Add address.FormatHandler for serving address formats via JSON.

http.go

@@ -0,0 +1,79 @@
+// Copyright (c) 2020 Bojan Zivanovic and contributors
+// SPDX-License-Identifier: MIT
+
+package address
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+)
+
+// FormatHandler is an HTTP handler for serving address formats.
+// Response size is ~45kb, or ~14kb if gzip compression is used.
+type FormatHandler struct{}
+
+// ServeHTTP implements the http.Handler interface.
+func (h FormatHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	locale := h.getLocale(r)
+	// Preselecting the layout and regions reduces HTTP request size by ~20%.
+	type localizedFormat struct {
+		Locale            string            `json:"locale,omitempty"`
+		Layout            string            `json:"layout,omitempty"`
+		Required          []Field           `json:"required,omitempty"`
+		SublocalityType   SublocalityType   `json:"sublocality_type,omitempty"`
+		LocalityType      LocalityType      `json:"locality_type,omitempty"`
+		RegionType        RegionType        `json:"region_type,omitempty"`
+		PostalCodeType    PostalCodeType    `json:"postal_code_type,omitempty"`
+		PostalCodePattern string            `json:"postal_code_pattern,omitempty"`
+		ShowRegionID      bool              `json:"show_region_id,omitempty"`
+		Regions           map[string]string `json:"regions,omitempty"`
+	}
+	data := make(map[string]localizedFormat, len(formats))
+	for countryCode, format := range formats {
+		data[countryCode] = localizedFormat{
+			Locale:            format.Locale.String(),
+			Layout:            format.SelectLayout(locale),
+			Required:          format.Required,
+			SublocalityType:   format.SublocalityType,
+			LocalityType:      format.LocalityType,
+			RegionType:        format.RegionType,
+			PostalCodeType:    format.PostalCodeType,
+			PostalCodePattern: format.PostalCodePattern,
+			ShowRegionID:      format.ShowRegionID,
+			Regions:           format.SelectRegions(locale),
+		}
+	}
+
+	jsonData, _ := json.Marshal(data)
+	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Content-Language", locale.String())
+	w.WriteHeader(http.StatusOK)
+	w.Write(jsonData)
+}
+
+// getLocale returns the locale to use.
+//
+// Priority:
+// 1) Query string (?locale=fr)
+// 2) Header (Accept-Language=fr)
+// 3) English
+//
+func (h FormatHandler) getLocale(r *http.Request) Locale {
+	var locale Locale
+	if param := r.URL.Query().Get("locale"); param != "" {
+		locale = NewLocale(param)
+	} else if accept := r.Header.Get("Accept-Language"); accept != "" {
+		for _, sep := range []string{",", ";"} {
+			if strings.Index(accept, sep) != -1 {
+				acceptParts := strings.Split(accept, sep)
+				accept = acceptParts[0]
+			}
+		}
+		locale = NewLocale(strings.TrimSpace(accept))
+	} else {
+		locale = Locale{Language: "en"}
+	}
+
+	return locale
+}

