Web Apps: Lazy loads case list

src/cli/java/org/commcare/util/screen/EntityScreenHelper.java

@@ -1,8 +1,11 @@
 package org.commcare.util.screen;
 
+import org.commcare.cases.entity.AsyncEntity;
+import org.commcare.cases.entity.AsyncNodeEntityFactory;
 import org.commcare.cases.entity.Entity;
 import org.commcare.cases.entity.EntitySortNotificationInterface;
 import org.commcare.cases.entity.EntitySorter;
+import org.commcare.cases.entity.EntityStorageCache;
 import org.commcare.cases.entity.EntityStringFilterer;
 import org.commcare.cases.entity.NodeEntityFactory;
 import org.commcare.suite.model.Detail;
@@ -13,6 +16,7 @@
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
+import java.util.Hashtable;
 import java.util.List;
 import java.util.Map;
 
@@ -32,7 +36,12 @@ public class EntityScreenHelper {
      */
     public static List<Entity<TreeReference>> initEntities(EvaluationContext context, Detail detail,
             EntityScreenContext entityScreenContext, TreeReference[] entitiesRefs) {
-        NodeEntityFactory nodeEntityFactory = new NodeEntityFactory(detail, context);
+        NodeEntityFactory nodeEntityFactory;
+        if (detail.isLazyLoading()) {
+            nodeEntityFactory = new AsyncNodeEntityFactory(detail, context, null);
+        } else {
+            nodeEntityFactory = new NodeEntityFactory(detail, context);
+        }
         List<Entity<TreeReference>> entities = new ArrayList<>();
         for (TreeReference reference : entitiesRefs) {
             entities.add(nodeEntityFactory.getEntity(reference));

src/main/java/org/commcare/cases/entity/AsyncEntity.java

@@ -3,6 +3,7 @@
 
 import org.commcare.cases.util.StringUtils;
 import org.commcare.suite.model.DetailField;
+import org.commcare.suite.model.DetailGroup;
 import org.commcare.suite.model.Text;
 import org.javarosa.core.model.condition.EvaluationContext;
 import org.javarosa.core.model.instance.TreeReference;
@@ -15,6 +16,8 @@
 import java.util.Enumeration;
 import java.util.Hashtable;
 
+import javax.annotation.Nullable;
+
 /**
  * An AsyncEntity is an entity reference which is capable of building its
  * values (evaluating all Text elements/background data elements) lazily
@@ -38,10 +41,12 @@ public class AsyncEntity extends Entity<TreeReference> {
     private final String[][] sortDataPieces;
     private final EvaluationContext context;
     private final Hashtable<String, XPathExpression> mVariableDeclarations;
+    private final DetailGroup mDetailGroup;
     private boolean mVariableContextLoaded = false;
     private final String mCacheIndex;
     private final String mDetailId;
 
+    @Nullable
     private final EntityStorageCache mEntityStorageCache;
 
     /*
@@ -59,8 +64,8 @@ public class AsyncEntity extends Entity<TreeReference> {
 
     public AsyncEntity(DetailField[] fields, EvaluationContext ec,
                        TreeReference t, Hashtable<String, XPathExpression> variables,
-                       EntityStorageCache cache, String cacheIndex, String detailId,
-                       String extraKey) {
+                       @Nullable EntityStorageCache cache, String cacheIndex, String detailId,
+                       String extraKey, DetailGroup detailGroup) {
         super(t, extraKey);
 
         this.fields = fields;
@@ -77,6 +82,7 @@ public AsyncEntity(DetailField[] fields, EvaluationContext ec,
         this.mCacheIndex = cacheIndex;
 
         this.mDetailId = detailId;
+        this.mDetailGroup = detailGroup;
     }
 
     private void loadVariableContext() {
@@ -121,47 +127,55 @@ public String getNormalizedField(int i) {
 
     @Override
     public String getSortField(int i) {
-        if (mEntityStorageCache.lockCache()) {
-            //get our second lock.
-            synchronized (mAsyncLock) {
-                if (sortData[i] == null) {
-                    // sort data not in search field cache; load and store it
-                    Text sortText = fields[i].getSort();
-                    if (sortText == null) {
-                        mEntityStorageCache.releaseCache();
-                        return null;
-                    }
+        try {
+            if (mEntityStorageCache == null || mEntityStorageCache.lockCache()) {
+                //get our second lock.
+                synchronized (mAsyncLock) {
+                    if (sortData[i] == null) {
+                        // sort data not in search field cache; load and store it
+                        Text sortText = fields[i].getSort();
+                        if (sortText == null) {
+                            return null;
+                        }
 
-                    String cacheKey = mEntityStorageCache.getCacheKey(mDetailId, String.valueOf(i));
+                        String cacheKey = null;
+                        if (mEntityStorageCache != null) {
+                            cacheKey = mEntityStorageCache.getCacheKey(mDetailId, String.valueOf(i));
 
