.net core 資料表多語系設計方法

1. An Approach to Design .net
core Translation Tables
資料庫多語系設計

2. About
這篇文在做什麼？
To solve i18n requirements of database.
解決資料庫表格若有多語系需求，應如何實作的問題？
reference：Separate translation table approach

3. Concept
概念
資料表以最小異動的幅度，以「擴充」的概念新增某功能的語系擴充表，讓原
本的功能擁有多語系的資料集。
Using the idea of “extent” the original table to minimize the mofification of
original data.

4. Final Result using API
指定適當語系，相對應的資源
(如API) 回傳對應語系的內容
By specifing language code to
retrieve the contents in correct
language.

5. Table design

6. .net core - 設定支援的語系及預設語系
Supported Language and Default Language
public Startup(IConfiguration configuration)
{
Configuration = configuration;
_defaultCulture = new RequestCulture("en", "en");
_supportedCultures = new List<CultureInfo>
{
new CultureInfo("en"),
new CultureInfo("zh-CN"),
new CultureInfo("zh-TW"),
new CultureInfo("vi")
};
}
● 若相關資源找無對應語系，將rollback 回預設語系

7. Setup dotnet core localization
public void ConfigureServices(IServiceCollection services)
{
#region Localization
// Add the localization services to the services container
services.AddLocalization();
services.Configure<RequestLocalizationOptions>(
opts =>
{
/* your configurations*/
opts.DefaultRequestCulture = _defaultCulture;
// Formatting numbers, dates, etc.
opts.SupportedCultures = _supportedCultures;
// UI strings that we have localized.
opts.SupportedUICultures = _supportedCultures;
// Add Route provider to enable language selection via URL
opts.RequestCultureProviders.Insert(0, new RouteCultureProvider(_defaultCulture));
});
#endregion
}
● RouteCultureProvider 讓localization 機制可在網址列直接指定語系，如 /zh-TW/api

8. 後端程式設計 - 將語系作為查詢條件的一部分
Language Code as Part of the Searching Criteria
/// <summary>
/// 設定檔的查詢條件
/// </summary>
public class ConfigCriteria :SearchCriteria
{
/// <summary>
/// 主設定檔的ID；可用來識別如多語系設定檔會有多個設定時，其上層的主設定檔為何。
/// </summary>
public string ConfigId { get; set; }
/// <summary>
/// 語系代碼
/// </summary>
public string Language { get; set; }
}

9. 後端程式設計 - repository 針對語系進行查詢
Implement Query Predications
/// <summary>
/// 搜尋設定檔
/// </summary>
/// <param name="criteria"></param>
/// <returns></returns>
public IQueryable<Config> Search(ConfigCriteria criteria)
{
if (criteria == null)
return null;
IQueryable<Config> entities = this.GetAll();
if (!string.IsNullOrWhiteSpace(criteria.ConfigId))
entities = entities.Where(o => o.Id == criteria.ConfigId);
if (!string.IsNullOrWhiteSpace(criteria.Language))
{
var translations = this._Context.ConfigTranslation.Where(o => o.Lang.Equals(criteria.Language,
StringComparison.CurrentCultureIgnoreCase));
entities = from config in entities
select new Config
{
Id = config.Id,
Key = config.Key,
Value = config.Value,
Translations = translations.Where(t => t.ConfigId == config.Id).ToList()
};
}