10n_name", locale.Language)
+}
+
 type FormValidator struct {
 	Valid bool
 }
@@ -88,22 +130,51 @@ func (v *FormValidator) AllOK() bool {
 }
 
 func (v *FormValidator) CheckRequiredInput(field *InputField, message string) bool {
-	return v.checkInput(field, field.Value != "", message)
+	return v.checkInput(field, field.Val != "", message)
 }
 
 func (v *FormValidator) CheckValidEmailInput(field *InputField, message string) bool {
-	_, err := mail.ParseAddress(field.Value)
+	_, err := mail.ParseAddress(field.Val)
 	return v.checkInput(field, err == nil, message)
 }
 
+func (v *FormValidator) CheckValidVATINInput(field *InputField, country string, message string) bool {
+	// TODO: actual VATIN validation
+	return v.checkInput(field, true, message)
+}
+
+func (v *FormValidator) CheckValidPhoneInput(field *InputField, country string, message string) bool {
+	// TODO: actual phone validation
+	return v.checkInput(field, true, message)
+}
+
 func (v *FormValidator) CheckPasswordConfirmation(password *InputField, confirm *InputField, message string) bool {
-	return v.checkInput(confirm, password.Value == confirm.Value, message)
+	return v.checkInput(confirm, password.Val == confirm.Val, message)
 }
 
 func (v *FormValidator) CheckValidSelectOption(field *SelectField, message string) bool {
 	return v.checkSelect(field, field.HasValidOption(), message)
 }
 
+func (v *FormValidator) checkValidURL(field *InputField, message string) bool {
+	_, err := url.ParseRequestURI(field.Val)
+	return v.checkInput(field, err == nil, message)
+}
+
+func (v *FormValidator) CheckValidPostalCode(ctx context.Context, conn *Conn, field *InputField, country string, message string) bool {
+	pattern := "^" + conn.MustGetText(ctx, ".{1,255}", "select postal_code_regex from country where country_code = $1", country) + "$"
+	match, err := regexp.MatchString(pattern, field.Val)
+	if err != nil {
+		panic(err)
+	}
+	return v.checkInput(field, match, message)
+}
+
+func (v *FormValidator) CheckValidInteger(field *InputField, min int, max int, message string) bool {
+	value, err := strconv.Atoi(field.Val)
+	return v.checkInput(field, err == nil && value >= min && value <= max, message)
+}
+
 func (v *FormValidator) checkInput(field *InputField, ok bool, message string) bool {
 	if !ok {
 		field.Errors = append(field.Errors, errors.New(message))

pkg/login.go

@@ -3,6 +3,7 @@ package pkg
 import (
 	"context"
 	"errors"
+	"html/template"
 	"net"
 	"net/http"
 	"time"
@@ -33,10 +34,10 @@ func newLoginForm(locale *Locale) *loginForm {
 			Label:    pgettext("input", "Email", locale),
 			Type:     "email",
 			Required: true,
-			Attributes: []*Attribute{
+			Attributes: []template.HTMLAttr{
-				{"autofocus", "autofocus"},
+				`autofocus="autofocus"`,
-				{"autocomplete", "username"},
+				`autocomplete="username"`,
-				{"autocapitalize", "none"},
+				`autocapitalize="none"`,
 			},
 		},
 		Password: &InputField{
@@ -44,8 +45,8 @@ func newLoginForm(locale *Locale) *loginForm {
 			Label:    pgettext("input", "Password", locale),
 			Type:     "password",
 			Required: true,
-			Attributes: []*Attribute{
+			Attributes: []template.HTMLAttr{
-				{"autocomplete", "current-password"},
+				`autocomplete="current-password"`,
 			},
 		},
 	}
@@ -86,7 +87,7 @@ func LoginHandler() http.Handler {
 			}
 			if form.Validate() {
 				conn := getConn(r)
-				cookie := conn.MustGetText(r.Context(), "", "select login($1, $2, $3)", form.Email.Value, form.Password.Value, remoteAddr(r))
+				cookie := conn.MustGetText(r.Context(), "", "select login($1, $2, $3)", form.Email, form.Password, remoteAddr(r))
 				if cookie != "" {
 					setSessionCookie(w, cookie)
 					http.Redirect(w, r, "/", http.StatusSeeOther)

pkg/profile.go

@@ -2,6 +2,7 @@ package pkg
 
 import (
 	"context"
+	"html/template"
 	"net/http"
 )
 
