From 072e5261554a5114fe7a18ab7241934bd55ddfb4 Mon Sep 17 00:00:00 2001
From: Ryan McKinley <ryan@apache.org>
Date: Sat, 8 Dec 2007 07:27:49 +0000
Subject: [PATCH] SOLR-281 -- building a SearchComponent registry with
 components initialized via the standard plugin utils method.

git-svn-id: https://svn.apache.org/repos/asf/lucene/solr/trunk@602341 13f79535-47bb-0310-9956-ffa450edef68
---
 example/solr/conf/solrconfig.xml              |  59 +++++++--
 src/java/org/apache/solr/core/Config.java     |   7 +-
 src/java/org/apache/solr/core/SolrCore.java   |  40 ++++++
 .../apache/solr/handler/SearchHandler.java    | 122 +++++++++++++-----
 .../solr/handler/StandardRequestHandler.java  |  23 +---
 .../handler/component/DebugComponent.java     |  26 +++-
 .../handler/component/FacetComponent.java     |   5 +-
 .../handler/component/HighlightComponent.java |   9 +-
 .../component/MoreLikeThisComponent.java      |   5 +-
 .../handler/component/QueryComponent.java     |   2 +
 .../handler/component/ResponseBuilder.java    |  18 +++
 .../handler/component/SearchComponent.java    |  10 +-
 src/java/org/apache/solr/search/SortSpec.java |   5 +
 .../solr/handler/SearchHandlerTest.java       |  77 +++++++++++
 14 files changed, 324 insertions(+), 84 deletions(-)
 create mode 100644 src/test/org/apache/solr/handler/SearchHandlerTest.java

diff --git a/example/solr/conf/solrconfig.xml b/example/solr/conf/solrconfig.xml
index d33c2339361..4b9cb741b00 100755
--- a/example/solr/conf/solrconfig.xml
+++ b/example/solr/conf/solrconfig.xml
@@ -288,19 +288,6 @@
   </requestHandler>
 
 
-  <requestHandler name="/search" class="solr.SearchHandler">
-    <lst name="defaults">
-      <str name="echoParams">explicit</str>
-    </lst>
-    <arr name="components">
-      <str>org.apache.solr.handler.component.QueryComponent</str>
-      <str>org.apache.solr.handler.component.FacetComponent</str>
-      <str>org.apache.solr.handler.component.MoreLikeThisComponent</str>
-      <str>org.apache.solr.handler.component.HighlightComponent</str>
-      <str>org.apache.solr.handler.component.DebugComponent</str>
-    </arr>
-  </requestHandler>
-
   <!-- DisMaxRequestHandler allows easy searching across multiple fields
        for simple user-entered phrases. 
        see http://wiki.apache.org/solr/DisMaxRequestHandler
@@ -439,6 +426,52 @@
      </lst>
    </requestHandler>
   
+  
+  <!--
+   
+   Search components are registered to SolrCore and used by Search Handlers
+   
+   By default, the following components are avaliable:
+    
+   <searchComponent name="query"     class="org.apache.solr.handler.component.QueryComponent" />
+   <searchComponent name="facet"     class="org.apache.solr.handler.component.FacetComponent" />
+   <searchComponent name="mlt"       class="org.apache.solr.handler.component.MoreLikeThisComponent" />
+   <searchComponent name="highlight" class="org.apache.solr.handler.component.HighlightComponent" />
+   <searchComponent name="debug"     class="org.apache.solr.handler.component.DebugComponent" />
+  
+   If you register a searchComponent to one of the standard names, that will be used instead.
+  
+   -->
+ 
+  <requestHandler name="/search" class="solr.SearchHandler">
+    <lst name="defaults">
+      <str name="echoParams">explicit</str>
+    </lst>
+    <!--
+    By default, this will register the following components:
+    
+    <arr name="components">
+      <str>query</str>
+      <str>facet</str>
+      <str>mlt</str>
+      <str>highlight</str>
+      <str>debug</str>
+    </arr>
+    
+    To insert handlers before or after the 'standard' components, use:
+    
+    <arr name="first-components">
+      <str>first</str>
+    </arr>
+    
+    <arr name="last-components">
+      <str>last</str>
+    </arr>
+    
+    -->
+  </requestHandler>
+  
+  
   <!-- Update request handler.  
   
