[OpenLayers-Dev] ESRI and OpenLayers
Tim Schaub
tschaub at opengeo.org
Tue Mar 10 15:03:44 EDT 2009
Hey-
David Zwarg wrote:
> Greetings community,
>
> One thing to note for the ArcIMS and ArcXML patches: they are a best
> effort to implement the most commonly used functions in ArcXML. This
> includes get image and get feature requests.
>
> Anyone who's looked at the ArcXML specification knows that it's very
> thorough, and supports a myriad of operations. The ArcXML support in
> the patch mentioned implements image requests and feature requests.
> However, there are limits to what is implemented. The entire ArcXML
> schema is not replicated in the ArcXML patch, so it's not a complete
> port. As with most projects, the current patch satisfies the business
> need that I have with the resources that I have.
>
> I am willing and able to be the custodian of that component, but will
> need more feedback from users of the ArcIMS layer for advanced
> operations (geocoding, projection (have you heard of this proj4js
> library?), etc.).
Count this as a tentative offer to help review stuff and get it in the
trunk. We (OpenGeo) are interested in Arc* support in OpenLayers as well.
I'll follow up on the ticket(s) when we've got the back end stuff set up
for testing.
Tim
>
> Thanks,
> z
>
> On Sun, Mar 8, 2009 at 10:03 AM, carls <carlshe at 163.com
> <mailto:carlshe at 163.com>> wrote:
>
>
> I had tested
> 'root/sandbox/dzwarg/openlayers/lib/OpenLayers/Layer/ArcIMS.js'
> and 'root/sandbox/dzwarg/openlayers/lib/OpenLayers/Format/ArcXML.js'
> with
> OL2.7. It works well.
>
> I hope and would like to see the support of ArcIMS in OL2.8, if
> possible.
>
> Thanks.
>
>
> Christopher Schmidt-2 wrote:
> >
> > Eric,
> >
> > Your email led me into a response that is really far more
> appropriate to
> > the entire dev list in my opinion. ESRI and OpenLayers is a
> particularly
> > large hole in the library support, and I wanted to really get
> down a lot
> > of my thoughts on why this is. Please take all this with a large
> grain
> > of salt as being my personal point of view... but perhaps not an
> > entirely-inaccurate one, given my level of involvement in the
> project.
> >
> > On Mon, Mar 02, 2009 at 04:27:21PM -0700, Eric Wolf wrote:
> >> Christopher,
> >>
> >> I hate to open old wounds, but I'm preparing a presentation centered
> >> around generating a tile cache consumable by OpenLayers but based on
> >> an ArcGIS map layout. I've tried some different configurations:
> >
> > So, I want to start off by saying this: No existing OpenLayers core
> > contributor has, in any major way, a personal or professional
> motivation
> > towards supporting ESRI's web services, so far as I am aware. This
> > includes the OpenGeo community (generally speaking, tightly
> coupled with
> > GeoServer), the Camptocamp group (which works almost exclusively
> outside
> > the realm of ESRI, as far as I've observed: possibly motivated by
> > Europe's lack of proprietary buy-in, hooray), or the DM Solutions
> > (primarily around MapGuide, and MapServer) or MapGears (primarily
> around
> > MapServer) contributors. I expect that if you came with $$ to any of
> > these groups, they would be likely to be able to help you, but
> it's not
> > so common of a problem to make it worthwhile for them to spend time
> > maintaining ESRI-specific code without a customer asking for it.
> >
> > With that in mind, almost all work on ESRI-related developments
> thus far
> > has been by non-core contributors to the project, and OpenLayers has,
> > in some cases, not had a great track record with non-core
> contributors
> > of content doing the work to get their code in trunk.
> >
> > The ESRI AGS code developed thus far has been prey to this: several
> > people have used it, but not:
> >
> > * Documented it
> > * Tested it
> > * Created examples for it
> >
> > As such, the code is not something that the OpenLayers community can
> > support without a strong leader stepping up and taking on the task on
> > the code.
> >
> > Some counter-examples to this are:
> >
> > * The recently committed ArcGIS 9.3 REST API layer.
> > * The in-review ESRI ArcXML layer.
> >
> > Both of these sets of code have had committed developers who have
> > written tests, provided documented examples, etc. in clean, well-laid
> > out patches.
> >
> > Based on your problem description on the mailing list --
> something you
> > neglected to include in this email, which makes it difficult to
> respond
> > to precisely -- I can not describe what the best solution is for you,
> > based on my personal knowledge. I don't use any ESRI products or
> > anything else.
> >
> > Though I don't know if it's the best thing for your use case, I
> do feel
> > that it would be beneficial to the OpenLayers community to have
> access
> > to ESRI's map caches. Cached map tiles are clearly much faster than
> > non-cached map tiles, and the recent developments of ESRI's -- making
> > available, for example, sampleserver.esri.com
> <http://sampleserver.esri.com> or whatever it is -- make
> > this type of development much simpler.
> >
> > However, to accomplish this goal, there still needs to be a
> champion of
> > the task -- someone who is reasonably experienced in Javascript, and
> > willing to step up and take on the task of providing the OpenLayers
> > community with the support it needs to get this support into the
> > library. This means that, for example, documentation and examples
> would
> > need to be written, etc. and the contributo would likely need to
> > demonstrate some willingness to continue to support developers in
> > maintaining the code, since none of us are, as far as i know,
> > particularly well-versed or highly motivated to maintain the code
> at a
> > reasonable level of quality on our own.