@@ -29,8 +30,8 @@ func newProfileForm(ctx context.Context, conn *Conn, locale *Locale) *profileFor
 			Label:    pgettext("input", "User name", locale),
 			Type:     "text",
 			Required: true,
-			Attributes: []*Attribute{
+			Attributes: []template.HTMLAttr{
-				{"autocomplete", "name"},
+				`autocomplete="name"`,
 			},
 		},
 		Email: &InputField{
@@ -38,30 +39,33 @@ func newProfileForm(ctx context.Context, conn *Conn, locale *Locale) *profileFor
 			Label:    pgettext("input", "Email", locale),
 			Type:     "email",
 			Required: true,
-			Attributes: []*Attribute{
+			Attributes: []template.HTMLAttr{
-				{"autocomplete", "username"},
+				`autocomplete="username"`,
 			},
 		},
 		Password: &InputField{
 			Name:  "password",
 			Label: pgettext("input", "Password", locale),
 			Type:  "password",
-			Attributes: []*Attribute{
+			Attributes: []template.HTMLAttr{
-				{"autocomplete", "new-password"},
+				`autocomplete="new-password"`,
 			},
 		},
 		PasswordConfirm: &InputField{
 			Name:  "password_confirm",
 			Label: pgettext("input", "Password Confirmation", locale),
 			Type:  "password",
-			Attributes: []*Attribute{
+			Attributes: []template.HTMLAttr{
-				{"autocomplete", "new-password"},
+				`autocomplete="new-password"`,
 			},
 		},
 		Language: &SelectField{
 			Name:    "language",
 			Label:   pgettext("input", "Language", locale),
 			Options: languages,
+			Attributes: []template.HTMLAttr{
+				`autocomplete="language"`,
+			},
 		},
 	}
 }
@@ -102,10 +106,10 @@ func ProfileHandler() http.Handler {
 			}
 			if ok := form.Validate(); ok {
 				//goland:noinspection SqlWithoutWhere
-				cookie := conn.MustGetText(r.Context(), "", "update user_profile set name = $1, email = $2, lang_tag = $3 returning build_cookie()", form.Name.Value, form.Email.Value, form.Language.Selected)
+				cookie := conn.MustGetText(r.Context(), "", "update user_profile set name = $1, email = $2, lang_tag = $3 returning build_cookie()", form.Name, form.Email, form.Language)
 				setSessionCookie(w, cookie)
-				if form.Password.Value != "" {
+				if form.Password.Val != "" {
-					conn.MustExec(r.Context(), "select change_password($1)", form.Password.Value)
+					conn.MustExec(r.Context(), "select change_password($1)", form.Password)
 				}
 				company := getCompany(r)
 				http.Redirect(w, r, "/company/"+company.Slug+"/profile", http.StatusSeeOther)
@@ -113,8 +117,8 @@ func ProfileHandler() http.Handler {
 			}
 			w.WriteHeader(http.StatusUnprocessableEntity)
 		} else {
-			form.Name.Value = conn.MustGetText(r.Context(), "", "select name from user_profile")
+			form.Name.Val = conn.MustGetText(r.Context(), "", "select name from user_profile")
-			form.Email.Value = user.Email
+			form.Email.Val = user.Email
 			form.Language.Selected = user.Language.String()
 		}
 		mustRenderAppTemplate(w, r, "profile.gohtml", form)

pkg/template.go

@@ -26,6 +26,14 @@ func mustRenderTemplate(wr io.Writer, r *http.Request, layout string, filename s
 			}
 			return "/company/" + company.Slug + uri
 		},
+		"addInputAttr": func(attr string, field *InputField) *InputField {
+			field.Attributes = append(field.Attributes, template.HTMLAttr(attr))
+			return field
+		},
+		"addSelectAttr": func(attr string, field *SelectField) *SelectField {
+			field.Attributes = append(field.Attributes, template.HTMLAttr(attr))
+			return field
+		},
 	})
 	if _, err := t.ParseFiles(templateFile(filename), templateFile(layout), templateFile("form.gohtml")); err != nil {
 		panic(err)

