69 lines
1.8 KiB
Elixir
69 lines
1.8 KiB
Elixir
defmodule Readability.CandidateFinder do
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@moduledoc """
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The builing and finding candidates engine
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It traverses the HTML tree searching, removing, socring nodes
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"""
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alias Readability.Helper
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alias Readability.Candidate
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alias Readability.Candidate.Scoring
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@type html_tree :: tuple | list
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@type options :: list
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@doc """
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Find candidates that shuld be meaningful article by analysing nodes
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"""
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@spec find(html_tree, options, number) :: [Candidate.t()]
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def find(_, opts \\ [], tree_depth \\ 0)
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def find([], _, _), do: []
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def find([h | t], opts, tree_depth) do
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[find(h, opts, tree_depth) | find(t, opts, tree_depth)]
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|> List.flatten()
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end
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def find(text, _, _) when is_binary(text), do: []
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def find({tag, attrs, inner_tree}, opts, tree_depth) do
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html_tree = {tag, attrs, inner_tree}
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if candidate?(html_tree) do
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candidate = %Candidate{
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html_tree: html_tree,
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score: Scoring.calc_score(html_tree, opts),
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tree_depth: tree_depth
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}
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[candidate | find(inner_tree, opts, tree_depth + 1)]
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else
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find(inner_tree, opts, tree_depth + 1)
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end
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end
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@doc """
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Find the highest score candidate.
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"""
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@spec find_best_candidate([Candidate.t()]) :: Candidate.t()
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def find_best_candidate([]), do: nil
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def find_best_candidate(candidates) do
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candidates
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|> Enum.max_by(fn candidate -> candidate.score end)
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end
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defp candidate?(_, depth \\ 0)
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defp candidate?(_, depth) when depth > 2, do: false
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defp candidate?([h | t], depth), do: candidate?(h, depth) || candidate?(t, depth)
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defp candidate?([], _), do: false
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defp candidate?(text, _) when is_binary(text), do: false
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defp candidate?({_, _, inner_tree} = html_tree, depth) do
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if Helper.candidate_tag?(html_tree) do
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true
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else
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candidate?(inner_tree, depth + 1)
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end
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end
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end
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