:fast_html (FastHtml v2.4.0)

A module to decode html into a tree structure.

Summary

Types

attr()
attr_list()
comment_node3()
comment_node()
format_flag()
tag()
tree()

Functions

decode(bin, opts \\ [])

Returns a tree representation from the given html string.

decode_fragment(bin, opts \\ [])

Like decode/2, but for parsing HTML fragments.

open_port()

Types

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attr()

@type attr() :: {String.t(), String.t()}
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attr_list()

@type attr_list() :: [] | [attr()]
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comment_node3()

@type comment_node3() :: {:comment, [], String.t()}
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comment_node()

@type comment_node() :: {:comment, String.t()}
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format_flag()

@type format_flag() :: :html_atoms | :nil_self_closing | :comment_tuple3
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tag()

@type tag() :: String.t() | atom()
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tree()

@type tree() ::
  {tag(), attr_list(), tree()}
  | {tag(), attr_list(), nil}
  | comment_node()
  | comment_node3()

Functions

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decode(bin, opts \\ [])

@spec decode(String.t(), [{:format, [format_flag()]}]) ::
  {:ok, tree()} | {:error, String.t() | atom()}

Returns a tree representation from the given html string.

opts is a keyword list of options, the options available:

  • timeout - Call timeout. If pooling is used and the worker doesn't return the result in time, the worker will be killed with a warning.
  • format - Format flags for the tree.

The following format flags are available:

  • :html_atoms uses atoms for known html tags (faster), binaries for everything else.
  • :nil_self_closing uses nil to designate void elements. For example <br> is then being represented like {"br", [], nil}. See http://w3c.github.io/html-reference/syntax.html#void-elements for a full list of void elements.
  • :comment_tuple3 uses 3-tuple elements for comments, instead of the default 2-tuple element.

Examples 

iex> :fast_html.decode("<h1>Hello world</h1>")
{:ok, [{"html", [], [{"head", [], []}, {"body", [], [{"h1", [], ["Hello world"]}]}]}]}

iex> :fast_html.decode("Hello world", timeout: 0)
{:error, :timeout}

iex> :fast_html.decode("<span class='hello'>Hi there</span>")
{:ok, [{"html", [],
 [{"head", [], []},
  {"body", [], [{"span", [{"class", "hello"}], ["Hi there"]}]}]}]}

iex> :fast_html.decode("<body><!-- a comment --!></body>")
{:ok, [{"html", [], [{"head", [], []}, {"body", [], [comment: " a comment "]}]}]}

iex> :fast_html.decode("<br>")
{:ok, [{"html", [], [{"head", [], []}, {"body", [], [{"br", [], []}]}]}]}

iex> :fast_html.decode("<h1>Hello world</h1>", format: [:html_atoms])
{:ok, [{:html, [], [{:head, [], []}, {:body, [], [{:h1, [], ["Hello world"]}]}]}]}

iex> :fast_html.decode("<br>", format: [:nil_self_closing])
{:ok, [{"html", [], [{"head", [], []}, {"body", [], [{"br", [], nil}]}]}]}

iex> :fast_html.decode("<body><!-- a comment --!></body>", format: [:comment_tuple3])
{:ok, [{"html", [], [{"head", [], []}, {"body", [], [{:comment, [], " a comment "}]}]}]}

iex> html = "<body><!-- a comment --!><unknown /></body>"
iex> :fast_html.decode(html, format: [:html_atoms, :nil_self_closing, :comment_tuple3])
{:ok, [{:html, [],
 [{:head, [], []},
  {:body, [], [{:comment, [], " a comment "}, {"unknown", [], []}]}]}]}
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decode_fragment(bin, opts \\ [])

Like decode/2, but for parsing HTML fragments.

opts is a keyword list of options, the options available are the same as in decode/2 with addition of:

  • context - Name of the context element, defaults to div

Example:

iex> :fast_html.decode_fragment("rin is the <i>best</i> girl")
{:ok, ["rin is the ", {"i", [], ["best"]}, " girl"]}
iex> :fast_html.decode_fragment("rin is the <i>best</i> girl", context: "title")
{:ok, ["rin is the <i>best</i> girl"]}
iex> :fast_html.decode_fragment("rin is the <i>best</i> girl", context: "objective_truth")
{:error, :unknown_context_tag}
iex> :fast_html.decode_fragment("rin is the <i>best</i> girl", format: [:html_atoms])
{:ok, ["rin is the ", {:i, [], ["best"]}, " girl"]}
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open_port()