# `Premailex.HTMLParser.Xmerl`
[🔗](https://github.com/danschultzer/premailex/blob/v1.0.0/lib/premailex/html_parser/xmerl.ex#L1)

A simple HTML parser using Erlang's built-in `m::xmerl` library.

This is used as a fallback when no other HTML parsing libraries are
available. It is designed for well-formed XML-like HTML, but it does not
support real-world HTML, which is often not valid XML.

For more robust HTML parsing, use `Premailex.HTMLParser.LazyHTML`,
`Premailex.HTMLParser.Floki`, or `Premailex.HTMLParser.Meeseeks`.

`m::xmerl_sax_parser` is used to prevent atom leaks.

## Parser limitations

  * Only well-formed XML-like HTML is supported. HTML5 syntax such as
    unquoted attribute values (`<div data-x=a>`) or unclosed non-void tags is
    rejected.

  * A round-trip through this parser is not lossless:

    * XML normalises whitespace in attribute values (newlines and tabs become
      spaces).

    * Named entities are decoded to characters and serialized as the literal
      character (e.g. `&copy;` round-trips as `©`).

    * `xmlns:*` namespace declarations always appear first in the attribute
      list, regardless of source position (`m::xmerl_sax_parser` removes them
      from the element's attribute list).

    * Void elements always serialize as `<br>` (HTML style), regardless of
      whether the source used `<br/>`.

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*Consult [api-reference.md](api-reference.md) for complete listing*