feat: [ANDROSDK-2309] fix search online operators

Author: andresmr

core/src/main/java/org/hisp/dhis/android/core/arch/repositories/scope/internal/FilterItemOperator.kt

@@ -40,8 +40,8 @@ enum class FilterItemOperator(val sqlOperator: String, val apiOperator: String,
     SW("LIKE", "sw", "SW"),
     EW("LIKE", "ew", "EW"),
     VOID("", "", ""),
-    NULL_OR_BLANK("", "null_or_blank", "NULL_OR_BLANK"),
-    NOT_NULL_AND_NOT_BLANK("", "not_null_and_not_blank", "NOT_NULL_AND_NOT_BLANK"),
+    NULL_OR_BLANK("", "null", "NULL"),
+    NOT_NULL_AND_NOT_BLANK("", "!null", "!NULL"),
     ;
 
     /**

core/src/main/java/org/hisp/dhis/android/core/trackedentity/search/TrackedEntityInstanceQueryOnlineHelper.kt

@@ -150,25 +150,26 @@ internal class TrackedEntityInstanceQueryOnlineHelper(
                     val clause = items.map { item ->
                         val operator = if (upper) item.operator().apiUpperOperator else item.operator().apiOperator
 
-                        ":" + operator + ":" + getAPIValue(item)
+                        ":" + operator + (getAPIValue(item)?.let { ":$it" } ?: "")
                     }
 
                     key + clause.joinToString(separator = "")
                 }
         }
 
-        private fun getAPIValue(item: RepositoryScopeFilterItem): String {
+        private fun getAPIValue(item: RepositoryScopeFilterItem): String? {
+            val value = item.value() ?: return null
             return when (item.operator) {
                 FilterItemOperator.IN -> {
-                    val list = FilterOperatorsHelper.strToList(item.value()!!).map { escapeChars(it) }
+                    val list = FilterOperatorsHelper.strToList(value).map { escapeChars(it) }
                     list.joinToString(";")
                 }
 
                 FilterItemOperator.NOT_NULL_AND_NOT_BLANK,
                 FilterItemOperator.NULL_OR_BLANK,
-                -> ""
+                -> null
 
-                else -> escapeChars(item.value()!!)
+                else -> escapeChars(value)
             }
         }