Floki (Floki v0.32.0) View Source

Floki is a simple HTML parser that enables search for nodes using CSS selectors.

Example

Assuming that you have the following HTML:

<!doctype html>
<html>
<body>
  <section id="content">
    <p class="headline">Floki</p>
    <a href="http://github.com/philss/floki">Github page</a>
    <span data-model="user">philss</span>
  </section>
</body>
</html>

To parse this, you can use the function Floki.parse_document/1:

{:ok, html} = Floki.parse_document(doc)
# =>
# [{"html", [],
#   [
#     {"body", [],
#      [
#        {"section", [{"id", "content"}],
#         [
#           {"p", [{"class", "headline"}], ["Floki"]},
#           {"a", [{"href", "http://github.com/philss/floki"}], ["Github page"]},
#           {"span", [{"data-model", "user"}], ["philss"]}
#         ]}
#      ]}
#   ]}]

With this document you can perform queries such as:

  • Floki.find(html, "#content")
  • Floki.find(html, ".headline")
  • Floki.find(html, "a")
  • Floki.find(html, "[data-model=user]")
  • Floki.find(html, "#content a")
  • Floki.find(html, ".headline, a")

Each HTML node is represented by a tuple like:

{tag_name, attributes, children_nodes}

Example of node:

{"p", [{"class", "headline"}], ["Floki"]}

So even if the only child node is the element text, it is represented inside a list.

Link to this section Summary

Functions

Changes the attribute values of the elements matched by selector with the function mutation and returns the whole element tree.

Returns a list with attribute values from elements.

Returns a list with attribute values for a given selector.

Returns the direct child nodes of a HTML node.

Returns the nodes from a HTML tree that don't match the filter selector.

Find elements inside a HTML tree or string.

Searches for elements inside the HTML tree and update those that matches the selector.

parse(html) deprecated

Parses a HTML Document from a String.

Parses a HTML Document from a string.

Parses a HTML Document from a string.

Parses a HTML fragment from a string.

Parses a HTML fragment from a string.

Converts HTML tree to raw HTML. Note that the resultant HTML may be different from the original one. Spaces after tags and doctypes are ignored.

Traverses and updates a HTML tree structure.

Traverses and updates a HTML tree structure with an accumulator.

Link to this section Types

Specs

css_selector() :: String.t() | Floki.Selector.t() | [Floki.Selector.t()]

Specs

html_attribute() :: {String.t(), String.t()}

Specs

html_comment() :: {:comment, String.t()}

Specs

html_declaration() :: {:pi, String.t(), [html_attribute()]}

Specs

html_doctype() :: {:doctype, String.t(), String.t(), String.t()}

Specs

html_node() ::
  html_tag()
  | html_comment()
  | html_doctype()
  | html_declaration()
  | html_text()

Specs

html_tag() :: {String.t(), [html_attribute()], [html_node()]}

Specs

html_text() :: String.t()

Specs

html_tree() :: [html_node()]

Link to this section Functions

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attr(html_elem_tuple, selector, attribute_name, mutation)

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Specs

attr(
  binary() | html_tree() | html_node(),
  css_selector(),
  binary(),
  (binary() -> binary())
) :: html_tree()

Changes the attribute values of the elements matched by selector with the function mutation and returns the whole element tree.

Examples

iex> Floki.attr([{"div", [{"id", "a"}], []}], "#a", "id", fn(id) -> String.replace(id, "a", "b") end)
[{"div", [{"id", "b"}], []}]

iex> Floki.attr([{"div", [{"class", "name"}], []}], "div", "id", fn _ -> "b" end)
[{"div", [{"id", "b"}, {"class", "name"}], []}]
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attribute(html, attribute_name)

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Specs

attribute(binary() | html_tree() | html_node(), binary()) :: list()

Returns a list with attribute values from elements.

Examples

iex> Floki.attribute([{"a", [{"href", "https://google.com"}], ["Google"]}], "href")
["https://google.com"]
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attribute(html, selector, attribute_name)

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Specs

attribute(binary() | html_tree() | html_node(), binary(), binary()) :: list()

Returns a list with attribute values for a given selector.