        Note: Since solr1.1 requestHandlers requires a valid content type header if posted in 
diff --git a/src/java/org/apache/solr/core/Config.java b/src/java/org/apache/solr/core/Config.java
index 480eea96fd7..8fd6c1abf35 100644
--- a/src/java/org/apache/solr/core/Config.java
+++ b/src/java/org/apache/solr/core/Config.java
@@ -51,13 +51,16 @@ public class Config {
     this( null, name, is, prefix );
   }
 
-  public Config(String instanceDir, String name) throws ParserConfigurationException, IOException, SAXException 
+  public Config(SolrResourceLoader loader, String name) throws ParserConfigurationException, IOException, SAXException 
   {
-    this( new SolrResourceLoader( instanceDir ), name, null, null );
+    this( loader, name, null, null );
   }
   
   public Config(SolrResourceLoader loader, String name, InputStream is, String prefix) throws ParserConfigurationException, IOException, SAXException 
   {
+    if( loader == null ) {
+      loader = new SolrResourceLoader( null );
+    }
     this.loader = loader;
     this.name = name;
     this.prefix = prefix;
diff --git a/src/java/org/apache/solr/core/SolrCore.java b/src/java/org/apache/solr/core/SolrCore.java
index 4b1e44c4e3a..73323a377f6 100644
--- a/src/java/org/apache/solr/core/SolrCore.java
+++ b/src/java/org/apache/solr/core/SolrCore.java
@@ -44,6 +44,12 @@ import org.apache.solr.common.util.DOMUtil;
 import org.apache.solr.common.util.NamedList;
 import org.apache.solr.common.util.SimpleOrderedMap;
 import org.apache.solr.handler.PingRequestHandler;
+import org.apache.solr.handler.component.DebugComponent;
+import org.apache.solr.handler.component.FacetComponent;
+import org.apache.solr.handler.component.HighlightComponent;
+import org.apache.solr.handler.component.MoreLikeThisComponent;
+import org.apache.solr.handler.component.QueryComponent;
+import org.apache.solr.handler.component.SearchComponent;
 import org.apache.solr.highlight.SolrHighlighter;
 import org.apache.solr.request.JSONResponseWriter;
 import org.apache.solr.request.PythonResponseWriter;
@@ -86,6 +92,7 @@ public final class SolrCore {
   private final long startTime;
   private final RequestHandlers reqHandlers;
   private final SolrHighlighter highlighter;
+  private final Map<String,SearchComponent> searchComponents;
   private final Map<String,UpdateRequestProcessorFactory> updateProcessors;
   private final Map<String,SolrInfoMBean> infoRegistry = new java.util.HashMap<String,SolrInfoMBean>();
   
@@ -309,6 +316,8 @@ public final class SolrCore {
       
       initWriters();
       initQParsers();
+      
+      this.searchComponents = loadSearchComponents( config );
 
       // Processors initialized before the handlers
       updateProcessors = loadUpdateProcessors();
@@ -465,6 +474,37 @@ public final class SolrCore {
     return reqHandlers.register(handlerName,handler);
   }
   
