option to ignore empty query for analyzers with stop words

Author: lgrignon

README.md

@@ -613,6 +613,16 @@ MyDomainClass.search().list {
 }
 ```
 
+### Options 
+
+```groovy
+grails.plugins.hibernatesearch = {
+	rebuildIndexOnStart false // see related section above
+	throwOnEmptyQuery false // throw or not exception when Hibernate Search raises an EmptyQueryException
+	fullTextFilter /* ... */ // see related section above
+}
+```
+
 ## Change log
 
 ### v2.0.2

build.gradle

@@ -10,7 +10,7 @@ buildscript {
 	}
 }
 
-version "2.0.2"
+version "2.0.3"
 group "org.grails.plugins"
 
 apply plugin:"eclipse"

src/main/groovy/grails/plugins/hibernate/search/HibernateSearchConfig.groovy

@@ -17,6 +17,8 @@ class HibernateSearchConfig {
     private final FullTextSession fullTextSession
     private static final List MASS_INDEXER_METHODS = MassIndexer.methods.findAll { it.returnType == MassIndexer }*.name
 
+	boolean throwExceptionOnEmptyQuery
+	
     HibernateSearchConfig( Session session ) {
         this.fullTextSession = Search.getFullTextSession( session )
     }
@@ -55,6 +57,16 @@ class HibernateSearchConfig {
 
         massIndexer = fullTextSession.createIndexer().startAndWait()
     }
+	
+	/**
+	 * Throws exception if Hibernate Search raises an EmptyQueryException, (could occur if analyzer has stop words) default false
+	 */
+	def throwOnEmptyQuery( boolean throwException ) {
+		
+		log.debug "throwExceptionOnEmptyQuery = " + throwException
+		
+		throwExceptionOnEmptyQuery = throwException
+	}
 
     Object invokeMethod( String name, Object args ) {
         if ( name in MASS_INDEXER_METHODS ) {

src/main/groovy/grails/plugins/hibernate/search/HibernateSearchGrailsPlugin.groovy

@@ -17,6 +17,8 @@ class HibernateSearchGrailsPlugin extends Plugin {
 
 	private final static Logger log = LoggerFactory.getLogger(this)
 
+	public static HibernateSearchConfig pluginConfig;
+	
 	def grailsVersion = "3.1.12 > *"
 
 	def profiles = ['web']
@@ -70,12 +72,12 @@ class HibernateSearchGrailsPlugin extends Plugin {
 				log.info "* " + clazz.getSimpleName() + " is indexed"
 				grailsClass.metaClass.static.search = {
 
-					new HibernateSearchQueryBuilder( clazz, applicationContext.sessionFactory.getCurrentSession() )
+					new HibernateSearchQueryBuilder( clazz, applicationContext.sessionFactory.getCurrentSession(), pluginConfig )
 				}
 
 				grailsClass.metaClass.search = {
 					def instance = delegate
-					new HibernateSearchQueryBuilder( clazz, instance, applicationContext.sessionFactory.getCurrentSession() )
+					new HibernateSearchQueryBuilder( clazz, instance, applicationContext.sessionFactory.getCurrentSession(), pluginConfig )
 				}
 			}
 		}
@@ -88,7 +90,8 @@ class HibernateSearchGrailsPlugin extends Plugin {
 			log.debug 'hibernatesearch config found'
 			Session session = applicationContext.sessionFactory.openSession();
 
-			hibernateSearchConfig.delegate = new HibernateSearchConfig( session )
+			pluginConfig = new HibernateSearchConfig( session )
+			hibernateSearchConfig.delegate = pluginConfig
 			hibernateSearchConfig.resolveStrategy = Closure.DELEGATE_FIRST
 			hibernateSearchConfig.call()
 		}

src/main/groovy/grails/plugins/hibernate/search/HibernateSearchQueryBuilder.groovy

@@ -26,6 +26,7 @@ import org.hibernate.search.FullTextQuery
 import org.hibernate.search.FullTextSession
 import org.hibernate.search.MassIndexer
 import org.hibernate.search.Search
+import org.hibernate.search.exception.EmptyQueryException;
 import org.hibernate.search.query.dsl.FieldCustomization
 import org.hibernate.search.query.dsl.QueryBuilder
 import org.slf4j.Logger;
@@ -65,6 +66,38 @@ class HibernateSearchQueryBuilder {
             children << component
         }
 
+		/**
+		 * @return true if composite contains at least one valid (not empty) query
+		 */
+		protected boolean forEachQuery( Closure action ) {
+			
+			boolean notEmpty = false;
+			if (children) {
+				
+				for (child in children) {
+					try {
