[14:00:33] <wm-bot>	 Technical Advice IRC meeting starting in 60 minutes in channel #wikimedia-tech, hosts:  - all questions welcome, more infos: https://www.mediawiki.org/wiki/Technical_Advice_IRC_Meeting
[14:50:17] <wm-bot>	 Technical Advice IRC meeting starting in 10 minutes in channel #wikimedia-tech, hosts: @Lucas_WMDE & @James_F - all questions welcome, more infos: https://www.mediawiki.org/wiki/Technical_Advice_IRC_Meeting
[14:50:29] * James_F waves.
[14:51:39] * Lucas_WMDE waves back
[15:00:11] <James_F>	 Okie-dokie, that's the time.
[15:00:21] <James_F>	 Welcome all to the weekly Technical Advice meeting.
[15:00:36] <James_F>	 Lucas_WMDE and are here and happy to answer any questions you might have.
[15:00:49] <Lucas_WMDE>	 o/
[15:15:52] <apergos>	 sure is a quiet session today
[15:15:59] <James_F>	 Indeed.
[15:17:02] <apergos>	 well, since no one else is asking anything, here's a question for you (for some vague value of "you"): why can I not via the mw api export all revisions of some set of pages, but only the current ones? 
[15:17:20] <apergos>	 you would think that if special:export lets me do it from the browser, I ought to be able to do it from the api, but no.
[15:17:29] <James_F>	 I think that's for performance reasons.
[15:17:38] <James_F>	 Special:Export is very locked-down.
[15:17:55] <James_F>	 But a rights-restricted API would be fine.
[15:18:00] <apergos>	 well, presumably you can only get x number of revisions per request, you pass in a continue param, etc like all the batched api queries
[15:18:24] <James_F>	 The "and transcluded content" flag expands the scope a great deal.
[15:18:32] <James_F>	 And makes batching hard.
[15:18:43] <apergos>	 ugh transcluded
[15:18:44] <James_F>	 But yeah, we could do that.
[15:19:01] <apergos>	 but we could ("we", i.e. $someone) 
[15:19:14] <apergos>	 ...could do it for a stright up list of pages, no transclusions
[15:19:15] <James_F>	 Transcluded is the only valuable flag. "Get me this template and all its documentation, templatestyles, Scribunto modules, and sub-templates".
[15:19:32] <James_F>	 Sure, but would that be significantly useful?
[15:19:49] <James_F>	 (I don't use the API for content access, so I'm not the best judge of utility.)
[15:19:55] <apergos>	 it could save people the headache of digging out 10 pages from a 200gb dump set
[15:20:40] <apergos>	 just a 'nice to have'
[15:20:55] <James_F>	 Yes, but do they definitely want plain content without transclusions?
[15:20:57] * James_F nods.
[15:21:00] <Lucas_WMDE>	 not sure how continuation would work here… would users have to “glue” the XML together themselves?
[15:21:21] <ankry>	 I have a question about processing templates provided to LUA function via frame:getParent().args
[15:21:21] <apergos>	 each xml file would have to have the full mediawiki, siteinfo, and page/title tags
[15:21:30] <apergos>	 then a set of revisions
[15:21:36] <apergos>	 oooh a question!  woo
[15:22:31] <James_F>	 This is related to T40669 but AFAICT not the same, right?
[15:22:32] <stashbot>	 T40669: API export action does not support exporting specific revisions - https://phabricator.wikimedia.org/T40669
[15:22:56] <ankry>	 if a template calling LUA code is transcluded, the templates provided inside arguments are sometimes processed in wrong context (namespace)
[15:22:56] <apergos>	 James_F: yep, but I'm going to defer in favor of ankry's question, I can follow up at any time
[15:23:07] <ankry>	 any hint ow to avoid this?
[15:23:07] <James_F>	 Sure.
[15:23:17] <James_F>	 Lucas_WMDE: Do you know Lua enough to help ankry?
[15:23:33] <Lucas_WMDE>	 probably not :/
[15:23:37] <ankry>	 :(
[15:23:40] <Lucas_WMDE>	 ankry: do you have an example somewhere?
[15:24:30] <ankry>	 I have the templates, but not an example calling them
[15:25:01] <ankry>	 If I need to construct an example, then mabe till next meeting?
[15:26:31] <Lucas_WMDE>	 I have no idea who will be at the next meeting, tbh
[15:26:36] <Lucas_WMDE>	 but an example would probably help in general
[15:26:49] <Lucas_WMDE>	 are any Lua experts online at the moment who could help out?
[15:30:55] <ankry>	 Lucas_WMDE: If I do not use the templates in arguments, but replace them with their code ("substitute" them), everything works fine
[15:33:04] <ankry>	 looks like templates were processed in some context, their result cached some way and then the cached data used in another context. Unsure if this is a bug or feature
[15:43:50] <Lucas_WMDE>	 as far as I’m aware, Lua invocations are generally supposed to be pretty independent of each other
[15:43:57] <Lucas_WMDE>	 unless you opt into some sharing with mw.loadData()
[15:44:23] <Lucas_WMDE>	 so to me that sounds more like a potential bug
[15:45:37] <Lucas_WMDE>	 but multi-level substitution can also be terribly confusing – there’s some safesubst thing that I don’t understand at all
[15:48:43] <James_F>	 No-one does.
[15:56:43] <apergos>	 are there debugging tips you can provide for wading through the multiple levels of substitution? even that could help
[15:57:56] <James_F>	 With MW template craziness, generally I recommend simplifying as a way to avoid unexpected issues.
[15:58:07] <James_F>	 So instead of four levels of template indirection, try to do it in one or two.
[15:58:08] <James_F>	 Etc.
[15:58:27] <James_F>	 Each Lua call multiplies up the "bug surface" of things that can wrong.
[15:58:42] <James_F>	 ankry: Good luck. :-(
[16:01:38] <Lucas_WMDE>	 yeah, I don’t have any tips for this, sorry :/
[16:01:48] <Lucas_WMDE>	 guess that concludes the Technical Advice IRC Meeting…
[16:01:52] <James_F>	 OK, that's us at time.
[16:02:03] <Lucas_WMDE>	 you could try asking at https://discourse-mediawiki.wmflabs.org/
[19:37:11] <domas>	 hi!