+  /**
+   * Register the default search components
+   */
+  private static Map<String, SearchComponent> loadSearchComponents( SolrConfig config )
+  {
+    Map<String, SearchComponent> components = new HashMap<String, SearchComponent>();
+    components.put( QueryComponent.COMPONENT_NAME,        new QueryComponent()        );
+    components.put( FacetComponent.COMPONENT_NAME,        new FacetComponent()        );
+    components.put( MoreLikeThisComponent.COMPONENT_NAME, new MoreLikeThisComponent() );
+    components.put( HighlightComponent.COMPONENT_NAME,    new HighlightComponent()    );
+    components.put( DebugComponent.COMPONENT_NAME,        new DebugComponent()        );
+  
+    String xpath = "searchComponent";
+    NamedListPluginLoader<SearchComponent> loader = new NamedListPluginLoader<SearchComponent>( xpath, components );
+    loader.load( config.getResourceLoader(), (NodeList)config.evaluate( xpath, XPathConstants.NODESET ) );
+  
+    return components;
+  }
+  
+  /**
+   * @return a Search Component registered to a given name.  Throw an exception if the component is undefined
+   */
+  public SearchComponent getSearchComponent( String name )
+  {
+    SearchComponent component = searchComponents.get( name );
+    if( component == null ) {
+      throw new SolrException( SolrException.ErrorCode.BAD_REQUEST,
+          "Unknown Search Component: "+name );
+    }
+    return component;
+  }
   
   ////////////////////////////////////////////////////////////////////////////////
   // Update Handler
diff --git a/src/java/org/apache/solr/handler/SearchHandler.java b/src/java/org/apache/solr/handler/SearchHandler.java
index f712072b21c..57cf55ccd2a 100644
--- a/src/java/org/apache/solr/handler/SearchHandler.java
+++ b/src/java/org/apache/solr/handler/SearchHandler.java
@@ -18,18 +18,25 @@
 package org.apache.solr.handler;
 
 import org.apache.lucene.queryParser.ParseException;
+import org.apache.solr.common.SolrException;
 import org.apache.solr.common.params.CommonParams;
 import org.apache.solr.common.util.NamedList;
 import org.apache.solr.common.util.RTimer;
 import org.apache.solr.common.util.SimpleOrderedMap;
+import org.apache.solr.core.SolrCore;
+import org.apache.solr.handler.component.DebugComponent;
+import org.apache.solr.handler.component.FacetComponent;
+import org.apache.solr.handler.component.HighlightComponent;
+import org.apache.solr.handler.component.MoreLikeThisComponent;
+import org.apache.solr.handler.component.QueryComponent;
 import org.apache.solr.handler.component.ResponseBuilder;
 import org.apache.solr.handler.component.SearchComponent;
 import org.apache.solr.request.SolrQueryRequest;
 import org.apache.solr.request.SolrQueryResponse;
+import org.apache.solr.util.plugin.SolrCoreAware;
 
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.List;
 import java.util.logging.Logger;
 
@@ -37,56 +44,106 @@ import java.util.logging.Logger;
  *
  * Refer SOLR-281
  *
+ * @since solr 1.3
  */
-public class SearchHandler extends RequestHandlerBase
+public class SearchHandler extends RequestHandlerBase implements SolrCoreAware
 {
-  private static final String RESPONSE_BUILDER_CONTEXT_KEY = "ResponseBuilder";
+  static final String RESPONSE_BUILDER_CONTEXT_KEY = "ResponseBuilder";
+  
+  static final String INIT_COMPONENTS = "components";
+  static final String INIT_FISRT_COMPONENTS = "first-components";
+  static final String INIT_LAST_COMPONENTS = "last-components";
   
   protected static Logger log = Logger.getLogger(SearchHandler.class.getName());
   
-  protected Collection<SearchComponent> components;
+  protected List<SearchComponent> components = null;
+  protected NamedList initArgs = null;
   
