[Patch] Detect preset wiki languages automatically

[simon04]

Instead of maintaining various OSM wiki languages in defaultpresets.xml, maintaining presets_lang.pl, running presets_lang.pl from time to time, still applying manual changes (cf. #17171), let JOSM detect the wiki language automatically. This features has been implemented long ago in HelpAction.displayHelp: it opens https://wiki.openstreetmap.org/wiki/[lang]:[page] if it exists and falls back to https://wiki.openstreetmap.org/wiki/[page].

So in a nutshell …

data/defaultpresets.xml

@@ -326 +326 @@
         <reference ref="voltage_frequency" />
     </chunk>
     <chunk id="power_generator">
-        <link href="https://wiki.openstreetmap.org/wiki/Tag:power=generator"
-                  cs.href="https://wiki.openstreetmap.org/wiki/Cs:Tag:power=generator"
-                  de.href="https://wiki.openstreetmap.org/wiki/DE:Tag:power=generator"
-                  es.href="https://wiki.openstreetmap.org/wiki/ES:Tag:power=generator"
-                  fr.href="https://wiki.openstreetmap.org/wiki/FR:Tag:power=generator"
-                  it.href="https://wiki.openstreetmap.org/wiki/IT:Tag:power=generator"
-                  ja.href="https://wiki.openstreetmap.org/wiki/JA:Tag:power=generator"
-                  pl.href="https://wiki.openstreetmap.org/wiki/Pl:Tag:power=generator"
-                  pt.href="https://wiki.openstreetmap.org/wiki/Pt:Tag:power=generator"
-                  ru.href="https://wiki.openstreetmap.org/wiki/RU:Tag:power=generator" />
+        <link wiki="Tag:power=generator" />
         <space />
         <key key="power" value="generator" />
         <reference ref="name_ref_operator" />

In total: 719 insertions(+), 5651 deletions(-)

Relates to this discussion at josm-dev@: ​https://lists.openstreetmap.org/pipermail/josm-dev/2018-November/008171.html (Add templated version of wiki href to link element in presets)

[stoecker]

It's not so easy. You overlooked all these cases where the links don't have the same name.

[naoliv]

For pt_BR it will be necessary to consider the language as pt, since pt_BR was unified into pt (ie, people using JOSM in pt or pt_BR should open the same Portuguese wiki pages).
With the patch (actually after [14617]), using pt_BR only opens the English pages.

[simon04]

Replying to stoecker:

It's not so easy. You overlooked all these cases where the links don't have the same name.

Please name one. I only stumbled over ​https://wiki.openstreetmap.org/wiki/Link_(highway vs. ​https://wiki.openstreetmap.org/wiki/Cs:Highway_link, but the former redirects to ​https://wiki.openstreetmap.org/wiki/Highway_link. IMO we could accept 0.1% non-detected language links in favour of simplicity / elegance / reduced code / reduced maintenance burden.

Replying to naoliv:

For pt_BR it will be necessary to consider the language as pt, since pt_BR was unified into pt (ie, people using JOSM in pt or pt_BR should open the same Portuguese wiki pages).
With the patch (actually after [14617]), using pt_BR only opens the English pages.

Good to know… We should reflect the merge in LanguageInfo. The merge has taken place on the OSM wiki, the JOSM wiki, the JOSM i18n?

[naoliv]

Replying to simon04:

Good to know… We should reflect the merge in LanguageInfo. The merge has taken place on the OSM wiki, the JOSM wiki, the JOSM i18n?

Only OSM wiki was unified. The rest are still (and I guess will stay) different.

[stoecker]

Replying to simon04:

Replying to stoecker:

It's not so easy. You overlooked all these cases where the links don't have the same name.

Please name one. I only stumbled over ​https://wiki.openstreetmap.org/wiki/Link_(highway vs. ​https://wiki.openstreetmap.org/wiki/Cs:Highway_link, but the former redirects to ​https://wiki.openstreetmap.org/wiki/Highway_link. IMO we could accept 0.1% non-detected language links in favour of simplicity / elegance / reduced code / reduced maintenance burden.

Hmm, seems the wiki situation changed. E.g. Link_(highway) or Highway_link actually has references to "Pt:Tag:highway=motorway_link", but this is missing totally now. Also the wiki does not refernce redirects in the language pages. Maybe they broke the wiki in that instance? That would mean that your approach would actually be better, as the links then work again.

Can you please extract the code changes and attach them separately for review?

Replying to naoliv:

For pt_BR it will be necessary to consider the language as pt, since pt_BR was unified into pt (ie, people using JOSM in pt or pt_BR should open the same Portuguese wiki pages).
With the patch (actually after [14617]), using pt_BR only opens the English pages.

Good to know… We should reflect the merge in LanguageInfo. The merge has taken place on the OSM wiki, the JOSM wiki, the JOSM i18n?

JOSM wiki and JOSM i18n is not affected. That would only be the case, when pt_BR translation gets dropped. But we need to change JOSM code, that the OSM wiki prefix for pt_BR is "Pt:".

Note that JOSM wiki uses language code derived rules, whereas the prefix for OSM wiki seems to be manually decided. They are not identical.

[stoecker]

Ticket #17171 has been marked as a duplicate of this ticket.

[stoecker]

If we go this way we need to:

• test that the added English links actually refer to non-redirect pages
• have a way to test redirects later (i.e. modify the wiki scraper)

If not:

• update the wiki scraper to handle redirects correct