Under Review
Last Updated: 20 Jun 2022 18:52 by ADMIN

This is a strange bug I came across when making a simple grid for a small personal project. I created a class called Book, which looks like this:

[Table("Books")]
    public class Book
    {
        [Key]
        public int Id { get; set; }
        [Required]
        public string Title { get; set; } = null!;

        public Checkout? Checkout { get; set; }

        [NotMapped]
        public bool CheckedOut => Checkout != null;
    }

I then created a simple Razor view on which to show the books on a grid. Here is what the code for the page looks like:

@{
    ViewData["Title"] = "All Books";
}

@(
    Html.Kendo().Grid<LibraryMvc.Core.Entities.Book>()
        .Name("bookGrid")
        .Pageable(p => {
            p.PageSizes(new[] {20, 50, 100 });
            p.Numeric(true);
            p.Input(true);
        })
        .Editable(e => e.Mode(GridEditMode.InLine))
        .Filterable()
        .Sortable()
        .Scrollable()
        .ToolBar(t => t.Create())
        .Columns(col => {
            col.Bound(c => c.Id).Title("ID");
            col.Bound(c => c.Title).Title("Title");
            col.Bound(c => c.CheckedOut).Title("Checked Out");
            col.Command(com => {
                com.Edit();
                com.Destroy();
            }).Title("Manage");
        })
        .DataSource(ds => 
            ds.Ajax()
            .PageSize(20)
            .Model(md => {
                md.Id(f => f.Id);
                md.Field(f => f.Id).Editable(false);
                md.Field(f => f.CheckedOut).Editable(false);
            })
            .Read(r => r.Action("Book_Read", "Book"))
            .Create(c => c.Action("Book_Create", "Book"))
            .Update(c => c.Action("Book_Update", "Book"))
            .Destroy(c => c.Action("Book_Destroy", "Book"))
        )
)

When running my app with this code, I noticed that client-side validation would not work on the grid. Nothing would stop me from adding multiple Book rows with empty Titles, despite Title being a [Required] property based on my Book class's Data Annotations:

I assumed I did something wrong, so I scoured the internet and Telerik's support items in hopes of finding something, but then I came across this when inspecting the page's elements in Chrome's dev tools:

Look at the script tag. For whatever reason, the kendoTextBox ended up using the Razor view's ViewData["Title"] property. Oops!

To work around this, I ended up changing my Book class's Title field to BookTitle, as shown below:

[Table("Books")]
    public class Book
    {
        [Key]
        public int Id { get; set; }
        [Required]
        [Column("Title")]
        public string BookTitle { get; set; } = null!;

        public Checkout? Checkout { get; set; }

        [NotMapped]
        public bool CheckedOut => Checkout != null;
    }

With this property name changed, I was able to get client-side validation to work as needed:

A second workaround involved getting rid of the ViewData["Title"] definition on my Razor view:

Given all this, it looks like something that's generating the client-side validation on the page is getting tripped up over the word "Title" being used by multiple items on the page.