source: trunk/gsdl3/src/java/org/greenstone/gsdl3/action/BrowseAction.java@ 4080

Last change on this file since 4080 was 4080, checked in by kjdon, 21 years ago

what metadata to ask for is now dynamically determined from the xslt using a method from GSXSLT.java
  • Property svn:keywords set to Author Date Id Revision
File size: 12.8 KB
Line 
1package org.greenstone.gsdl3.action;
2
3import org.greenstone.gsdl3.core.ModuleInterface;
4import org.greenstone.gsdl3.util.*;
5// XML classes
6import org.w3c.dom.Node;
7import org.w3c.dom.NodeList;
8import org.w3c.dom.Document;
9import org.w3c.dom.Element;
10
11import java.util.HashMap;
12import java.util.Vector;
13import java.io.File;
14
15/** action for classifier browsing */
16public class BrowseAction extends Action {
17
18 public static final String CLASSIFIER_ARG = "cl";
19
20 /* add the action specific args to the cgi param list
21 */
22 public void addCGIParams() {
23 cgi_.addStaticParam(CLASSIFIER_ARG);
24 }
25
26 /** process the request */
27 public Element process (Element message) {
28
29 // get the request - assume only one
30 Element request = (Element)GSXML.getChildByTagName(message, GSXML.REQUEST_ELEM);
31
32 // create the return page tree
33 Element page = doc_.createElement(GSXML.PAGE_ELEM);
34 page.setAttribute(GSXML.LANG_ATT, request.getAttribute(GSXML.LANG_ATT));
35 // add the lang stuff from message
36 page.appendChild(doc_.importNode(GSXML.getChildByTagName(message, GSXML.DISPLAY_ELEM), true));
37 // add the system stuff from message
38 page.appendChild(doc_.importNode(GSXML.getChildByTagName(message, GSXML.CONFIGURATION_ELEM), true));
39
40 return classifierBrowse(page, request);
41
42 }
43
44
45 protected Element classifierBrowse(Element page, Element request) {
46
47 // check that the stylesheet is present - cant output a page without one. we may adapt this to use unknownquery stylesheet? - or ask for one from the MR
48 String stylesheet = GSFile.stylesheetFile(config_, "classifier.xsl");
49 if (stylesheet==null) {
50 System.err.println("BrowseAction Error: classifier stylesheet not found!");
51 return null;
52 }
53 Document style_doc = converter_.getDOM(new File(stylesheet));
54
55 // the first part of the data for the page is the cgi-params
56 Element page_request = GSXML.duplicateWithNewName(doc_, request, GSXML.PAGE_REQUEST_ELEM, true);
57 page.appendChild(page_request);
58
59 // extract the params from the cgi-request, and check that we have a coll specified
60 Element cgi_paramList = (Element)GSXML.getChildByTagName(request, GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
61 HashMap params = GSXML.extractParams(cgi_paramList, false);
62
63 String service_name = (String)params.get(GSCGI.SERVICE_ARG);
64 String collection = (String)params.get(GSCGI.COLLECTION_ARG);
65 if (collection == null || collection.equals("")) {
66 System.err.println("BrowseAction Error:classifierbrowse, need to specify a collection!");
67 return null;
68
69 }
70
71 // the main response for the page is in a pageResponse element
72 Element page_response = doc_.createElement(GSXML.PAGE_RESPONSE_ELEM);
73 page.appendChild(page_response);
74
75 String lang = request.getAttribute(GSXML.LANG_ATT);
76 String to = GSPath.appendLink(collection, service_name);
77
78 // the second part of the page is the service description
79 // for now get this again from the service.
80 // this will probably need to be cached somehow later on.
