How to store and display decimal numbers in CB

I am completely lost, hope you might help:

In prev versions of CB there was a decimal field plugin. How can I replace this functionality in CB 2 as there is no decimal field anymore?

We don't have a decimal field plugin. I'm guessing you had some sort of 3rd party plugin installed to provide that. Best I can suggest is use CB Query Field to query for the field value and try using MYSQL functions to format it however you want. A code fieldtype is planned that works like query field except executes PHP that'd better help with this, but that's not yet available at this time.

Thanks for your quick reply. For output the number, the query type would solve this but I need some sort of input validation ... Any idea for that?

Did you consider to support the native joomla form fields and the possibility to extend the form field by own classes? that would be great

but I need some sort of input validation ... Any idea for that?

You could use CB Auto Actions and its Code action to output jQuery to add input masks to the input. Aside from that there's regex validation for the field, but that'll just error until they get the format right. We have an input mask jQuery plugin and it can be loaded by CB Auto Actions by loading the jQuery plugin "inputmask" (specifically it's github.com/RobinHerbots/jquery.inputmask ), but we don't currently utilize it.

Did you consider to support the native joomla form fields and the possibility to extend the form field by own classes? that would be great

No, CB has its entirely own API for handling fields as well as a base field class that we extend from.