Merge pull request #779 from seadowg/filter-strategy

Fix interaction between function and filter plugins
getodk · Jul 15, 2024 · be1508c · be1508c
2 parents 882d0f8 + 5aa051f
commit be1508c
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diff --git a/PLUGINS.md b/PLUGINS.md
@@ -27,4 +27,18 @@ Inspect external instances (their ID and parsed XML) after parsing or provide cu
 ### API
 - `ExternalInstanceParser#addFileInstanceParser`
 
-The default `ExternalInstanceParser` can be overridden by creating an implementation of `ExternalInstanceParserFactory` and calling `XFormUtils.setExternalInstanceParserFactory` with it.
+The default `ExternalInstanceParser` can be overridden by creating an implementation of `ExternalInstanceParserFactory` and calling `XFormUtils.setExternalInstanceParserFactory` with it.
+
+## Function
+
+Add custom functions that can be called from XPath.
+
+### API
+- `FormEntryController#addFunctionHandler`
+
+## Predicate evaluation
+
+Add custom strategies for filtering nodes for predicate expressions.
+
+### API
+- `FormEntryController#addFilterStrategy`
diff --git a/src/main/java/org/javarosa/core/model/FormDef.java b/src/main/java/org/javarosa/core/model/FormDef.java
@@ -16,25 +16,6 @@
 
 package org.javarosa.core.model;
 
-import static java.util.Collections.emptyList;
-
-import java.io.DataInputStream;
-import java.io.DataOutputStream;
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.Enumeration;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Map;
-import java.util.NoSuchElementException;
-import java.util.Queue;
-import java.util.Set;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
 import org.javarosa.core.model.TriggerableDag.EventNotifierAccessor;
 import org.javarosa.core.model.actions.ActionController;
 import org.javarosa.core.model.actions.Actions;
@@ -85,6 +66,26 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Queue;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static java.util.Collections.emptyList;
+
 /**
  * Definition of a form. This has some meta data about the form definition and a
  * collection of groups together with question branching or skipping rules.
@@ -162,10 +163,10 @@ public static IDataReference getAbsRef(IDataReference ref, TreeReference parentR
 
     private TriggerableDag dagImpl;
 
-    private boolean predicateCaching = true;
     private final FilterStrategy comparisonExpressionCacheFilterStrategy = new ComparisonExpressionCacheFilterStrategy();
     private final FilterStrategy equalityExpressionIndexFilterStrategy = new EqualityExpressionIndexFilterStrategy();
     private final Queue<FilterStrategy> customFilterStrategies = new LinkedList<>();
+    private final List<IFunctionHandler> customFunctionHandlers = new ArrayList<>();
 
     private QuestionPreloader preloader = new QuestionPreloader();
 
@@ -829,13 +830,15 @@ public boolean realTime() {
                 evaluationContext.addFunctionHandler(new ChoiceNameFunctionHandler(this) );
             }
 
-            if (predicateCaching) {
-                List<FilterStrategy> filters = Stream.concat(
-                    customFilterStrategies.stream(),
-                    Stream.of(equalityExpressionIndexFilterStrategy, comparisonExpressionCacheFilterStrategy)
-                ).collect(Collectors.toList());
+            List<FilterStrategy> filters = Stream.concat(
+                customFilterStrategies.stream(),
+                Stream.of(equalityExpressionIndexFilterStrategy, comparisonExpressionCacheFilterStrategy)
+            ).collect(Collectors.toList());
+
+            evaluationContext = new EvaluationContext(evaluationContext, filters);
 
-                evaluationContext = new EvaluationContext(evaluationContext, filters);
+            for (IFunctionHandler functionHandler : customFunctionHandlers) {
+                evaluationContext.addFunctionHandler(functionHandler);
             }
         }
 
@@ -1626,13 +1629,14 @@ public Extras<Externalizable> getExtras() {
         return extras;
     }
 
-    public void disablePredicateCaching() {
-        predicateCaching = false;
-        dagImpl.disablePredicateCaching();
-    }
-
     public void addFilterStrategy(FilterStrategy filterStrategy) {
         customFilterStrategies.add(filterStrategy);
+        resetEvaluationContext();
+    }
+
+    public void addFunctionHandler(IFunctionHandler functionHandler) {
+        customFunctionHandlers.add(functionHandler);
+        resetEvaluationContext();
     }
 
     private void resetEvaluationContext() {

diff --git a/src/main/java/org/javarosa/form/api/FormEntryController.java b/src/main/java/org/javarosa/form/api/FormEntryController.java
@@ -22,6 +22,7 @@
 import org.javarosa.core.model.IFormElement;
 import org.javarosa.core.model.QuestionDef;
 import org.javarosa.core.model.condition.FilterStrategy;
+import org.javarosa.core.model.condition.IFunctionHandler;
 import org.javarosa.core.model.data.IAnswerData;
 import org.javarosa.core.model.instance.InvalidReferenceException;
 import org.javarosa.core.model.instance.TreeElement;
@@ -347,11 +348,11 @@ private static FormIndex getRepeatGroupIndex(FormIndex index, FormDef formDef) {
         }
     }
 
-    public void disablePredicateCaching() {
-        model.getForm().disablePredicateCaching();
-    }
-
     public void addFilterStrategy(FilterStrategy filterStrategy) {
         model.getForm().addFilterStrategy(filterStrategy);
     }
+
+    public void addFunctionHandler(IFunctionHandler functionHandler) {
+        model.getForm().addFunctionHandler(functionHandler);
+    }
 }