[LON-CAPA-admin] Images not showing up in student view for some questions

Stuart Raeburn raeburn at msu.edu
Tue Oct 29 22:30:03 EDT 2013


Hi,

>> Just checked again. I must have been mistaken. I do find that   
>> image. Same behaviour as you observed. I.e. Course coord can see   
>> the image in the problem but a student in a course cannot.

A Course Coordinator will be able to see a published image used in a  
problem, in cases where the the allow tag is malformed, because a CC  
is permitted to display any resources published with a system-wide  
right of use.

Students, however, will not see the image in cases where the allow tag  
is malformed.

That is what happened in this case in:
/res/vcu/s2bdedmo/SOL05_HS_Chemistry/SOL05_HSChem_19_Acids.problem

If the current allow tag in this problem:

<allow  
src="/res/vcu/s2bdedmo/SOL05_HS_Chemistry/images/SOLHS05_Chemistry_19_MixingSolutionsTable.JPG"/  
 >

is replaced with a well-formed self-closing allow tag:

<allow  
src="/res/vcu/s2bdedmo/SOL05_HS_Chemistry/images/SOLHS05_Chemistry_19_MixingSolutionsTable.JPG"  
/>

then students will also be able to see the image.

It seems likely that other resources published by this particular  
author may also have similarly malformed, manually entered <allow> tags.

Anyway, I have updated the bug filed for this issue:
http://bugs.loncapa.org/show_bug.cgi?id=6683

to request a change to LON-CAPA to include correction of malformed  
<allow> tags during publication of a resource.

I have also sent an e-mail to the resource author.


Stuart Raeburn
LON-CAPA Academic Consortium


Quoting loncapa_admin <loncapa_admin at johnabbott.qc.ca>:

