title | page_title | description | slug | tags | published | position |
---|---|---|---|---|---|---|
Validation |
Upload Validation |
Validate chosen and uploaded files in the File Upload for Blazor. |
upload-validation |
telerik,blazor,upload,async,validate,validation |
true |
5 |
The Blazor Upload component can perform client-side validation.
To validate uploaded files, implement the validation in two parts:
- client validation - by the Telerik Upload component
- server validation - in the application endpoints
The Telerik Upload component offers parameters to validate selected files on the client:
Accept
-string
- not validation per se, but this parameter can instruct the browser what file types to allow users to select.AllowedExtensions
-List<string>
- a list of valid file extensions. Choosing other file types will mark them as invalid in the UI. The default value isnull
, which allows all extensions.MaxFileSize
- the maximum file size in bytes. Larger selected files will be marked as invalid and will not be uploaded.MinFileSize
- the minimum size of a file in bytes. Smaller selected files will be marked as invalid and will not be uploaded.
Removing invalid files with the [x] button in the Upload interface will not call the RemoveUrl
endpoint.
caption Client validation by the Telerik Upload
@* Upload Word and Excel files between 100 KB and 2 MB *@
<TelerikUpload AllowedExtensions="@ValidFiles"
MinFileSize="@MinFileSize"
MaxFileSize="@MaxFileSize"
SaveUrl="/api/upload/save"
RemoveUrl="/api/upload/remove" />
@code{
List<string> ValidFiles { get; set; }= new List<string>() { ".docx", ".xlsx" };
int MinFileSize { get; set; } = 100 * 1024; // 100 KB
int MaxFileSize { get; set; } = 2 * 1024 * 1024; // 2 MB
}
note The Blazor framework does not support form validation for files. We made an example that creates similar experience. Use it as base for your implementation.
- [Upload Overview]({%slug upload-overview%})
- [Upload Events]({%slug upload-events%})
- Live Demo: Upload Validation