[Building Sakai] help with a PermissionException problem

[Xiaolin Xie]

Hi Chris.

Thank you so much for the prompt reply. Your explanation makes perfect
sense to me. If you had a moment, that would be great if you could point
out some specific examples of security advisors in matrix code. Thanks a
lot!

Xiaolin.

On Thu, Aug 23, 2012 at 10:24 AM, Maurer, Christopher Wayne <
chmaurer at iupui.edu> wrote:

>  If your custom tool is just gathering those things together, there's
> nothing in your tool that allows instructors to view that data.  Parts of
> the Matrix code are granting access to instructors because of their
> association to the student in the matrix.  You'll probably need to do the
> same thing in your code.  Add a security advisor right before you try to
> get that "restricted" data and that should give appropriate access to the
> instructor.  I'd recommend for the advisor to be as specific as possible in
> that grant the content.read permission to that instructor for that
> particular resource item (or form).  That way you don't accidentally give
> too much permissions for things they shouldn't be seeing.  There should be
> lots of examples of security advisors in matrix code, but I'd be happy to
> point out specific cases if you need it.
>
>  Chris
>
>   From: Xiaolin Xie <alphabnu at gmail.com>
> Date: Thursday, August 23, 2012 11:17 AM
> To: "sakai-dev at collab.sakaiproject.org" <sakai-dev at collab.sakaiproject.org
> >
> Subject: [Building Sakai] help with a PermissionException problem
>
>   Hi Sakai developers.
>
>
>
> I am developing an instructor only tool that compiles student answers to
> forms in a matrix. It works fine when the Sakai administrator accesses this
> tool. However, there is a problem with instructor access.
>
>
>
> This is the exception stack trace:
>
> INFO: [SuTool] Username admin becoming xxxxx (2012-08-22 09:50:17,570
> TP-Processor10_org.sakaiproject.tool.su.SuTool)
>
> org.sakaiproject.exception.PermissionException
> user=70382d1d-a91d-4913-a41d-4e6996a1a5ba lock=content.read
> resource=/content/user/5cd94b20-4948-4711-9846-debd42fa3988/portfolio-interaction/demo_coe_2/BF9F9D8DE3B53AC9FE5792CA9BC074BF/6FE9B7A62C703EED28E04E0B3F9B20BB/E55398AAA29DC42C4A05937209D0B57D
>
> at
> org.sakaiproject.content.impl.BaseContentService.unlock(BaseContentService.java:1677)
>
> at
> org.sakaiproject.content.impl.BaseContentService.getResource(BaseContentService.java:4174)
>
> at
> org.sakaiproject.matrixreport.logic.ExternalLogicImpl.getContentStringByUuid(ExternalLogicImpl.java:232)
>
>
>
>
>
> This is the code where the exception happens. It tries to access the xml
> content of students’ answers to forms in matrix.
>
>    *public* String getContentStringByUuid(String uuid){
>
>             String str=*null*;
>
>             ContentResource cr;
>
>             *try* {
>
>                   String id=contentHostingService.resolveUuid(uuid);
>
>                   cr = contentHostingService.getResource(id);
>
>                   str=*new* String(cr.getContent());
>
>             } *catch* (PermissionException e) {
>
>                   e.printStackTrace();
>
>             } *catch* (IdUnusedException e) {
>
>                   e.printStackTrace();
>
>             } *catch* (TypeException e) {
>
>                   e.printStackTrace();
>
>             } *catch* (ServerOverloadException e) {
>
>                   e.printStackTrace();
>
>             }
>
>             *return* str;
>
>       }
>
>
>
> I don’t understand why instructor does not have the access to students’
> answers to forms in the matrix because the instructor can view it through
> the  matrix tool.
>
>
>
> Are there any problems with my code? Or how should I access these
> resourceses?  Do you guys have any idea what might cause that exception?
> Thanks a lot! I really appreciate any help you can offer.
>
>
>
> Xiaolin
>
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