Re: [Talk-de] Potlatch (Re: Multi-User "randale" ( s?dlich Reutlingen/T?bingen ))
On Mon, Jun 9, 2008 at 5:05 PM, Christian Koerner <[EMAIL PROTECTED]> wrote:
> The conflict management could be simple, a new API call 'lock' could be
> introduced to lock and unlock ways for editing (online editors only?).
I agree, that this would be solution, but good locking is really hard
to implement. And if you deal with an request-based architecture like
the web it's even harder.
Atomic locking (= for every street/point) also increases DB load (this
can by avoided by holding locks in memory).
Maybe an area lock ("User XX locked a rectangle from lat,lng to
lat,lng") would be better. If the user pans out of this area, the
frontend would asked "Save changes" and releases the lock.
Best
Martin
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Re: [Talk-de] Potlatch (Re: Multi-User "randale" ( s?dlich Reutlingen/T?bingen ))
On Sun, 8 Jun 2008 21:52:27 +0100 Richard Fairhurst <[EMAIL PROTECTED]> wrote: > > Andre Rechelt wrote: > > > Ich frage mich ganz einfach, was sich die Entwickler von Potlach > > heraus nehmen, um im Gegensatz zu ALLEN ANDEREN direkt in der > > Datenbank herumzupfuschen und nicht den Weg ?ber die API gehen. > > Potlatch does not have, as you have put it elsewhere, a "direct > tunnel to the data". This just isn't true. > > Potlatch (the application) uses an API, just as JOSM does, which > sanitises requests, requires authentication, etc. There are three > significant differences between that part of the API used by > Potlatch, and that part of the API used by JOSM etc. > > - Potlatch uses a different encoding (AMF rather than XML). This is > simply for the sake of efficiency: older (Actionscript 1)/free > (Gnash) Flash players work much better with AMF than with XML. > Encoding, of course, makes no difference to the data. > > - Some of Potlatch's calls are constructed differently. Some of this > is for historical reasons - you might be too new to realise this, > but in earlier versions of the API, we had three object types: ways > (comprising a chain of segments), segments (connecting two nodes), > and nodes. Potlatch (which has always had broadly the same UI) > abstracted segments away from the user. Therefore the API functions > provided _at_the_time_ were not particularly suitable. > > Since then, the rest of the API has in fact moved closer to Potlatch > through the abolition of segments (Frederik and Gabriel's work, > thanks :) ). I believe that there is some will to provide the rest > of the API with the remaining Potlatch-only functionality (in > particular, a PUT /way//full method). > > Bear in mind too that, at present, the design of the main API calls > are better suited to an offline editor (like JOSM) than an online > one (like Potlatch). In particular, the /map call pulls down the > entire contents of the bounding box every single time. This would > mean that, every time the user panned the map in Potlatch, all the > ways and nodes would be sent again - even if the user had only panned > left by 10% of the screen area. Instead, Potlatch takes an approach > which does not require already-loaded ways to be resent, with > significant benefits for bandwidth and server load. > > - A significant proportion of the code in amf_controller.rb uses SQL > rather than Rails objects. Except in some cases where SQL provides a > significant speed advantage, this is generally accepted as a defect. > It's only the case because I don't speak Rails. If you want to do > something constructive, fixing this would be the single best place > to start, and would be enormously welcomed by many people including > myself. Please take it forward to the dev list if so - you'll find > lots of people willing to help you! > > > > While I'm here I might as well say something about the lack of a > Save button. > > I'm not violently against the concept: I think "unconvinced" is > perhaps the best way to describe my opinion. > > There are two big issues with it. One is that for edit sessions > lasting more than a couple of seconds, there has to be conflict > management. If you're a JOSM user, then you are de facto a > clued-up, computer-savvy type, so conflict management doesn't worry > you. But if you are a newbie - maybe even a schoolkid - trying just > to edit your local area, then being presented with "The following > conflicts were detected. Accept/Resolve/Revert?" will just utterly > confuse you, and you'll click the wrong thing and cause more errors. > Or maybe just close Potlatch and never return to OSM. > > The second is that, in JOSM, your "canvas" is usually quite small - > i.e. you have downloaded a particular area and are working on that > exclusively. In Potlatch, because you can pan around an infinite > map, your canvas may be much bigger. You may