> Thanks again, Ray.
>
> At least I know it's not some local phenomenon.  Always worried that  
>  I've muffed a config file or two.
>
> Digging through the black hole that is my admin notes, another   
> teacher had noticed a similar behaviour with some of her   
> self-authored problems.  Didn't make the connection at first,   
> thought this was either a problem with a poorly-written or published  
>  problem.  Or something about our local config.  Had put that into   
> the "look at this over the Christmas break" pile.  Going to look at   
> the bugzilla to see if there's any related tickets.
>
> Thanks again,
>
> Cheers,
> Michael
>
> On 2013-10-18, at 10:37 AM, Raymond Batchelor <batchelo at sfu.ca> wrote:
>
>> Just checked again. I must have been mistaken. I do find that   
>> image. Same behaviour as you observed. I.e. Course coord can see   
>> the image in the problem but a student in a course cannot.
>>
>> Student sees large square blank space where image should be.
>>
>> ----- Original Message -----
>> From: Michael Dugdale <michael.dugdale at johnabbott.qc.ca>
>> To: list about administration and system updating   
>> <lon-capa-admin at mail.lon-capa.org>
>> Sent: Fri, 18 Oct 2013 05:57:37 -0700 (PDT)
>> Subject: Re: [LON-CAPA-admin] Images not showing up   
>> in	student	view	for	some	questions
>>
>> Thanks again Mark,
>>
>> We're running 1 library and 2 access servers --- the behaviour is   
>> repeatable on all of them. Our access servers are a little bit of   
>> an unusual configuration (PPC64) so that's the first thing I   
>> checked: it's happening on our stock RedHat 5 X86_64 library server  
>>  too.
>>
>> I don't think it's a replication problem: the file's on each of the  
>>  servers, with modification dates that vary slightly (I'm   
>> interpreting that as an indicator of when the resource was   
>> replicated).
>>
>> Hmm... interesting observation about the version #... hadn't   
>> noticed that. It does seem strange.
>>
>> On 2013-10-17, at 11:11 PM, Mark Lucas <lucasm at ohio.edu> wrote:
>>
>>> Is it sometimes taking a while for things to get replicated over   
>>> to the server if it's
>>> not already cached? How many different servers do your students   
>>> log in on, just one?
>>>
>>> The only other strange thing I see is Version: -1 for the image.
>>> Is that a stray hyphen or really minus one? What does version -1 mean?
>>>
>>> Later,
>>> Mark
>>>
>>> On Oct 17, 2013, at 9:28 PM, Michael Dugdale wrote:
>>>
>>>> Thanks for the observation ray.
>>>>
>>>>
>>>> It's strange that you can't see it. We're not vcu so we're only   
>>>> seeing what's been published system-wide. As course coordinator,   
>>>> it's visible. Only student roles are being denied access.
>>>>
>>>> Browsing to the image file, the meta-data page (copy/pasted   
>>>> below) has the line "Copyright/Distribution:	System wide - can be  
>>>>  used for any courses system wide".
>>>>
>>>> Strange that you're not able to see it out west.
>>>>
>>>> ---------------------------
>>>>
>>>> Metadata
>>>>
>>>> Untitled Resource
>>>> /res/vcu/s2bdedmo/SOL05_HS_Chemistry/images/SOLHS05_Chemistry_19_MixingSolutionsTable.JPG
>>>> Version: -1
>>>>
>>>> Title:
>>>> Author(s):	Josephus Ferguson
>>>> Subject:
>>>> Keyword(s):
>>>> Notes:
>>>> Abstract:
>>>> Lowest Grade Level:	Not specified
>>>> Highest Grade Level:	Not specified
>>>> Standards:
>>>> MIME Type:	<jpg.gif> JPEG Image Document
>>>> Language:	Not set -
>>>> Creation Date:	Mon Jun 2 09:37:25 pm 2008 (EDT)
>>>> Last Revision Date:	Mon Jun 2 09:37:25 pm 2008 (EDT)
>>>> Publisher/Owner:	Bartlett zzEdmonds [s2bdedmo:vcu]
>>>> Copyright/Distribution:	System wide - can be used for any courses  
>>>>  system wide
>>>> Custom Distribution File:
>>>> Source Available:	Closed - XML source is closed to everyone
>>>> Source Custom Distribution File:
>>>> Obsolete:
>>>> Suggested Replacement for Obsolete File:
>>>>
>>>>
>>>>
>>>> On 2013-10-17, at 9:08 PM, Raymond Batchelor <batchelo at sfu.ca> wrote:
>>>>
>>>>> Well, that particular image is not published system wide,   
>>>>> because it does not appear on this side of the continent.
>>>>> :-)
>>>>> Perhaps the author (s2bdedmo:vcu) did not allow Sytemwide   
