Changeset 5191

Timestamp:

2003-08-19T14:46:30+12:00 (21 years ago)

Author:

kjdon

Message:

now we are doing query results paging in tehaction, not the xslt - this saves us retrieving metadata for docs which are not displayed.

File:

• trunk/gsdl3/src/java/org/greenstone/gsdl3/action/QueryAction.java (modified) (6 diffs)

trunk/gsdl3/src/java/org/greenstone/gsdl3/action/QueryAction.java

@@ -29 +29 @@
     // create the return message
     Element result = this.doc.createElement(GSXML.MESSAGE_ELEM);
-    // for now we only have one type of query - subaction not used
     Element response = basicQuery(request);
     result.appendChild(this.doc.importNode(response, true));
@@ -36 +35 @@
     
     /** a generic query handler 
-     * this gets the service description, does the query (just passes all teh 
+     * this gets the service description, does the query (just passes all the 
      * params to the service, then gets the titles for any results 
      */
@@ -112 +111 @@
         return page_response;
     }
-    Element query_param_list = GSXML.createParameterList(this.doc, service_params);//(Element)this.doc.importNode(cgi_param_list, true);
-    System.out.println("service params are "+this.converter.getString(query_param_list));
+    Element query_param_list = GSXML.createParameterList(this.doc, service_params);
+    ///ystem.out.println("service params are "+this.converter.getString(query_param_list));
     mr_query_request.appendChild(query_param_list);
 
@@ -145 +144 @@
     }
     
-    // do the metadata request
+    // paging of the results is done here - we filter the list to remove unwanted entries before retrieving metadata
+    Element filtered_doc_list = filterDocList(params, service_description, document_list);
+    
+    // do the metadata request on the filtered list
     Element mr_metadata_message = this.doc.createElement(GSXML.MESSAGE_ELEM);
     Element mr_metadata_request = this.doc.createElement(GSXML.REQUEST_ELEM);
@@ -164 +166 @@
     
     // add in the doc node list too
-    mr_metadata_request.appendChild(this.doc.importNode(document_list, true));
+    mr_metadata_request.appendChild(filtered_doc_list);
+
     Element mr_metadata_response = (Element) this.mr.process(mr_metadata_message);  
     
@@ -177 +180 @@
     return page_response;
     }
+
+    /** this filters out some of the doc results for result paging */
+    protected Element filterDocList(HashMap params, Element service_description, Element orig_doc_list) {
+    
+    // check in the service descripiton to see if hitsPerpage is a param
+    Element service_p_list = (Element)GSXML.getChildByTagName(service_description, GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
+    Element hits_param = GSXML.getNamedElement(service_p_list, GSXML.PARAM_ELEM, GSXML.NAME_ATT, "hitsPerPage");
+    
+    boolean service_paging = false;
+    if (hits_param != null) {
+        service_paging = true;
+    }
+    if (service_paging) {
+        // the service is doing the paging, so we want to display all of teh returned docs
+        return (Element)this.doc.importNode(orig_doc_list, true);
+    }
+    
+    String hits_pp = (String)params.get("hitsPerPage");
+    int hits = 20;
+    if (hits_pp != null && !hits_pp.equals("")) {
+        try {
+        hits = Integer.parseInt(hits_pp);
+        } catch (Exception e) {
+        hits=20;
+        }
+    }
+
+    if (hits == -1) { // all
+        return (Element)this.doc.importNode(orig_doc_list, true);
+    }
+    NodeList result_docs = orig_doc_list.getElementsByTagName(GSXML.DOC_NODE_ELEM);
+    
+    int num_docs = result_docs.getLength();
+    if (num_docs <= hits) {
+        // too few docs to do paging
+        return (Element)this.doc.importNode(orig_doc_list, true);
+    }
+
+    // now we need our own doc list
+    Element result_list = this.doc.createElement(GSXML.DOC_NODE_ELEM + GSXML.LIST_MODIFIER);
+    String start_p = (String)params.get("startPage");
+    int start = 1;
+    if (start_p != null && !start_p.equals("")) {
+        try {
+        start = Integer.parseInt(start_p);
+        } catch (Exception e) {
+        start = 1;
+        }
+    }
+
+    int start_from = (start-1)*hits;
+    int end_at = (start*hits)-1;
+
+    if (start_from > num_docs) {
+        // something has gone wrong
+        return result_list;
+    }
+    
+    if (end_at > num_docs) {
+        end_at = num_docs-1;
+    }
+
+    // now we finally have the docs numbers to use
+    for (int i=start_from; i<=end_at; i++) {
+        result_list.appendChild(this.doc.importNode(result_docs.item(i), true));
+    }
+
+    return result_list;
+    }
+
 }