.. include:: /Includes.rst.txt

Conclusion
==========

In this chapter we have considered tasks that touch several layer of
the MVC architecture. First we have seen how to cover extensions for multi
languages by adjust static text in the templates and also country-specific
formats like date or time are adjusted. In addition we have shown that also
the domain model itself can be translated. After this we show the check of
invariants in the model, inclusive the display of error messages in the
template and the possibility to correct wrong entries by the user. At last
we have shown concepts that apply to the security of the extension.
Important by this is tha you have understand what are request hashes and how
to prevent against cross site scripting.