Field processing without submitting?

[stephen.friedrich]

This is probably more a JSF than a Seam question, but because of Seam I can use my entity as JSF bean, which is now causing me this issue:

I have a simple @Entity CalRule with name and script fields where script holds some script code that calculates some output value based on an input value.

So, on my (currently seam-gen'd) CalcRule edit page: How can I add an input field plus "Test" button and output text that let's the user try the currently edited script with different input values without saving it to the DB?

I can't submit the form, because Seam will automagically save it to the DB.

Any ideas?

[smithbstl]

This is sort of heavy handed but can you call entityManager.clear() first to detach the entity? This will detach ALL entities from your pc. Unfortunately clear() is not overloaded to take a particular class or object :(

[jacob.orshalick]

By default, the persistence context is going to be flushed after every transaction but if you are using an SMPC you can use specify flush mode as manual when beginning your conversation. This allows you to control when your entities are flushed to the DB. This is described in the documentation at:

http://docs.jboss.com/seam/2.0.0.CR1/reference/en/html/persistence.html#d0e5862

[stephen.friedrich]

Thanks to you two.
I was pondering to fall back to hibernate specific api to be able to call evict() for a single entity instance.

Probably the suggestion Jacob made is cleaner. I just have to learn and understand where and how to start/end my conversation.

For now I have a third solution working: I marked my Test button as immediate="false" and for both the script field and the test value input field I used binding attribute to be able to get the submitted value directly from the component.
Then I do
FacesContext.getCurrentInstance().renderResponse();
to skip the remaining phases.