Fix for issue 91 and issue 93 and issue 94

shapes/lv.ttl

@@ -312,3 +312,33 @@ rmlsh:InclusionAnnotationShape a sh:NodeShape;
         sh:maxCount 1 ;
         sh:nodeKind sh:BlankNodeOrIRI ;
     ] .
+
+rmlsh:parentCyclesShape a sh:NodeShape ;
+    sh:targetSubjectsOf rml:viewOn ;
+    sh:targetSubjectsOf rml:field ;
+    sh:sparql [
+        a sh:SPARQLConstraint ;
+        sh:message "There must be no cycles via rml:viewOn or rml:Field." ;
+        sh:select """
+            PREFIX rml: <http://w3id.org/rml/>
+            SELECT ?this
+            WHERE {
+              ?this (rml:viewOn|rml:field)+ ?this .
+            }
+        """ ;
+    ] .
+
+rmlsh:joinCyclesShape a sh:NodeShape ;
+    sh:targetSubjectsOf rml:viewOn ;
+    sh:sparql [
+        a sh:SPARQLConstraint ;
+        sh:message "There must be no cycles via rml:viewOn and rml:leftJoin or rml:innerJoin." ;
+        sh:select """
+            PREFIX rml: <http://w3id.org/rml/>
+            SELECT ?this
+            WHERE {
+              ?this a rml:LogicalView .
+              ?this ((rml:leftJoin|rml:innerJoin)/rml:parentLogicalView)+ ?this .
+            }
+        """ ;
+    ] .

spec/section/views.md

@@ -88,7 +88,7 @@ When a non-existing or a non-referenceable key is referenced, RML processors sho
   rml:field [
     a rml:IterableField ;
     rml:fieldName "item" ;
-    rml:reference "$.items[*]" ;
+    rml:iterator "$.items[*]" ;
     rml:field [
       a rml:ExpressionField ;
       rml:fieldName "type" ;

test-cases/RMLLVTC0008d/README.md

@@ -0,0 +1,39 @@
+## RMLLVTC0008a
+
+**Title**: Cycle: Fields
+
+**Description**: Test a cycle in nested fields
+
+**Error expected?** Yes
+
+**Mapping**
+```
+@prefix rml: <http://w3id.org/rml/> .
+@prefix : <http://example.org/> .
+
+:jsonSource a rml:LogicalSource ;
+  rml:source [
+    a rml:RelativePathSource , rml:Source ;
+    rml:root rml:MappingDirectory ;
+    rml:path "people.json" ;
+  ] ;
+  rml:referenceFormulation rml:JSONPath ;
+  rml:iterator "$.people[*]" .
+
+:jsonView a rml:LogicalView ;
+  rml:viewOn :jsonSource ;
+  rml:field :field1 .
+
+:field1 a rml:IterableField ;
+  rml:fieldName "item" ;
+  rml:referenceFormulation rml:JSONPath ;
+  rml:iterator "$.items[*]" ;
+  rml:field :field2.
+
+:field2 a rml:ExpressionField ;
+  rml:fieldName "type" ;
+  rml:reference "$.type" ;
+  rml:field :field1.
+
+```
+

test-cases/RMLLVTC0008d/mapping.ttl

@@ -0,0 +1,26 @@
+@prefix rml: <http://w3id.org/rml/> .
+@prefix : <http://example.org/> .
+
+:jsonSource a rml:LogicalSource ;
+  rml:source [
+    a rml:RelativePathSource , rml:Source ;
+    rml:root rml:MappingDirectory ;
+    rml:path "people.json" ;
+  ] ;
+  rml:referenceFormulation rml:JSONPath ;
+  rml:iterator "$.people[*]" .
+
+:jsonView a rml:LogicalView ;
+  rml:viewOn :jsonSource ;
+  rml:field :field1 .
+
+:field1 a rml:IterableField ;
+  rml:fieldName "item" ;
+  rml:referenceFormulation rml:JSONPath ;
+  rml:iterator "$.items[*]" ;
+  rml:field :field2.
+
+:field2 a rml:ExpressionField ;
+  rml:fieldName "type" ;
+  rml:reference "$.type" ;
+  rml:field :field1.

test-cases/RMLLVTC0008d/people.json

@@ -0,0 +1,26 @@
+{
+  "people": [
+    {
+      "name": "alice",
+      "items": [
+        {
+          "type": "sword",
+          "weight": 1500
+        },
+        {
+          "type": "shield",
+          "weight": 2500
+        }
+      ]
+    },
+    {
+      "name": "bob",
+      "items": [
+        {
+          "type": "flower",
+          "weight": 15
+        }
+      ]
+    }
+  ]
+}