107 lines
2.7 KiB
Elixir
107 lines
2.7 KiB
Elixir
defmodule FeedParser.Parser.RSS2 do
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@moduledoc """
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A `FeedParser.Parser` that handles [RSS 2.0 feeds](https://cyber.harvard.edu/rss/rss.html).
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"""
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alias FeedParser.XML
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require XML
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@behaviour FeedParser.Parser
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@impl FeedParser.Parser
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def accepts(data, content_type) do
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cond do
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content_type in ["application/rss+xml", "text/rss+xml"] ->
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case XML.parse(data) do
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{:error, _} -> false
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{:ok, doc} -> {true, doc}
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end
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content_type in ["text/xml", "application/xml"] ->
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case XML.parse(data) do
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{:error, _} ->
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false
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{:ok, doc} ->
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if XML.xmlElement(doc, :name) == :rss do
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{true, doc}
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else
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false
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end
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end
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true ->
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false
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end
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end
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@impl FeedParser.Parser
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def parse_feed(rss) do
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[channel] = :xmerl_xpath.string('/rss/channel', rss)
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title = text('/channel/title/text()', channel)
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link = text('/channel/link/text()', channel)
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image = text('/channel/image/url/text()', channel)
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last_updated =
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text('/channel/lastBuildDate/text()', channel)
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|> Timex.parse("{RFC1123}")
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|> case do
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{:ok, date} -> date
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_ -> nil
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end
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items =
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:xmerl_xpath.string('/channel/item', channel)
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|> Enum.map(fn item ->
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guid = text('/item/guid/text()', item)
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title = text('/item/title/text()', item)
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link = text('/item/link/text()', item)
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description = text('/item/description/text()', item)
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# http://purl.org/rss/1.0/modules/content/
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content = text('/item/content:encoded/text()', item)
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pubDate =
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text('/item/pubDate/text()', item)
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|> Timex.parse("{RFC1123}")
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|> case do
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{:ok, date} -> date
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_ -> nil
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end
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# from Dublin Core extension: https://www.rssboard.org/rss-profile#namespace-elements-dublin
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# todo: should this only be attempted if the xmlns:dc is defined?
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creator = text('/item/dc:creator/text()', item)
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%FeedParser.Item{
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guid: guid,
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title: title,
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url: link,
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links: [{link, nil}],
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content: content || description,
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date: pubDate,
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creator: creator
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}
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end)
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{:ok,
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%FeedParser.Feed{
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site_url: link,
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title: title,
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image_url: image,
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last_updated: last_updated,
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items: items
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}}
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end
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defp text(xpath, element) do
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case :xmerl_xpath.string(xpath, element) do
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[el] ->
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XML.xmlText(el, :value) |> List.to_string() |> String.trim()
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_ ->
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nil
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end
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end
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end
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