Help with a pattern

[Spondishy]

Hi,

I have a problem with a pattern that has probably been solved a 1000
times before, but I'd appreciate some advice.

I have a scenario where I have a couple of data classes with getters
and setters called HTMLLink and DocumentLink classes, which are
extended from a LinkBase class. I'm wanting to pass these to a service
layer class which has a create method and carries out some business
logic depending on the object type passed in.

I'm in the position where I either have the HTMLLink and DocumentLink
classes with an implementation of the create method, or a big switch
statement in the service object. I'm not too keen on the link classes
having the create because they were supposed to be simple DTO style
objects. On the other hand I don't want a big switch statement in the
service either.

Is there any other way I can cut this? Thanks.

[Joanna Carter [TeamB]]

"Spondishy" <sp*******@tiscali.co.uka écrit dans le message de news:
11**********************@b28g2000cwb.googlegroups. com...
| I have a scenario where I have a couple of data classes with getters
| and setters called HTMLLink and DocumentLink classes, which are
| extended from a LinkBase class. I'm wanting to pass these to a service
| layer class which has a create method and carries out some business
| logic depending on the object type passed in.
|
| I'm in the position where I either have the HTMLLink and DocumentLink
| classes with an implementation of the create method, or a big switch
| statement in the service object. I'm not too keen on the link classes
| having the create because they were supposed to be simple DTO style
| objects. On the other hand I don't want a big switch statement in the
| service either.

Separate creation and processing :

public class ServiceLayer
{
public static LinkBase CreateLink<linkT>() where linkT : LinkBase, new()
{
return new linkT();
}

public void ProcessLink(HTMLLink link)
{
...
}

public void ProcessLink(DocumentLink link)
{
...
}

...
}

....Or combined :

public class ServiceLayer
{
public void CreateAndProcessLink<linkT>() where linkT : LinkBase, new()
{
linkT link = new linkT();
ProcessLink(link);
}

private void ProcessLink(HTMLLink link)
{
...
}

private void ProcessLink(DocumentLink link)
{
...
}
...
}

Joanna

--
Joanna Carter [TeamB]
Consultant Software Engineer

[Spondishy]

Joanna Carter [TeamB] wrote:

"Spondishy" <sp*******@tiscali.co.uka écrit dans le message de news:
11**********************@b28g2000cwb.googlegroups. com...
| I have a scenario where I have a couple of data classes with getters
| and setters called HTMLLink and DocumentLink classes, which are
| extended from a LinkBase class. I'm wanting to pass these to a service
| layer class which has a create method and carries out some business
| logic depending on the object type passed in.
|
| I'm in the position where I either have the HTMLLink and DocumentLink
| classes with an implementation of the create method, or a big switch
| statement in the service object. I'm not too keen on the link classes
| having the create because they were supposed to be simple DTO style
| objects. On the other hand I don't want a big switch statement in the
| service either.

Separate creation and processing :

public class ServiceLayer
{
public static LinkBase CreateLink<linkT>() where linkT : LinkBase, new()
{
return new linkT();
}

public void ProcessLink(HTMLLink link)
{
...
}

public void ProcessLink(DocumentLink link)
{
...
}

...
}

...Or combined :

public class ServiceLayer
{
public void CreateAndProcessLink<linkT>() where linkT : LinkBase, new()
{
linkT link = new linkT();
ProcessLink(link);
}

private void ProcessLink(HTMLLink link)
{
...
}

private void ProcessLink(DocumentLink link)
{
...
}
...
}

Joanna

--
Joanna Carter [TeamB]
Consultant Software Engineer

Thanks for the response, it's really appreciated... Unfortunately the
code doesn't appear to work. The ProcessLink method says it cannot
convert LinkT to DocumentLink?