Examples

iex> Floki.attribute([{"a", [{"href", "https://google.com"}], ["Google"]}], "a", "href")
["https://google.com"]

iex> Floki.attribute([{"a", [{"class", "foo"}, {"href", "https://google.com"}], ["Google"]}], "a", "class")
["foo"]
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children(html_node, opts \\ [include_text: true])

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Specs

children(html_node(), Keyword.t()) :: html_tree() | nil

Returns the direct child nodes of a HTML node.

By default, it will also include all texts. You can disable this behaviour by using the option include_text to false.

If the given node is not an HTML tag, then it returns nil.

Examples

iex> Floki.children({"div", [], ["text", {"span", [], []}]})
["text", {"span", [], []}]

iex> Floki.children({"div", [], ["text", {"span", [], []}]}, include_text: false)
[{"span", [], []}]

iex> Floki.children({:comment, "comment"})
nil
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filter_out(html, selector)

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Specs

filter_out(html_node() | html_tree() | binary(), Floki.FilterOut.selector()) ::
  html_node() | html_tree()

Returns the nodes from a HTML tree that don't match the filter selector.

Examples

iex> Floki.filter_out({"div", [], [{"script", [], ["hello"]}, " world"]}, "script")
{"div", [], [" world"]}

iex> Floki.filter_out([{"body", [], [{"script", [], []}, {"div", [], []}]}], "script")
[{"body", [], [{"div", [], []}]}]

iex> Floki.filter_out({"div", [], [{:comment, "comment"}, " text"]}, :comment)
{"div", [], [" text"]}

iex> Floki.filter_out({"div", [], ["text"]}, :text)
{"div", [], []}

Specs

find(binary() | html_tree() | html_node(), css_selector()) :: html_tree()

Find elements inside a HTML tree or string.

Examples

iex> {:ok, html} = Floki.parse_fragment("<p><span class=hint>hello</span></p>")
iex> Floki.find(html, ".hint")
[{"span", [{"class", "hint"}], ["hello"]}]

iex> {:ok, html} = Floki.parse_fragment("<div id=important><div>Content</div></div>")
iex> Floki.find(html, "#important")
[{"div", [{"id", "important"}], [{"div", [], ["Content"]}]}]

iex> {:ok, html} = Floki.parse_fragment("<p><a href='https://google.com'>Google</a></p>")
iex> Floki.find(html, "a")
[{"a", [{"href", "https://google.com"}], ["Google"]}]

iex> Floki.find([{ "div", [], [{"a", [{"href", "https://google.com"}], ["Google"]}]}], "div a")
[{"a", [{"href", "https://google.com"}], ["Google"]}]
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find_and_update(html_tree, selector, fun)

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Specs

find_and_update(
  html_tree(),
  css_selector(),
  ({String.t(), [html_attribute()]} ->
     {String.t(), [html_attribute()]} | :delete)
) :: html_tree()

Searches for elements inside the HTML tree and update those that matches the selector.

It will return the updated HTML tree.

This function works in a way similar to traverse_and_update, but instead of updating the children nodes, it will only updates the tag and attributes of the matching nodes.

If fun returns :delete, the HTML node will be removed from the tree.

Examples

iex> Floki.find_and_update([{"a", [{"href", "http://elixir-lang.com"}], ["Elixir"]}], "a", fn
iex>   {"a", [{"href", href}]} ->
iex>     {"a", [{"href", String.replace(href, "http://", "https://")}]}
iex>   other ->
iex>     other
iex> end)
[{"a", [{"href", "https://elixir-lang.com"}], ["Elixir"]}]
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map(html_tree_list, fun)

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This function is deprecated. Use `find_and_update/3` or `Enum.map/2` instead. .
This function is deprecated. Use `parse_document/1` or `parse_fragment/1` instead..

