52 lines
1.4 KiB
Elixir
52 lines
1.4 KiB
Elixir
defmodule FeedParser do
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@moduledoc """
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FeedParser is a for parsing feeds of various formats into a unified representation.
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The currently supported formats are:
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- RSS 2.0
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- Atom
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- JSON Feed
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- RSS-in-JSON
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"""
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@default_parsers [
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FeedParser.Parser.RSS2,
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FeedParser.Parser.Atom,
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FeedParser.Parser.JSONFeed,
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FeedParser.Parser.RSSInJSON
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]
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@doc """
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Parses a feed from the given data string and MIME type.
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An extended set of parsers may also be provided, otherwise the default set (supporting RSS 2.0, Atom, JSON Feed, and RSS-in-JSON) will be used. Parsers are modules that implement the `FeedParser.Parser` behaviour.
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"""
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@spec parse(data :: String.t(), content_type :: String.t(), parsers :: [module()]) ::
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{:ok, feed :: FeedParser.Feed.t()} | {:error, reason :: term()}
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def parse(data, content_type, parsers \\ @default_parsers)
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def parse(nil, _, _) do
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{:error, :no_data}
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end
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def parse(data, content_type, parsers) when is_binary(data) do
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parsers
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|> Enum.reduce_while(false, fn parser, acc ->
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case parser.accepts(data, content_type) do
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{true, result} ->
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{:halt, {parser, result}}
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_ ->
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{:cont, acc}
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end
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end)
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|> case do
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{parser, result} ->
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parser.parse_feed(result)
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false ->
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{:error, "no parser matched the given content type ('#{content_type}') and data"}
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end
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end
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end
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