更改字段值以在达到Web API 控制器之前的最佳方法

huangapple
go评论94阅读模式
英文:

Best way to change field value before it reaches the webapi controller

问题

  1. [ApiController]
  2. Route("v1/[controller]/[action]")]
  3. public class AccountController : Controller
  4. {
  5.     private readonly IClient _client;
  6.     public AccountController(IClient client)
  7.     {
  8.         _client = client;
  9.     }
  11.     [HttpPost]
  12.     public async Task<IActionResult> SomeAction([FromBody] SomeRequestModel request)
  13.     {
  14.         if (_client.SomeId == null) return BadRequest("Something could not be resolved");
  15.         request.SomeId = _client.SomeId.Value;
  17.         // Do further processing
  18.     }
  19. }

SomeRequestModel.cs

  1. public class SomeRequestModel 
  2. {
  3.     public long SomeId;
  4.     // other fields
  5. }

有大约100个不同的操作，每个操作都有大约100个不同的请求模型。但是这些模型不继承自具有 SomeId 字段的单个类。由于它们来自另一个项目，更改请求模型是不可行的。

我需要检查 SomeId 是否已解析并返回BadRequest或设置该字段。但我不想在每个请求上都写这两行代码。如何处理这种情况的最佳方法？或者只写这两行是否可以？

我考虑过使用 System.Web.Http.AuthorizeAttribute 并解析 JSON 体并在那里更新值，但这似乎非常低效。

  2. <details>
  3. <summary>英文:</summary>
  5. ```csharp
  6. [ApiController]
  7. Route(&quot;v1/[controller]/[action]&quot;)]
  8. public class AccountController : Controller
  9. {
  10.         private readonly IClient _client;
  11.         public AccountController(IClient client,)
  12.         {
  13.             _client = client;
  14.         }
  16.         [HttpPost]
  17.         public async Task&lt;IActionResult&gt; SomeAction([FromBody] SomeRequestModel request)
  18.         {
  19.             if (_client.SomeId == null) return BadRequest(&quot;Something could not be resolved&quot;);
  20.             request.SomeId = _client.SomeId.Value;
  22.             // Do further processing
  23.         }
  24. }

SomeRequestModel.cs

  1. public class SomeRequestModel 
  2. {
  3.     public long SomeId;
  4.     // other fields
  5. }

There are about 100 different actions that take in about 100 different request models. But those models don't inherit from a single class that has SomeId field. Changing the requests is not feasible since they are from another project.

I need to check if SomeId is resolved and return BadRequest or set the field. But I dont wnat to write these 2 lines on every request. What would be the best way of handling this. Or just writing the lines okay.

I thought of using System.Web.Http.AuthorizeAttribute and parsing the body as json and updating the value there but that seems extremely inefficient.