Specs

parse(binary()) :: html_tag() | html_tree() | String.t()

Parses a HTML Document from a String.

The expect string is a valid HTML, but the parser will try to parse even with errors.

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parse_document(document, opts \\ [])

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Specs

parse_document(binary(), Keyword.t()) ::
  {:ok, html_tree()} | {:error, String.t()}

Parses a HTML Document from a string.

It will use the available parser from application env or the one from the :html_parser option. Check https://github.com/philss/floki#alternative-html-parsers for more details.

Examples

iex> Floki.parse_document("<html><head></head><body>hello</body></html>")
{:ok, [{"html", [], [{"head", [], []}, {"body", [], ["hello"]}]}]}

iex> Floki.parse_document("<html><head></head><body>hello</body></html>", html_parser: Floki.HTMLParser.Mochiweb)
{:ok, [{"html", [], [{"head", [], []}, {"body", [], ["hello"]}]}]}
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parse_document!(document, opts \\ [])

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Specs

parse_document!(binary(), Keyword.t()) :: html_tree()

Parses a HTML Document from a string.

Similar to Floki.parse_document/1, but raises Floki.ParseError if there was an error parsing the document.

Example

iex> Floki.parse_document!("<html><head></head><body>hello</body></html>")
[{"html", [], [{"head", [], []}, {"body", [], ["hello"]}]}]
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parse_fragment(fragment, opts \\ [])

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Specs

parse_fragment(binary(), Keyword.t()) ::
  {:ok, html_tree()} | {:error, String.t()}

Parses a HTML fragment from a string.

It will use the available parser from application env or the one from the :html_parser option.

Check https://github.com/philss/floki#alternative-html-parsers for more details.

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parse_fragment!(fragment, opts \\ [])

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Specs

parse_fragment!(binary(), Keyword.t()) :: html_tree()

Parses a HTML fragment from a string.

Similar to Floki.parse_fragment/1, but raises Floki.ParseError if there was an error parsing the fragment.

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raw_html(html_tree, options \\ [])

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Specs

raw_html(html_tree() | binary(), keyword()) :: binary()

Converts HTML tree to raw HTML. Note that the resultant HTML may be different from the original one. Spaces after tags and doctypes are ignored.

Options

  • :encode: accepts true or false. Will encode html special characters to html entities. You can also control the encoding behaviour at the application level via config :floki, :encode_raw_html, true | false

  • :pretty: accepts true or false. Will format the output, ignoring breaklines and spaces from the input and putting new ones in order to pretty format the html.

Examples

iex> Floki.raw_html({"div", [{"class", "wrapper"}], ["my content"]})
~s(<div class="wrapper">my content</div>)

iex> Floki.raw_html({"div", [{"class", "wrapper"}], ["10 > 5"]}, encode: true)
~s(<div class="wrapper">10 &gt; 5</div>)

iex> Floki.raw_html({"div", [{"class", "wrapper"}], ["10 > 5"]}, encode: false)
~s(<div class="wrapper">10 > 5</div>)

iex> Floki.raw_html({"div", [], ["\n   ", {"span", [], "Fully indented"}, "    \n"]}, pretty: true)
"""
<div>
  <span>
    Fully indented
  </span>
</div>
"""
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text(html, opts \\ [deep: true, js: false, style: true, sep: ""])

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Returns the text nodes from a HTML tree.

By default, it will perform a deep search through the HTML tree. You can disable deep search with the option deep assigned to false. You can include content of script tags with the option js assigned to true. You can specify a separator between nodes content.

