XAF: Enhancements to Existing Features & Performance Tuning (Coming soon in v14.2)

Grid Designer for List View

In XAF v14.2, responding to customer feedback, we introduce a new easy-to-use way to configure List View columns at design time. Model Editor now includes a designer that imitates the grid filled with sample data. When the ListView | Columns node is focused, the property list to the right is replaced with a design surface. This allows you to see how the grid will be displayed at runtime. Take special note that while the WinForms Data Grid control is displayed at design time. However, the customizations are correctly applied for both WinForms and ASP.NET applications.

The designer provides the same configuration capabilities that are available in XAF WinForms applications at runtime. You can:

• resize columns;
• drag and drop column headers to re-arrange columns;
• hide a column by dragging it outside the grid;
• show hidden columns using Column Chooser;
• apply sorting, grouping and filtering;
• display summaries (when you enable the IsFooterVisible property).

Data-Specific Column Types for ASPxGridView

Starting from version 14.2, opening, paging, grouping, sorting and filtering of lists displayed through the ASPxGridView control in XAF works noticeably faster. We extended our code to use data-specific column types whenever possible. The use of data-specific columns for simple types like System.String, System.DateTime, System.Boolean, etc. allows reducing the request processing time on the server side, reducing rendering time in the browser and reducing traffic due to the simplified page structure. 

Take a look at the video that demonstrates an XAF Web application displaying a grid with 50 objects and 13 columns within Internet Explorer 11 on the test machine with Intel(R) Core(TM) i7-3770 CPU 3.40GHz, 16384MB RAM, Windows 8 Enterprise 64-bit and IIS 7 

These are the results of our measurements of this application:

Please note the following limitations of the new mode.

protectedvoid Application_Start(Object sender, EventArgs e) {
    ASPxGridListEditor.UseASPxGridViewDataSpecificColumns = false;
// ... 
}

New Image Property Editor

As a part of the effort to speed up XAF applications, we will introduced support of byte array image storage for Image Property Editors (in both WinForms and ASP.NET). This allows us to decrease web server memory consumption, because the byte array can contain an image in a compressed format and the server does not have to unpack it. Additionally, you can enable the delayed (or lazy) loading of images to further decrease memory usage. Practically, this means that you can display large list views with lots of images and experience no performance issues. 

Another nice thing about the new editor is that we made it possible to navigate to a detail form when clicking on the image cell in the ListView, which was not present previously.

To use a byte array persistent property as an image storage, simply decorate it with the ImageEditor attribute:

[ImageEditor]
public Byte[] Photo { get; set; }

If you want to implement lazy loading for such properties, check out the examples for Entity Framework and XPO when v14.2 is out.

Notice that the previous approach with the System.Drawing.Image type property is still supported, but we recommend that you migrate to the byte array storage to get the performance benefits described above.

Solution Wizard Improvements

Now you can run the Solution Wizard from an existing solution to add extra XAF projects (Application Server,Workflow Server, etc.):

Additionally the wizard is now included in the DevExpress Template Gallery. Our future plans regarding the wizard include better organization of the XAF Item Templates (ViewController, Frame Templates, etc.) and capability to create test data and configuration for all the XAF extra modules.

Data View Mode for List View

The Data View mode released as a beta in v14.1 is now fully released in 14.2. In this mode, a lightweight read-only list of data records (a data view) is retrieved from a database in a single request without loading complete business objects. This list can be queried much more quickly than a real objects collection. You can now use this feature in your production environment to improve performance for use-case scenarios involving large volumes of data.

Miscellaneous Improvements