Maybe a custom attribute that would add a schema validation step (or you want to provide a schema to 3rd party developers so that they can self check if needed if the json they generate is what your API expect ?)
By adding a custom filter to the method like this:
[ValidateUserModelAttribute]
public HttpResponseMessage CreateUser([FromBody]User user)
{
And creating the filter:
public class ValidateUserModelAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(HttpActionContext actionContext)
{
// Read request via stream:
string request;
using (var stream = new StreamReader(actionContext.Request.Content.ReadAsStreamAsync().Result))
{
stream.BaseStream.Position = 0;
request = stream.ReadToEnd();
}
// Convert request to JSON-Object:
JObject jsonObject = (JObject)JsonConvert.DeserializeObject(request);
// Number of properties from request:
int numberOfRequestProperties = jsonObject.Count;
// Number of proeprties the request should have:
int numberOfModelProperties = typeof(User).GetProperties().Length;
if (numberOfRequestProperties != numberOfModelProperties)
{
string message = string.Format("There should be {0} key/value pairs in your json request. But there are {1}",
numberOfModelProperties, numberOfRequestProperties);
actionContext.Response = actionContext.Request.CreateErrorResponse(HttpStatusCode.BadRequest, message);
}
}
}
Additional you can check for duplcate keys if you insert this into the code:
// Return bad request message if there are duplicate keys:
try
{
// Set JsonReaderException to be thrown via .Error if there are duplicate keys:
var jsonLoadSettings = new JsonLoadSettings { DuplicatePropertyNameHandling = DuplicatePropertyNameHandling.Error };
// This throws a JsonReaderExpection due to the settings if there is a duplicate key:
JConstructor.Parse(request, jsonLoadSettings);
}
catch (JsonReaderException e)
{
string message = string.Format("Duplicate key found: {0}", e.Message);
actionContext.Response = actionContext.Request.CreateErrorResponse(HttpStatusCode.BadRequest, message);
}
None
0 Points
3 Posts
ASP.NET Web API 2 - Validation
Apr 26, 2019 08:33 AM|RESTAPI|LINK
How would you check when using a [FromBody] User user in a [HttpPost] method, if the JSON-Object has more keys than needed for the User.
Take in mind that the ModelState is being validated and all properties from User are [Required].
In result i don't want it to be possible for the client to send a JSON-Object to this endpoint which has more keys than a User-Object has properties.
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21348 Posts
Re: ASP.NET Web API 2 - Validation
Apr 26, 2019 11:02 AM|mgebhard|LINK
Users can send anything to a Web API end point. Can you post code that illustrates the problem you are trying to solve?
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17437 Posts
Re: ASP.NET Web API 2 - Validation
Apr 26, 2019 11:14 AM|PatriceSc|LINK
Hi,
It will be just ignored but if you want it seems you are looking for something such as https://www.newtonsoft.com/jsonschema
Maybe a custom attribute that would add a schema validation step (or you want to provide a schema to 3rd party developers so that they can self check if needed if the json they generate is what your API expect ?)
None
0 Points
3 Posts
Re: ASP.NET Web API 2 - Validation
Apr 26, 2019 12:51 PM|RESTAPI|LINK
Well i got a solution now:
By adding a custom filter to the method like this:
[ValidateUserModelAttribute] public HttpResponseMessage CreateUser([FromBody]User user) {And creating the filter:
public class ValidateUserModelAttribute : ActionFilterAttribute { public override void OnActionExecuting(HttpActionContext actionContext) { // Read request via stream: string request; using (var stream = new StreamReader(actionContext.Request.Content.ReadAsStreamAsync().Result)) { stream.BaseStream.Position = 0; request = stream.ReadToEnd(); } // Convert request to JSON-Object: JObject jsonObject = (JObject)JsonConvert.DeserializeObject(request); // Number of properties from request: int numberOfRequestProperties = jsonObject.Count; // Number of proeprties the request should have: int numberOfModelProperties = typeof(User).GetProperties().Length; if (numberOfRequestProperties != numberOfModelProperties) { string message = string.Format("There should be {0} key/value pairs in your json request. But there are {1}", numberOfModelProperties, numberOfRequestProperties); actionContext.Response = actionContext.Request.CreateErrorResponse(HttpStatusCode.BadRequest, message); } } }Additional you can check for duplcate keys if you insert this into the code:
// Return bad request message if there are duplicate keys: try { // Set JsonReaderException to be thrown via .Error if there are duplicate keys: var jsonLoadSettings = new JsonLoadSettings { DuplicatePropertyNameHandling = DuplicatePropertyNameHandling.Error }; // This throws a JsonReaderExpection due to the settings if there is a duplicate key: JConstructor.Parse(request, jsonLoadSettings); } catch (JsonReaderException e) { string message = string.Format("Duplicate key found: {0}", e.Message); actionContext.Response = actionContext.Request.CreateErrorResponse(HttpStatusCode.BadRequest, message); }Participant
840 Points
497 Posts
Re: ASP.NET Web API 2 - Validation
Apr 29, 2019 06:07 AM|AddWeb Solution|LINK
You Can Refer Microsoft Official site for more and Pure problem solving technique.
https://docs.microsoft.com/en-us/aspnet/web-api/overview/formats-and-model-binding/model-validation-in-aspnet-web-api
Thanks.