The encoder property defines an HTMLEncoder object (javadoc here) which allows safe encoding of various types.

You should always use the encoder as protection against cross site-scripting and other attacks.

 Methods available are

encodeForHTML

This is used for to encode HTML text.

Example
$encoder.encodeForHTML($someProperty)

encodeForHTMLAttribute

This is used to encode an HTML attribute

Example
<a href="$encoder.encodeForHTMLAttribute($someProperty)">Link</a>