答案1

得分: 1

以下是翻译好的代码部分：

  1. 这是一个示例
  2. [ApiController]
  3. [Route("v1/[controller]/[action]")]
  4. public class AccountController : Controller
  5. {
  6.     public AccountController()
  7.     {
  8.     }
  10.     [HttpPost]
  11.     public async Task<IActionResult> SomeAction([FromBody] SomeRequestModel request)
  12.     {
  13.         return Ok(request.SomeId);
  14.     }
  15. }
  17. [ModelBinder(BinderType = typeof(SomeRequestModelBinder))]
  18. public class SomeRequestModel
  19. {
  20.     public long SomeId { get; set; }
  21.     // other fields
  22. }
  24. public class SomeRequestModelBinder : IModelBinder
  25. {
  26.     public async Task BindModelAsync(ModelBindingContext bindingContext)
  27.     {
  28.         using (var reader = new StreamReader(bindingContext.HttpContext.Request.Body))
  29.         {
  30.             var json = await reader.ReadToEndAsync();
  31.             var model = JsonSerializer.Deserialize<SomeRequestModel>(json);
  32.             model.SomeId = model.SomeId + 100;
  33.             bindingContext.Result = ModelBindingResult.Success(model);
  34.         }
  35.     }
  36. }
  38. 更新 1:
  39. Peter注意到你需要更新100个模型。也可以通过实现IModelBinderProvider来实现。以下是更新后的版本。
  41. [ApiController]
  42. [Route("v1/[controller]/[action]")]
  43. public class AccountController : Controller
  44. {
  45.     public AccountController()
  46.     {
  47.     }
  49.     [HttpPost]
  50.     public async Task<IActionResult> SomeAction([FromBody] SomeRequestModel request)
  51.     {
  52.         return Ok(request.SomeId);
  53.     }
  54. }
  56. public interface IHaveSomeId
  57. {
  58.     long SomeId { get; set; }
  59. }
  61. public class SomeRequestModel : IHaveSomeId
  62. {
  63.     public long SomeId { get; set; }
  64.     // other fields
  65. }
  67. public class MyModelBinder : IModelBinder
  68. {
  69.     public async Task BindModelAsync(ModelBindingContext bindingContext)
  70.     {
  71.         using (var reader = new StreamReader(bindingContext.HttpContext.Request.Body))
  72.         {
  73.             var json = await reader.ReadToEndAsync();
  74.             var model = JsonSerializer.Deserialize(json, bindingContext.ModelType);
  75.             if (model is IHaveSomeId someIdModel)
  76.                 someIdModel.SomeId = someIdModel.SomeId + 100;
  77.             bindingContext.Result = ModelBindingResult.Success(model);
  78.         }
  79.     }
  80. }
  82. public class MyModelBinderProvider : IModelBinderProvider
  83. {
  84.     public IModelBinder? GetBinder(ModelBinderProviderContext context)
  85.     {
  86.         return new MyModelBinder();
  87.     }
  88. }
  90. 更新 2:
  91. 如果没有一个所有模型都可以实现的接口，可以使用反射或表达式树来修改值。以下示例使用反射。
  93. [ApiController]
  94. [Route("v1/[controller]/[action]")]
  95. public class AccountController : Controller
  96. {
  97.     public AccountController()
  98.     {
  99.     }
  101.     [HttpPost]
  102.     public async Task<IActionResult> SomeAction([FromBody] SomeRequestModel request)
  103.     {
  104.         return Ok(request.SomeId);
  105.     }
  106. }
  108. public class SomeRequestModel
  109. {
  110.     public long SomeId { get; set; }
  111.     // other fields
  112. }
  114. public class MyModelBinder : IModelBinder
  115. {
  116.     public async Task BindModelAsync(ModelBindingContext bindingContext)
  117.     {
  118.         using (var reader = new StreamReader(bindingContext.HttpContext.Request.Body))
  119.         {
  120.             var json = await reader.ReadToEndAsync();
  121.             var doc = JsonSerializer.Deserialize<JsonDocument>(json);
  122.             if (!doc.RootElement.TryGetProperty("SomeId", out JsonElement someIdElement))
  123.                 throw new BadHttpRequestException("No SomeId in the request.");
  125.             var model = doc.Deserialize(bindingContext.ModelType);
  126.             TryToUpdateSomeId(model);
  127.             bindingContext.Result = ModelBindingResult.Success(model);
  128.         }
  129.     }
  131.     private void TryToUpdateSomeId(object? model)
  132.     {
  133.         if (model == null) return;
  134.         var propInfo = model.GetType().GetProperty("SomeId");
  135.         if (propInfo == null)
  136.             return;
  138.         var getMethod = propInfo.GetGetMethod();
  139.         var setMethod = propInfo.GetSetMethod();
  140.         if (getMethod == null || setMethod == null)
  141.             return;
  143.         var currentValue = (long)getMethod.Invoke(model, null);
  144.         setMethod?.Invoke(model, new object[] { currentValue + 100 });
  145.     }
  146. }
  148. public class MyModelBinderProvider : IModelBinderProvider
  149. {
  150.     public IModelBinder? GetBinder(ModelBinderProviderContext context)
  151.     {
  152.         return new MyModelBinder();
  153.     }
  154. }
  156. 不要忘记注册提供程序。
  158. builder.Services.AddControllers(options =>
  159. {
  160.     options.ModelBinderProviders.Insert(0, new MyModelBinderProvider());
  161. });
英文:

It is quite easy. You need to apply a model binder to SomeRequestModel. Here is an example

  1. [ApiController]
  2. [Route(&quot;v1/[controller]/[action]&quot;)]
  3. public class AccountController : Controller
  4. {
  5. public AccountController()
  6. {
  7. }
  8. [HttpPost]
  9. public async Task&lt;IActionResult&gt; SomeAction([FromBody] SomeRequestModel request)
  10. {
  11. return Ok(request.SomeId);
  12. }
  13. }
  14. [ModelBinder(BinderType = typeof(SomeRequestModelBinder))]
  15. public class SomeRequestModel
  16. {
  17. public long SomeId { get; set; }
  18. // other fields
  19. }
  20. public class SomeRequestModelBinder : IModelBinder
  21. {
  22. public async Task BindModelAsync(ModelBindingContext bindingContext)
  23. {
  24. using (var reader = new StreamReader(bindingContext.HttpContext.Request.Body))
  25. {
  26. var json = await reader.ReadToEndAsync();
  27. var model = JsonSerializer.Deserialize&lt;SomeRequestModel&gt;(json);
  28. model.SomeId = model.SomeId + 100;
  29. bindingContext.Result = ModelBindingResult.Success(model);
  30. }
  31. }
  32. }

UPDATE 1:
Peter paid attention that you need to update 100 models. It is also can be achieved by implementing IModelBinderProvider. Here is an updated version.