+	
+						Query subQuery = child.createQuery();
+						
+						action.delegate = subQuery
+						action.resolveStrategy = Closure.DELEGATE_FIRST
+						action.call(subQuery)
+						notEmpty = true;
+						
+					} catch (EmptyQueryException e) {
+						if (HibernateSearchGrailsPlugin.pluginConfig.throwExceptionOnEmptyQuery) {
+							throw e
+						} else {
+							log.warn 'empty Hibernate search query ignored! ' + child, e
+						}
+					}
+				}
+			
+			}
+			
+			return notEmpty
+		}
+		
         def toString( indent ) {
             [( "-" * indent ) + this.class.simpleName, children.collect { it.toString( indent + 1 ) }].flatten().findAll {it}.join( "\n" )
         }
@@ -100,54 +133,47 @@ class HibernateSearchQueryBuilder {
 
     private static class MustNotComponent extends Composite {
         Query createQuery( ) {
-            if ( children ) {
 
-                def query = queryBuilder.bool()
+            def query = queryBuilder.bool()
+			boolean notEmpty = forEachQuery { subQuery ->
+				query = query.must( subQuery ).not()
+			}
 
-                children*.createQuery().each {
-                    query = query.must( it ).not()
-                }
-
-                query.createQuery()
-
-            } else {
-                queryBuilder.all().createQuery()
-            }
+			if (notEmpty) {
+				return query.createQuery()
+			} else {
+				return queryBuilder.all().createQuery()
+			}
+			
         }
     }
     private static class MustComponent extends Composite {
         Query createQuery( ) {
-            if ( children ) {
-
-                def query = queryBuilder.bool()
-
-                children*.createQuery().each {
-                    query = query.must( it )
-                }
-
-                query.createQuery()
-
-            } else {
-                queryBuilder.all().createQuery()
-            }
+            def query = queryBuilder.bool()
+			boolean notEmpty = forEachQuery { subQuery ->
+				query = query.must( subQuery )
+			}
+
+			if (notEmpty) {
+				return query.createQuery()
+			} else {
+				return queryBuilder.all().createQuery()
+			}
         }
     }
 
     private static class ShouldComponent extends Composite {
         Query createQuery( ) {
-            if ( children ) {
-
-                def query = queryBuilder.bool()
-
-                children*.createQuery().each {
-                    query = query.should( it )
-                }
-
-                query.createQuery()
-
-            } else {
-                queryBuilder.all().createQuery()
-            }
+            def query = queryBuilder.bool()
+			boolean notEmpty = forEachQuery { subQuery ->
+				query = query.should( subQuery )
+			}
+
+			if (notEmpty) {
+				return query.createQuery()
+			} else {
+				return queryBuilder.all().createQuery()
+			}
         }
     }
 
@@ -219,6 +245,8 @@ class HibernateSearchQueryBuilder {
 
     private static final List MASS_INDEXER_METHODS = MassIndexer.methods.findAll { it.returnType == MassIndexer }*.name
 
+	private final HibernateSearchConfig pluginConfig;
+	
     private final FullTextSession fullTextSession
     private final clazz
     private final instance
@@ -241,15 +269,16 @@ class HibernateSearchQueryBuilder {
 
     Filter filter
 
-    HibernateSearchQueryBuilder( clazz, instance, Session session ) {
+    HibernateSearchQueryBuilder( clazz, instance, Session session, HibernateSearchConfig pluginConfig ) {
         this.clazz = clazz
         this.fullTextSession = Search.getFullTextSession( session )
         this.instance = instance
         this.staticContext = instance == null
+		this.pluginConfig = pluginConfig;
     }
 
-    HibernateSearchQueryBuilder( clazz, Session session ) {
-        this( clazz, null, session )
+    HibernateSearchQueryBuilder( clazz, Session session, HibernateSearchConfig pluginConfig ) {
+        this( clazz, null, session, pluginConfig )
     }
 
     private FullTextQuery createFullTextQuery( ) {