   @Override
   public void init(NamedList args) {
     super.init( args );
-    initComponents(args);
+    initArgs = args;
   }
-  
-  // TODO: should there be a way to append components from solrconfig w/o having to
-  // know the complete standard list (which may expand over time?)
-  protected void initComponents(NamedList args){
-    if( args != null ) {
-      try {
-        Object declaredComponents = args.get("components");
-        if (declaredComponents != null && declaredComponents instanceof List) {
-          List list = (List) declaredComponents;
-          components = new ArrayList<SearchComponent>(list.size());
-          for(Object c : list){
-            // TODO: an init() with args for components?
-            SearchComponent comp = (SearchComponent) Class.forName((String) c).newInstance();
-            components.add(comp);
-            log.info("Adding  component:"+comp);
-          }
-        }
-      } catch (Exception e) {
-        throw new RuntimeException(e);
-      } 
+
+  protected List<String> getDefaultComponets()
+  {
+    ArrayList<String> names = new ArrayList<String>(5);
+    names.add( QueryComponent.COMPONENT_NAME );
+    names.add( FacetComponent.COMPONENT_NAME );
+    names.add( MoreLikeThisComponent.COMPONENT_NAME );
+    names.add( HighlightComponent.COMPONENT_NAME );
+    names.add( DebugComponent.COMPONENT_NAME );
+    return names;
+  }
+
+  /**
+   * Initialize the components based on name
+   */
+  @SuppressWarnings("unchecked")
+  public void inform(SolrCore core) 
+  {
+    Object declaredComponents = initArgs.get(INIT_COMPONENTS);
+    List<String> first = (List<String>) initArgs.get(INIT_FISRT_COMPONENTS);
+    List<String> last  = (List<String>) initArgs.get(INIT_LAST_COMPONENTS);
+
+    List<String> list = null;
+    if( declaredComponents == null ) {
+      // Use the default component list
+      list = getDefaultComponets();
+      
+      if( first != null ) {
+        List<String> clist = first;
+        clist.addAll( list );
+        list = clist;
+      }
+      
+      if( last != null ) {
+        list.addAll( last );
+      }
+    }
+    else {
+      list = (List<String>)declaredComponents;
+      if( first != null || last != null ) {
+        throw new SolrException( SolrException.ErrorCode.SERVER_ERROR,
+            "First/Last components only valid if you do not declare 'components'");
+      }
+    }
+    
+    // Build the component list
+    components = new ArrayList<SearchComponent>( list.size() );
+    for(String c : list){
+      SearchComponent comp = core.getSearchComponent( c );
+      components.add(comp);
+      log.info("Adding  component:"+comp);
     }
   }
 
+  public List<SearchComponent> getComponents() {
+    return components;
+  }
+  
   public static ResponseBuilder getResponseBuilder(SolrQueryRequest req) 
   {
     return (ResponseBuilder) req.getContext().get( RESPONSE_BUILDER_CONTEXT_KEY );
   }
   
+  //---------------------------------------------------------------------------------------
+  // SolrRequestHandler
+  //---------------------------------------------------------------------------------------
+  
   @Override
   public void handleRequestBody(SolrQueryRequest req, SolrQueryResponse rsp) throws IOException, ParseException, InstantiationException, IllegalAccessException 
   {
     ResponseBuilder builder = new ResponseBuilder();
     req.getContext().put( RESPONSE_BUILDER_CONTEXT_KEY, builder );
     
-    // The semantics of debugging vs not debugging are different enough that 
-    // it makes sense to have two control loops
+    if( components == null ) {
+      throw new SolrException( SolrException.ErrorCode.SERVER_ERROR,
+          "SearchHandler not initialized properly.  No components registered." );
+    }
+    
+    // The semantics of debugging vs not debugging are distinct enough 
+    // to justify two control loops
     if( !req.getParams().getBool( CommonParams.DEBUG_QUERY, false ) ) {
       // Prepare
       for( SearchComponent c : components ) {
@@ -122,15 +179,14 @@ public class SearchHandler extends RequestHandlerBase
       timer.stop();
       
       // add the timing info
-      if( builder.getDebugInfo() == null ) {
-        builder.setDebugInfo( new SimpleOrderedMap<Object>() );
-      }
-      builder.getDebugInfo().add( "timing", timer.asNamedList() );
+      builder.addDebugInfo( "timing", timer.asNamedList() );
     }
   }
 
