Modifying Web.config

When a file uploading request is sent to the server, to avoid other modules fetches the form data before EO.Web.AJAXUploader, EO.Web.AJAXUploader must be the first to that handles the request. As such it is recommended to add EO.Web.Runtime into your web.config's httpModules list.

Setting TempFileLocation

Unlike standard ASP.NET HtmlInputFile control, EO.Web AJAXUploader does not read the entire uploaded file into memory. It streams the data into a temporary file while the data is received. For this reason, you must specify a temporary file location via TempFileLocation property. ASP.NET worker process must have read/write permission to the specified folder.

Setting MaxDataSize

For security purpose, you should specify the limit for the size of uploaded file through AJAXUploader.MaxDataSize, in kilobytes. This limit can be used to prevent denial of service attacks that are caused, for example, by users uploading large files to the server. The default is no limit.

Additionally, you can set maximum request size through web.config. For example, the following code set the maximum request size to 1000K:

<system.webServer>
  <security>
    <requestFiltering>
      <requestLimits maxAllowedContentLength="1024000" />
    </requestFiltering>
  </security>
</system.webServer>

If you received error "The size of the submitted data exceeded the maximum allowed size." while trying to upload large files, you may wish to check both AJAXUploader.MaxDataSize property and maxAllowedContentLength setting in your web.config. Note that MaxDataSize is in kilobytes, while maxAllowedContentLength is in bytes.