MapServer 5.0 WMS, requiring styles...

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Re: MapServer 5.0 WMS, requiring styles...

Bart van den Eijnden-3
I second Daniel's response, this makes sense to me.

Best regards,
Bart

On 10/16/07, Daniel Morissette <[hidden email]> wrote:
Frank Warmerdam wrote:
>
> Following up on this, the RFC is at:
>
>   http://mapserver.gis.umn.edu/development/rfc/ms-rfc-35
>
> I would appreciate comment for a day or two and then I will call for a
> vote.
>

I understand the STYLES issue is real and needs to be addressed, but I
don't like where this is going.

The RFC is encouraging developers and users to add a bunch of permissive
exceptions in 5.1 and future releases that may not really be needed to
achieve interoperability. This would just result in bloating the code
and making it more complex and harder to test. BBOX and SIZE may have
some defaults in the mapfile, but a GetMap request without them makes
little sense so I would be against making them optional again (even if I
used to use GetMap without them a lot myself when testing mapfiles in
the past). OTOH, the STYLES option has a logical default stated in the
spec (STYLES=<empty>) and I think we all agree that it would have made
sense for STYLES to be optional in the spec in the first place.

I'd be more in favor of calling the options "pedantic" (with its
negative connotation) and "permissive", with permissive being the
default, and for the time being stating in the RFC that STYLES is the
only parameter that changes behavior in permissive mode... and that
adding more exceptions in the permissive mode should not be taken
lightly as this encourages misuse of the specs and bloats the code with
unnecessary exceptions.

With respect to scanning the WARNINGS in capabilities. At least in the
case of WMS, MapServer should already be producing suitable defaults in
addition to the warnings (making the response compliant anyway). If it
is not possible to produce a suitable default then an exception is
already issued, so there should be nothing to do on that front, unless
WFS or WCS were implemented differently.

Finally, in case anyone is worried about that, making STYLES optional
will not prevent us from getting compliance certification since the CITE
tests do not check whether a server enforces the requirement for the
STYLES parameter. That could be why so many servers out there never
implemented the requirement for STYLES and so many clients were able to
get away without it.

Daniel
--
Daniel Morissette
http://www.mapgears.com/

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Re: MapServer 5.0 WMS, requiring styles...

Kralidis,Tom [Ontario]
In reply to this post by Paul Spencer-2
 
It's really too bad this was not implemented initially.
 
..Tom
 

________________________________

From: UMN MapServer Developers List on behalf of Paul Spencer
Sent: Tue 16-Oct-07 10:17
To: [hidden email]
Subject: Re: [UMN_MAPSERVER-DEV] MapServer 5.0 WMS, requiring styles...



I find it amusing that the standard is about interoperability but
implementing the standard breaks interoperability :)

All major web browsers implement support for various HTML standards
in 'Standards Compliance Mode' and include a nasty thing called
'Quirks Mode' which allows the browsers to handle all kinds of non-
compliant HTML markup.  Users of web browsers expect them to 'just
work' when viewing content over the web.  I doubt a browser would get
much adoption if some/most of the content on the web was not viewable
because it wasn't compliant with some standard.

Users of ArcXxxx, GE, and any other WMS client are going to feel the
same way.  If they connect to content, they want to be able to see
it, not be told their client software isn't implementing the standard
exactly and completely.  I know the analogy isn't quite right, but at
the end of the day the same thing will happen.  Users will complain
that they can't work with MapServer-based WMS servers and that will
push people to use something other than MapServer to publish to WMS.

Paul

On 16-Oct-07, at 9:34 AM, Steve Lime wrote:

