The calli:render-html step populates a template using RDF data. The data is retrived using the calli:sparql step.

<p:declare-step name="render-html" type="calli:render-html">
    <p:serialization port="result" media-type="text/html" method="html" doctype-system="about:legacy-compat" />
    <p:input port="source" sequence="true" primary="true" />
    <p:input port="parameters" kind="parameter" primary="true" />
    <p:input port="query" sequence="false" />
    <p:input port="template" sequence="false" />
    <p:output port="result" sequence="true" primary="true" />
    <p:option name="output-base-uri" select="''" />
    <p:option name="endpoint" select="''" />

The RDF data can be provided in the source port as RDF/XML or with the provided SPARQL endpoint.

The SELECT query (and its parameters) are used to select the (exactly one) variable and zero or more bindings. The actualy SPARQL Query sent to the endpoint will be created as a combination of the provided query and the properties and relationships referenced in the template.