Will perform search before expanding relations

examples/simple-action.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<actions>
+    <properties>
+        <lang>
+            <default>en</default>
+            <other>de</other>
+            <other>es</other>
+            <other>fr</other>
+            <other>ja</other>
+        </lang>
+        <tags>
+            <display>short_name</display>
+            <display>website</display>
+        </tags>
+    </properties>
+    <extracts>
+        <relation id="9936954"/>
+        <way id="79289788"/>
+        <node id="6720935522"/>
+    </extracts>
+</actions>

pom.xml

@@ -52,6 +52,23 @@
             <artifactId>junit-jupiter-api</artifactId>
             <version>5.9.0</version>
         </dependency>
+        <dependency>
+            <groupId>de.topobyte</groupId>
+            <artifactId>osm4j-pbf</artifactId>
+            <version>0.1.0</version>
+        </dependency>
     </dependencies>
+    <repositories>
+        <repository>
+            <id>topobyte</id>
+            <name>topobyte</name>
+            <url>https://mvn.topobyte.de</url>
+        </repository>
+        <repository>
+            <id>Slimjars</id>
+            <name>Slimjars</name>
+            <url>https://mvn.slimjars.com</url>
+        </repository>
+    </repositories>
 
 </project>

src/main/java/org/leolo/map/osm/extract/ExtractElement.java

@@ -64,7 +64,11 @@ public class ExtractElement {
     private Map<Long, Relation> relations = new Hashtable<>();
     private Map<Long, Way> ways = new Hashtable<>();
     private Map<Long, Node> nodes = new Hashtable<>();
-    private Set<Integer> strings = new HashSet<>();
+
+    private HashSet<Long> pendingRelations = new HashSet<>();
+    private HashSet<Long> pendingWays = new HashSet<>();
+    private HashSet<Long> pendingNodes = new HashSet<>();
+
 
 
     private CliOpt cliOpt = new CliOpt();
@@ -146,20 +150,29 @@ public class ExtractElement {
             System.exit(3);
             return;
         }
-        expandRelations(dbFile, af, af.getRelation());
-        processWay(dbFile, af);
-        processNode(dbFile, af);
+        doSearch(dbFile, af);
+        expandRelations(dbFile);
+        processWay(dbFile);
+        processNode(dbFile);
+    }
+
+    /**
+     * Perform search as defined in the action file, and add them to relevant pending items
+     * @param dbFile The database file going to be searched
+     * @param af The file which defines the action to be performed
+     */
+    private void doSearch(File dbFile, ActionFile af) {
     }
 
-    private void processNode(File dbFile, ActionFile af) {
+    private void processNode(File dbFile) {
 
     }
 
-    private void processWay(File dbFile, ActionFile af) {
+    private void processWay(File dbFile) {
 
     }
 
-    private void expandRelations(File dbFile, ActionFile af, Collection<ExtractItem> relations) {
+    private void expandRelations(File dbFile) {
 
     }