> Bart: In principle I agree with you.
>
> From a practical point point of view I think it's silly not to work
> with the largest
> WMS clients out there without additional configuration on the users
> part. I wasn't
> aware of the ArcMap issue but would advocate supporting that
> variation too. It's
> not like we're talking about some minor client, I mean, it's Google
> Earth and ArcGIS.
>
> Fine, we should let them know they are not compliant (good luck),
> but making it
> hard for the users of those packages doesn't help. They are
> unlikely to have
> read the WMS spec and will blame the service provider more often
> than the
> client vendor. These are folks (on the ArcGIS side especially) that
> we really want
> to have a positive experience with open source and open standards.
>
> I need to go back to the documents Tom references but at face value
> I'd prefer to
> see MapServer work seamlessly with *major* clients if at all possible.
>
> Steve
>
>>>> Bart van den Eijnden <[hidden email]> 10/14/07 3:22 PM >>>
> I tend to disagree. As a person having worked a lot with standards,
> I think
> all vendors implementing a standard should comply with the contract
> lay down
> in the standard.
>
> Remember ESRI's ArcMap up until 9.1 did not send the required
> parameter
> QUERY_LAYERS in a GetFeatureInfo request. I did not hear anybody on
> this
> list advocate that Mapserver should be made permissive and assume
> QUERY_LAYERS equals LAYERS. If you would go this path then the end
> is near.
> Though it would have solved a long-standing irritating/frustrating
> issue
> between Mapserver WMS and ESRI's ArcMap (and there are still a lot
> of 9.0/9.1
> ArcMap's out there).
>
> Also, imagine falling back on the MAP file's width and height if not
> specified, I could write a simple WMS javascript client and forget
> the width
> and height parameters in the url, the WMS client would write out <img
> src="..." width="650" height="450"> and the browser would totally
> distort
> the image if the MAP file says something else then SIZE 650 450.
>
> It just shows which clients are not correctly implementing a spec, and
> frankly, the sooner the better. Go and bother the GE people and say
> they are
> missing a required parameter.
>
> Personally I can not think of a reason why styles is required but
> has a
> default value, but maybe the people who wrote the WMS spec had a
> perfectly
> good reason for it. But if you do not agree it is a required
> parameter, go
> to the OGC and debate why styles should not be a required
> parameter ...
>
> Best regards,
> Bart
>
> On 10/14/07, Howard Butler <[hidden email]> wrote:
>>
>> On Oct 13, 2007, at 5:26 PM, Frank Warmerdam wrote:
>>
>>> Steve Lime wrote:
>>>> Hi all: Is anyone else running into problems with clients and
>>>> requiring the
>>>> styles parameter? I'm putzing with Google Earth which doesn't seem
>>>> to send
>>>> that parameter which makes using 5.0-based WMS servers a bit
>>>> useless. Or am
>>>> I missing something with?
>>>
>>> Steve,
>>>
>>> I haven't run into this myself, but I have heard problems on IRC.
>>>
>>> I personally think it is wrong headed for us to require the styles
>>> parameter.  If we want to have a "pendantic" mode that requires it
>>> that
>>> would be find, but I don't see why we should require it by default
>>> regardless of what the standard might say.
>>>
>>> I would suggest we be permissive in what we require.
>>>
>>> I think this is something that ought to be "fixed" in 5.0.1.
>>>
>>
>> I agree.  The benefit of enforcing this is negligible.  Same for
>> width and height too, frankly.  Do the CITE tests require these?
>>
>> I would like to go back to being more lax about these, especially
>> when we can get reasonable defaults from the map file for width/
>> height and when styles= infers absolutely nothing to anyone.
>>
>> Howard
>>

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Re: MapServer 5.0 WMS, requiring styles...

Kralidis,Tom [Ontario]
In reply to this post by Frank Warmerdam
 
Comments on STYLES= :
 
- So if one builds MapServer and wants, say, WFS support, --with-wfs, for example, means "sorta WFS", and you would need additional mapfile metadata to ensure WFS proper?
- if someone wants to serve up quick and dirty maps, then CGI mode mode=map&... is great for that
- I think this introduces a long term hassle just to band-aid this particular issue
- In MapServer's case, because we don't support multiple WMS STYLES, STYLES= or STYLES=default is what we support.  If/when we ever support multiple WMS STYLES (I think I came across this a week or so ago), then STYLES= becomes especially important.
 
I think this is an example of a circumstance on a relatively lax implemented (i.e.alot of WMS software implements the venerable 'default', but they implement it nonetheless), but REQUIRED, parameter in an OGC spec, which has little relevance to the MapServer world, hence the evolution of this issue, IMHO.
 
