1 ikiwiki's simple podcasting, while elegant and minimal, doesn't (as
2 mentioned in [[todo/blogging]]) produce full-featured feeds. In
3 fancy podcasts, episodes are accompanied by text content. The feeds
4 also have lots more metadata.
10 [[!template id=gitbranch branch=schmonz/fancypodcast author="[[schmonz]]"]]
13 In summary, the branch preserves ikiwiki's existing podcast behavior,
14 adds more featureful behavior, and has been tested to work well in
15 some common podcatchers. I believe it is ready for review and
16 possible integration, and I'd like to get feedback to that effect
17 (or to the contrary) before making further enhancements. I know
18 [[joey]]'s the final arbiter here, but I'd appreciate any qualified,
19 critical eyes ([[smcv]]?) raking over my diffs. --[[schmonz]]
24 Feature |iTunes RSS|iTunes Atom|Downcast RSS|Downcast Atom
26 Feed title |(./) |(./) |(./) |(./)
27 Feed publisher | | | |
28 Feed "category" | | | |
29 Feed date |(./) |(./) |(./) |(./)
30 Feed description |(./) |(./) |(./) |
32 Episode title |(./) |(./) |(./) |(./)
33 Episode date |(./) |(./) |(./) |(./)
34 Episode duration | | | |
35 Episode author | | | |
36 Episode description|(./) |(./) |(./) |
37 Episode enclosure |(./) |(./) |(./) |(./)
42 7. For each fancy podcast episode, write a blog post containing
43 `\[[!meta enclosure="WikiLink/to/media.mp3"]]`. (Don't specify
44 more than one enclosure -- but if you do, last one wins.)
45 7. When rendering to HTML (single-page or inlined), append a link
47 7. When rendering to RSS/Atom, the text is the entry's content and
48 the media file is its enclosure.
49 7. Don't break simple podcasts in pursuit of fancy podcasts.
55 * Cover the existing simple podcast behavior with tests.
56 * Add an `enclosure` field to [[plugins/meta]] that expands the
57 given [[ikiwiki/WikiLink]] to an absolute URL (feed enclosures
58 pretty much need to be, and the reference feeds I've looked at
60 * Write failing tests for the desired single-page and inlined
61 HTML behavior, then make them pass by adding enclosure stanzas
62 to `{,inline}page.tmpl`.
63 * Write failing tests for the desired RSS/Atom behavior, then make
64 them pass via changes to `{atom,rss}item.tmpl` and [[plugins/inline]].
65 * Match feature-for-feature with
66 [tru_podcast](http://www.rainskit.com/blog/542/tru_podcast-a-podcasting-plugin-for-textpattern)
67 (what [[schmonz]] will be migrating from).
68 * Enrich [feed metadata](http://cyber.law.harvard.edu/rss/rss.html)
69 by catching up `rsspage.tmpl` to `atompage.tmpl`.
70 * Verify that [[plugins/more]] plays well with fancy podcasts.
71 * Verify that the feeds validate.
72 * Subscribe to a fancy feed in some common podcatchers and verify
73 display details against a reference podcast.
74 * Verify smooth transitions for two common use cases (see testing
77 ### Must-have (for [[schmonz]], anyway)
79 * Think carefully about UTF-8.
80 * Verify that _all_ the tests pass (not just my new ones).
84 ### Upgrading within ikiwiki: from simple to fancy
88 For this test, I chose a podcast that tries to work around ikiwiki's
89 current limitations by issuing two separate `inline`s:
91 * One with `feedonly=yes` that includes `.mdwn`, `.pdf`, and `.mp3`
92 * One with `feeds=no` that includes only `.mdwn` (and makes a trail)
94 This has the following effects:
96 * Browser: sees just the articles (each of which has a manually
97 created link to its corresponding media file)
98 * Feedreader: sees all the articles and media in one flat stream
99 * Podcatcher: sees just the media (sans articles)
101 I want instead to write one `inline` with these effects:
103 * Browser: sees just the articles (each of which automatically links
105 * Feedreader: sees just the articles (each of which specifies its
107 * Podcatcher: sees just the enclosures (each of which has an enclosing
108 article, rendered as the media's "description")
112 7. Set up a non-production copy of the podcast.
113 7. Visually diff RSS and Atom feeds against production.
114 7. Subscribe to the copy (both feeds) in `r2e`, iTunes, Downcast.
115 7. Apply fancypodcast patch to the installed ikiwiki:
116 7. `cd ~/Documents/trees/ikiwiki && git checkout fancypodcast`
117 7. `git diff --no-prefix master > ~/Documents/trees/localpatches/www/ikiwiki/fancypodcast.diff`
118 7. `cd ~/Documents/trees/pkgsrc-current/www/ikiwiki && make deinstall && make install clean`
119 7. Verify that simple podcasts are unaffected:
120 7. Rerun `ikiwiki --setup`.