Examples

iex> Floki.text({"div", [], [{"span", [], ["hello"]}, " world"]})
"hello world"

iex> Floki.text({"div", [], [{"span", [], ["hello"]}, " world"]}, deep: false)
" world"

iex> Floki.text({"div", [], [{"script", [], ["hello"]}, " world"]})
" world"

iex> Floki.text({"div", [], [{"script", [], ["hello"]}, " world"]}, js: true)
"hello world"

iex> Floki.text({"ul", [], [{"li", [], ["hello"]}, {"li", [], ["world"]}]}, sep: "-")
"hello-world"

iex> Floki.text([{"div", [], ["hello world"]}])
"hello world"

iex> Floki.text([{"p", [], ["1"]},{"p", [], ["2"]}])
"12"

iex> Floki.text({"div", [], [{"style", [], ["hello"]}, " world"]}, style: false)
" world"

iex> Floki.text({"div", [], [{"style", [], ["hello"]}, " world"]}, style: true)
"hello world"
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traverse_and_update(html_tree, fun)

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Specs

traverse_and_update(
  html_tree(),
  (html_tag() | html_comment() | html_doctype() | html_declaration() ->
     html_node() | nil)
) :: html_tree()

Traverses and updates a HTML tree structure.

This function returns a new tree structure that is the result of applying the given fun on all nodes except text nodes. The tree is traversed in a post-walk fashion, where the children are traversed before the parent.

When the function fun encounters HTML tag, it receives a tuple with {name, attributes, children}, and should either return a similar tuple or nil to delete the current node.

The function fun can also encounter HTML doctype, comment or declaration and will receive, and should return, different tuple for these types. See the documentation for html_comment/0, html_doctype/0 and html_declaration/0 for details.

Note: this won't update text nodes, but you can transform them when working with children nodes.

Examples

iex> html = [{"div", [], ["hello"]}]
iex> Floki.traverse_and_update(html, fn
...>   {"div", attrs, children} -> {"p", attrs, children}
...>   other -> other
...> end)
[{"p", [], ["hello"]}]

iex> html = [{"div", [], [{:comment, "I am comment"}, {"span", [], ["hello"]}]}]
iex> Floki.traverse_and_update(html, fn
...>   {"span", _attrs, _children} -> nil
...>   {:comment, text} -> {"span", [], text}
...>   other -> other
...> end)
[{"div", [], [{"span", [], "I am comment"}]}]
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traverse_and_update(html_tree, acc, fun)

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Specs

traverse_and_update(
  html_tree(),
  traverse_acc,
  (html_tag()
   | html_comment()
   | html_doctype()
   | html_declaration(),
   traverse_acc ->
     {html_node() | nil, traverse_acc})
) :: {html_node(), traverse_acc}
when traverse_acc: any()

Traverses and updates a HTML tree structure with an accumulator.

This function returns a new tree structure and the final value of accumulator which are the result of applying the given fun on all nodes except text nodes. The tree is traversed in a post-walk fashion, where the children are traversed before the parent.

When the function fun encounters HTML tag, it receives a tuple with {name, attributes, children} and an accumulator. It and should return a 2-tuple like {new_node, new_acc}, where new_node is either a similar tuple or nil to delete the current node, and new_acc is an updated value for the accumulator.

The function fun can also encounter HTML doctype, comment or declaration and will receive, and should return, different tuple for these types. See the documentation for html_comment/0, html_doctype/0 and html_declaration/0 for details.

Note: this won't update text nodes, but you can transform them when working with children nodes.

Examples

iex> html = [{"div", [], [{:comment, "I am a comment"}, "hello"]}, {"div", [], ["world"]}]
iex> Floki.traverse_and_update(html, 0, fn
...>   {"div", attrs, children}, acc ->
...>     {{"p", [{"data-count", to_string(acc)} | attrs], children}, acc + 1}
...>   other, acc -> {other, acc}
...> end)
{[
   {"p", [{"data-count", "0"}], [{:comment, "I am a comment"}, "hello"]},
   {"p", [{"data-count", "1"}], ["world"]}
 ], 2}

iex> html = {"div", [], [{"span", [], ["hello"]}]}
iex> Floki.traverse_and_update(html, [deleted: 0], fn
...>   {"span", _attrs, _children}, acc ->
...>     {nil, Keyword.put(acc, :deleted, acc[:deleted] + 1)}
...>   tag, acc ->
...>     {tag, acc}
...> end)
{{"div", [], []}, [deleted: 1]}