From the service provider point of view, you either want to support OGC specifications or you don't.  Having all sorts of hooks in the code as a result of, say, ticket 1088, is not the way to go.
 
At the same time, there are a lot of users who are tripped up in the WMS clients now.  My question then is that the software they use to connect to MapServer via WMS will trigger a ServiceException on ANY WMS server (CubeWerx, etc.) implementation.  So this is as much a Google Earth or ArcIMS issue.
 
hobu warned me...
 
..Tom
 

________________________________

From: UMN MapServer Developers List on behalf of Frank Warmerdam
Sent: Tue 16-Oct-07 11:33
To: [hidden email]
Subject: Re: [UMN_MAPSERVER-DEV] MapServer 5.0 WMS, requiring styles...



Frank Warmerdam wrote:
> I will write a tiny RFC on this issue.


Folks,

Following up on this, the RFC is at:

   http://mapserver.gis.umn.edu/development/rfc/ms-rfc-35

I would appreciate comment for a day or two and then I will call for a vote.

Best regards,
--
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, [hidden email]
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGeo, http://osgeo.org <http://osgeo.org/>
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Re: MapServer 5.0 WMS, requiring styles...

Frank Warmerdam
In reply to this post by Daniel Morissette
Daniel Morissette wrote:
> I'd be more in favor of calling the options "pedantic" (with its
> negative connotation) and "permissive", with permissive being the
> default, and for the time being stating in the RFC that STYLES is the
> only parameter that changes behavior in permissive mode... and that
> adding more exceptions in the permissive mode should not be taken
> lightly as this encourages misuse of the specs and bloats the code with
> unnecessary exceptions.

Daniel,

OK, I'm agreeable .. would you be willing to update the RFC accordingly
and add yourself as a co-author?

Best regards,
--
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, [hidden email]
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGeo, http://osgeo.org
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Re: MapServer 5.0 WMS, requiring styles...

Paul Spencer-2
In reply to this post by Kralidis,Tom [Ontario]
Tom, I agree that the problem is in the client software, but the  
point is that the users of Google Earth or ArcIMS will expect it to  
just work because it is *WMS* and it will be difficult to explain to  
them that the reason it doesn't work is the fault of their software.  
They will think that it is MapServer that is broken ... and will say  
that MapServer sucks because it doesn't work with Google Earth ...

The MapServer PSC needs to decide if they want to shut the door on  
client software that misbehaves or not.

Cheers

Paul

On 17-Oct-07, at 3:07 PM, Kralidis,Tom [Burlington] wrote:

> So this is as much a Google Earth or ArcIMS issue.

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Re: MapServer 5.0 WMS, requiring styles...

Steve Lime
In reply to this post by Steve Lime
We may be partly to blame. Since MapServer is relatively popular who
knows what folks used to test clients and since pre-5.0 versions of MapServer
were more forgiving it's possible that they thought they could get away with it.

Yes, they should have read the standard, but...

Steve

>>> Paul Spencer <[hidden email]> 10/17/07 2:41 PM >>>
Tom, I agree that the problem is in the client software, but the  
point is that the users of Google Earth or ArcIMS will expect it to  
just work because it is *WMS* and it will be difficult to explain to  
them that the reason it doesn't work is the fault of their software.  
They will think that it is MapServer that is broken ... and will say  
that MapServer sucks because it doesn't work with Google Earth ...

The MapServer PSC needs to decide if they want to shut the door on  
client software that misbehaves or not.

Cheers

Paul

On 17-Oct-07, at 3:07 PM, Kralidis,Tom [Burlington] wrote:

> So this is as much a Google Earth or ArcIMS issue.

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Re: MapServer 5.0 WMS, requiring styles...

Yewondwossen Assefa-2
In reply to this post by Kralidis,Tom [Ontario]
> - In MapServer's case, because we don't support multiple WMS STYLES, STYLES= or STYLES=default is what we support.  
If/when we ever support multiple WMS STYLES (I think I came across this
a week or so ago), then STYLES=
becomes especially important.

Tom, my hope is  that when we will add support for multiple styles, we
would still have some reasonable fall back if STYLES is not provided.