121 7. `diff -uB simple-before.rss simple-after.rss`
122 * A few new elements and attributes, as expected.
123 7. `diff -uB simple-before.atom simple-after.atom`
125 7. Remove the feed-only `inline` and enable feeds on the remaining one.
126 7. Convert articles' manual download links to `\[[!meta enclosure=""]]`.
127 7. I want existing and future podcatchers to get my new fancy
128 episodes, and I know my podcast isn't in any planets, so I'm
129 going to skip [[tips/howto avoid flooding aggregators]].
130 7. Rerun `ikiwiki --setup`.
131 7. Verify browser shows the same stuff.
132 7. `diff -uB simple-after.rss fancy-after.rss # and atom`
133 * MP3s and PDFs are no longer naked enclosures, but belong to
134 articles as they should.
135 * Articles have updated modification times, as they should.
136 7. `r2e run` (both RSS and Atom)
137 * Nothing new with the default `trust-guid = True` (otherwise
138 would expect updated articles).
139 7. iTunes "Update Podcast" (both RSS and Atom)
140 * Added one episode per article, with article text as the episode
142 * Kept old naked-enclosure episodes around.
143 7. Downcast refresh (RSS):
144 * Added one episode per article, with article text as the episode
146 * Kept old naked-enclosure episodes around.
147 7. Downcast refresh (Atom):
148 * Added one episode per article, with no episode description
149 (expected, see feature table).
150 * Kept old naked-enclosure episodes around.
152 Different tradeoffs are possible. These seem okay to me.
154 ### Importing into ikiwiki: fancy (from another CMS)
158 For this test, I chose a podcast currently being published with
159 Textpattern and tru_podcast, because I'd strongly prefer to publish
160 it with ikiwiki instead.
164 7. Set up a non-production copy of the podcast.
165 7. Visually diff RSS and Atom feeds against production.
166 7. Subscribe to the copy (both feeds) in `r2e`, iTunes, Downcast.
167 7. With a fancypodcast-enabled ikiwiki installed:
168 7. Copy content from Textpattern to ikiwiki:
169 7. Match article paths to preserve `/YYYY/MM/DD/post-title` permalinks.
170 7. Match enclosure paths (or redirect) to preserve Textpattern's URLs.
171 7. Match titles, post dates, and guids with `\[[!meta]]`.
172 7. Match feed paths with permanent redirects from `/atom/` to
173 `/index.atom` (and same for RSS).
174 7. `\[[!inline]]` the articles.
175 7. Rerun `ikiwiki --setup`.
176 7. Stop Textpattern, start ikiwiki.
177 7. Verify that podcatchers see the feeds and don't redownload anything.
178 7. Naively add two new blog posts, one with an enclosure.
179 7. Verify that podcatchers download the new enclosures.
183 ## Future improvements
185 ### iTunes fancy podcasting
187 * [iTunes-specific tags](https://www.apple.com/itunes/podcasts/specs.html)
188 appear to be RSS-only
189 * If they work in Atom, teach `inline` to optionally iTunesify RSS/Atom.
190 * Else, add `itunes` as a third kind of feed (RSS plus more stuff).
191 * Notable tags for feeds:
194 * `itunes:summary` (same as `description`)
195 * `itunes:owner` (includes `itunes:name` and `itunes:email`)
196 * `itunes:image href=''`
198 * `itunes:category text=''` (can contain subcategories)
200 * Notable tags for entries:
202 * [[!cpan Audio::TagLib]] might be fastest, if present and applicable
203 * [ffprobe](http://ffmpeg.org/ffprobe.html) is reasonably fast
204 * [mediainfo](http://mediainfo.sourceforge.net/) is way slower
205 * Cache computed durations as pagestate
207 ### Fancy podcast aggregating
209 * Write tests comparing a fancy podcast (HTML and feeds) against
210 the same podcast aggregated and republished, then make them pass
211 via changes to `aggregatepost.impl` and [[plugins/aggregate]].
215 * Don't render template text (e.g., "Use this template to insert a
216 note into a page") in feeds.
217 * Optionally specify the enclosure's:
218 * MIME type, in case `File::MimeInfo` guesses wrong.
219 * Duration, in case `ffprobe` guesses wrong.
220 * Optionally specify enclosures outside the wiki:
221 * Some people don't want to store big unchanging files in the VCS.
222 * Other people like [podcasting found media](http://huffduffer.com/about).
223 * We'd have to download the file just to compute some metadata
224 about it, and then somehow not frequently re-download it.
225 * Configurably generate additional subscription links (such as
226 iTunes) alongside the RSS/Atom ones in [[plugins/inline]].
