Custom Serverside Validation

mumfie · November 27, 2018, 10:26am

Do you have an example of custom serverside validation ?
I followed the instructions at https://www.radzen.com/documentation/customizing-generated-application/#a-idcustom-server-validationcustom-server-validationa however was unable to retain the edit form onscreen to allow correction. The following image should indicate what I tried to date.

korchev · November 27, 2018, 3:51pm

Hi @mumfie,

You are right - the instructions are outdated and we will fix them shortly.

Here is what you need to do:

Throw exception when validation fails.

partial void OnCategoryUpdated(Category item)
{
     if (item.CategoryName == "Test")
     {
         throw new Exception("Custom error");
     }
}

In order for the form to remain editable update the code which sets the Value of the canEdit property. From !(result.status == 400) to result.status != 400 || result.error

Screen Shot 2018-11-27 at 17.47.17.png1736×906 64.2 KB
Finally if you want to display the error message update the Notify action. Set Detail to Unable to update Category: ${result.error.message}
Screen Shot 2018-11-27 at 17.50.33.png1746×918 70.5 KB

Cheers!

mumfie · November 27, 2018, 4:07pm

Thanks Korchev. That works great. Thanks.

radzenuser1 · June 23, 2020, 11:18am

Let me bump this thread up.

I am having a similar problem. I am using an upload component and some business logic to parse the uploaded file. During that process many errors could happen which I want to display to the users. How is the current process of throwing custom errors? And if I throw an exception in the backend, how can I display its message in a notification?

Thanks in regards

korchev · June 23, 2020, 12:29pm

Hi @radzenuser1,

Are you using Angular or Blazor? Also are how are you uploading the file?

radzenuser1 · June 23, 2020, 12:40pm

I am using Angular and I am using the Upload Component

korchev · June 23, 2020, 12:50pm

In this case you can check this section from the documentation. It shows how to upload files with a custom method and return JSON from the server. You can include any errors in the JSON response. Then you could use the Notify action with a condition to display some error message e.g.

radzenuser1 · June 23, 2020, 2:39pm

Thank you for the advice. I followed the steps in your link, but the request does not reach the specified custom method (UploadRechnungen()). I set a breakpoint right into it but it never triggers. Logging output is as follows:

info: Microsoft.AspNetCore.Authentication.JwtBearer.JwtBearerHandler[2]
Successfully validated the token.
info: Microsoft.AspNetCore.Authentication.JwtBearer.JwtBearerHandler[2]
Successfully validated the token.
info: Microsoft.AspNetCore.Authorization.DefaultAuthorizationService[1]
Authorization was successful.
info: Microsoft.AspNetCore.Authorization.DefaultAuthorizationService[1]
Authorization was successful.
info: Microsoft.EntityFrameworkCore.Infrastructure[10403]
Entity Framework Core 2.1.14-servicing-32113 initialized 'ApplicationIdentityDbContext' using provider 'Npgsql.EntityFrameworkCore.PostgreSQL' with options: None
info: Microsoft.EntityFrameworkCore.Infrastructure[10403]
Entity Framework Core 2.1.14-servicing-32113 initialized 'ApplicationIdentityDbContext' using provider 'Npgsql.EntityFrameworkCore.PostgreSQL' with options: None
info: Microsoft.EntityFrameworkCore.Database.Command[20101]
Executed DbCommand (8ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
SELECT EXISTS (SELECT 1 FROM pg_catalog.pg_class c JOIN pg_catalog.pg_namespace n ON n.oid=c.relnamespace WHERE c.relname='__EFMigrationsHistory');
info: Microsoft.EntityFrameworkCore.Database.Command[20101]
Executed DbCommand (8ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
SELECT EXISTS (SELECT 1 FROM pg_catalog.pg_class c JOIN pg_catalog.pg_namespace n ON n.oid=c.relnamespace WHERE c.relname='__EFMigrationsHistory');
info: Microsoft.EntityFrameworkCore.Database.Command[20101]
Executed DbCommand (8ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
SELECT EXISTS (SELECT 1 FROM pg_catalog.pg_class c JOIN pg_catalog.pg_namespace n ON n.oid=c.relnamespace WHERE c.relname='__EFMigrationsHistory');
info: Microsoft.EntityFrameworkCore.Database.Command[20101]
Executed DbCommand (8ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
SELECT EXISTS (SELECT 1 FROM pg_catalog.pg_class c JOIN pg_catalog.pg_namespace n ON n.oid=c.relnamespace WHERE c.relname='__EFMigrationsHistory');
info: Microsoft.EntityFrameworkCore.Database.Command[20101]
Executed DbCommand (8ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
SELECT "MigrationId", "ProductVersion"
FROM "__EFMigrationsHistory"
ORDER BY "MigrationId";
info: Microsoft.EntityFrameworkCore.Database.Command[20101]
Executed DbCommand (8ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
SELECT "MigrationId", "ProductVersion"
FROM "__EFMigrationsHistory"
ORDER BY "MigrationId";
infoinfo: Microsoft.EntityFrameworkCore.Migrations[20405]
No migrations were applied. The database is already up to date.
: Microsoft.EntityFrameworkCore.Migrations[20405]
No migrations were applied. The database is already up to date.
info: Microsoft.AspNetCore.Mvc.Infrastructure.ObjectResultExecutor[1]
Executing ObjectResult, writing value of type 'Microsoft.AspNetCore.Mvc.SerializableError'.
info: Microsoft.AspNetCore.Mvc.Infrastructure.ObjectResultExecutor[1]
Executing ObjectResult, writing value of type 'Microsoft.AspNetCore.Mvc.SerializableError'.
infoinfo: Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker[2]
Executed action RadzenPm.Controllers.ServerMethodsController.UploadRechnungen (server) in 286.5926ms
: Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker[2]
Executed action RadzenPm.Controllers.ServerMethodsController.UploadRechnungen (server) in 286.5926ms
infoinfo: Microsoft.AspNetCore.Hosting.Internal.WebHost[2]
Request finished in 315.1863ms 400 application/json; charset=utf-8
: Microsoft.AspNetCore.Hosting.Internal.WebHost[2]
Request finished in 315.1863ms 400 application/json; charset=utf-8

korchev · June 23, 2020, 2:45pm

The last line from the log actually says it executed the action:

Executed action RadzenPm.Controllers.ServerMethodsController.UploadRechnungen (server) in 286.5926ms

Make sure you have attached to the right process.

radzenuser1 · July 3, 2020, 9:56am

You were right, somehow it only did not geht the breakpoint.

Another question: What is the best option to pass another parameter to the backend alongside the file? I would like to pass a date from the calendar to the custom method in the servermethodscontroller. However I am not quite shure what to pass for the parameters in radzen?

korchev · July 3, 2020, 10:06am

You need to create a property and data-bind the Value of the DatePicker to it. Then use that property for the method parameter.

radzenuser1 · July 20, 2020, 3:11pm

I extracted the logic from the servermethodscontroller class to an own one for single responsibility purposes. Now everthing works fine using the upload component. Now I can no figure out how to display mesages not coming from the servermethodscontroller but from an own one wich handles file uploads.

Thanks in advance

korchev · July 20, 2020, 3:20pm

@radzenuser1 I am not sure what you are trying to achieve and what you have implemented so far. Also please open a new thread as this isn't related to custom server validation.