-  //////////////////////// SolrInfoMBeans methods //////////////////////
-
+  //---------------------------------------------------------------------------------------
+  // SolrInfoMBeans
+  //---------------------------------------------------------------------------------------
+  
   @Override
   public String getDescription() {
     StringBuilder sb = new StringBuilder();
diff --git a/src/java/org/apache/solr/handler/StandardRequestHandler.java b/src/java/org/apache/solr/handler/StandardRequestHandler.java
index 97bcfb40a29..d9fe08218f7 100644
--- a/src/java/org/apache/solr/handler/StandardRequestHandler.java
+++ b/src/java/org/apache/solr/handler/StandardRequestHandler.java
@@ -19,15 +19,6 @@ package org.apache.solr.handler;
 
 import java.net.MalformedURLException;
 import java.net.URL;
-import java.util.ArrayList;
-
-import org.apache.solr.common.util.NamedList;
-import org.apache.solr.handler.component.DebugComponent;
-import org.apache.solr.handler.component.FacetComponent;
-import org.apache.solr.handler.component.HighlightComponent;
-import org.apache.solr.handler.component.MoreLikeThisComponent;
-import org.apache.solr.handler.component.QueryComponent;
-import org.apache.solr.handler.component.SearchComponent;
 
 /**
  * @version $Id$
@@ -48,18 +39,8 @@ import org.apache.solr.handler.component.SearchComponent;
  * </ul>
  *
  */
-public class StandardRequestHandler extends SearchHandler {
-
-  @Override
-  protected void initComponents(NamedList args) {
-    components = new ArrayList<SearchComponent>(5);
-    components.add( new QueryComponent() );
-    components.add( new FacetComponent() );
-    components.add( new MoreLikeThisComponent() );
-    components.add( new HighlightComponent() );
-    components.add( new DebugComponent() );
-  }
-
+public class StandardRequestHandler extends SearchHandler 
+{
   //////////////////////// SolrInfoMBeans methods //////////////////////
 
   @Override
diff --git a/src/java/org/apache/solr/handler/component/DebugComponent.java b/src/java/org/apache/solr/handler/component/DebugComponent.java
index 9b63fcd52ea..053f8fc5315 100644
--- a/src/java/org/apache/solr/handler/component/DebugComponent.java
+++ b/src/java/org/apache/solr/handler/component/DebugComponent.java
@@ -24,8 +24,8 @@ import java.net.URL;
 import java.util.ArrayList;
 import java.util.List;
 
-import org.apache.lucene.queryParser.ParseException;
 import org.apache.lucene.search.Query;
+import org.apache.solr.common.util.NamedList;
 import org.apache.solr.handler.SearchHandler;
 import org.apache.solr.request.SolrQueryRequest;
 import org.apache.solr.request.SolrQueryResponse;
@@ -40,32 +40,44 @@ import org.apache.solr.util.SolrPluginUtils;
  */
 public class DebugComponent extends SearchComponent
 {
+  public static final String COMPONENT_NAME = "debug";
+  
   @Override
-  public void prepare(SolrQueryRequest req, SolrQueryResponse rsp) throws IOException, ParseException 
+  public void prepare(SolrQueryRequest req, SolrQueryResponse rsp) throws IOException 
   {
     
   }
 
+  @SuppressWarnings("unchecked")
   @Override
   public void process(SolrQueryRequest req, SolrQueryResponse rsp) throws IOException 
   {
     ResponseBuilder builder = SearchHandler.getResponseBuilder( req );
     if( builder.isDebug() ) {
-      builder.setDebugInfo( SolrPluginUtils.doStandardDebug( req, 
-          builder.getQueryString(), builder.getQuery(), builder.getResults().docList) );
-
+      NamedList stdinfo = SolrPluginUtils.doStandardDebug( req, 
+          builder.getQueryString(), builder.getQuery(), builder.getResults().docList);
+      
+      NamedList info = builder.getDebugInfo();
+      if( info == null ) {
+        builder.setDebugInfo( stdinfo );
+        info = stdinfo;
+      }
+      else {
+        info.addAll( stdinfo );
+      }
+      
       if (builder.getQparser() != null) {
         builder.getQparser().addDebugInfo(builder.getDebugInfo());
       }
 