227 * Support Apple's "enhanced podcasts" (if they're still relevant).
231 + # XXX better way to compute relative to srcdir?
232 + my $file = $absurl;
233 + $file =~ s|^$config{url}/||;
235 I don't think ikiwiki offers a better way to do that, because there is
236 normally no reason to do that. Why does it need an url of this form here?
239 > In all the popular, production-quality podcast feeds I've looked
240 > at, enclosure URLs are always absolute (even when they could be
241 > expressed concisely as relative). [Apple's
242 > example](http://www.apple.com/itunes/podcasts/specs.html#example)
243 > does too. So I told \[[!meta]] to call `urlto()` with the third
244 > parameter true, which means the \[[!inline]] code here gets an
245 > absolute URL in `$pagestate{$p}{meta}{enclosure}`. To compute the
246 > enclosure's metadata, though, we of course need it as a local path.
247 > I didn't see a less
248 > [ongepotchket](http://www.jewish-languages.org/jewish-english-lexicon/words/1402)
249 > way at the time. If you have a better idea, I'm happy to hear it;
250 > if not, I'll add an explanatory comment. --[[schmonz]]
252 >> I would be more comfortable with this if two two different forms of url
253 >> you need were both generated by calling urlto. It'd be fine to call
254 >> it more than once. --[[Joey]]
256 +<TMPL_IF HTML5><section id="inlineenclosure"><TMPL_ELSE><div id="inlineenclosure"></TMPL_IF>
259 Can't we avoid adding this div when there's no enclosure? --[[Joey]]
261 > Sure, I've moved the `<TMPL_IF ENCLOSURE>` check to outside the
262 > section-and-div block for `{,inline}page.tmpl`. --[[schmonz]]
264 +<a href="<TMPL_VAR ENCLOSURE>">Download this episode</a>
266 "Download this episode" is pretty specific to particular use cases.
267 Can this be made more generic, perhaps just "Download"? --[[Joey]]
269 > Yep, I got a little carried away. Done. --[[schmonz]]
272 - <title><TMPL_VAR AUTHOR ESCAPE=HTML>: <TMPL_VAR TITLE></title>
273 - <dcterms:creator><TMPL_VAR AUTHOR ESCAPE=HTML></dcterms:creator>
275 This change removes the author name from the title of the rss feed, which
276 does not seem necessary for fancy podcasts. And it is a change that
277 could negatively impact eg, Planet style aggregators using ikiwiki. --[[Joey]]
279 > While comparing how feeds render in podcatchers, I noticed that
280 > RSS and Atom were inconsistent in a couple ways, of which this was
281 > one. The way I noticed it: with RSS, valuable title space was being
282 > spent to display the author. I figured Atom's display was the one
283 > worth matching. You're right, of course, that planets using the
284 > default template and somehow relying on the current author-in-the-title
285 > rendering for RSS feeds (but not Atom feeds!) would be broken by
286 > this change. I'm having trouble imagining exactly what would break,
287 > though, since guids and timestamps are unaffected. Would it suffice
288 > to provide a note in the changelog warning people to be careful
289 > upgrading their planets, and to customize `rssitem.tmpl` if they
290 > really prefer the old behavior (or don't want to take any chances)?
293 >> A specific example I know of is updo.debian.net, when used with
294 >> rss2email. Without the author name there, one cannot see who posted
295 >> an item. It's worth noting that planet.debian.org does the same thing
296 >> with its rss feed. (That's probably what I copied.) Atom feeds may
297 >> not have this problem, don't know. --[[Joey]]
299 +++ b/templates/rsspage.tmpl
300 + xmlns:atom="http://www.w3.org/2005/Atom"
301 +<atom:link href="<TMPL_VAR FEEDURL>" rel="self" type="application/rss+xml" />
303 Why is it using atom namespace inside an rss feed? What are the chances
304 every crummy rss reader on earth is going to understand this? I'd put it at
305 about 0%; I doubt ikiwiki's own rss reader understands such a mashup.
308 > The validator I used (<http://validator.w3.org/>, I think) told me to.
309 > Pretty sure it doesn't make anything work better in the podcatchers
310 > I tried. Hadn't considered that it might break some readers.
311 > Removed. --[[schmonz]]
313 +<generator>ikiwiki</generator>
315 Does this added tag provide any benefits? --[[Joey]]
317 > Consistency with the Atom feed, and of course it trumpets ikiwiki
318 > to software and/or curious humans who inspect their feeds. The tag
319 > arrived only in RSS 2.0, but that's already the version we're
320 > claiming to be, and it's over a decade old. Seems much less risky
321 > than the atom namespace bits. --[[schmonz]]
323 >> Sounds ok then. --[[Joey]]