# Editing

## Content



The server side [CollectionViewHelper](/componentone/api/mvc/online-mvc-core/dotnet-api/C1.AspNetCore.Mvc/C1.Web.Mvc.CollectionViewHelper.html) class defines a Edit request to handle updates. This example shows how to define update action which enables updating records in source database by handling **Edit** request of CollectionViewHelper. It lets a user edit the data in the FlexGrid, and update it in the source database.

The following image shows how the FlexGrid appears after the [CollectionViewEditRequest](/componentone/api/mvc/online-mvc-core/dotnet-api/C1.AspNetCore.Mvc/C1.Web.Mvc.CollectionViewEditRequest-1.html) is used in the controller.

The example uses C1NWind datasource, which was configured in the application in the [Quick Start](/componentone/docs/mvc/online-mvc-core/WorkingwithControls/CollectionView/CVQuickStart):<br />

![](https://cdn.mescius.io/document-site-files/images/9b6a6cfe-b8e8-42e9-8a04-da6cb7762977/images/collectionviewupdate.png)

The following code example demonstrates how to handle [CollectionViewEditRequest](/componentone/api/mvc/online-mvc-core/dotnet-api/C1.AspNetCore.Mvc/C1.Web.Mvc.CollectionViewEditRequest-1.html) to enable editing and updating of a record in the FlexGrid:

#### In Code

**EditController.cs**

```csharp
//Define datasource for FlexGrid
private C1NWindEntities db = new C1NWindEntities();
public ActionResult Index()
{
    return View(db);
}
//Instantiate a JSON request
public ActionResult GridUpdateCategory([C1JsonRequest]CollectionViewEditRequest<Category> requestData)
{
    return Update(requestData, db.Categories);
}
private ActionResult Update<T>(CollectionViewEditRequest<T> requestData, DbSet<T> data) where T : class
{
    return this.C1Json(CollectionViewHelper.Edit<T>(requestData, item =>
    {
        string error = string.Empty;
        bool success = true;
        try
        {
            db.Entry(item as object).State = EntityState.Modified;
            db.SaveChanges();
        }
        catch (DbEntityValidationException e)
        {
            error = string.Join(",", e.EntityValidationErrors.Select(result =>
            {
                return string.Join(",", result.ValidationErrors.Select(err => err.ErrorMessage));
            }));
            success = false;
        }
        catch (Exception e)
        {
            error = e.Message;
            success = false;
        }
        return new CollectionViewItemResult<T>
        {
            Error = error,
            Success = success && ModelState.IsValid,
            Data = item
        };
    }, () => data.ToList<T>()));
}
```

In this example, the **Update** action is assigned to the Update property of FlexGrid's [ItemSource](/componentone/api/mvc/online-mvc-core/dotnet-api/C1.AspNetCore.Mvc/C1.Web.Mvc.IItemsSource-1.html).

**Edit.cshtml**

```html
<c1-flex-grid id="fGUCView" auto-generate-columns="false">
    <c1-items-source update-action-url="@Url.Action("GridUpdateCategory")"></c1-items-source>
    <c1-flex-grid-column binding="CategoryID" is-read-only="true"></c1-flex-grid-column>
    <c1-flex-grid-column binding="CategoryName"></c1-flex-grid-column>
    <c1-flex-grid-column binding="Description" width="500"></c1-flex-grid-column>
</c1-flex-grid>
```