web/template/contacts-new.gohtml

@@ -50,7 +50,7 @@
 		<div class="input">
 			<select id="country" name="country" class="width-fixed">
 				{{- range $country := .Countries }}
-				<option value="{{ .Code }}" {{ if eq .Code $.CountryCode }}selected="selected"{{ end }}>{{ .Name }}</option>
+				<option value="{{ .Value }}" {{ if eq .Value $.CountryCode }}selected="selected"{{ end }}>{{ .Label }}</option>
 				{{- end }}
 			</select>
 			<label for="country">{{( pgettext "Country" "input" )}}</label>

web/template/form.gohtml

@@ -1,8 +1,8 @@
 {{ define "input-field" -}}
     <div class="input {{ if .Errors }}has-errors{{ end }}">
         <input type="{{ .Type }}" name="{{ .Name }}" id="{{ .Name }}-field"
-        {{- range $attribute := .Attributes }} {{$attribute.Key}}="{{$attribute.Val}}" {{ end -}}
+        {{- range $attribute := .Attributes }} {{$attribute}} {{ end }}
-        {{ if .Required }}required="required"{{ end }} value="{{ .Value }}" placeholder="{{ .Label }}">
+        {{ if .Required }}required="required"{{ end }} value="{{ .Val }}" placeholder="{{ .Label }}">
         <label for="{{ .Name }}-field">{{ .Label }}</label>
         {{- if .Errors }}
             <ul>
@@ -16,19 +16,21 @@
 
 {{ define "select-field" -}}
     <div class="input {{ if .Errors }}has-errors{{ end }}">
-        <select id="{{ .Name }}-field" name="{{ .Name }}">
+        <select id="{{ .Name }}-field" name="{{ .Name }}"
-            {{- range $option := .Options }}
+        {{- range $attribute := .Attributes }} {{$attribute}} {{ end -}}
-                <option value="{{ .Value }}"
+        >
-                        {{ if eq .Value $.Selected }}selected="selected"{{ end }}>{{ .Label }}</option>
+        {{- range $option := .Options }}
-            {{- end }}
+            <option value="{{ .Value }}"
+                    {{- if eq .Value $.Selected }} selected="selected"{{ end }}>{{ .Label }}</option>
+        {{- end }}
         </select>
         <label for="{{ .Name }}-field">{{ .Label }}</label>
-        {{ if .Errors }}
+        {{- if .Errors }}
             <ul>
                 {{- range $error := .Errors }}
                     <li>{{ . }}</li>
                 {{- end }}
             </ul>
-        {{ end }}
+        {{- end }}
     </div>
 {{- end }}

web/template/tax-details.gohtml

@@ -1,136 +1,89 @@
 {{ define "title" -}}
-{{( pgettext "Tax Details" "title" )}}
+    {{( pgettext "Tax Details" "title" )}}
 {{- end }}
 