>>>>> Copyright/Diustribution or did not yet publish it. Better try to  
>>>>>  contact them.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> ----- Original Message -----
>>>>> From: "Michael Dugdale" <michael.dugdale at johnabbott.qc.ca>
>>>>> To: "list about administration and system updating"   
>>>>> <lon-capa-admin at mail.lon-capa.org>
>>>>> Sent: Thursday, 17 October, 2013 17:52:40
>>>>> Subject: [LON-CAPA-admin] Images not showing up in student view   
>>>>> for some	questions
>>>>>
>>>>>
>>>>> Hi,
>>>>>
>>>>>
>>>>> Looking for some help here. A chemistry teacher has reported a   
>>>>> number of cases where the images associated with a problem don't  
>>>>>  show up for students. It loads fine for course coordinators.   
>>>>> It's just the images that are included in the problem that are   
>>>>> not showing up; the rest of the problem loads fine.
>>>>>
>>>>>
>>>>> Trying to open just the image in a new tab (as student) gives   
>>>>> the following error:
>>>>>
>>>>>
>>>>> -----------------------------
>>>>> LON-CAPA Access Control
>>>>>
>>>>>
>>>>> Access : Browse resources
>>>>> Resource:   
>>>>> /res/vcu/s2bdedmo/SOL05_HS_Chemistry/images/SOLHS05_Chemistry_19_MixingSolutionsTable.JPG
>>>>> Action : Access Denied
>>>>> Sorry ...
>>>>> This action is currently not authorized.
>>>>> ------------------------------
>>>>>
>>>>>
>>>>> I've looked in the file system, and the files are there,   
>>>>> owner/group are www:www with permissions -rw-r--r--
>>>>>
>>>>>
>>>>> As far as Apache logs go, I see many remarks of the form:
>>>>>
>>>>>
>>>>> [Thu Oct 17 20:23:36 2013] [error] access to   
>>>>> /res/vcu/s2bdedmo/SOL05_HS_Chemistry/images/SOLHS05_Chemistry_19_MixingSolutionsTable.JPG failed for 74.57.249.17, reason: Access Denied for michaeldugdale domain johnabbott access   
>>>>> bre
>>>>>
>>>>>
>>>>> Trying to get a sense of what's going on, I checked the problem   
>>>>> file on the server's file system and it does, indeed have the line
>>>>> <allow   
>>>>> src="/res/vcu/s2bdedmo/SOL05_HS_Chemistry/images/SOLHS05_Chemistry_19_MixingSolutionsTable.JPG"/   
>>>>> >
>>>>>
>>>>>
>>>>> And I've double-checked that SELINUX is disabled...
>>>>>
>>>>>
>>>>> I'm fresh out of ideas about where to look next. Does anyone   
>>>>> have any thoughts on where I should look?
>>>>>
>>>>>
>>>>> Thanks in advance,
>>>>>
>>>>>
>>>>> Michael Dugdale
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Michael Dugdale
>>>>> Co-chair (Scheduling)
>>>>> Department of Physics
>>>>> John Abbott College
>>>>> 21,275 Lakeshore Road
>>>>> Ste. Anne de Bellevue, Québec
>>>>> H9X 3L9, Canada
>>>>> (514) 457-6610 Ext. 5888
>>>>> michael.dugdale at johnabbott.qc.ca
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> LON-CAPA-admin mailing list
>>>>> LON-CAPA-admin at mail.lon-capa.org
>>>>> http://mail.lon-capa.org/mailman/listinfo/lon-capa-admin
>>>>>
>>>>> --
>>>>> Raymond J. Batchelor, PhD.
>>>>> Department of Chemistry
>>>>> Simon Fraser University
>>>>>
>>>>> Phone: 778-782-5635
>>>>> _______________________________________________
>>>>> LON-CAPA-admin mailing list
>>>>> LON-CAPA-admin at mail.lon-capa.org
>>>>> http://mail.lon-capa.org/mailman/listinfo/lon-capa-admin
>>>>
>>>> _______________________________________________
>>>> LON-CAPA-admin mailing list
>>>> LON-CAPA-admin at mail.lon-capa.org
>>>> http://mail.lon-capa.org/mailman/listinfo/lon-capa-admin
>>>
>>> --
>>> Mark Lucas 								email: lucasm at ohiou.edu
>>> 252D Clippinger Lab						phone: (740)597-2984
>>> Department of Physics and Astronomy		fax: (740)593-0433
>>> Ohio University
>>> Athens, OH 45701
>>>
>>> _______________________________________________
>>> LON-CAPA-admin mailing list
>>> LON-CAPA-admin at mail.lon-capa.org
>>> http://mail.lon-capa.org/mailman/listinfo/lon-capa-admin
>>>
>>
>>
>> _______________________________________________
>> LON-CAPA-admin mailing list
>> LON-CAPA-admin at mail.lon-capa.org
>> http://mail.lon-capa.org/mailman/listinfo/lon-capa-admin
>>
>> --
>> Raymond J. Batchelor, PhD.
>> Department of Chemistry
>> Simon Fraser University
>>
>> Phone: 778-782-5635





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