Tech Articles


Dynamic Runtime DataWindow Group Creation


Here’s a DataWindow tip…and a half.

Unless you want to dynamically build a DataWindow object from scratch at runtime (it’s do-able…but quite involved), there’s no direct way to create a group for a DataWindow object in an ad hoc manner. Here’s a workaround.

First, insert a computed field in an extant DataWindow object and give it an expression that’s an empty string. For the sake of this tip the computed field’s name will be “dynamicgroup”.

image

 

 

 

 

 

 

 

 

Then create a group based on this computed field.

Image

 

 

 

 

 

 

 

 

 

 

image

 

 

 

 

 

 

 

Format the DataWindow object according to your needs and save.

Now at runtime, modify the computed field’s expression to have the value of the column name by which you wish to group the result set.

dw_employees.setredraw( FALSE )

dw_employees.Modify(“dynamicgroup.Expression='” + as_coltogroup + “‘” )

dw_employees.setsort( as_coltogroup + ” A”)

dw_employees.sort( )

dw_employees.groupcalc( )

dw_employees.setredraw( TRUE )

After calling SetSort() and Sort() to sort by the column on which you’re grouping, don’t forget to call GroupCalc() to recalculate the breaks in the groupings.

Certainly this technique may be adapted to implement more than one grouping level. For those of you who maintain and enhance frameworks, the sample code fragment can certainly be made more generic as far as the reference to the DataWindow control and to the name of the computed field(s).

OK, here’s the half (.5) tip.

You’ve defaulted the value of the computed field’s expression to an empty string. This will work fine for grouping on columns of type string. However, for columns of other data types, you’ll need to invoke the DataWindow expression function String() to convert the non-string columns’ values to strings in order for the runtime modification to have the desired effect. Here’s how the accommodation appears in the sample code from earlier in this tip…

dw_employees.Modify(“dynamicgroup.Expression=’String(” + as_coltogroup + “)'” )

Comments (0)
There are no comments posted here yet

Find Articles by Tag

WinAPI Branch & Merge Linux OS Export Mobile Validation PFC DataWindow RibbonBar Builder PDF DataType Debugger XML Graph Transaction OLE Event Handler IDE Jenkins Database Table Data Variable Azure Automated Testing .NET DataStore Migration API Bug .NET Std Framework Repository Windows OS JSONGenerator Source Code InfoMaker DragDrop PowerServer Mobile Database Table Design Class SqlExecutor Script COM SqlModelMapper Authentication TFS Database Error Web Service Proxy Web API Database Object C# UI Themes CI/CD JSONParser Database Table Schema Syntax Interface UI CoderObject Event Android ODBC Charts TreeView Event Handling Import JSON PowerServer Web License RibbonBar Model TLS/SSL BLOB Excel OAuth 2.0 Trial Database Profile Authorization Messagging OAuth Database Connection Encoding SnapDevelop Stored Procedure Configuration Resize Expression Import DLL Installation NativePDF PowerBuilder Compiler HTTPClient DevOps SnapObjects Debug Platform Source Control OrcaScript 32-bit SDK SVN WebBrowser Windows 10 Icons Deployment Menu CrypterObject SQL Outlook Performance PDFlib .NET Assembly Window Icon File Text PBDOM RichTextEdit Control GhostScript PowerBuilder (Appeon) PostgreSQL Testing Array PostgreSQL ODBC driver Export JSON iOS Application ActiveX Open Source SQL Server Sort RESTClient Git DataWindow JSON Encryption PowerScript (PS) UI Modernization Debugging PowerBuilder External Functions 64-bit Filter Service Data Database Painter REST Elevate Conference JSON Oracle MessageBox SOAP TortoiseGit