-                    if (mCacheIndex != null) {
-                        //Check the cache!
-                        String value = mEntityStorageCache.retrieveCacheValue(mCacheIndex, cacheKey);
-                        if (value != null) {
-                            this.setSortData(i, value);
-                            mEntityStorageCache.releaseCache();
-                            return sortData[i];
+                            if (mCacheIndex != null) {
+                                //Check the cache!
+                                String value = mEntityStorageCache.retrieveCacheValue(mCacheIndex, cacheKey);
+                                if (value != null) {
+                                    this.setSortData(i, value);
+                                    return sortData[i];
+                                }
+                            }
                         }
-                    }
 
-                    loadVariableContext();
-                    try {
-                        sortText = fields[i].getSort();
-                        if (sortText == null) {
-                            this.setSortData(i, getFieldString(i));
-                        } else {
-                            this.setSortData(i, StringUtils.normalize(sortText.evaluate(context)));
+                        loadVariableContext();
+                        try {
+                            sortText = fields[i].getSort();
+                            if (sortText == null) {
+                                this.setSortData(i, getFieldString(i));
+                            } else {
+                                this.setSortData(i, StringUtils.normalize(sortText.evaluate(context)));
+                            }
+                            if (mEntityStorageCache != null) {
+                                mEntityStorageCache.cache(mCacheIndex, cacheKey, sortData[i]);
+                            }
+                        } catch (XPathException xpe) {
+                            Logger.exception("Error while evaluating sort field", xpe);
+                            xpe.printStackTrace();
+                            sortData[i] = "<invalid xpath: " + xpe.getMessage() + ">";
                         }
-
-                        mEntityStorageCache.cache(mCacheIndex, cacheKey, sortData[i]);
-                    } catch (XPathException xpe) {
-                        Logger.exception("Error while evaluating sort field", xpe);
-                        xpe.printStackTrace();
-                        sortData[i] = "<invalid xpath: " + xpe.getMessage() + ">";
                     }
+
+                    return sortData[i];
                 }
+            }
+        } finally {
+            if (mEntityStorageCache != null) {
                 mEntityStorageCache.releaseCache();
-                return sortData[i];
             }
         }
         return null;
@@ -218,6 +232,9 @@ private void setSortData(int i, String val) {
     }
 
     public void setSortData(String cacheKey, String val) {
+        if (mEntityStorageCache == null) {
+            throw new IllegalStateException("No entity cache defined");
+        }
         int sortIndex = mEntityStorageCache.getSortFieldIdFromCacheKey(mDetailId, cacheKey);
         if (sortIndex != -1) {
             setSortData(sortIndex, val);
@@ -233,4 +250,13 @@ private static String[] breakUpField(String input) {
             return input.split("\\s+");
         }
     }
+
+    @Nullable
+    @Override
+    public String getGroupKey() {
+        if (mDetailGroup != null) {
+            return  (String)mDetailGroup.getFunction().eval(context);
+        }
+        return null;
+    }
 }

src/main/java/org/commcare/cases/entity/AsyncNodeEntityFactory.java

@@ -11,6 +11,8 @@
 import java.util.Hashtable;
 import java.util.List;
 
+import javax.annotation.Nullable;
+
 /**
  * @author ctsims
  */
@@ -19,6 +21,7 @@ public class AsyncNodeEntityFactory extends NodeEntityFactory {
     private final OrderedHashtable<String, XPathExpression> mVariableDeclarations;
 
     private final Hashtable<String, AsyncEntity> mEntitySet = new Hashtable<>();
+    @Nullable
     private final EntityStorageCache mEntityCache;
 
     private CacheHost mCacheHost = null;
@@ -29,7 +32,8 @@ public class AsyncNodeEntityFactory extends NodeEntityFactory {
     // Don't show entity list until we primeCache and caches all fields
     private final boolean isBlockingAsyncMode;
 
-    public AsyncNodeEntityFactory(Detail d, EvaluationContext ec, EntityStorageCache entityStorageCache) {
+    public AsyncNodeEntityFactory(Detail d, EvaluationContext ec,
+            @Nullable EntityStorageCache entityStorageCache) {
         super(d, ec);
 
         mVariableDeclarations = detail.getVariableDeclarations();
@@ -54,7 +58,7 @@ public Entity<TreeReference> getEntity(TreeReference data) {
         String entityKey = loadCalloutDataMapKey(nodeContext);
         AsyncEntity entity =
                 new AsyncEntity(detail.getFields(), nodeContext, data, mVariableDeclarations,
-                        mEntityCache, mCacheIndex, detail.getId(), entityKey);
+                        mEntityCache, mCacheIndex, detail.getId(), entityKey, detail.getGroup());
 
         if (mCacheIndex != null) {
             mEntitySet.put(mCacheIndex, entity);
@@ -77,7 +81,7 @@ protected void setEvaluationContextDefaultQuerySet(EvaluationContext ec,
      * Note that the cache is lazily built upon first case list search.
      */
     private void primeCache() {
-        if (mTemplateIsCachable == null || !mTemplateIsCachable || mCacheHost == null) {
+        if (mEntityCache == null || mTemplateIsCachable == null || !mTemplateIsCachable || mCacheHost == null) {
             return;
         }
 

src/main/java/org/commcare/suite/model/Detail.java

@@ -104,6 +104,9 @@ public class Detail implements Externalizable {
     // equal to its width, rather than being computed independently
     private boolean useUniformUnitsInCaseTile;
 
