Blazor app, how to add model state validation error?

Question

How do I add a custom validation message in the SaveItem event (prefer not to use data annotations)? It should show up in the "ValidationMessage For=" context.

@using System.ComponentModel.DataAnnotations
@page "/edititem"


<EditForm Model="@model" OnSubmit="@Submit" OnValidSubmit="@SaveItem">
    <DataAnnotationsValidator />
    <ValidationSummary />

    <InputText id="ItemName" @bind-Value="@model.ItemName" />
    <ValidationMessage For="@(() => model.ItemName)" />
    <button type="submit">Submit</button>
</EditForm>

@code {
    ItemModel model = new ItemModel();

    private void Submit()
    {

    }
    private void SaveItem()
    {


    }

    public class ItemModel
    {
        [Required]
        public string ItemName{ get; set; }
    }
}

well, you could create your own custom component but for most uses that would surely be overkill. What's your objection to using data annotations? [Required(ErrorMessage ="xxx Is Required")] — App Pack
For this validation, I have to check the database and would prefer to do it in the component event rather than data annotation. — xam86

Nguyễn Văn Biên Nguyễn Văn Biên · Accepted Answer · 2019-11-14T17:46:51

You can add custom validation in server side by add some Component which contain error message. Display validation error from the server

Blazor app, how to add model state validation error?

1 Answers