Maybe it's a dumb question, but in Primefaces's <p:dialog> there's property which called appendTo which described in manual as:
Appends the dialog to the element defined by the given search expression.
I can't realize what it useful for?
See Question&Answers more detail:os
From the PrimeFaces User Guide (currently p. 185):
Do not place dialog inside tables, containers likes divs with relative positioning or with nonvisible overflow defined, in cases like these functionality might be broken. This is not a limitation but a result of DOM model. For example dialog inside a layout unit, tabview, accordion are a couple of examples. Same applies to confirmDialog as well.
You can overcome this by using appendTo="@(body)" and your dialog will be attached as a child of the <body> node.
One of the main dialog option is modal and you could quickly end up with your dialog behind the overlay if you are not using appendTo as shown below:
See also http://forum.primefaces.org/viewtopic.php?f=3&t=16504
Notes:
appendToBody="true". This was changed for 5.0.dialog contains some buttons don't forget to surround them by <h:form> (see Proper Construct for Primefaces Dialog)