Hi Cliff, thanks again for your answer.

Maybe "string" was a little bit misleading. Its not an input string from a text field. Actually the string is a path which is used for navigation inside the page. The validation checks if all pre-conditions for the requested content are met. After the validation it's not sent back to the mediator it comes from, but to other ones which are responsible for showing the content, updating SWFAddress ect.

In the scenario you described in your last post the validation should be in view component, no doubt. But in my case it rather is responsible for the page flow. Maybe I should have put more details in my earlier posts, I'm sorry.

Thanks for your advice!

The data comes from several view components and the validation process involves sending different notifications depending on the result. If I put this into the view components, I would have to modify all of them if the validation changes - and I'm sure it will change =)

I wasn't sure if should put it into a command or if its the job of a proxy. But according to the second part of your answer, I'll put it into a command.

Hi, I need to validate data (a string) which is send as notification body by several mediators. Should I do this validation in a command or in a proxy?

Doing it ina command would mean that the command has to execute other commands or send notifications depending on the validation result. Is this common practice?

Thanks,
Andreas