http_test.go

@@ -0,0 +1,144 @@
+// Copyright (c) 2020 Bojan Zivanovic and contributors
+// SPDX-License-Identifier: MIT
+
+package address_test
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"reflect"
+	"testing"
+
+	"github.com/bojanz/address"
+)
+
+// testFormat is a reduced format for testing purposes.
+type testFormat struct {
+	Locale     string            `json:"locale"`
+	Layout     string            `json:"layout"`
+	RegionType string            `json:"region_type"`
+	Regions    map[string]string `json:"regions"`
+}
+
+func TestFormatHandlerNoLocale(t *testing.T) {
+	req, err := http.NewRequest("GET", "/address-formats", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	rr := httptest.NewRecorder()
+	handler := address.FormatHandler{}
+	handler.ServeHTTP(rr, req)
+
+	if status := rr.Code; status != http.StatusOK {
+		t.Errorf("got HTTP %v want HTTP %v", status, http.StatusOK)
+	}
+	if contentType := rr.Header().Get("Content-Type"); contentType != "application/json" {
+		t.Errorf("got %v want %v", contentType, "application/json")
+	}
+	if contentLanguage := rr.Header().Get("Content-Language"); contentLanguage != "en" {
+		t.Errorf("got %v want %v", contentLanguage, "en")
+	}
+
+	var data map[string]testFormat
+	err = json.Unmarshal(rr.Body.Bytes(), &data)
+	if err != nil {
+		t.Fatal(err)
+	}
+	format, ok := data["TW"]
+	wantFormat := address.GetFormat("TW")
+	if !ok {
+		t.Errorf(`address format "TW" not found.`)
+	}
+	// Confirm that Locale and RegionType were correctly converted to strings.
+	if format.Locale != wantFormat.Locale.String() {
+		t.Errorf("got %v, want %v", format.Locale, wantFormat.Locale.String())
+	}
+	if format.RegionType != wantFormat.RegionType.String() {
+		t.Errorf("got %v, want %v", format.Layout, wantFormat.Layout)
+	}
+	// Confirm that the correct layout and regions were selected.
+	if format.Layout != wantFormat.Layout {
+		t.Errorf("got %q, want %q", format.Layout, wantFormat.Layout)
+	}
+	if !reflect.DeepEqual(format.Regions, wantFormat.Regions) {
+		t.Errorf("got %v, want %v", format.Regions, wantFormat.Regions)
+	}
+}
+
+func TestFormatHandlerLocaleQuery(t *testing.T) {
+	req, err := http.NewRequest("GET", "/address-formats?locale=zh", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	rr := httptest.NewRecorder()
+	handler := address.FormatHandler{}
+	handler.ServeHTTP(rr, req)
+
+	if status := rr.Code; status != http.StatusOK {
+		t.Errorf("got HTTP %v want HTTP %v", status, http.StatusOK)
+	}
+	if contentType := rr.Header().Get("Content-Type"); contentType != "application/json" {
+		t.Errorf("got %v want %v", contentType, "application/json")
+	}
+	if contentLanguage := rr.Header().Get("Content-Language"); contentLanguage != "zh" {
+		t.Errorf("got %v want %v", contentLanguage, "zh")
+	}
+
+	var data map[string]testFormat
+	err = json.Unmarshal(rr.Body.Bytes(), &data)
+	if err != nil {
+		t.Fatal(err)
+	}
+	format, ok := data["TW"]
+	wantFormat := address.GetFormat("TW")
+	if !ok {
+		t.Errorf(`address format "TW" not found.`)
+	}
+	// Confirm that the correct layout and regions were selected.
+	if format.Layout != wantFormat.LocalLayout {
+		t.Errorf("got %q, want %q", format.Layout, wantFormat.LocalLayout)
+	}
+	if !reflect.DeepEqual(format.Regions, wantFormat.LocalRegions) {
+		t.Errorf("got %v, want %v", format.Regions, wantFormat.LocalRegions)
+	}
+}
+
+func TestFormatHandlerLocaleHeader(t *testing.T) {
+	req, err := http.NewRequest("GET", "/address-formats", nil)
+	req.Header.Add("Accept-Language", "zh-hant, zh, en;q=0.8")
+	if err != nil {
+		t.Fatal(err)
+	}
+	rr := httptest.NewRecorder()
+	handler := address.FormatHandler{}
+	handler.ServeHTTP(rr, req)
+
+	if status := rr.Code; status != http.StatusOK {
+		t.Errorf("got HTTP %v want HTTP %v", status, http.StatusOK)
+	}
+	if contentType := rr.Header().Get("Content-Type"); contentType != "application/json" {
+		t.Errorf("got %v want %v", contentType, "application/json")
+	}
+	if contentLanguage := rr.Header().Get("Content-Language"); contentLanguage != "zh-Hant" {
+		t.Errorf("got %v want %v", contentLanguage, "zh-Hant")
+	}
+
+	var data map[string]testFormat
+	err = json.Unmarshal(rr.Body.Bytes(), &data)
+	if err != nil {
+		t.Fatal(err)
+	}
+	format, ok := data["TW"]
+	wantFormat := address.GetFormat("TW")
+	if !ok {
+		t.Errorf(`address format "TW" not found.`)
+	}
+	// Confirm that the correct layout and regions were selected.
+	if format.Layout != wantFormat.LocalLayout {
+		t.Errorf("got %q, want %q", format.Layout, wantFormat.LocalLayout)
+	}
+	if !reflect.DeepEqual(format.Regions, wantFormat.LocalRegions) {
+		t.Errorf("got %v, want %v", format.Regions, wantFormat.LocalRegions)
+	}
+}