Only load dynamic preload data when needed

collect_app/src/main/java/org/odk/collect/android/dynamicpreload/DynamicPreloadXFormParserFactory.kt

@@ -1,11 +1,13 @@
 package org.odk.collect.android.dynamicpreload
 
 import org.javarosa.core.model.FormDef
+import org.javarosa.core.model.QuestionDef
 import org.javarosa.core.util.externalizable.ExtUtil
 import org.javarosa.core.util.externalizable.Externalizable
 import org.javarosa.core.util.externalizable.PrototypeFactory
 import org.javarosa.xform.parse.IXFormParserFactory
 import org.javarosa.xform.parse.XFormParser
+import org.javarosa.xpath.expr.XPathExpression
 import java.io.DataInputStream
 import java.io.DataOutputStream
 
@@ -19,10 +21,36 @@ class DynamicPreloadXFormParserFactory(base: IXFormParserFactory) :
     }
 }
 
-class DynamicPreloadParseProcessor : XFormParser.FormDefProcessor {
+class DynamicPreloadParseProcessor :
+    XFormParser.XPathProcessor,
+    XFormParser.QuestionProcessor,
+    XFormParser.FormDefProcessor {
+
+    private var containsPullData = false
+    private var containsSearch = false
+
+    override fun processXPath(xPathExpression: XPathExpression) {
+        if (containsPullData) {
+            return // No need to search if we already found pulldata
+        }
+
+        if (xPathExpression.containsFunc("pulldata")) {
+            containsPullData = true
+        }
+    }
+
+    override fun processQuestion(question: QuestionDef) {
+        if (containsSearch) {
+            return // No need to search if we already found search
+        }
+
+        if (ExternalDataUtil.getSearchXPathExpression(question.appearanceAttr) != null) {
+            containsSearch = true
+        }
+    }
 
     override fun processFormDef(formDef: FormDef) {
-        formDef.extras.put(DynamicPreloadExtra(true))
+        formDef.extras.put(DynamicPreloadExtra(containsPullData || containsSearch))
     }
 }
 

collect_app/src/test/java/org/odk/collect/android/dynamicpreload/DynamicPreloadParseProcessorTest.kt

@@ -3,24 +3,75 @@ package org.odk.collect.android.dynamicpreload
 import org.hamcrest.MatcherAssert.assertThat
 import org.hamcrest.Matchers.equalTo
 import org.javarosa.core.model.FormDef
+import org.javarosa.core.model.QuestionDef
+import org.javarosa.xpath.expr.XPathExpression
 import org.junit.Test
+import org.mockito.kotlin.doReturn
+import org.mockito.kotlin.mock
 
 class DynamicPreloadParseProcessorTest {
 
     private val processor = DynamicPreloadParseProcessor()
 
-    /**
-     * This is currently a "stub" implementation until we have a good way of determining whether
-     * a form contains search/pulldata.
-     */
     @Test
-    fun `usesDynamicPreload is true`() {
+    fun `usesDynamicPreload is false when xpath does not contain pulldata`() {
         val formDef = FormDef()
 
+        processor.processXPath(createNonPullDataExpression())
+        processor.processFormDef(formDef)
+        assertThat(
+            formDef.extras.get(DynamicPreloadExtra::class.java).usesDynamicPreload,
+            equalTo(false)
+        )
+    }
+
+    @Test
+    fun `usesDynamicPreload is true when xpath does contain pulldata`() {
+        val formDef = FormDef()
+
+        processor.processXPath(createPullDataExpression())
+        processor.processFormDef(formDef)
+        assertThat(
+            formDef.extras.get(DynamicPreloadExtra::class.java).usesDynamicPreload,
+            equalTo(true)
+        )
+    }
+
+    @Test
+    fun `usesDynamicPreload is false when question appearance does not contain search`() {
+        val formDef = FormDef()
+
+        processor.processQuestion(createQuestion(appearance = "minimal"))
+        processor.processFormDef(formDef)
+        assertThat(
+            formDef.extras.get(DynamicPreloadExtra::class.java).usesDynamicPreload,
+            equalTo(false)
+        )
+    }
+
+    @Test
+    fun `usesDynamicPreload is true when question appearance does contain search`() {
+        val formDef = FormDef()
+
+        processor.processQuestion(createQuestion(appearance = "search('fruits')"))
         processor.processFormDef(formDef)
         assertThat(
             formDef.extras.get(DynamicPreloadExtra::class.java).usesDynamicPreload,
             equalTo(true)
         )
     }
+
+    private fun createNonPullDataExpression() = mock<XPathExpression> {
+        on { containsFunc("pulldata") } doReturn false
+    }
+
+    private fun createPullDataExpression() = mock<XPathExpression> {
+        on { containsFunc("pulldata") } doReturn true
+    }
+
+    private fun createQuestion(appearance: String): QuestionDef {
+        return mock() {
+            on { appearanceAttr } doReturn appearance
+        }
+    }
 }