81
82 Element info_message = doc_.createElement(GSXML.MESSAGE_ELEM);
83 Element info_request = GSXML.createBasicRequest(doc_, GSXML.REQUEST_TYPE_DESCRIBE, to, lang);
84 info_message.appendChild(info_request);
85
86 // also get the collection description (should be just metadata?) for the http address stuff
87 Element coll_info_request = GSXML.createBasicRequest(doc_, GSXML.REQUEST_TYPE_DESCRIBE, collection, lang);
88 info_message.appendChild(coll_info_request);
89 // also get the format stuff now if there is some
90 Element format_request = GSXML.createBasicRequest(doc_, GSXML.REQUEST_TYPE_FORMAT, to, lang);
91 info_message.appendChild(format_request);
92 // process the requests
93
94 Element info_response = (Element) mr_.process(info_message);
95
96 // the three responses
97 NodeList responses = info_response.getElementsByTagName(GSXML.RESPONSE_ELEM);
98 Element service_response = (Element)responses.item(0);
99 Element coll_response = (Element)responses.item(1);
100 Element format_response = (Element)responses.item(2);
101
102 Element service_description = (Element)GSXML.getChildByTagName(service_response, GSXML.SERVICE_ELEM);
103 page_response.appendChild(doc_.importNode(service_description, true));
104
105 Element coll_description = (Element)GSXML.getChildByTagName(coll_response, GSXML.COLLECTION_ELEM);
106 page_response.appendChild(doc_.importNode(coll_description, true));
107
108
109 // get the node that the user has clicked on
110 String classifier_node = (String)params.get(CLASSIFIER_ARG);
111
112 // if the node is not defined, return the page that we have so far
113 if (classifier_node ==null || classifier_node.equals("")) {
114 GSXSLT.absoluteIncludePaths(style_doc, config_);
115 return (Element)transformer_.transform(style_doc, page);
116 }
117
118 // create a classifier elem to return in the page
119 Element page_classifier = doc_.createElement(GSXML.CLASSIFIER_ELEM);
120 page_response.appendChild(page_classifier);
121
122 // the id of the classifier is the top id of the selected node
123 String top_id = OID.getTop(classifier_node);
124 page_classifier.setAttribute(GSXML.NAME_ATT, top_id);
125
126 // add in the format info into the stylesheet
127 System.out.println("transforming format:"+converter_.getString(format_response));
128 Element format_elem = getAndTransformFormat(format_response);
129 System.out.println("transformed format:"+converter_.getString(format_elem));
130 if (format_elem != null) {
131 Element this_format = GSXML.getNamedElement(format_elem, GSXML.CLASSIFIER_ELEM, GSXML.NAME_ATT, top_id);
132 if (this_format != null) {
133 GSXSLT.mergeStylesheets(style_doc, this_format);
134 }
135 }
136
137 // get the browse structure for the selected node
138 Element classify_message = doc_.createElement(GSXML.MESSAGE_ELEM);
139 Element classify_request = doc_.createElement(GSXML.REQUEST_ELEM);
140 classify_message.appendChild(classify_request);
141
142 classify_request.setAttribute(GSXML.TYPE_ATT, GSXML.REQUEST_TYPE_PROCESS);
143 classify_request.setAttribute(GSXML.TO_ATT, to);
144 classify_request.setAttribute(GSXML.LANG_ATT, lang);
145
146
147 //Create a parameter list to specify the required structure information
148 // for now, always get ancestors and children
149 Element param_list = doc_.createElement(GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
150 classify_request.appendChild(param_list);
151 Element param = doc_.createElement(GSXML.PARAM_ELEM);
152 param_list.appendChild(param);
