dk.simongray.podcast.format.opml — dk.simongray/podcast-clj 0.1.0

Subscription lists as OPML 2.0, the format that every podcast app imports and exports.

A subscription list is a map:

{:title         "My podcasts"
 :date-created  #inst "…" ; and the other head elements
 :subscriptions [{:text     "A show"
                  :xml-url  "https://example.org/feed.xml"
                  :html-url "https://example.org"
                  :path     ["Tech"]
                  :category ["Daily" "/News/Denmark"]
                  :created  #inst "…"}]
 :includes      [{:text "A list"
                  :url  "https://example.org/list.opml"
                  :path ["News"]}]
 :comments      [{:text "An audiobook"
                  :guid "…"}]}

The folders of the OPML become the :path of the subscriptions inside them, and back again. In an outline:

• the categories become a vector, which OPML writes as one comma-separated attribute of tags and slash-delimited paths
• the time it was created becomes an instant, as do the dates of the head
• any other attribute stays a string
• the episodes inside it, as Overcast's extended export writes them, become its :episodes, maps of their attributes, e.g. {:enclosure-url "…" :played "1" :progress "754"}

An outline that includes another OPML list becomes one of the :includes, with the :path of its folders. It has the type include, or the type link to a URL that ends in .opml.

An outline with isComment="true" is commented out, and so is all that's inside it. It becomes one of the :comments, with its attributes and the :path of its folders, and never a subscription, even with an xmlUrl. Other apps skip a comment, so it can name a show that they can't fetch, e.g. one of local files.

emit clj/s

(emit subscription-list)

The OPML 2.0 document of the subscription-list, with the inclusions and then the comments after the subscriptions of their folder.

OPML separates the categories of an outline with commas, and it can't escape a comma. So a comma in a category goes out as an underscore.

parse clj/s

(parse s)

The subscription list of the OPML document s. It throws when s isn't XML, or its root element isn't opml.

try-parse clj/s

(try-parse s)

(try-parse s {:keys [url] :as opts})

Parse the OPML string s with the opts below, and give a map of the :list, or of the :error when it isn't OPML.

The error is the diagnostic :fetch/malformed with the :reason, for a list that came from somewhere else, such as a server. The opts give the :url of the list for the diagnostic. A platform without an XML parser isn't the fault of the list, so that error is still thrown.