 {{ define "content" }}
-			<section class="dialog-content">
+    <section class="dialog-content">
-				<h2>{{(pgettext "Tax Details" "title")}}</h2>
+        <h2>{{(pgettext "Tax Details" "title")}}</h2>
-				<form id="details" method="POST">
+        {{ with .DetailsForm }}
-					<div class="input">
+            <form id="details" method="POST">
-						<input type="text" name="business_name" id="business_name" required="required" value="{{ .BusinessName }}" placeholder="{{( pgettext "Business name" "input" )}}">
+                {{ template "input-field" .BusinessName }}
-						<label for="business_name">{{( pgettext "Business name" "input" )}}</label>
+                {{ template "input-field" .VATIN }}
-					</div>
+                {{ template "input-field" .TradeName }}
-					<div class="input">
+                {{ template "input-field" .Phone }}
-						<input type="text" name="vatin" id="vatin" required="required" value="{{ .VATIN }}" placeholder="{{( pgettext "VAT number" "input" )}}">
+                {{ template "input-field" .Email }}
-						<label for="vatin">{{( pgettext "VAT number" "input" )}}</label>
+                {{ template "input-field" .Web }}
-					</div>
+                {{ template "input-field" .Address | addInputAttr `class="width-2x"` }}
-					<div class="input">
+                {{ template "input-field" .City }}
-						<input type="text" name="trade_name" id="trade_name" value="{{ .TradeName }}" placeholder="{{( pgettext "Trade name" "input" )}}">
+                {{ template "input-field" .Province }}
-						<label for="trade_name">{{( pgettext "Trade name" "input" )}}</label>
+                {{ template "input-field" .PostalCode }}
-					</div>
+                {{ template "select-field" .Country | addSelectAttr `class="width-fixed"` }}
-					<div class="input">
-						<input type="tel" name="phone" id="phone" required="required" value="{{ .Phone }}" placeholder="{{( pgettext "Phone" "input" )}}">
-						<label for="phone">{{( pgettext "Phone" "input" )}}</label>
-					</div>
-					<div class="input">
-						<input type="email" name="email" id="email" required="required" value="{{ .Email }}" placeholder="{{( pgettext "Email" "input" )}}">
-						<label for="email">{{( pgettext "Email" "input" )}}</label>
-					</div>
-					<div class="input">
-						<input type="url" name="web" id="web" value="{{ .Web }}" placeholder="{{( pgettext "Web" "input" )}}">
-						<label for="web">{{( pgettext "Web" "input" )}}</label>
-					</div>
-					<div class="input">
-						<input type="text" name="address" id="address" class="width-2x" required="required" value="{{ .Address }}" placeholder="{{( pgettext "Address" "input" )}}">
-						<label for="address">{{( pgettext "Address" "input" )}}</label>
-					</div>
-					<div class="input">
-						<input type="text" name="city" id="city" required="required" value="{{ .City }}" placeholder="{{( pgettext "City" "input" )}}">
-						<label for="city">{{( pgettext "City" "input" )}}</label>
-					</div>
-					<div class="input">
-						<input type="text" name="province" id="province" required="required" value="{{ .City }}" placeholder="{{( pgettext "Province" "input" )}}">
-						<label for="province">{{( pgettext "Province" "input" )}}</label>
-					</div>
-					<div class="input">
-						<input type="text" name="postal_code" id="postal_code" required="required" value="{{ .PostalCode }}" placeholder="{{( pgettext "Postal code" "input" )}}">
-						<label for="postal_code">{{( pgettext "Postal code" "input" )}}</label>
-					</div>
 
-					<div class="input">
+                <fieldset>
-						<select id="country" name="country" class="width-fixed">
+                    <legend id="currency-legend">{{( pgettext "Currency" "title" )}}</legend>
-							{{- range $country := .Countries }}
-							<option value="{{ .Code }}" {{ if eq .Code $.CountryCode }}selected="selected"{{ end }}>{{ .Name }}</option>
-							{{- end }}
-						</select>
-						<label for="country">{{( pgettext "Country" "input" )}}</label>
-					</div>
 
-					<fieldset>
+                    {{ template "select-field" .Currency }}
-						<legend id="currency-legend">{{( pgettext "Currency" "input" )}}</legend>
+                </fieldset>
+            </form>
+        {{ end }}
 
-						<select id="currency" name="currency" aria-labelledby="currency-legend">
+        <form id="newtax" method="POST" action="{{ companyURI "/tax" }}">
-							{{- range $currency := .Currencies }}
+        </form>
-							<option value="{{ .Code }}" {{ if eq .Code $.CurrencyCode }}selected="selected"{{ end }}>{{ .Symbol }} ({{ .Code }})</option>
-							{{- end }}
-						</select>
-					</fieldset>
-				</form>
 