153 param.setAttribute(GSXML.NAME_ATT, "structure");
154 param.setAttribute(GSXML.VALUE_ATT, "ancestors");
155 param = doc_.createElement(GSXML.PARAM_ELEM);
156 param_list.appendChild(param);
157 param.setAttribute(GSXML.NAME_ATT, "structure");
158 param.setAttribute(GSXML.VALUE_ATT, "children");
159
160 // put the classifier node into a classifier node list
161 Element classifier_list = doc_.createElement(GSXML.CLASS_NODE_ELEM+GSXML.LIST_MODIFIER);
162 Element classifier = doc_.createElement(GSXML.CLASS_NODE_ELEM);
163 classifier.setAttribute(GSXML.NODE_ID_ATT, classifier_node);
164 classifier_list.appendChild(classifier);
165 classify_request.appendChild(classifier_list);
166
167 // process the request
168 Element classify_response = (Element)mr_.process(classify_message);
169 // get the structure element
170 String path = GSPath.appendLink(GSXML.RESPONSE_ELEM, GSXML.CLASS_NODE_ELEM+GSXML.LIST_MODIFIER);
171 path = GSPath.appendLink(path, GSXML.CLASS_NODE_ELEM);
172 path = GSPath.appendLink(path, GSXML.NODE_STRUCTURE_ELEM);
173 // assume that we always get back the top level CL1 node - want to throw this away
174 path = GSPath.appendLink(path, GSXML.CLASS_NODE_ELEM);
175 Element cl_structure = (Element)GSXML.getNodeByPath(classify_response,
176 path);
177 if (cl_structure ==null) {
178 System.err.println("BrowseAction: classifier structure request returned no structure");
179
180 // return the page so far
181 GSXSLT.absoluteIncludePaths(style_doc, config_);
182 return (Element)transformer_.transform(style_doc, page);
183 }
184
185 // add the classifier nodes from the structure request into teh page_classifier
186 NodeList cl_nodes = cl_structure.getChildNodes();
187 for (int i=0; i<cl_nodes.getLength(); i++) {
188 Node n = cl_nodes.item(i);
189 if (n.getNodeType() == Node.TEXT_NODE) {
190 // ignore
191 continue;
192 }
193 page_classifier.appendChild(doc_.importNode(n, true));
194 }
195
196
197 // get the metadata for each classifier node,
198 // then for each document node
199
200 Element metadata_message = doc_.createElement(GSXML.MESSAGE_ELEM);
201
202 boolean did_classifier = false;
203 boolean did_documents = false;
204
205
206 // if there are classifier nodes
207 // create a metadata request for the classifier, and add it to
208 // the the message
209 cl_nodes = page_classifier.getElementsByTagName(GSXML.CLASS_NODE_ELEM);
210
211 if (cl_nodes.getLength() > 0) {
212 did_classifier = true;
213 Element cl_meta_request = doc_.createElement(GSXML.REQUEST_ELEM);
214 metadata_message.appendChild(cl_meta_request);
215 cl_meta_request.setAttribute(GSXML.TO_ATT, to+"MetadataRetrieve");
216 cl_meta_request.setAttribute(GSXML.TYPE_ATT, GSXML.REQUEST_TYPE_PROCESS);
217 cl_meta_request.setAttribute(GSXML.LANG_ATT, lang);
218
219 Element new_cl_nodes_list = doc_.createElement(GSXML.CLASS_NODE_ELEM+GSXML.LIST_MODIFIER);
220 cl_meta_request.appendChild(new_cl_nodes_list);
221
222 for (int c=0; c<cl_nodes.getLength(); c++) {
223
224 Element cl = doc_.createElement(GSXML.CLASS_NODE_ELEM);
225 cl.setAttribute(GSXML.NODE_ID_ATT, ((Element)cl_nodes.item(c)).getAttribute(GSXML.NODE_ID_ATT));
226 new_cl_nodes_list.appendChild(cl);
227 }
228
229 // create and add in the param list
230 Vector classifier_metadata = GSXSLT.extractWantedMetadata(style_doc, GSXML.CLASS_NODE_ELEM);
231 if (classifier_metadata.isEmpty()) {
232 System.err.println("BrowseAction: no classifier metadata specified!!");
233 did_classifier = false;
234 metadata_message.removeChild(cl_meta_request);
235 } else {