  I tend to generally agree with Daniel's comment, let address for now
only the STYLES issue for the upcoming release as proposed in the RFC35.

Later,


>  
>
> ________________________________
>
> From: UMN MapServer Developers List on behalf of Frank Warmerdam
> Sent: Tue 16-Oct-07 11:33
> To: [hidden email]
> Subject: Re: [UMN_MAPSERVER-DEV] MapServer 5.0 WMS, requiring styles...
>
>
>
> Frank Warmerdam wrote:
>> I will write a tiny RFC on this issue.
>
>
> Folks,
>
> Following up on this, the RFC is at:
>
>    http://mapserver.gis.umn.edu/development/rfc/ms-rfc-35
>
> I would appreciate comment for a day or two and then I will call for a vote.
>
> Best regards,
> --
> ---------------------------------------+--------------------------------------
> I set the clouds in motion - turn up   | Frank Warmerdam, [hidden email]
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush    | President OSGeo, http://osgeo.org <http://osgeo.org/>
>


--
----------------------------------------------------------------
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Software Analyst

Email: [hidden email]
http://www.dmsolutions.ca/

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Fax:   (613) 565-0925
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Re: MapServer 5.0 WMS, requiring styles...

Kralidis,Tom [Ontario]
In reply to this post by Kralidis,Tom [Ontario]
FYI I've started a note to Google Earth Help via Google Groups (I think
this is the right place) at:

http://groups.google.com/group/earth-free/browse_thread/thread/d95d6a64b
86cbed1

..Tom


> -----Original Message-----
> From: UMN MapServer Developers List
> [mailto:[hidden email]] On Behalf Of
> Kralidis,Tom [Burlington]
> Sent: 17 October, 2007 3:08 PM
> To: [hidden email]
> Subject: Re: [UMN_MAPSERVER-DEV] MapServer 5.0 WMS, requiring
> styles...
>
>  
> Comments on STYLES= :
>  
> - So if one builds MapServer and wants, say, WFS support,
> --with-wfs, for example, means "sorta WFS", and you would
> need additional mapfile metadata to ensure WFS proper?
> - if someone wants to serve up quick and dirty maps, then CGI
> mode mode=map&... is great for that
> - I think this introduces a long term hassle just to band-aid
> this particular issue
> - In MapServer's case, because we don't support multiple WMS
> STYLES, STYLES= or STYLES=default is what we support.  
> If/when we ever support multiple WMS STYLES (I think I came
> across this a week or so ago), then STYLES= becomes
> especially important.
>  
> I think this is an example of a circumstance on a relatively
> lax implemented (i.e.alot of WMS software implements the
> venerable 'default', but they implement it nonetheless), but
> REQUIRED, parameter in an OGC spec, which has little
> relevance to the MapServer world, hence the evolution of this
> issue, IMHO.
>  
> From the service provider point of view, you either want to
> support OGC specifications or you don't.  Having all sorts of
> hooks in the code as a result of, say, ticket 1088, is not
> the way to go.
>  
> At the same time, there are a lot of users who are tripped up
> in the WMS clients now.  My question then is that the
> software they use to connect to MapServer via WMS will
> trigger a ServiceException on ANY WMS server (CubeWerx, etc.)
> implementation.  So this is as much a Google Earth or ArcIMS issue.
>  
> hobu warned me...
>  
> ..Tom
>  
>
> ________________________________
>
> From: UMN MapServer Developers List on behalf of Frank Warmerdam
> Sent: Tue 16-Oct-07 11:33
> To: [hidden email]
> Subject: Re: [UMN_MAPSERVER-DEV] MapServer 5.0 WMS, requiring
> styles...
>
>
>
> Frank Warmerdam wrote:
> > I will write a tiny RFC on this issue.
>
>
> Folks,
>
> Following up on this, the RFC is at:
>
>    http://mapserver.gis.umn.edu/development/rfc/ms-rfc-35
>
> I would appreciate comment for a day or two and then I will
> call for a vote.
>
> Best regards,
> --
> ---------------------------------------+----------------------
> ----------
> ---------------------------------------+------
> I set the clouds in motion - turn up   | Frank Warmerdam,
> [hidden email]
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush    | President OSGeo,
> http://osgeo.org <http://osgeo.org/>
>
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Re: MapServer 5.0 WMS, requiring styles...

