/*
* AbstractSearch.java
* Copyright (C) 2005 New Zealand Digital Library, http://www.nzdl.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
package org.greenstone.gsdl3.service;
// Greenstone classes
import org.greenstone.gsdl3.util.GSXML;
import org.greenstone.gsdl3.util.GSPath;
import org.greenstone.gsdl3.util.AbstractSimpleDocument;
import org.greenstone.gsdl3.util.SimpleDocument;
// XML classes
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
// java classes
import java.util.ArrayList;
import java.util.HashMap;
import org.apache.log4j.*;
/**
* Partially implements a generic search service
*
* @author Katherine Don
*/
public abstract class AbstractSearch extends ServiceRack
{
static Logger logger = Logger.getLogger(org.greenstone.gsdl3.service.AbstractSearch.class.getName());
// the search service
protected String QUERY_SERVICE = null; // set by subclass
// compulsory params
protected static final String INDEX_PARAM = "index";
protected static final String QUERY_PARAM = "query";
protected static final String RAW_PARAM = "rawquery";
// optional standard params - some of these have to be implemented
protected static final String MAXDOCS_PARAM = "maxDocs";
protected static final String HITS_PER_PAGE_PARAM = "hitsPerPage";
protected static final String START_PAGE_PARAM = "startPage";
protected AbstractSimpleDocument gs_doc = null;
/** can more than one index be searched at the same time? */
protected boolean does_multi_index_search = false;
/** does this service support paging of results? */
protected boolean does_paging = false;
/** does this service support asking for a subset of results? */
protected boolean does_chunking = false;
/**
* the default document type - use if all documents are the same type
*/
protected String default_document_type = null;
/**
* the default index, or comma separated list if more than one is the
* default (with start and end commas, eg ,TI,SU,). Should be set by
* configure()
*/
protected String default_index = "";
protected String default_max_docs = "100";
protected String default_hits_per_page = "10";
public AbstractSearch()
{
}
/**
* Sets up the short service info for service by QUERY_SERVICE (e.g.
* TextQuery or AudioQuery) If other services will be provided, should be
* added in the subclass configure also looks for search format info, and
* document format info
*/
public boolean configure(Element info, Element extra_info)
{
if (!super.configure(info, extra_info))
{
return false;
}
logger.info("Configuring AbstractSearch...");
this.config_info = info;
// set up short_service_info_
// => for now just has id and type. the name (lang dependent)
// will be added in if the list is requested.
Element tq_service = this.doc.createElement(GSXML.SERVICE_ELEM);
tq_service.setAttribute(GSXML.TYPE_ATT, GSXML.SERVICE_TYPE_QUERY);
tq_service.setAttribute(GSXML.NAME_ATT, QUERY_SERVICE);
this.short_service_info.appendChild(tq_service);
// add some format info to service map if there is any
// => lookin extra info first look in buildConfig
Element format = (Element) GSXML.getChildByTagName(info, GSXML.FORMAT_ELEM);
if (format == null)
{
String path = GSPath.appendLink(GSXML.SEARCH_ELEM, GSXML.FORMAT_ELEM);
// Note by xiao: instead of retrieving the first 'format'
// element inside the 'search' element, we are trying to
// find the real format element which has at least one
// 'gsf:template' child element. (extra_info is
// collectionConfig.xml)
//format = (Element) GSXML.getNodeByPath(extra_info, path);
Element search_elem = (Element) GSXML.getChildByTagName(extra_info, GSXML.SEARCH_ELEM);
NodeList format_elems = null;
if (search_elem != null)
{
format_elems = search_elem.getElementsByTagName(GSXML.FORMAT_ELEM);
}
for (int i = 0; i < format_elems.getLength(); i++)
{
format = (Element) format_elems.item(i);
if (format.getElementsByTagName("gsf:template").getLength() != 0)
{
break;
}
}
}//end of if(format==null)
//
if (format != null)
{
this.format_info_map.put(QUERY_SERVICE, this.doc.importNode(format, true));
}
// look for document display format - for documentType
String path = GSPath.appendLink(GSXML.DISPLAY_ELEM, GSXML.FORMAT_ELEM);
Element display_format = (Element) GSXML.getNodeByPath(extra_info, path);
if (display_format != null)
{
// check for docType option.
