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Model view presenter

In my project,asp.net 2.0,i am implementing MVP pattern..what i am confused about is how to move data from view to presenter..example..
On a form,user has to give percentage,for which i am using textbox,now presenter can access this value through a property on IView(which returns string),but in domain model ,the class which has percentage property is integer...so,what happens now? Should,the presenter cast
the string into int,and then initialize the property of class(which takes int)? or what else could be done?

Another,issue..say my class TransportPackage is composed of Destination object..now on form,user selects destination for a package using a combobox,again presenter gets the selected value as string(destination name)..now how to initialize the Destination object of TransportPackage?
Should,i search in collection of destination,which will return a destination object,and then assign this object to TransportPackage object..


thks
vishy
vishy
Friday, July 14, 2006
 
 
RE: Question 1
IView should return Integer as opposed to String for percentage.

RE: Question 2, Two Options,

Option 1:
Presenter converts from String to Destination object.

Option 2:
Destination Domain Object implements "TryParse" and "Parse" methods as in Int32.TryParse and Parse, which esstentially parses String to obtain object.

For 9 out of 10 times, I go with option 2 as it keeps all conversion code in the same place as the domain object.

Here is a recent articles on MVP, http://msdn.microsoft.com/msdnmag/issues/06/08/DesignPatterns/default.aspx

Saturday, July 15, 2006
 
 
yu say view should return int for percentage..but i am going with string only..and parse it in presenter..and assign to domain object...

yur second option seems a good option..
vishy
Sunday, July 16, 2006
 
 
Option 1:
Presenter converts from String to Destination object.


can yu give an example of how to do it?

Because,to convert it into Destination object it seems,i need to get destinationcollection,match string and get that object..
thks
vishy
Monday, July 17, 2006
 
 
In a nutshell,

Destination userPercentage = new Destination( Textbox.value )

The problem with code like this is that there are a LOT of ways to do this, and it really depends on what you're trying to do. Nobody ever told me I needed to use a DestinationCollection or try to find an existing object instead of creating a new one, so I didn't.
TheDavid
Monday, July 17, 2006
 
 
thks david
vishy
Tuesday, July 18, 2006
 
 

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