readability/lib/readability.ex

125 lines
3.7 KiB
Elixir

defmodule Readability do
@moduledoc """
Readability library for extracting & curating articles.
## Example
```elixir
@type html :: binary
# Extract title
Readability.title(html)
# Extract only text from article
article = html
|> Readability.article
|> Readability.readable_text
# Extract article with transformed html
article = html
|> Readability.article
|> Readability.raw_html
```
"""
alias Readability.TitleFinder
alias Readability.ArticleBuilder
@default_options [retry_length: 250,
min_text_length: 25,
remove_unlikely_candidates: true,
weight_classes: true,
clean_conditionally: true,
remove_empty_nodes: true,
min_image_width: 130,
min_image_height: 80,
ignore_image_format: [],
blacklist: nil,
whitelist: nil
]
@regexes [unlikely_candidate: ~r/combx|comment|community|disqus|extra|foot|header|hidden|lightbox|modal|menu|meta|nav|remark|rss|shoutbox|sidebar|sponsor|ad-break|agegate|pagination|pager|popup/i,
ok_maybe_its_a_candidate: ~r/and|article|body|column|main|shadow/i,
positive: ~r/article|body|content|entry|hentry|main|page|pagination|post|text|blog|story/i,
negative: ~r/hidden|^hid|combx|comment|com-|contact|foot|footer|footnote|link|masthead|media|meta|outbrain|promo|related|scroll|shoutbox|sidebar|sponsor|shopping|tags|tool|utility|widget/i,
div_to_p_elements: ~r/<(a|blockquote|dl|div|img|ol|p|pre|table|ul)/i,
replace_brs: ~r/(<br[^>]*>[ \n\r\t]*){2,}/i,
replace_fonts: ~r/<(\/?)font[^>]*>/i,
normalize: ~r/\s{2,}/,
video: ~r/\/\/(www\.)?(dailymotion|youtube|youtube-nocookie|player\.vimeo)\.com/i
]
@type html_tree :: tuple | list
@type options :: list
@doc """
Extract title
## Example
iex> title = Readability.title(html_str)
"Some title in html"
"""
@spec title(binary) :: binary
def title(html) when is_binary(html), do: html |> parse |> title
def title(html_tree), do: TitleFinder.title(html_tree)
@doc """
Using a variety of metrics (content score, classname, element types), find the content that is
most likely to be the stuff a user wants to read
## Example
iex> article_tree = Redability(html_str)
# returns article that is tuple
"""
@spec article(binary, options) :: html_tree
def article(raw_html, opts \\ []) do
opts = Keyword.merge(@default_options, opts)
raw_html
|> parse
|> ArticleBuilder.build(opts)
end
@doc """
return raw html binary from html_tree
"""
@spec raw_html(html_tree) :: binary
def raw_html(html_tree) do
html_tree |> Floki.raw_html
end
@doc """
return only text binary from html_tree
"""
@spec raw_html(html_tree) :: binary
def readable_text(html_tree) do
# TODO: Remove image caption when extract only text
tags_to_br = ~r/<\/(p|div|article|h\d)/i
html_str = html_tree |> raw_html
Regex.replace(tags_to_br, html_str, &("\n#{&1}"))
|> Floki.parse
|> Floki.text
|> String.strip
end
@doc """
Normalize and Parse to html tree(tuple or list)) from binary html
"""
@spec parse(binary) :: html_tree
def parse(raw_html) do
raw_html
|> String.replace(Readability.regexes[:replace_brs], "</p><p>")
|> String.replace(Readability.regexes[:replace_fonts], "<\1span>")
|> String.replace(Readability.regexes[:normalize], " ")
|> Floki.parse
|> Floki.filter_out(:comment)
end
def regexes, do: @regexes
def default_options, do: @default_options
end