These is a little thing to point out.
Using the function pg_get_viewdef or pg_views or information_schema.views you will always get a rewrited version of your original DDL.
The rewited version may or not be the same as your originl DDL script.
If the Rule Manager rewrite your view definition your original DLL will be lost and you will able to read the only the rewrited version of your view definition.
Not all views are rewrited but if you use sub-select or joins probably your views will be rewrited.