       if (null != builder.getDebugInfo() ) {
         if (null != builder.getFilters() ) {
-          builder.getDebugInfo().add("filter_queries",req.getParams().getParams(FQ));
+          info.add("filter_queries",req.getParams().getParams(FQ));
           List<String> fqs = new ArrayList<String>(builder.getFilters().size());
           for (Query fq : builder.getFilters()) {
             fqs.add(QueryParsing.toString(fq, req.getSchema()));
           }
-          builder.getDebugInfo().add("parsed_filter_queries",fqs);
+          info.add("parsed_filter_queries",fqs);
         }
         
         // Add this directly here?
diff --git a/src/java/org/apache/solr/handler/component/FacetComponent.java b/src/java/org/apache/solr/handler/component/FacetComponent.java
index 9ad79ab15b5..81f5a77e76a 100644
--- a/src/java/org/apache/solr/handler/component/FacetComponent.java
+++ b/src/java/org/apache/solr/handler/component/FacetComponent.java
@@ -20,7 +20,6 @@ package org.apache.solr.handler.component;
 import java.io.IOException;
 import java.net.URL;
 
-import org.apache.lucene.queryParser.ParseException;
 import org.apache.solr.common.params.FacetParams;
 import org.apache.solr.common.params.SolrParams;
 import org.apache.solr.handler.SearchHandler;
@@ -36,8 +35,10 @@ import org.apache.solr.request.SolrQueryResponse;
  */
 public class FacetComponent extends SearchComponent
 {
+  public static final String COMPONENT_NAME = "facet";
+  
   @Override
-  public void prepare(SolrQueryRequest req, SolrQueryResponse rsp) throws IOException, ParseException 
+  public void prepare(SolrQueryRequest req, SolrQueryResponse rsp) throws IOException 
   {
     SolrParams params = req.getParams();
     if (params.getBool(FacetParams.FACET,false)) {
diff --git a/src/java/org/apache/solr/handler/component/HighlightComponent.java b/src/java/org/apache/solr/handler/component/HighlightComponent.java
index e045faf6b22..d1e500a3dda 100644
--- a/src/java/org/apache/solr/handler/component/HighlightComponent.java
+++ b/src/java/org/apache/solr/handler/component/HighlightComponent.java
@@ -17,7 +17,6 @@
 
 package org.apache.solr.handler.component;
 
-import org.apache.lucene.queryParser.ParseException;
 import org.apache.solr.common.SolrException;
 import org.apache.solr.common.params.CommonParams;
 import org.apache.solr.common.params.SolrParams;
@@ -36,9 +35,13 @@ import java.net.URL;
  * @version $Id$
  * @since solr 1.3
  */
-public class HighlightComponent extends SearchComponent {
+public class HighlightComponent extends SearchComponent 
+{
+  public static final String COMPONENT_NAME = "highlight";
+  
   @Override
-  public void prepare(SolrQueryRequest req, SolrQueryResponse rsp) throws IOException, ParseException {
+  public void prepare(SolrQueryRequest req, SolrQueryResponse rsp) 
+  {
     
   }
   
diff --git a/src/java/org/apache/solr/handler/component/MoreLikeThisComponent.java b/src/java/org/apache/solr/handler/component/MoreLikeThisComponent.java
index 7c78b35f4a8..a860b526e7e 100644
--- a/src/java/org/apache/solr/handler/component/MoreLikeThisComponent.java
+++ b/src/java/org/apache/solr/handler/component/MoreLikeThisComponent.java
@@ -20,7 +20,6 @@ package org.apache.solr.handler.component;
 import java.io.IOException;
 import java.net.URL;
 
