#3745 Upload depiction suggestions not following text input - on upstream error emit empty list (#3751)

app/src/main/java/fr/free/nrw/commons/explore/depictions/DepictsClient.kt

@@ -40,7 +40,7 @@ class DepictsClient @Inject constructor(
         return depictsInterface.searchForDepicts(query, "$limit", language, language, "$offset")
             .map { it.search.joinToString("|") { searchItem -> searchItem.id } }
             .flatMap(::getEntities)
-            .map { it.entities()?.values?.map(::DepictedItem) ?: emptyList() }
+            .map { it.entities().values.map(::DepictedItem) }
     }
 
     /**
@@ -81,7 +81,7 @@ class DepictsClient @Inject constructor(
     fun toDepictions(sparqlResponse: Observable<SparqlResponse>): Observable<List<DepictedItem>> {
         return sparqlResponse.map { it.results.bindings.joinToString("|", transform = Binding::id) }
             .flatMap { getEntities(it).toObservable() }
-            .map { it.entities()?.values?.map(::DepictedItem) ?: emptyList() }
+            .map { it.entities().values.map(::DepictedItem) }
     }
 
     companion object {

app/src/main/java/fr/free/nrw/commons/upload/structure/depictions/DepictModel.kt

@@ -3,7 +3,9 @@ package fr.free.nrw.commons.upload.structure.depictions
 import fr.free.nrw.commons.explore.depictions.DepictsClient
 import fr.free.nrw.commons.nearby.Place
 import io.reactivex.Flowable
+import io.reactivex.Single
 import io.reactivex.processors.BehaviorProcessor
+import timber.log.Timber
 import javax.inject.Inject
 import javax.inject.Singleton
 
@@ -15,7 +17,6 @@ class DepictModel @Inject constructor(private val depictsClient: DepictsClient)
 
     val nearbyPlaces: BehaviorProcessor<List<Place>> = BehaviorProcessor.createDefault(emptyList())
 
-
     companion object {
         private const val SEARCH_DEPICTS_LIMIT = 25
     }
@@ -24,23 +25,24 @@ class DepictModel @Inject constructor(private val depictsClient: DepictsClient)
      * Search for depictions
      */
     fun searchAllEntities(query: String): Flowable<List<DepictedItem>> {
-        if (query.isBlank()) {
+        return if (query.isBlank())
-            return nearbyPlaces.switchMap { places: List<Place> ->
+            nearbyPlaces.switchMap { places: List<Place> ->
-                depictsClient.getEntities(
+                depictsClient.getEntities(places.toIds())
-                    places.mapNotNull { it.wikiDataEntityId }.joinToString("|")
-                )
                     .map {
-                        it.entities()!!.values.mapIndexed { index, entity ->
+                        it.entities()
-                            DepictedItem(entity, places[index])
+                            .values
-                        }
+                            .mapIndexed { index, entity -> DepictedItem(entity, places[index]) }
-                    }.toFlowable()
+                    }
+                    .onErrorResumeWithEmptyList()
+                    .toFlowable()
             }
-        }
+        else
-        return networkItems(query)
+            networkItems(query)
     }
 
     private fun networkItems(query: String): Flowable<List<DepictedItem>> {
         return depictsClient.searchForDepictions(query, SEARCH_DEPICTS_LIMIT, 0)
+            .onErrorResumeWithEmptyList()
             .toFlowable()
     }
 
@@ -49,3 +51,9 @@ class DepictModel @Inject constructor(private val depictsClient: DepictsClient)
     }
 
 }
+
+private fun List<Place>.toIds() = mapNotNull { it.wikiDataEntityId }.joinToString("|")
+
+private fun <T> Single<List<T>>.onErrorResumeWithEmptyList() = onErrorResumeNext { t: Throwable ->
+    Single.just(emptyList<T>()).also { Timber.e(t) }
+}

data-client/src/main/java/org/wikipedia/wikidata/Entities.java

@@ -7,6 +7,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import org.apache.commons.lang3.StringUtils;
+import org.jetbrains.annotations.NotNull;
 import org.wikipedia.dataclient.mwapi.MwResponse;
 import org.wikipedia.json.PostProcessingTypeAdapter;
 
@@ -15,8 +16,9 @@ public class Entities extends MwResponse implements PostProcessingTypeAdapter.Po
     @Nullable private Map<String, Entity> entities;
     private int success;
 
-    @Nullable public Map<String, Entity> entities() {
+    @NotNull
-        return entities;
+    public Map<String, Entity> entities() {
+        return entities != null ? entities : Collections.emptyMap();
     }
 
     public int getSuccess() {