HTML Module

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Revision as of 22:23, 12 June 2016 by CG (talk | contribs) (→‎html:parse)
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This XQuery Module provides functions for converting HTML to XML. Conversion will only take place if TagSoup is included in the classpath (see HTML Parsing for more details).

Conventions

All functions in this module are assigned to the http://basex.org/modules/html namespace, which is statically bound to the html prefix.
All errors are assigned to the http://basex.org/errors namespace, which is statically bound to the bxerr prefix.

Functions

html:parser

Signatures html:parser() as xs:string
Summary Returns the name of the applied HTML parser (currently: TagSoup). If an empty string is returned, TagSoup was not found in the classpath, and the input will be treated as well-formed XML.

html:parse

Signatures html:parse($input as xs:anyAtomicType) as document-node()
html:parse($input as xs:anyAtomicType, $options as map(xs:string, item())) as document-node()
Summary Converts the HTML document specified by $input to XML, and returns a document node:
  • The input may either be a string or a binary item (xs:hexBinary, xs:base64Binary).
  • If the input is passed on in its binary representation, the HTML parser will try to automatically choose the correct encoding.

The $options argument can be used to set TagSoup Options.

Errors BXHL0001: the input cannot be converted to XML.

Examples

Basic Example

The following query converts the specified string to an XML document node.

Query
html:parse("<html>")
Result
<html xmlns="http://www.w3.org/1999/xhtml"/>

Specifying Options

The next query creates an XML document without namespaces:

Query
html:parse("<a href='ok.html'/>", map { 'nons': true() })
Result
<html>
  <body>
    <a shape="rect" href="ok.html"/>
  </body>
</html>

Parsing Binary Input

If the input encoding is unknown, the data to be processed can be passed on in its binary representation. The HTML parser will automatically try to detect the correct encoding:

Query
html:parse(fetch:binary("http://en.wikipedia.org"))
Result
<html xmlns="http://www.w3.org/1999/xhtml" class="client-nojs" dir="ltr" lang="en">
  <head>
    <title>Wikipedia, the free encyclopedia</title>
    <meta charset="UTF-8"/>
    ...

Errors

Code Description
BXHL0001 The input cannot be converted to XML.

Changelog

The module was introduced with Version 7.6.