-import org.apache.lucene.queryParser.ParseException;
 import org.apache.solr.common.params.MoreLikeThisParams;
 import org.apache.solr.common.params.SolrParams;
 import org.apache.solr.common.util.NamedList;
@@ -39,8 +38,10 @@ import org.apache.solr.search.SolrIndexSearcher;
  */
 public class MoreLikeThisComponent extends SearchComponent
 {
+  public static final String COMPONENT_NAME = "mlt";
+  
   @Override
-  public void prepare(SolrQueryRequest req, SolrQueryResponse rsp) throws IOException, ParseException 
+  public void prepare(SolrQueryRequest req, SolrQueryResponse rsp) throws IOException 
   {
     
   }
diff --git a/src/java/org/apache/solr/handler/component/QueryComponent.java b/src/java/org/apache/solr/handler/component/QueryComponent.java
index b54442d89e4..7abb5d90ed6 100644
--- a/src/java/org/apache/solr/handler/component/QueryComponent.java
+++ b/src/java/org/apache/solr/handler/component/QueryComponent.java
@@ -40,6 +40,8 @@ import java.util.List;
  */
 public class QueryComponent extends SearchComponent
 {
+  public static final String COMPONENT_NAME = "query";
+  
   @Override
   public void prepare(SolrQueryRequest req, SolrQueryResponse rsp) throws IOException, ParseException 
   {
diff --git a/src/java/org/apache/solr/handler/component/ResponseBuilder.java b/src/java/org/apache/solr/handler/component/ResponseBuilder.java
index 52fa220998d..ad5bd76f003 100644
--- a/src/java/org/apache/solr/handler/component/ResponseBuilder.java
+++ b/src/java/org/apache/solr/handler/component/ResponseBuilder.java
@@ -20,6 +20,7 @@ package org.apache.solr.handler.component;
 import org.apache.lucene.search.Query;
 import org.apache.solr.common.util.NamedList;
 import org.apache.solr.common.util.RTimer;
+import org.apache.solr.common.util.SimpleOrderedMap;
 import org.apache.solr.search.DocListAndSet;
 import org.apache.solr.search.QParser;
 import org.apache.solr.search.SortSpec;
@@ -50,7 +51,24 @@ public class ResponseBuilder
   private RTimer timer = null;
   
   private Query highlightQuery = null;
+  
 
+  //-------------------------------------------------------------------------
+  //-------------------------------------------------------------------------
+  
+  /**
+   * Utility function to add debugging info.  This will make sure a valid 
+   * debugInfo exists before adding to it.
+   */
+  public void addDebugInfo( String name, Object val )
+  {
+    if( debugInfo == null ) {
+      debugInfo = new SimpleOrderedMap<Object>();
+    }
+    debugInfo.add( name, val );
+  }
+
+  //-------------------------------------------------------------------------
   //-------------------------------------------------------------------------
   
   public boolean isDebug() {
diff --git a/src/java/org/apache/solr/handler/component/SearchComponent.java b/src/java/org/apache/solr/handler/component/SearchComponent.java
index 4741543bc7b..b9a893ff552 100644
--- a/src/java/org/apache/solr/handler/component/SearchComponent.java
+++ b/src/java/org/apache/solr/handler/component/SearchComponent.java
@@ -26,6 +26,7 @@ import org.apache.solr.common.util.SimpleOrderedMap;
 import org.apache.solr.core.SolrInfoMBean;
 import org.apache.solr.request.SolrQueryRequest;
 import org.apache.solr.request.SolrQueryResponse;
+import org.apache.solr.util.plugin.NamedListInitializedPlugin;
 
