c.xmlMethodExists ([target : xlink], method : string) : boolean

The method “xmlMethodExists” checks whether the type hidden behind the XLink has an XML method with the specified name. If the Xlink is not specified, then it is checked whether there is an XML method for the current object.

<xsl:variable name="target" select="'onion://data/objects/100'" />
<xsl:if test="c.xmlMethodExists($target, 'meta')">
<xsl:variable name="meta" select="c.xmlCall($target, 'meta')/meta" />
<xsl:value-of select="$meta/@label" />
Check before calling a method

A slight interface-like behaviour can be implemented via this method. The existence of a method says nothing about the executability however. The method may need further parameters.