Hm, hm… the more we track this down, the less I’m convinced Panel should restrict field names by design…
Looks like the panel can live with field names that are used in page models …
However, supposed you have a function cover() in your page model and a field “cover” in your text file, $page->cover() would return whatever you return in your page model; and you would have to use $page->content()->cover() to output the value of your text field.
and you would have to use $page->content()->cover() to output the value of your text field.
That’s exactly why I doubt it’s wise to limit Panel to field names that are named after a Page method name: Why breaking on legacy field names, if one can actually use them perfectly fine by accessing them through content()-method chaining?
Sorry for being late to the discussion. I agree with Moritz, that it might not have been the best idea to be so restrictive about it. I added that to avoid problems with form fields trying to fetch content from restricted methods. I will try to find a work-around for this and remove the error message in the next patch release.