Textual Rules: allow XBase between then … end (#5398)

* changes the Rules.xtext grammar not to use explicitly the Script object
from the Script.xtext grammar. This allows at a later time to extend DSL
Scripts to start with `import`s, without allowing `import` statements right
after `rule … when … then <IMPORT> … end`.

* also allows at a later moment to merge DSL Rules and DSL Scripts into one.

bundles/org.openhab.core.model.rule.runtime/src/org/openhab/core/model/rule/runtime/internal/DSLRuleProvider.java

@@ -25,7 +25,6 @@ import org.eclipse.emf.ecore.EObject;
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.xtext.nodemodel.util.NodeModelUtils;
-import org.eclipse.xtext.xbase.XBlockExpression;
 import org.eclipse.xtext.xbase.XExpression;
 import org.eclipse.xtext.xbase.interpreter.IEvaluationContext;
 import org.openhab.core.automation.Action;
@@ -272,7 +271,7 @@ public class DSLRuleProvider
 
         // Create Action
         String context = DSLScriptContextProvider.CONTEXT_IDENTIFIER + modelName + "-" + index + "\n";
-        XBlockExpression expression = rule.getScript();
+        XExpression expression = rule.getScript();
         String script = NodeModelUtils.findActualNodeFor(expression).getText();
         Configuration cfg = new Configuration();
         cfg.put("script", context + removeIndentation(script));

bundles/org.openhab.core.model.rule/src/org/openhab/core/model/rule/Rules.xtext

@@ -22,7 +22,7 @@ VariableDeclaration:
 Rule:
 	'rule' name=(STRING|ID)
 	'when' eventtrigger+=EventTrigger ('or' eventtrigger+=EventTrigger)*
-	'then' script=Script
+	'then' script=XExpressionInClosure
 	'end'
 ;