selecting 'Hide Contents' may crash MinimServer

[simoncn]

(13-08-2012 19:40)bubbleguuum Wrote:  Yes, I understand what you mean.

A CP doing a recursive browse should filter duplicates (note that neither BubbleUPnP / BubbleDS do it). It is easy to filter as the item id uniquely identify each item (provided that the server use the same id for identical items!). It could also further try to detect duplicates comparing a few attributes that are likely to uniquely identify an item.

As you say, filtering duplicates is very easy. However, I'm not aware of any control point that does it. And even if 80% if the control points were to start doing it, MinimServer would still have to jump through hoops to accommodate the 20% that don't.

Quote:There are 2 scenarios where recursive browsing can happen:

- initiated by a user from any folder with a CP that allow this. Not many CP have this functionality. And I'm not sure how often users recursively load a folder.

Do you mean the "play all" action to put a complete album/artist/genre/etc. into the playlist? This is supported by most control points, and I don't know of any that are smart enough to eliminate duplicates.

Quote:- initiated by the program to crawl the whole Content directory. A program that would do this and not filter duplicates is flawed in my optionion. Unfortunatly WMP do this and do not filter duplicates (more on this below).

PlugPlayer also does this, but seems not to go as far as WMP in crawling the complete contents. I came across another CP that also crawls the complete contents, but I don't remember which it was.

Quote:Personaly I'm not too keen on deep and complicated hierarchy. Anything over 3 or 4 levels is too much I think.

With MinimServer, that's up to each user to decide. Each time they look for content, they dynamically create their own hierarchy and browse down as far as they want to. At any point, they can bale out and view a flat list of albums or items (with or without alpha-grouping).

Quote:The UPnP standard has something for this: the UpdateID return value of the Browse action. Theorically a browsing CP would need to reinitialize an ongoing Browse on a container if it receives a different UpdateID. In pratice I'm certain very few CP uses this value.
A container whose content changes can also be notified to clients through an eventing variable I forgot the name but it is also probably not taken into account by many CP.
So in theory dynamically chaing containers are possible but in reality there is very little support for it.

This doesn't do anything for the problem of the control point letting the server know that's it's finished using a container.

It also doesn't solve the problem of setting rules for when the control point needs to refresh its view of a container. There are three steps:
1) The control point decides that it feels like re-reading the container.
2) In response, the server sends an incremented UpdateID value for that container.
3) The control point refreshes its view.

Step 3 is required, but step 1 isn't. So if a control never re-reads any containers (perfectly legal), it will never see an incremented UpdateID value.

I've only come across one control point that does the 1/2/3 sequence correctly, and that control point is ChorusDS.

The evented variable (ContainerUpdateIDs) is another of those optional things that servers don't need to implement.

Quote:WMP does indeed crawl the MS and do not remove duplicates as mentionned aboved. However it crawls the MS as a last resort if a particular search query fails:

upnp:class derivedfrom "object.item.audioItem"

If you implement that search query and returns all tracks it will solve the problem.

I didn't know that. So when MinimServer supports UPnP Search, there's some hope that it might start to work with WMP.

Quote:Do you mean using paging with RequestedCount for display purpose ?
This can be done but it is not very user friendly introducing lag. I dislike apps using lazy loading of lists. Some UPnP apps do it btw.

Yes, I do mean that. Can you name a control point that does this? I haven't found any.

I don't believe this would cause a lag if the control point implements it correctly and the server is very responsive. It should be like AJAX (Google Maps) where a background thread is reading slightly ahead to anticipate user scrolling. If the user jumps to a completely different point in the list, the time lag to get the necessary data would be a few ms (with MinimServer), which shouldn't be noticeable to the user.

Quote:I consider that if a container has two many items, it should be further split, for example by first letter (or group of letters).

MinimServer supports this as an option.

Quote:And to some extend, hierarchical browsing shows its limit with huge collections. That's where UPnP Search becomes useful.

There's a place for both. I'm not a great fan of typing search queries, but I understand that some people like to do that.