Fri, 10 Apr 2026 09:35:39 +0000 https://bugs.horde.org/ticket/8196 Dimp folder list never shows up when there is many (>1000) folders Hi, When there is a great number of imap folder, dimp portal never load the folder list (and links to applications such as kronolith or turba). The javascript seems to wait for the complete folder list, and processing them takes a long time, eventually the browser gives up. However, the "folder" view in imp is OK (it seems it does not load the subfolder unless needed). Regards, Thu, 16 Apr 2009 08:16:37 +0000 https://bugs.horde.org/ticket/8196#t53664 Why do you have >1000 folders? This is what IMAP subscriptions are for. This would probably be an issue, since not only do you have to process the JSON return with all this data, but you have to insert all those DOM elements into the page - which is a significant browser slowdown. In IMP it is not an issue because we don't need to load the entire folder list. But to open a folder, it takes another page load so this adds a different layer of load. Theoretically we could workaround this - but at some point, too many folders will crash the display no matter how we implement. This is no different than trying to view a 10 MB text message or a MIME part with 100 nested parts. The best solution is, once a certain number of folders are reached, to tell the user they should be using less folders. Thu, 16 Apr 2009 20:12:07 +0000 https://bugs.horde.org/ticket/8196#t53675 > Why do you have >1000 folders? This is what IMAP subscriptions are > for. This would probably be an issue, since not only do you have to > process the JSON return with all this data, but you have to insert > all those DOM elements into the page - which is a significant browser > slowdown. > > In IMP it is not an issue because we don't need to load the entire > folder list. But to open a folder, it takes another page load so > this adds a different layer of load. > > Theoretically we could workaround this - but at some point, too many > folders will crash the display no matter how we implement. This is > no different than trying to view a 10 MB text message or a MIME part > with 100 nested parts. The best solution is, once a certain number > of folders are reached, to tell the user they should be using less > folders. I agree, there should be a limit., but this is confusing for the user. In Dimp, there is no way to work with only some folders (say, personal folder and no shared / other user namespace) and access the other folders in a more static way like in Imp. In this case, there are shared folders with customer informations (a customer = a folder). They are nested (no more than 100 at a given level, so if it where possible to request and display only the top folders it would be ok. I'm not that experienced in web programming (especially json, ajax etc), but isn't there a way to ask IMP the top folders list only, and to refresh the list only when a subfolder is requested ? I know there is a hook to hide shared folders, but when using it, is there a way to access hidden folders (other than going to imp) ? Also, would this be a setting that could be changed for some users only ? Regards, Clément Hermann Fri, 17 Apr 2009 07:57:33 +0000 https://bugs.horde.org/ticket/8196#t53746 > In Dimp, there is no way to work with only some folders (say, > personal folder and no shared / other user namespace) and access the > other folders in a more static way like in Imp. Correct - this is by design. > In this case, there are shared folders with customer informations (a > customer = a folder). They are nested (no more than 100 at a given > level, so if it where possible to request and display only the top > folders it would be ok. > > I'm not that experienced in web programming (especially json, ajax > etc), but isn't there a way to ask IMP the top folders list only, and > to refresh the list only when a subfolder is requested ? Technically this is possible, but it adds a bunch of complexity, provides for a much slower UI (certain IMAP servers are notoriously slow at returning mailbox lists), and for the 99.9% of people without 1000's of folders, it is not needed. I optimized a few things in IMP 5 in the last few days to cut down on the JSON data size. JSON data size is one of the areas that might cause a slowdown - older browsers can take a long time to parse a long JSON string. But even with 1000's of folders the JSON data size is only 70-100KB. And upcoming browsers will have json parsing support built-in so this will become less of an issue going forward. The more important issue has to do with javascript event handling. In DIMP 1.x, each folder inserted into the DOM required at least 1 event handler to be attached (others were attached on the first mouseover). Thus, inserting 1500 folders into the DOM required 2000+ event handlers. This is not a great thing and I guarantee older browsers would probably be sluggish simply because of this issue. The dimp interface in IMP 5 has already had its event model rewritten. Now, even after inserting 1500 folders, the dimp screen only has 7 total event handlers registered. This alone should fix any problems with display. FWIW, I can display 1500 folders just fine on DIMP 1.x, albeit with a bit of a lag during loading (I am using a reasonably fast Dual Core machine running FF 3). With the improvements mentioned above that have already been implemented in IMP 5, I don't think there is much more we need to do going forward - squeezing out even more performance for those .1% of people who have thousands of mailboxes simply isn't worth it. > I know there is a hook to hide shared folders, but when using it, is > there a way to access hidden folders (other than going to imp) ? > Also, would this be a setting that could be changed for some users > only ? I assume you are talking about IMAP subscriptions and, at the moment, there is no support for this in dimp (although it is on the TODO list). Fri, 17 Apr 2009 19:20:58 +0000 https://bugs.horde.org/ticket/8196#t53762