74 lines
1.5 KiB
Elixir
74 lines
1.5 KiB
Elixir
defmodule Readability.TitleFinder do
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@moduledoc """
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The TitleFinder engine traverses HTML tree searching for finding title.
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"""
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@title_suffix ~r/\s(?:\-|\:\:|\|)\s/
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@h_tag_selector "h1, h2, h3"
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@type html_tree :: tuple | list
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@doc """
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Find proper title
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"""
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@spec title(html_tree) :: binary
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def title(html_tree) do
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case og_title(html_tree) do
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"" ->
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title = tag_title(html_tree)
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if good_title?(title) do
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title
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else
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h_tag_title(html_tree)
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end
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title when is_binary(title) ->
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title
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end
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end
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@doc """
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Find title from title tag
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"""
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@spec tag_title(html_tree) :: binary
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def tag_title(html_tree) do
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html_tree
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|> Floki.find("head title")
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|> clean_title()
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|> String.split(@title_suffix)
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|> hd()
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end
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@doc """
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Find title from og:title property of meta tag
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"""
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@spec og_title(html_tree) :: binary
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def og_title(html_tree) do
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html_tree
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|> Floki.find("meta[property=og:title]")
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|> Floki.attribute("content")
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|> clean_title()
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end
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@doc """
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Find title from h tag
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"""
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@spec h_tag_title(html_tree, String.t) :: binary
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def h_tag_title(html_tree, selector \\ @h_tag_selector) do
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html_tree
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|> Floki.find(selector)
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|> hd()
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|> clean_title()
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end
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defp clean_title(html_tree) do
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html_tree
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|> Floki.text()
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|> String.strip()
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end
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defp good_title?(title) do
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length(String.split(title, " ")) >= 4
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end
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end
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