Element doc_type_opt = GSXML.getNamedElement(display_format, "gsf:option", GSXML.NAME_ATT, "documentType");
if (doc_type_opt != null)
{
String value = doc_type_opt.getAttribute(GSXML.VALUE_ATT);
if (!value.equals(""))
{
this.default_document_type = value;
}
}
}
// Base line for document (might be overriden by sub-classes)
gs_doc = new SimpleDocument(this.doc, this.default_document_type);
return true;
}
/**
* returns a basic description for QUERY_SERVICE. If a subclass provides
* other services they need to provide their own descriptions
*/
protected Element getServiceDescription(String service, String lang, String subset)
{
if (!service.equals(QUERY_SERVICE))
{
return null;
}
Element tq_service = this.doc.createElement(GSXML.SERVICE_ELEM);
tq_service.setAttribute(GSXML.TYPE_ATT, GSXML.SERVICE_TYPE_QUERY);
tq_service.setAttribute(GSXML.NAME_ATT, QUERY_SERVICE);
if (subset == null || subset.equals(GSXML.DISPLAY_TEXT_ELEM + GSXML.LIST_MODIFIER))
{
tq_service.appendChild(GSXML.createDisplayTextElement(this.doc, GSXML.DISPLAY_TEXT_NAME, getServiceName(QUERY_SERVICE, lang)));
tq_service.appendChild(GSXML.createDisplayTextElement(this.doc, GSXML.DISPLAY_TEXT_SUBMIT, getServiceSubmit(QUERY_SERVICE, lang)));
tq_service.appendChild(GSXML.createDisplayTextElement(this.doc, GSXML.DISPLAY_TEXT_DESCRIPTION, getServiceDescription(QUERY_SERVICE, lang)));
}
if (subset == null || subset.equals(GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER))
{
Element param_list = this.doc.createElement(GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
addCustomQueryParams(param_list, lang);
addStandardQueryParams(param_list, lang);
tq_service.appendChild(param_list);
}
return tq_service;
}
// perhaps these should be changed to search down the class hierarchy for
// values - do can just put the info in the resource bundle to use it
/** returns the default name for the TextQuery service */
protected String getServiceName(String service_id, String lang)
{
return getTextString(service_id + ".name", lang);
}
/** returns the default description for the TextQuery service */
protected String getServiceDescription(String service_id, String lang)
{
return getTextString(service_id + ".description", lang);
}
/** returns the default submit button text for the TextQuery service */
protected String getServiceSubmit(String service_id, String lang)
{
return getTextString(service_id + ".submit", lang);
}
/** adds the standard query params into the service description */
protected void addStandardQueryParams(Element param_list, String lang)
{
// this test is not so good. here we are using absence of default index
// to determine whether we have indexes or not. But in other places,
// absence of default index just means to use the first one as default.