 /**
  * TODO!
@@ -33,10 +34,17 @@ import org.apache.solr.request.SolrQueryResponse;
  * @version $Id$
  * @since solr 1.3
  */
-public abstract class SearchComponent implements SolrInfoMBean
+public abstract class SearchComponent implements SolrInfoMBean, NamedListInitializedPlugin
 {
   public abstract void prepare( SolrQueryRequest req, SolrQueryResponse rsp ) throws IOException, ParseException;
   public abstract void process( SolrQueryRequest req, SolrQueryResponse rsp ) throws IOException;
+
+  //////////////////////// NamedListInitializedPlugin methods //////////////////////
+  
+  public void init( NamedList args )
+  {
+    // By default do nothing
+  }
   
   //////////////////////// SolrInfoMBeans methods //////////////////////
 
diff --git a/src/java/org/apache/solr/search/SortSpec.java b/src/java/org/apache/solr/search/SortSpec.java
index baa4111cd2d..f73e374e38a 100644
--- a/src/java/org/apache/solr/search/SortSpec.java
+++ b/src/java/org/apache/solr/search/SortSpec.java
@@ -38,6 +38,11 @@ public class SortSpec
     this.offset=offset;
     this.num=num;
   }
+  
+  public void setSort( Sort s )
+  {
+    sort = s;
+  }
 
   /**
    * Gets the Lucene Sort object, or null for the default sort
diff --git a/src/test/org/apache/solr/handler/SearchHandlerTest.java b/src/test/org/apache/solr/handler/SearchHandlerTest.java
new file mode 100644
index 00000000000..8a3fe0731bd
--- /dev/null
+++ b/src/test/org/apache/solr/handler/SearchHandlerTest.java
@@ -0,0 +1,77 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.solr.handler;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.solr.common.util.NamedList;
+import org.apache.solr.core.SolrCore;
+import org.apache.solr.handler.component.FacetComponent;
+import org.apache.solr.handler.component.MoreLikeThisComponent;
+import org.apache.solr.handler.component.SearchComponent;
+import org.apache.solr.util.AbstractSolrTestCase;
+
+
+public class SearchHandlerTest extends AbstractSolrTestCase 
+{
+  @Override public String getSchemaFile() { return "schema.xml"; }
+  @Override public String getSolrConfigFile() { return "solrconfig.xml"; }
+  
+  @SuppressWarnings("unchecked")
+  public void testInitalization()
+  {
+    SolrCore core = h.getCore();
+    
+    // Build an explicit list
+    //-----------------------------------------------
+    List<String> names0 = new ArrayList<String>();
+    names0.add( MoreLikeThisComponent.COMPONENT_NAME );
+    
+    NamedList args = new NamedList();
+    args.add( SearchHandler.INIT_COMPONENTS, names0 );
+    SearchHandler handler = new SearchHandler();
+    handler.init( args );
+    handler.inform( core );
+    
+    assertEquals( 1, handler.getComponents().size() );
+    assertEquals( core.getSearchComponent( MoreLikeThisComponent.COMPONENT_NAME ), 
+        handler.getComponents().get( 0 ) );
+    
+
+    // First/Last list
+    //-----------------------------------------------
+    names0 = new ArrayList<String>();
+    names0.add( MoreLikeThisComponent.COMPONENT_NAME );
+    
+    List<String> names1 = new ArrayList<String>();
+    names1.add( FacetComponent.COMPONENT_NAME );
+    
+    args = new NamedList();
+    args.add( SearchHandler.INIT_FISRT_COMPONENTS, names0 );
+    args.add( SearchHandler.INIT_LAST_COMPONENTS, names1 );
+    handler = new SearchHandler();
+    handler.init( args );
+    handler.inform( core );
+    
+    List<SearchComponent> comps = handler.getComponents();
+    assertEquals( 2+handler.getDefaultComponets().size(), comps.size() );
+    assertEquals( core.getSearchComponent( MoreLikeThisComponent.COMPONENT_NAME ), comps.get( 0 ) );
+    assertEquals( core.getSearchComponent( FacetComponent.COMPONENT_NAME ), comps.get( comps.size()-1 ) );
+  }
+}