-				<form id="newtax" method="POST" action="{{ companyURI "/tax" }}">
+        <fieldset>
-				</form>
+            <table>
+                <thead>
+                <tr>
+                    <th width="50%"></th>
+                    <th>{{( pgettext "Tax Name" "title" )}}</th>
+                    <th>{{( pgettext "Rate (%)" "title" )}}</th>
+                    <th></th>
+                </tr>
+                </thead>
+                <tbody>
+                {{ with .Taxes }}
+                    {{- range $tax := . }}
+                        <tr>
+                            <td></td>
+                            <td>{{ .Name }}</td>
+                            <td>{{ .Rate }}</td>
+                            <td>
+                                <form method="POST" action="{{ companyURI "/tax"}}/{{ .Id }}">
+                                    <input type="hidden" name="_method" value="DELETE"/>
+                                    <button class="icon" aria-label="{{( gettext "Delete tax" )}}" type="submit"><i
+                                                class="ri-delete-back-2-line"></i></button>
+                                </form>
+                            </td>
+                        </tr>
+                    {{- end }}
+                {{ else }}
+                    <tr>
+                        <td colspan="4">{{( gettext "No taxes added yet." )}}</td>
+                    </tr>
+                {{ end }}
+                </tbody>
+                <tfoot>
+                <tr>
+                    <th scope="row">{{( pgettext "New Line" "title")}}</th>
+                    <td>
+                        {{ template "input-field" .NewTaxForm.Name | addInputAttr `form="newtax"` }}
+                    </td>
+                    <td colspan="2">
+                        {{ template "input-field" .NewTaxForm.Rate | addInputAttr `form="newtax"` }}
+                    </td>
+                </tr>
+                <tr>
+                    <td colspan="2"></td>
+                    <td colspan="2">
+                        <button form="newtax" type="submit">{{( pgettext "Add new tax" "action" )}}</button>
+                    </td>
+                </tr>
+                </tfoot>
+            </table>
+        </fieldset>
 
-				<fieldset>
+        <fieldset>
-					<table>
+            <button form="details" type="submit">{{( pgettext "Save changes" "action" )}}</button>
-						<thead>
+        </fieldset>
-							<tr>
+    </section>
-								<th width="50%"></th>
-								<th>{{( pgettext "Tax Name" "title" )}}</th>
-								<th>{{( pgettext "Rate (%)" "title" )}}</th>
-								<th></th>
-							</tr>
-						</thead>
-						<tbody>
-							{{ with .Taxes }}
-							{{- range $tax := . }}
-							<tr>
-								<td></td>
-								<td>{{ .Name }}</td>
-								<td>{{ .Rate }}</td>
-								<td>
-									<form method="POST" action="{{ companyURI "/tax"}}/{{ .Id }}">
-										<input type="hidden" name="_method" value="DELETE"/>
-										<button class="icon" aria-label="{{( gettext "Delete tax" )}}" type="submit"><i class="ri-delete-back-2-line"></i></button>
-									</form>
-								</td>
-							</tr>
-							{{- end }}
-							{{ else }}
-							<tr>
-								<td colspan="4">{{( gettext "No taxes added yet." )}}</td>
-							</tr>
-							{{ end }}
-						</tbody>
-						<tfoot>
-							<tr>
-								<th scope="row">{{( pgettext "New Line" "title")}}</th>
-								<td>
-									<div class="input">
-										<input form="newtax" type="text" name="name" id="tax_name" required="required"
-												placeholder="{{( pgettext "Tax name" "input" )}}">
-										<label for="tax_name">{{( pgettext "Tax name" "input" )}}</label>
-									</div>
-								</td>
-								<td colspan="2">
-									<div class="input">
-										<input form="newtax" type="number" name="rate" id="tax_rate" min="-99" max="99"
-												required="required" placeholder="{{( pgettext "Rate (%)" "input" )}}">
-										<label for="tax_rate">{{( pgettext "Rate (%)" "input" )}}</label>
-									</div>
-								</td>
-							</tr>
-							<tr>
-								<td colspan="2"></td>
-								<td colspan="2">
-									<button form="newtax" type="submit">{{( pgettext "Add new tax" "action" )}}</button>
-								</td>
-							</tr>
-						</tfoot>
-					</table>
-				</fieldset>
-
-					<fieldset>
-						<button form="details" type="submit">{{( pgettext "Save changes" "action" )}}</button>
-					</fieldset>
-			</section>
 {{- end }}