# E.21 XsltFilter The `XsltFilter` applies a XSL template to the stream. Though you can use this filter directly, you should use XslTask [Appendix聽B](apb.html "Appendix B. Core tasks") which is shortcut to the following lines: ``` <filterchain> <xsltfilter style="somexslt.xsl" /> </filterchain> ``` This filter relies on PHP5 XSL support via `libxslt` which must be available for php5. Usually this means including the `php5_xsl` module when configuring PHP5. In essence this uses the same core libraries as "xsltproc" processor. Table E.17:聽 Attributes for the `<xsltfilter>` tag NameTypeDescriptionDefaultRequired`style``String`The XSLT stylesheet to use for transformation.n/aYes`html``Boolean`Whether to parse the input as HTML (using libxml2 DOMDocument::loadHTML()).`false`No`resolvedocumentexternals``Boolean`Whether to resolve entities in the XML document. (see [this link](http://www.php.net/manual/en/class.domdocument.php#domdocument.props.resolveexternals) for details)`false`No`resolvestylesheetexternals``Boolean`Whether to resolve entities in the stylesheet.`false`No E.21.1 Nested tags The `XsltFilter` filter may contain one or more `param` tags to pass any XSLT parameters to the stylesheet. These `param` tags must have `name` and `expression` attributes.