236 Element meta_param_list = GSXML.createMetadataParamList(doc_, classifier_metadata);
237 cl_meta_request.appendChild(meta_param_list);
238 }
239
240 }
241
242 // if there are document nodes in the classification (happens
243 // sometimes), create a second request for document metadata and
244 // append to the message
245 NodeList doc_nodes = page_classifier.getElementsByTagName(GSXML.DOC_NODE_ELEM);
246 if (doc_nodes.getLength() > 0) {
247 did_documents = true;
248 Element doc_meta_request = doc_.createElement(GSXML.REQUEST_ELEM);
249 metadata_message.appendChild(doc_meta_request);
250 doc_meta_request.setAttribute(GSXML.TO_ATT, GSPath.appendLink(collection, "DocumentMetadataRetrieve"));
251 doc_meta_request.setAttribute(GSXML.TYPE_ATT, GSXML.REQUEST_TYPE_PROCESS);
252 doc_meta_request.setAttribute(GSXML.LANG_ATT, lang);
253
254 Element doc_list = doc_.createElement(GSXML.DOC_NODE_ELEM+GSXML.LIST_MODIFIER);
255 doc_meta_request.appendChild(doc_list);
256
257 for (int c=0; c<doc_nodes.getLength(); c++) {
258
259 Element d = doc_.createElement(GSXML.DOC_NODE_ELEM);
260 d.setAttribute(GSXML.NODE_ID_ATT, ((Element)doc_nodes.item(c)).getAttribute(GSXML.NODE_ID_ATT));
261 doc_list.appendChild(d);
262 }
263
264 // create and add in the param list
265 Vector doc_metadata = GSXSLT.extractWantedMetadata(style_doc, GSXML.DOC_NODE_ELEM);
266 if (doc_metadata.isEmpty()) {
267 System.err.println("BrowseAction: no document metadata specified!!");
268 did_documents = false;
269 metadata_message.removeChild(doc_meta_request);
270 } else {
271 Element meta_param_list = GSXML.createMetadataParamList(doc_, doc_metadata);
272 doc_meta_request.appendChild(meta_param_list);
273 }
274
275
276 }
277
278 // process the metadata requests
279 Element metadata_response = (Element)mr_.process(metadata_message);
280 if (did_classifier) {
281 // the classifier one will be the first response
282 // add the metadata lists for each node back into the
283 // page_classifier nodes
284 path = GSPath.appendLink(GSXML.RESPONSE_ELEM,
285 GSXML.CLASS_NODE_ELEM+GSXML.LIST_MODIFIER);
286 NodeList meta_response_cls = GSXML.getNodeByPath(metadata_response, path).getChildNodes();
287 for (int i = 0; i < cl_nodes.getLength(); i++) {
288 GSXML.mergeMetadataLists(cl_nodes.item(i), meta_response_cls.item(i));
289 }
290 }
291 if (did_documents) {
292 NodeList meta_response_docs = null;
293 if (!did_classifier) {
294 // its the first response
295 path = GSPath.appendLink(GSXML.RESPONSE_ELEM,
296 GSXML.DOC_NODE_ELEM+GSXML.LIST_MODIFIER);
297 meta_response_docs = GSXML.getNodeByPath(metadata_response, path).getChildNodes();
298 } else { // its the second response
299 meta_response_docs = GSXML.getChildByTagName(metadata_response.getElementsByTagName(GSXML.RESPONSE_ELEM).item(1), GSXML.DOC_NODE_ELEM+GSXML.LIST_MODIFIER).getChildNodes();
300 }
301
302 for (int i = 0; i < doc_nodes.getLength(); i++) {
303 GSXML.mergeMetadataLists(doc_nodes.item(i), meta_response_docs.item(i));
304 }
305 }
306
307
308 //System.out.println("(BrowseAction) Page:\n" + converter_.getPrettyString(page));
309
310 // transform the page
311 GSXSLT.absoluteIncludePaths(style_doc, config_);
312 return (Element)transformer_.transform(style_doc, page);
313 }
314
315 protected Element unknownBrowse(Element page, Element request, String browse_type) {
316 System.err.println("BrowseAction Error: unknown browse subtype: "+browse_type);
317 return null;
318 }
319}
320
321
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