Daniel Morissette
Oh, and I plan to update the RFC when I have a minute based on what I
proposed earlier in this thread and with which at least Frank and Bart
seemed to agree, and I don't think anyone else objected to:

"I'd be more in favor of calling the options "pedantic" (with its
negative connotation) and "permissive", with permissive being the
default, and for the time being stating in the RFC that STYLES is the
only parameter that changes behavior in permissive mode... and that
adding more exceptions in the permissive mode should not be taken
lightly as this encourages misuse of the specs and bloats the code with
unnecessary exceptions."

Daniel

Kralidis,Tom [Burlington] wrote:

> FYI I've started a note to Google Earth Help via Google Groups (I think
> this is the right place) at:
>
> http://groups.google.com/group/earth-free/browse_thread/thread/d95d6a64b
> 86cbed1
>
> ..Tom
>
>
>> -----Original Message-----
>> From: UMN MapServer Developers List
>> [mailto:[hidden email]] On Behalf Of
>> Kralidis,Tom [Burlington]
>> Sent: 17 October, 2007 3:08 PM
>> To: [hidden email]
>> Subject: Re: [UMN_MAPSERVER-DEV] MapServer 5.0 WMS, requiring
>> styles...
>>
>>  
>> Comments on STYLES= :
>>  
>> - So if one builds MapServer and wants, say, WFS support,
>> --with-wfs, for example, means "sorta WFS", and you would
>> need additional mapfile metadata to ensure WFS proper?
>> - if someone wants to serve up quick and dirty maps, then CGI
>> mode mode=map&... is great for that
>> - I think this introduces a long term hassle just to band-aid
>> this particular issue
>> - In MapServer's case, because we don't support multiple WMS
>> STYLES, STYLES= or STYLES=default is what we support.  
>> If/when we ever support multiple WMS STYLES (I think I came
>> across this a week or so ago), then STYLES= becomes
>> especially important.
>>  
>> I think this is an example of a circumstance on a relatively
>> lax implemented (i.e.alot of WMS software implements the
>> venerable 'default', but they implement it nonetheless), but
>> REQUIRED, parameter in an OGC spec, which has little
>> relevance to the MapServer world, hence the evolution of this
>> issue, IMHO.
>>  
>> From the service provider point of view, you either want to
>> support OGC specifications or you don't.  Having all sorts of
>> hooks in the code as a result of, say, ticket 1088, is not
>> the way to go.
>>  
>> At the same time, there are a lot of users who are tripped up
>> in the WMS clients now.  My question then is that the
>> software they use to connect to MapServer via WMS will
>> trigger a ServiceException on ANY WMS server (CubeWerx, etc.)
>> implementation.  So this is as much a Google Earth or ArcIMS issue.
>>  
>> hobu warned me...
>>  
>> ..Tom
>>  
>>
>> ________________________________
>>
>> From: UMN MapServer Developers List on behalf of Frank Warmerdam
>> Sent: Tue 16-Oct-07 11:33
>> To: [hidden email]
>> Subject: Re: [UMN_MAPSERVER-DEV] MapServer 5.0 WMS, requiring
>> styles...
>>
>>
>>
>> Frank Warmerdam wrote:
>>> I will write a tiny RFC on this issue.
>>
>> Folks,
>>
>> Following up on this, the RFC is at:
>>
>>    http://mapserver.gis.umn.edu/development/rfc/ms-rfc-35
>>
>> I would appreciate comment for a day or two and then I will
>> call for a vote.
>>
>> Best regards,
>> --
>> ---------------------------------------+----------------------
>> ----------
>> ---------------------------------------+------
>> I set the clouds in motion - turn up   | Frank Warmerdam,
>> [hidden email]
>> light and sound - activate the windows | http://pobox.com/~warmerdam
>> and watch the world go round - Rush    | President OSGeo,
>> http://osgeo.org <http://osgeo.org/>
>>


--
Daniel Morissette
http://www.mapgears.com/
12