Code On Time: Web Application Generator

Tuesday, June 19, 2012Print Subscribe

Many applications require that the name and identity of the user be captured when a record is modified. Let’s create a ModifiedByID and ModifiedByName field in the Orders table that will be updated by an SQL Business Rule whenever an order is modified.

First, let’s add the columns to the table. Start SQL Server Management Studio. In the Object Explorer, right-click on Databases / Northwind / Tables / dbo.Orders table node, and select Design.

Configure two new columns:

Column Name	Data Type	Allow Nulls
ModifiedByID	uniqueidentifier	True
ModifiedByName	nvarchar(50)	True

Save the table modifications. Switch to the web application generator, and refresh the Orders controller.

Regenerate the web application. Next, let’s remove the ModifiedBy fields from the presentation, and create a business rule to update these fields.

Start the Project Designer. In the Project Explorer, switch to the Controllers tab. Right-click on Orders / Views / editForm1 / c1 – Orders / ModifiedByUserID data field node, and select Delete option.

Confirm the operation. Right-click on Orders / Views / editForm1 / c1 – Orders / ModifiedByUserName data field node, and delete this data field as well.

Right-click on Orders / Business Rules node, and select New Business Rule.

Assign this business rule the following properties:

Property	Value
Command Name	Insert\|Update
Name	UpdatingModifiedBy
Type	SQL
Phase	After
Script	update Orders set ModifiedByUserID = @BusinessRules_UserId, ModifiedByUserName = @BusinessRules_UserName where OrderID = @OrderID

Press OK to save the business rule.

Make sure to spell the business rule properties correctly – for example, if the “@BusinessRules_UserId” function was capitalized as “@BusinessRules_UserID”, the function will not be found and an exception will be thrown.

On the toolbar, press Browse to regenerate the web application.

Navigate to the Orders page, edit a record, and save.

View the record in SQL Server Management Studio. The relevant UserId and Name have been saved.

Labels: Business Rules/Logic, Security, Web Application Generator

Tuesday, June 19, 2012Print Subscribe

Value Conversion

Project requirements may dictate that conversion should be performed on field values.

For example, the Customer# field of the Customers table in the Northwind database may need to be converted to uppercase.

However, there is no mechanism preventing users from saving lowercase letters in the field.

Let’s create an SQL Business Rule to perform field value conversion.

Validate on Insert or Update

Start the Project Designer. In the Project Explorer, switch to the Controllers tab. Right-click on Customers / Business Rules node, and select New Business Rule.

Use the following properties:

Property	Value
Command Name	Insert\|Update
Type	SQL
Phase	Before
Script	set @CustomerID = UPPER(@CustomerID)

Press OK to save the business rule. On the toolbar, press Browse.

Navigate to the Customers page, and edit a record. Insert some mixed-case letters in the Customer# field.

Save the record. The field value will be converted to uppercase.

Validate on Calculate

You can also perform just-in-time value conversion, when the user moves focus away from the field.

Switch back to the Project Designer. In the Project Explorer, double-click on Customers / Business Rule / Insert|Update node.

Change the Command Name property:

Property	New Value
Command Name	Calculate

Press OK to save the business rule. In order for the calculation to be performed, the field needs to cause a server request.

In the Project Explorer, double-click on Customers / Fields / CustomerID field node.

Make the following changes:

Property	New Value
The value of this field is calculated by a business rule expression.	True
Context Fields	CustomerID

Press OK to save the field. On the toolbar, press Browse.

On the Customers page, edit a record. Insert mixed-case characters into the Customer# field.

Press Tab on your keyboard or click on another field. The client library will convert the value in Customer# field into uppercase.

Expanding the Business Rule

The user may still click on the OK button and save the lowercase characters in the field. Therefore, you may need to combine both Insert|Update and Calculate command handling. The following Command Name will cover all possible methods of changing the field.

Property	New Value
Command Name	Calculate\|Insert\|Update

The same business logic can be implemented with the help of C#/Visual Basic Business Rules.

Labels: Business Rules/Logic, Web Application Generator

Monday, June 18, 2012Print Subscribe

Working with Controls

Controls are instances of user controls that are placed in containers.

The picture below shows the default Home page with controls TableOfContents and Welcome placed in two containers.

Creating a Control

Controls can be added to a container by using the New Control option in the container context menu.

The New Control icon on the toolbar can also be used.

This will open the New Control form in the Project Designer window. The Id of the control will be automatically assigned, and can be changed in the Project Explorer.

Moving Controls

Dropping a control onto another control will place it after the target control.

The context menu actions Cut and Paste will also serve the same purpose.

Dropping a control to the right side of another control will place it after the target control.

Dropping a control to the left side of another control will place it before the target control.

Holding CTRL key while dropping on a page or container will duplicate the control. If a control with the same Id already exists in the page, the new control will be renamed.

Dropping a control onto a container will place the control at the bottom of the container.

Dropping a control onto a page will move that control onto that page in a new container.

Renaming a Control

Controls can be renamed using the Rename context menu option.

The keyboard shortcut F2 will also activate Rename command.

Editing Controls

A user control can be edited by using the context menu option Edit in Visual Studio. This option will only be present if the user control property Generate is set to “First Time Only”.

Deleting Controls

Controls can be deleted using the Delete context menu option.

The Delete key will activate Delete action.

Labels: Designer, Web Application Generator