> >
> > You proposed a number of possible solutions:
> >
> >> * Turning on WMS in ArcServer and pointing TileCache at it.
> Works but
> >> ArcServer wants to serve the layers independently, so I get back to
> >> the SLD problem.
> >
> > To me, this seems like a configuation issue. That is, the WMS serves
> > layers individually, but they're typically possible to combined, with
> > something like:
> >
> > layers=0,1,2
> >
> > In your TileCache config. However, I only know very little of ESRI's
> > software, so I can't comment on that for sure, and I haven't seen any
> > links that help me look at your setup to confirm-or-dis-confirm this
> > notion of mine.
> >
> >> * Generating a tile cache out of ArcServer and kludging TileCache to
> >> serve it up.
> >
> > I don't know what 'ArcServer' is, but I expect that this would have
> > essentially the same problem that has existed i ArcGIS caches in the
> > past, which is that most people who have access to caches don't know
> > what the parameters used to create the cache are.
> >
> >> And lastly:
> >>
> >> * Pulling the AGS plugin for OpenLayers out of the sandbox
> >
> > This code should probably be in trunk, as described above. The
> fact that
> > it is not is because no sufficiently motivated Javascript
> developer has
> > made it so. (As Mr. Schaub pointed out at one point, these things
> arent
> > meant to happen magically; in Open Source, you need to either pay
> > someone to do it, or do it yourself.)
> >
> >> I haven't actually tried the last bit because of some of your emails
> >> I've found from 2007. It sounds like AGS is a dead-end. Is this
> true?
> >> Is there a specific reason?
> >
> > AGS is not a dead-end, but you probably read emails where I was
> > expressing my frustration, centered mostly around the stuff above.
> > Specifically, the same problem as there is in many aspects of the
> > project has arisen here:
> > * Someone writes some code
> > * The code is insufficient, poorly documented, or simply 'not done'
> > * The author of the code expects it to get in trunk
> > * Requests to do more work to make it happen are ignored.
> >
> > The general assumption in these cases seems to be that if someone
> writes
> > some code, it will automatically be in trunk, which is simply
> > unrealistic. OpenLayers is a high quality code library, and it seems
> > completely reasonable to me that in order to keep it that way, we
> have
> > to maintain some standards. However, this means that some code
> does not
> > make it into trunk in a timely manner, and the patch authors feel
> > shunned or ignored. Although this is almost always not the case, the
> > emotions there are very frustrating as a developer: the
> expectation that
> > patches lead to changes in the library 'for free' is just unfair
> to the
> > core development team.
> >
> > In this case, I was unable to st up the ArcGIS cached layer code
> to talk
> > to any server I could find documented on the web. If I an't do it, I
> > can't imagine that most users can do it: I'm a pretty smart guy in
> > general. If I cant' pull it off, then it is probably the case that
> > others can't either, and that means that putting it in trunk is
> asking
> > for pain. With that in mind, I saw no significant personal benefit to
> > working on it, and the code has sat.
> >
> > My expressed frustration is/was probably unfair. I'm not aware of any
> > problem with the code as it exists -- except that people are
> using it,
> > and not giving back to the community by trying to get it into
> trunk. I
> > find that combination extremely unfair, given the amount of work
> that so
> > many people put in to make the library possible. I'd love to see some
> > organizations out there who are using this code really invest in
> it, and
> > make the library better for everyone as a result. This could come
> in the
> > form of paying developers to work on it, project sponsorship with a
> > stated request -- though not binding, clearly somewhat motivating
> -- or
> > other potential venues. Without any of this kind of support,
> > organizations -- of which there are several -- using the AGS code are
> > simply taking from the library, and not giving back. that type of
> > behavior is frustrating to me, and that has probably come through in
> > previous emails.
> >
> >> And input would be greatly appreciated.
> >
> > Using ESRI services in OpenLayers needs champions -- people who are
> > willing to truly support the cause. ArcXML has a champion in the
> form of
> > dzwarg, who has been working with me on an ArcXML ticket. ArcGIS rest
> > layer had a champion in the form of Jeff Adams. AGS cache needs the
> > same. The community could probably rally up and make this support
> > happen: lots of people have expressed interest. Open Source isnt all
> > about things being done for you, and I'd love to see some of the
> users
> > of the software really invest in OpenLayers more than they have up to
> > this point. ESRI-specific services are a great example of this, where
> > there's a lot of code floating about, but relatively limited
> support of
> > it outside of the companies using it or specific use cases, and
> that's
> > a great example of what I'd love to see change.
> >
> > Sorry for using you email as a jumping off point for a 'rant'
> like this,
> > but the state of ESRI-in-OpenLayers is an excellent example of what
> > *feels* like poor community support of library in favor of immediate
> > needs, and I really like the idea of that changing. (And if I'm
> > completely ignoring a significant effort in this regard, this is a
> > perfect oppourtunity for the existing community members whose work I
> > have been ignoring to step up and tell me how wrong I am!)
> >
> > Regards,
> > --
> > Christopher Schmidt
> > MetaCarta
> > _______________________________________________
> > Dev mailing list
> > Dev at openlayers.org <mailto:Dev at openlayers.org>
> > http://openlayers.org/mailman/listinfo/dev
> >
> >
>
>
> -----
> Regards, Carl SHE
> --
> View this message in context:
> http://n2.nabble.com/ESRI-and-OpenLayers-tp2412861p2444558.html
> Sent from the OpenLayers Dev mailing list archive at Nabble.com.
>
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--
Tim Schaub
OpenGeo - http://opengeo.org
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