have traced a 600km > cycle route (I know, I've done that! :) ) in one session. Yet you > can't zoom out to see the whole thing, because requesting a 600km > bounding box would break both the server and the browser. So you > would be clicking "Save" to upload changes that you can't actually > see or review, and that - in my opinion - defeats the point of it. > > But actually they're not my biggest problem with the idea. > > What worries me most, because I've seen it before, is that people > are seizing on the first thing they don't like, and thinking that's > the reason why there are bad edits. People used to criticise Potlatch > for causing bad edits because there was no 'revert' feature, so I > added a revert feature (the H key). Then they criticised Potlatch for > causing bad edits because there was no 'test' mode, so I added a test > mode. Then they criticised Potlatch because there was no 'splash > screen' explaining things, so I added a splash screen. Now they > criticise Potlatch because ther
Re: [Talk-de] Potlatch (Re: Multi-User "randale" ( s?dlich Reutlingen/T?bingen ))
Richard Fairhurst schrieb: > Apologies, as a non-German speaker I can only half-follow this > discussion through Google Translate, and I realise it's very rude to > post in English on a German-speaking list. I thought it would > nonetheless be valuable to follow up two points in particular, hope > you don't mind. Thanks for entering this discussion, i think it is mucht better to speak with the developer, not about/against him. [snip] > > > > That's not to say that Potlatch can't be improved. Of course it can, a > lot. One simple easy-to-fix thing which I'm planning to change soon, > and which I think would make an enormous difference, is actually to > have a very prominent "uploading..." display when a way is being > uploaded. This would make it pretty obvious the first time that you > changed something that it was writing to the map. You would make one > bad edit, maximum. (In general, making what's happening "transparent" > and obvious is a good thing, and Potlatch doesn't follow that > principle enough at the moment.) I think this would be a very good improvement. When i first worked with Potlach i didn´t understand/realize that my edits are saved/uploaded immediately. If you could add a single line under "uploading" like: "If you want to revert your Edits press H" (or they key for that) it would be perfect. > > Another thing is localisation, so that the advice at the start - "If > you click 'Start', you'll be editing the main map directly" - shows up > in German, too. Lots of you have offered help with that, which is > great - thank you all; I hope to have some more news on that really soon. If there are to less people I even could help translating. At last I want to say that Potlach got better a lot since I joined OSM last year. Jonas ___ Talk-de mailing list Talk-de@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk-de
Re: [Talk-de] Potlatch (Re: Multi-User "randale" ( s?dlich Reutlingen/T?bingen ))
My opinion as a newbie (potlatch & josm user)... Richard Fairhurst schrieb: > There are two big issues with it. One is that for edit sessions lasting > more than a couple of seconds, there has to be conflict management. If > you're a JOSM user, then you are de facto a clued-up, computer-savvy > type, so conflict management doesn't worry you. But if you are a newbie > - maybe even a schoolkid - trying just to edit your local area, then > being presented with "The following conflicts were detected. > Accept/Resolve/Revert?" will just utterly confuse you, and you'll click > the wrong thing and cause more errors. Or maybe just close Potlatch and > never return to OSM. You need a conflict management even if you edit the database directly. If one user change a point/way, and another user already loaded this section in potlatch and change this point/way different? - The last one wins without a warning ... In josm you have to initialize the "save" prozedure AND it shows you the changes bevor saving - potlatch just saves. Most editors for text, pictures and audio waits for a user action to save, that's in peoples mind. Potlatch helped me to get into this project, too. Many thanks for this "easy to use" tool! But I'm afraid of vandalism. In this short time I spend a lot of time to map... The more people know about this project, the more will make it bad. So the software (josm too) have to - minimize (newbie) user input mistaces - easy repair options against vandalism You're right, a "save" button is not the last change, but give it a try if this button decrease the newbie mistaces ... Regards, Robert ___ Talk-de mailing list Talk-de@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk-de
[Talk-de] Potlatch (Re: Multi-User "randale" ( s?dlich Reutlingen/T?bingen ))
