diff --git a/2-http-responses-slides.html b/2-http-responses-slides.html new file mode 100644 index 0000000..ba6c943 --- /dev/null +++ b/2-http-responses-slides.html @@ -0,0 +1,120 @@ +2. HTTP Responses
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HTTP Responses

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ASP.NET Status Codes

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    For a primer on HTTP status codes, check Frontend basics: Lecture 2

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    There are multiple possible status codes for each action

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    The ControllerBase the controllers should inherit from includes result methods for creating ActionResult objects

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    • All ActionResult objects implement the IActionResult interface
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    • Includes at least a status code, and can contain data such as view items or an error message
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    • This result is processed into a response to then sent to client
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Result methods

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Status CodeResult MethodUsage
200 - OKOk()GET, DELETE
201 - CreatedCreated()POST
204 - No contentNoContent()PUT, PATCH
400 - Bad requestBadRequest()POST, PUT, PATCH
404 - Not foundNotFound()All actions
CustomStatusCode()All actions
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Status code example

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[HttpGet("{id}")]
+public IActionResult GetContactById(int id)
+{
+  // Contacts = list of contact objects, fetched from some repository
+  var contact = Contacts.FirstOrDefault(c => c.Id == id);
+  if (contact == null)
+  {
+    return NotFound();
+  }
+  return Ok(contact);
+}
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  • The previous code first attempts to find a Contacts object using the ID provided in the URI parameter +
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    • If an item is not found, a 404 response is returned using NotFound()
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    • Otherwise, the object is sent as a payload with a 200 OK code response using Ok(contact)
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Exercise 1: Returning status codes

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  1. Without using parameter constraints, modify your number list method from Lecture 1, Exercise 3 to return a status code 400 (Bad Request) if is smaller than or larger than .
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  2. Add a helpful error message to the result for both cases. The message should be seen as a message body in the response.
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  3. Test with Swagger/Postman.
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\ No newline at end of file diff --git a/2-http-responses.md b/2-http-responses.md index c1f5260..6a74c45 100644 --- a/2-http-responses.md +++ b/2-http-responses.md @@ -1,69 +1,65 @@ -# HTTP Responses & Status Codes +--- +marp: true +paginate: true +math: mathjax +theme: buutti +title: 2. HTTP Responses +--- -## Check http request format from frontend-basics +# HTTP Responses -# ASP.NET Status Codes + + + +## ASP.NET Status Codes + +* For a primer on HTTP status codes, check [Frontend basics: Lecture 2](https://gitea.buutti.com/education/frontend-basics/src/branch/main/2-http.md#http-status-codes) * There are multiple possible status codes for each action -* The ControllerBase which the controllers should inherit from includes __result methods__ for creating ActionResult objects - * All ActionResult objects implement IActionResult +* The `ControllerBase` the controllers should inherit from includes *__result methods__* for creating `ActionResult` objects + * All `ActionResult` objects implement the `IActionResult` interface * Includes at least a status code, and can contain data such as view items or an error message - * This result is processed into a response to then send to client + * This result is processed into a response to then sent to client -# ASP.NET Result Methods +### Result methods -| __Status Code__ | __Result Method__ | __Use__ | -| :-: | :-: | :-: | -| __200 - OK__ | __Ok()_ | __GET, DELETE__ | -| __201 - Created__ | __Created()_ | __POST__ | -| __204 - No content__ | __NoContent()_ | __PUT, PATCH__ | -| __400 - Bad request__ | __BadRequest()_ | __POST, PUT, PATCH__ | -| __404 - Not found__ | __NotFound()_ | __All actions__ | -| __Custom__ | __StatusCode()_ | __All actions__ | +| Status Code | Result Method | Usage | +|:-------------------|:-----------------|:----------------------------| +| `200 - OK` | `Ok()` | `GET`, `DELETE` | +| `201 - Created` | `Created()` | `POST` | +| `204 - No content` | `NoContent()` | `PUT`, `PATCH` | +| `400 - Bad request` | `BadRequest()` | `POST`, `PUT`, `PATCH` | +| `404 - Not found` | `NotFound()` | `All actions` | +| `Custom` | `StatusCode()` | `All actions` | -# ASP.NET Status Codes (continued) -[HttpGet("{id}")] +### Status code example +```csharp +[HttpGet("{id}")] public IActionResult GetContactById(int id) - -{ - -// Contacts = list of contact objects, fetched from some repository - -var contact = Contacts.FirstOrDefault(c => c.Id == id); - -if (contact == null) - { - -return NotFound(); - + // Contacts = list of contact objects, fetched from some repository + var contact = Contacts.FirstOrDefault(c => c.Id == id); + if (contact == null) + { + return NotFound(); + } + return Ok(contact); } +``` +--- -return Ok(contact); - -} - -The previous code first attempts to find a Contacts object using the ID provided in the URI parameter - -If an item is not found, a 404 response is returned using NotFound() - -Otherwise, the object is sent as a payload with a 200 OK code response using Ok(contact) - -![](imgs/3-http-responses-and-status-codes_0.png) - -![](imgs/3-http-responses-and-status-codes_1.png) - -![](imgs/3-http-responses-and-status-codes_2.png) - -![](imgs/3-http-responses-and-status-codes_3.png) - -# Exercise 1: Returning Status Codes - -Without using parameter constraints, modify your number list method from Lecture 2, Exercise 2 to return a status code 400 (Bad Request) if _k_ is smaller than one or larger than 100. +* The previous code first attempts to find a `Contacts` object using the ID provided in the URI parameter + * If an item is not found, a 404 response is returned using `NotFound()` +![w:700](imgs/3-http-responses-and-status-codes_0.png) ➡ ![](imgs/3-http-responses-and-status-codes_1.png) + * Otherwise, the object is sent as a payload with a 200 OK code response using `Ok(contact)` +![w:700](imgs/3-http-responses-and-status-codes_2.png) ➡ ![](imgs/3-http-responses-and-status-codes_3.png) -Add a helpful error message to the result for both cases. The message should be seen as a message body in the response. +## Exercise 1: Returning status codes + -Test with Swagger/Postman. +1) Without using parameter constraints, modify your number list method from [Lecture 1, Exercise 3](1-aspnet-introduction#exercise-3-returning-your-own-list) to return a status code `400 (Bad Request)` if $k$ is smaller than $1$ or larger than $100$. +2) Add a helpful error message to the result for both cases. The message should be seen as a message body in the response. +3) Test with Swagger/Postman. diff --git a/README.md b/README.md index 73bb722..c3de02f 100644 --- a/README.md +++ b/README.md @@ -3,7 +3,7 @@ | # | Lecture | Slides | |:--|:--------------------------------------------------------------------------|:---------------------------------------------------------------------------| | 1 | [Introduction to ASP.NET](1-aspnet-introduction.md) | [Download slides](1-aspnet-introduction-slides.html?raw=1) | -| 3 | [HTTP Responses & Status Codes](3-http-responses-and-status-codes.md) | [Download slides](3-http-responses-and-status-codes-slides.html?raw=1) | +| 2 | [HTTP Responses](2-http-responses.md) | [Download slides](2-http-responses-slides.html?raw=1) | | 4 | [MVC Pattern & Repositories](4-mvc-pattern-and-repositories.md) | [Download slides](4-mvc-pattern-and-repositories-slides.html?raw=1) | | 5 | [5. REST Architecture](5-rest-architecture.md) | [Download slides](5-rest-architecture-slides.html?raw=1) | | 6 | [Model validation & API Design](6-model-validation-and-designing-apis.md) | [Download slides](6-model-validation-and-designing-apis-slides.html?raw=1) |