Introduce EngineConfig class to avoid manipulating JSON objects directly

main/src/com/google/refine/browsing/EngineConfig.java

@@ -0,0 +1,93 @@
+package com.google.refine.browsing;
+
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Properties;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.json.JSONWriter;
+
+import com.google.refine.Jsonizable;
+import com.google.refine.browsing.Engine.Mode;
+import com.google.refine.browsing.facets.FacetConfig;
+import com.google.refine.browsing.facets.ListFacet.ListFacetConfig;
+import com.google.refine.browsing.facets.RangeFacet.RangeFacetConfig;
+import com.google.refine.browsing.facets.ScatterplotFacet.ScatterplotFacetConfig;
+import com.google.refine.browsing.facets.TextSearchFacet.TextSearchFacetConfig;
+import com.google.refine.browsing.facets.TimeRangeFacet.TimeRangeFacetConfig;
+
+
+public class EngineConfig implements Jsonizable {
+    
+    protected final List<FacetConfig> _facets;
+    protected final Mode _mode;
+    
+    public EngineConfig(List<FacetConfig> facets, Mode mode) {
+        _facets = facets;
+        _mode = mode;
+    }
+    
+    public static EngineConfig reconstruct(JSONObject o) {
+        if (o == null) {
+            return null;
+        }
+
+        List<FacetConfig> facets = new LinkedList<>();
+        if (o.has("facets") && !o.isNull("facets")) {
+            JSONArray a = o.getJSONArray("facets");
+            int length = a.length();
+
+            for (int i = 0; i < length; i++) {
+                JSONObject fo = a.getJSONObject(i);
+                String type = fo.has("type") ? fo.getString("type") : "list";
+
+                FacetConfig facet = null;
+                if ("list".equals(type)) {
+                    facet = new ListFacetConfig();
+                } else if ("range".equals(type)) {
+                    facet = new RangeFacetConfig();
+                } else if ("timerange".equals(type)) {
+                    facet = new TimeRangeFacetConfig();
+                } else if ("scatterplot".equals(type)) {
+                    facet = new ScatterplotFacetConfig();
+                } else if ("text".equals(type)) {
+                    facet = new TextSearchFacetConfig();
+                }
+
+                if (facet != null) {
+                    facet.initializeFromJSON(fo);
+                    facets.add(facet);
+                }
+            }
+        }
+
+        Mode mode = Mode.RowBased;
+        // for backward compatibility
+        if (o.has(Engine.INCLUDE_DEPENDENT) && !o.isNull(Engine.INCLUDE_DEPENDENT)) {
+            mode = o.getBoolean(Engine.INCLUDE_DEPENDENT) ? Mode.RecordBased : Mode.RowBased;
+        }
+
+        if (o.has(Engine.MODE) && !o.isNull(Engine.MODE)) {
+            mode = Engine.MODE_ROW_BASED.equals(o.getString(Engine.MODE)) ? Mode.RowBased : Mode.RecordBased;
+        }
+        
+        return new EngineConfig(facets, mode);
+    }
+
+    @Override
+    public void write(JSONWriter writer, Properties options)
+            throws JSONException {
+        writer.object();
+        writer.key("facets");
+        writer.array();
+        for (FacetConfig facet : _facets) {
+            facet.write(writer, options);
+        }
+        writer.endArray();
+        writer.key(Engine.MODE); writer.value(_mode == Mode.RowBased ? Engine.MODE_ROW_BASED : Engine.MODE_RECORD_BASED);
+        writer.endObject();
+    }
+
+}

main/src/com/google/refine/browsing/facets/FacetConfig.java

@@ -1,5 +1,7 @@
 package com.google.refine.browsing.facets;
 
+import org.json.JSONObject;
+
 import com.google.refine.Jsonizable;
 import com.google.refine.model.Project;
 
@@ -14,6 +16,11 @@ import com.google.refine.model.Project;
  *
  */
 public interface FacetConfig extends Jsonizable {
+    /**
+     * Reads the facet configuration from a JSON object (will be removed once we migrate to Jackson)
+     * @param fo
+     */
+    public void initializeFromJSON(JSONObject fo);
     
     /**
      * Instantiates the given facet on a particular project.

main/src/com/google/refine/browsing/facets/ListFacet.java

@@ -101,6 +101,7 @@ public class ListFacet implements Facet {
             writer.endObject();
         }
         
+        @Override
         public void initializeFromJSON(JSONObject o) {
             name = o.getString("name");
             expression = o.getString("expression");

main/src/com/google/refine/browsing/facets/RangeFacet.java

@@ -96,6 +96,7 @@ public class RangeFacet implements Facet {
             
         }
         
+        @Override
         public void initializeFromJSON(JSONObject o) {
             _name = o.getString("name");
             _expression = o.getString("expression");

main/src/com/google/refine/browsing/facets/ScatterplotFacet.java

@@ -144,6 +144,7 @@ public class ScatterplotFacet implements Facet {
             return facet;
         }
         
+        @Override
         public void initializeFromJSON(JSONObject o) {
             name = o.getString(NAME);
             l = size = (o.has(SIZE)) ? o.getInt(SIZE) : 100;

main/src/com/google/refine/browsing/facets/TextSearchFacet.java

@@ -86,6 +86,7 @@ public class TextSearchFacet implements Facet {
             return facet;
         }
         
+        @Override
         public void initializeFromJSON(JSONObject o) {
             _name = o.getString("name");
             _columnName = o.getString("columnName");

main/src/com/google/refine/browsing/facets/TimeRangeFacet.java

@@ -95,6 +95,7 @@ public class TimeRangeFacet implements Facet {
             writer.endObject();
         }
         
+        @Override
         public void initializeFromJSON(JSONObject o) throws JSONException {        
             _name = o.getString("name");
             _expression = o.getString("expression");

main/tests/server/src/com/google/refine/tests/browsing/facets/EngineConfigTests.java

@@ -0,0 +1,32 @@
+package com.google.refine.tests.browsing.facets;
+
+import org.json.JSONObject;
+import org.testng.annotations.Test;
+
+import com.google.refine.browsing.EngineConfig;
+import com.google.refine.tests.util.TestUtils;
+
+public class EngineConfigTests {
+    
+    public static String engineConfigJson =
+              "{\n"
+            + "      \"mode\": \"row-based\",\n"
+            + "      \"facets\": [\n"
+            + "        {\n"
+            + "          \"mode\": \"text\",\n"
+            + "          \"invert\": false,\n"
+            + "          \"caseSensitive\": false,\n"
+            + "          \"query\": \"www\",\n"
+            + "          \"name\": \"reference\",\n"
+            + "          \"type\": \"text\",\n"
+            + "          \"columnName\": \"reference\"\n"
+            + "        }\n"
+            + "      ]\n"
+            + "    }";
+    
+    @Test
+    public void serializeEngineConfig() {
+        EngineConfig ec = EngineConfig.reconstruct(new JSONObject(engineConfigJson));
+        TestUtils.isSerializedTo(ec, engineConfigJson);
+    }
+}