Apologies, as a non-German speaker I can only half-follow this discussion through Google Translate, and I realise it's very rude to post in English on a German-speaking list. I thought it would nonetheless be valuable to follow up two points in particular, hope you don't mind. Andre Rechelt wrote: Ich frage mich ganz einfach, was sich die Entwickler von Potlach heraus nehmen, um im Gegensatz zu ALLEN ANDEREN direkt in der Datenbank herumzupfuschen und nicht den Weg ?ber die API gehen. Potlatch does not have, as you have put it elsewhere, a "direct tunnel to the data". This just isn't true. Potlatch (the application) uses an API, just as JOSM does, which sanitises requests, requires authentication, etc. There are three significant differences between that part of the API used by Potlatch, and that part of the API used by JOSM etc. - Potlatch uses a different encoding (AMF rather than XML). This is simply for the sake of efficiency: older (Actionscript 1)/free (Gnash) Flash players work much better with AMF than with XML. Encoding, of course, makes no difference to the data. - Some of Potlatch's calls are constructed differently. Some of this is for historical reasons - you might be too new to realise this, but in earlier versions of the API, we had three object types: ways (comprising a chain of segments), segments (connecting two nodes), and nodes. Potlatch (which has always had broadly the same UI) abstracted segments away from the user. Therefore the API functions provided _at_the_time_ were not particularly suitable. Since then, the rest of the API has in fact moved closer to Potlatch through the abolition of segments (Frederik and Gabriel's work, thanks :) ). I believe that there is some will to provide the rest of the API with the remaining Potlatch-only functionality (in particular, a PUT /way//full method). Bear in mind too that, at present, the design of the main API calls are better suited to an offline editor (like JOSM) than an online one (like Potlatch). In particular, the /map call pulls down the entire contents of the bounding box every single time. This would mean that, every time the user panned the map in Potlatch, all the ways and nodes would be sent again - even if the user had only panned left by 10% of the screen area. Instead, Potlatch takes an approach which does not require already-loaded ways to be resent, with significant benefits for bandwidth and server load. - A significant proportion of the code in amf_controller.rb uses SQL rather than Rails objects. Except in some cases where SQL provides a significant speed advantage, this is generally accepted as a defect. It's only the case because I don't speak Rails. If you want to do something constructive, fixing this would be the single best place to start, and would be enormously welcomed by many people including myself. Please take it forward to the dev list if so - you'll find lots of people willing to help you! While I'm here I might as well say something about the lack of a Save button. I'm not violently against the concept: I think "unconvinced" is perhaps the best way to describe my opinion. There are two big issues with it. One is that for edit sessions lasting more than a couple of seconds, there has to be conflict management. If you're a JOSM user, then you are de facto a clued-up, computer-savvy type, so conflict management doesn't worry you. But if you are a newbie - maybe even a schoolkid - trying just to edit your local area, then being presented with "The following conflicts were detected. Accept/Resolve/Revert?" will just utterly confuse you, and you'll click the wrong thing and cause more errors. Or maybe just close Potlatch and never return to OSM. The second is that, in JOSM, your "canvas" is usually quite small - i.e. you have downloaded a particular area and are working on that exclusively. In Potlatch, because you can pan around an infinite map, your canvas may be much bigger. You may have traced a 600km cycle route (I know, I've done that! :) ) in one session. Yet you can't zoom out to see the whole thing, because requesting a 600km bounding box would break both the server and the browser. So you would be clicking "Save" to upload changes that you can't actually see or review, and that - in my opinion - defeats the point of it. But actually they're not my biggest problem with the idea. What worries me most, because I've seen it before, is that people are seizing on the first thing they don't like, and thinking that's the reason why there are bad edits. People used to criticise Potlatch for causing bad edits because there was no 'revert' feature, so I added a revert feature (the H key). Then they criticised Potlatch for causing bad edits because there was no 'test' mode, so I added a test mode. Then they criticised Potlatch because there was no 'splash screen
