Bugfix: Return error message if a resource contains no content

changelog.html

@@ -8,6 +8,10 @@ <h1 data-template="config:app-title">Generated page</h1>
 			<div class="row-fluid">
 				<div class="span8">
 					<h2>Changelog</h2>
+					<h3>1.2.1</h3>
+					<ul>
+						<li>BUGFIX: Return error message if a resource contains no content</li>
+					</ul>
 					<h3>1.2.0</h3>
 					<ul>
 						<li>INFO: Minor changes to documentation.</li>

errors.xml

@@ -0,0 +1,5 @@
+<errors>
+    <error type="resource_no_content">
+        <message>Resource contains no content</message>
+    </error>
+</errors>

extract.xql

@@ -238,10 +238,12 @@ declare function xtriples:extractTriples($currentResource as node(), $resourceIn
 	(: set the content of the current resource :)
 	let $currentResource := 
 		(: it can be a resource tag with an URI :)
-		if (xs:anyURI($currentResource/@uri)) then 
+		if (xs:anyURI($currentResource/@uri) and fn:doc-available($currentResource/@uri)) then 
 			fn:doc($currentResource/@uri)
 		(: or a resource tag with children :)
-		else $currentResource/*
+		else if ($currentResource/*) then 
+			$currentResource/*
+		else fn:doc("errors.xml")//error[@type='resource_no_content']
 
 	(: start statement pattern extraction :)
 	for $statement in $configuration//triples/*