if (!default_index.equals(""))
{
createParameter(INDEX_PARAM, param_list, lang);
}
if (does_chunking)
{
createParameter(MAXDOCS_PARAM, param_list, lang);
}
if (does_paging)
{
createParameter(HITS_PER_PAGE_PARAM, param_list, lang);
createParameter(START_PAGE_PARAM, param_list, lang);
}
createParameter(QUERY_PARAM, param_list, lang);
}
/**
* adds any service specific query params into the service default
* implementation: add nothing. subclasses may need to override this to add
* in their specific parameters
*/
protected void addCustomQueryParams(Element param_list, String lang)
{
// default behaviour, do nothing
}
protected void createParameter(String name, Element param_list, String lang)
{
createParameter(name, param_list, lang, null);
}
protected void createParameter(String name, Element param_list, String lang, String default_value)
{
// at this level, not interested in boolean return type
createParameterChain(name, param_list, lang, default_value);
}
/**
* default implementations for the standard parameters plus some other
* common ones index, maxDocs, hitsPerPage, startPage
*/
protected boolean createParameterChain(String name, Element param_list, String lang, String default_value)
{
Element param = null;
String param_default = default_value;
if (name.equals(QUERY_PARAM) || name.equals(RAW_PARAM))
{
param = GSXML.createParameterDescription(this.doc, name, getTextString("param." + name, lang), GSXML.PARAM_TYPE_STRING, param_default, null, null);
param_list.appendChild(param);
return true;
}
else if (name.equals(INDEX_PARAM))
{
// should we make these class fields?
ArrayList index_ids = new ArrayList();
ArrayList index_names = new ArrayList();
getIndexData(index_ids, index_names, lang);
String param_type = GSXML.PARAM_TYPE_ENUM_SINGLE;
if (does_multi_index_search)
{
param_type = GSXML.PARAM_TYPE_ENUM_MULTI;
}
if (param_default == null)
{
param_default = this.default_index;
}
param = GSXML.createParameterDescription2(this.doc, INDEX_PARAM, getTextString("param." + INDEX_PARAM, lang), param_type, param_default, index_ids, index_names);
param_list.appendChild(param);
return true;
}
else if (name.equals(MAXDOCS_PARAM))
{
if (param_default == null)
{
param_default = this.default_max_docs;
}
param = GSXML.createParameterDescription(this.doc, name, getTextString("param." + name, lang), GSXML.PARAM_TYPE_INTEGER, param_default, null, null);
param_list.appendChild(param);
return true;
}
else if (name.equals(HITS_PER_PAGE_PARAM))
{
if (param_default == null)
{
param_default = this.default_hits_per_page;
}
param = GSXML.createParameterDescription(this.doc, name, getTextString("param." + name, lang), GSXML.PARAM_TYPE_INTEGER, param_default, null, null);
param_list.appendChild(param);
return true;
}
else if (name.equals(START_PAGE_PARAM))
{
if (param_default == null)
{
param_default = "1";
}
// start page - set to 1 for the search page
param = GSXML.createParameterDescription(this.doc, START_PAGE_PARAM, "", GSXML.PARAM_TYPE_INVISIBLE, param_default, null, null);
param_list.appendChild(param);
return true;
}
// Get to there then none of the above params matched
// => return false so the chain can continue
return false;
}
/**
* create an element to go into the search results list. A node element has
* the form
*/
protected Element createDocNode(String node_id, String rank)
{
return this.gs_doc.createDocNode(node_id, rank);
}
/**
* returns the document type of the doc that the specified node belongs to.
* should be one of GSXML.DOC_TYPE_SIMPLE, GSXML.DOC_TYPE_PAGED,
* GSXML.DOC_TYPE_HIERARCHY
*/
protected String getDocType(String node_id)
{
return this.gs_doc.getDocType(node_id);
}
/**
* returns the node type of the specified node. should be one of
* GSXML.NODE_TYPE_LEAF, GSXML.NODE_TYPE_INTERNAL, GSXML.NODE_TYPE_ROOT
*/
protected String getNodeType(String node_id, String doc_type)
{
return this.gs_doc.getNodeType(node_id, doc_type);
}
/** returns true if the node has child nodes */
protected boolean hasChildren(String node_id)
{
return this.gs_doc.hasChildren(node_id);
}
/** returns true if the node has a parent */
protected boolean hasParent(String node_id)
{
return this.gs_doc.hasParent(node_id);
}
/**
* get the details about the indexes available must be implemented by
* subclass there must be at least one index
*/
abstract protected void getIndexData(ArrayList index_ids, ArrayList index_names, String lang);
}