  1. [ApiController]
  2. [Route(&quot;v1/[controller]/[action]&quot;)]
  3. public class AccountController : Controller
  4. {
  5. public AccountController()
  6. {
  7. }
  8. [HttpPost]
  9. public async Task&lt;IActionResult&gt; SomeAction([FromBody] SomeRequestModel request)
  10. {
  11. return Ok(request.SomeId);
  12. }
  13. }
  14. public interface IHaveSomeId
  15. {
  16. long SomeId { get; set; }
  17. }
  18. public class SomeRequestModel : IHaveSomeId
  19. {
  20. public long SomeId { get; set; }
  21. // other fields
  22. }
  23. public class MyModelBinder : IModelBinder
  24. {
  25. public async Task BindModelAsync(ModelBindingContext bindingContext)
  26. {
  27. using (var reader = new StreamReader(bindingContext.HttpContext.Request.Body))
  28. {
  29. var json = await reader.ReadToEndAsync();
  30. var model = JsonSerializer.Deserialize(json, bindingContext.ModelType);
  31. if (model is IHaveSomeId someIdModel)
  32. someIdModel.SomeId = someIdModel.SomeId + 100;
  33. bindingContext.Result = ModelBindingResult.Success(model);
  34. }
  35. }
  36. }
  37. public class MyModelBinderProvider : IModelBinderProvider
  38. {
  39. public IModelBinder? GetBinder(ModelBinderProviderContext context)
  40. {
  41. return new MyModelBinder();
  42. }
  43. }

UPDATE 2:
If you do not have an interface that all models can implement, the value can be modified with reflection or expression trees. The example below uses reflection.

  1. [ApiController]
  2. [Route(&quot;v1/[controller]/[action]&quot;)]
  3. public class AccountController : Controller
  4. {
  5. public AccountController()
  6. {
  7. }
  8. [HttpPost]
  9. public async Task&lt;IActionResult&gt; SomeAction([FromBody] SomeRequestModel request)
  10. {
  11. return Ok(request.SomeId);
  12. }
  13. }
  14. public class SomeRequestModel
  15. {
  16. public long SomeId { get; set; }
  17. // other fields
  18. }
  19. public class MyModelBinder : IModelBinder
  20. {
  21. public async Task BindModelAsync(ModelBindingContext bindingContext)
  22. {
  23. using (var reader = new StreamReader(bindingContext.HttpContext.Request.Body))
  24. {
  25. var json = await reader.ReadToEndAsync();
  26. var doc = JsonSerializer.Deserialize&lt;JsonDocument&gt;(json);
  27. if (!doc.RootElement.TryGetProperty(&quot;SomeId&quot;, out JsonElement someIdElement))
  28. throw new BadHttpRequestException(&quot;No SomeId in the request.&quot;);
  29. var model = doc.Deserialize(bindingContext.ModelType);
  30. TryToUpdateSomeId(model);
  31. bindingContext.Result = ModelBindingResult.Success(model);
  32. }
  33. }
  34. private void TryToUpdateSomeId(object? model)
  35. {
  36. if (model == null) return;
  37. var propInfo = model.GetType().GetProperty(&quot;SomeId&quot;);
  38. if (propInfo == null)
  39. return;
  40. var getMethod = propInfo.GetGetMethod();
  41. var setMethod = propInfo.GetSetMethod();
  42. if (getMethod == null || setMethod == null)
  43. return;
  44. var currentValue = (long)getMethod.Invoke(model, null);
  45. setMethod?.Invoke(model, new object[] { currentValue + 100 });
  46. }
  47. }
  48. public class MyModelBinderProvider : IModelBinderProvider
  49. {
  50. public IModelBinder? GetBinder(ModelBinderProviderContext context)
  51. {
  52. return new MyModelBinder();
  53. }
  54. }

Do not forget to register the provider.

  1. builder.Services.AddControllers(options =&gt;
  2. {
  3. options.ModelBinderProviders.Insert(0, new MyModelBinderProvider());
  4. });

huangapple
  • 本文由 发表于 2023年7月13日 17:14:04
  • 转载请务必保留本文链接：https://go.coder-hub.com/76677748.html
  • asp.net-web-api
  • c#
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