Is it possible to write from Client App Part to a list in its Appweb?

Question

Didn´t find any information at google or at stackexchange for this topic. I wrote a sharepoint hosted app, which has a list. In default.aspx I get data from that list via Rest and have form to create new listitems. Works fine. I then added a Client Appart and adapted the code from default.aspx. After deploying that appart to my developersite, the REST GET is working fine and the items are rendered correctly. If I use the form to create a new item from that apppart, I got a 403 forbidden from list api. It´s the same REST POST as in default.aspx.

Is there something that technical that prevents the POST or do I have to use sp.requestexecutor? Thanks in advance for any suggenstions.

Answer 1

found the solution to my problem. As Steve pointed out, it is possible that an AppPart posts to its own AppWeb. The 403 was generated because I tried to get the RequestDigest this way: $('#__REQUESTDIGEST').val(). This works perfectly in masterpages, eg default.aspx. In an AppPart Page there is no __REQUESTDIGEST, so I didn´t get the correct value. Know I pull the Digest with REST from _api/contextinfo. Works!

What led me in the wrong way, was that in fiddler I saw a RequestDigest. Now I know that even if you put nothing in it, you will see a "wellformed" Digest in the JSON Call.

Thanks to Steve for making clear that it is possible what encouraged me to look further!