+    // Loads detail fields lazily when required
+    private boolean lazyLoading;
+
     private DetailGroup group;
 
     // ENDREGION
@@ -119,7 +122,8 @@ public Detail(String id, DisplayUnit title, Text noItemsText, String nodeset, Ve
                   Vector<DetailField> fieldsVector, OrderedHashtable<String, String> variables,
                   Vector<Action> actions, Callout callout, String fitAcross,
                   String uniformUnitsString, String forceLandscape, String focusFunction,
-                  String printPathProvided, String relevancy, Global global, DetailGroup group) {
+                  String printPathProvided, String relevancy, Global global, DetailGroup group,
+                  boolean lazyLoading) {
 
         if (detailsVector.size() > 0 && fieldsVector.size() > 0) {
             throw new IllegalArgumentException("A detail may contain either sub-details or fields, but not both.");
@@ -169,6 +173,7 @@ public Detail(String id, DisplayUnit title, Text noItemsText, String nodeset, Ve
         }
         this.global = global;
         this.group = group;
+        this.lazyLoading = lazyLoading;
     }
 
     /**
@@ -211,6 +216,10 @@ public Detail[] getDetails() {
         return details;
     }
 
+    public boolean isLazyLoading() {
+        return lazyLoading;
+    }
+
     /**
      * Given a detail, return an array of details that will contain either
      * - all child details
@@ -274,6 +283,7 @@ public void readExternal(DataInputStream in, PrototypeFactory pf) throws IOExcep
         parsedRelevancyExpression = (XPathExpression)ExtUtil.read(in, new ExtWrapNullable(new ExtWrapTagged()), pf);
         global = (Global)ExtUtil.read(in, new ExtWrapNullable(new ExtWrapTagged()), pf);
         group = (DetailGroup) ExtUtil.read(in, new ExtWrapNullable(DetailGroup.class), pf);
+        lazyLoading = ExtUtil.readBool(in);
     }
 
     @Override
@@ -296,6 +306,7 @@ public void writeExternal(DataOutputStream out) throws IOException {
                 parsedRelevancyExpression == null ? null : new ExtWrapTagged(parsedRelevancyExpression)));
         ExtUtil.write(out, new ExtWrapNullable(global == null ? null : new ExtWrapTagged(global)));
         ExtUtil.write(out, new ExtWrapNullable(group));
+        ExtUtil.writeBool(out, lazyLoading);
     }
 
     public OrderedHashtable<String, XPathExpression> getVariableDeclarations() {

src/main/java/org/commcare/xml/DetailParser.java

@@ -39,6 +39,7 @@ public Detail parse() throws InvalidStructureException, IOException, XmlPullPars
         String forceLandscapeView = parser.getAttributeValue(null, "force-landscape");
         String printTemplatePath = parser.getAttributeValue(null, "print-template");
         String relevancy = parser.getAttributeValue(null, "relevant");
+        boolean isLazyLoading = Boolean.parseBoolean(parser.getAttributeValue(null, "lazy_loading"));
 
         // First fetch the title
         getNextTagInBlock("detail");
@@ -131,7 +132,7 @@ public Detail parse() throws InvalidStructureException, IOException, XmlPullPars
 
         return new Detail(id, title, noItemsText, nodeset, subdetails, fields, variables, actions, callout,
                 fitAcross, useUniformUnits, forceLandscapeView, focusFunction, printTemplatePath,
-                relevancy, global, detailGroup);
+                relevancy, global, detailGroup, isLazyLoading);
     }
 
     protected DetailParser getDetailParser() {

src/test/java/org/commcare/backend/suite/model/test/AppStructureTests.java

@@ -234,6 +234,12 @@ public void testDetailWithBorder() {
         assertTrue(field1.getShowBorder());
     }
 
+    @Test
+    public void testDetailWithLazyLoadingSet() {
+        Detail detail = mApp.getSession().getPlatform().getDetail("m0_case_short");
+        assertTrue(detail.isLazyLoading());
+    }
+
     @Test
     public void testDefaultEndpointRelevancy_shouldBeTrue() {
         Endpoint endpoint = mApp.getSession().getPlatform().getEndpoint("endpoint_with_no_relevancy");

src/test/resources/app_structure/suite.xml

@@ -11,7 +11,7 @@
     </resource>
   </locale>
 
-  <detail id="m0_case_short">
+  <detail id="m0_case_short" lazy_loading="true">
     <title>
       <text>Case List</text>
     </title>