Manish Dalal's blog

ComboBox in DataGrid by manish.dalal

This post examines usage of ComboBox in DataGrid. In particular, it shows how to implement foreign key scenarios in lieu of missing SelectedValue property. It also highlights workaround for a bug in RC0 that causes ComboBox dropdown to close immediately...

Prevention : The first line of defense, with Attach Property Pixie dust! by manish.dalal

In the Building Business Application with Silverlight series we have seen how to validate data in various conditions. While it is necessary to validate data after user has entered it, it will be even better if we can prevent user from entering invalid...

Silverlight Business Application Part 6: IEditableobject and Add new item (Take 3!) by manish.dalal

This is part six of Building Business Application with Silverlight series that showcases the basic building blocks of a data centric application. Series Link: Part 0 , Part 1 , Part 2 , Part 3 , Part 4 , Part 5 We have seen how to add new items, delete...

Silverlight Business Application Part 5: Validation - Refactored! by manish.dalal

This is part five of Building Business Application with Silverlight series that showcases the basic building blocks of a data centric application. So far we have seen how to validate data in sync and async fashion. We did validation in response to the changes to data, in setter of the fields. This works fine for doing individual field validation, but we also need a way to validate and track state of the entire object. Rather than crowding the domain model, the Person class with validation and error state management logic, we will factor out validation into a separate class, PersonValidator. PersonValidator will house logic to validate individual fields and also provide method to validate entire object on demand, not just in response to changes to the data field. It will also be responsible for maintaining overall state of the object....

Silverlight Business Application Part 4: Validation (async) by manish.dalal

This is part four of Building Business Application with Silverlight series that showcases the basic building blocks of a data centric application. In the previous post we saw how to validate data on client side in a sync fashion. User enters data, it is immediately validated and any errors are displayed to user. However not all data can be validated on client side. Consider for example, we may be required to validate city from list of cities stored in some back end data store or a web service. In that case we will have to call back end application server and check for validity of city....