/
BaseHtmlProvider.java
270 lines (227 loc) · 10.3 KB
/
BaseHtmlProvider.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
/**
* Copyright 2013 DuraSpace, Inc.
*
* Licensed 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.fcrepo.http.commons.responses;
import static com.google.common.collect.ImmutableList.of;
import static com.google.common.collect.ImmutableMap.builder;
import static javax.ws.rs.core.MediaType.TEXT_HTML;
import static javax.ws.rs.core.MediaType.TEXT_HTML_TYPE;
import static org.fcrepo.kernel.rdf.SerializationUtils.getDatasetSubject;
import static org.fcrepo.kernel.rdf.SerializationUtils.unifyDatasetModel;
import static org.fcrepo.http.commons.responses.RdfSerializationUtils.getFirstValueForPredicate;
import static org.fcrepo.http.commons.responses.RdfSerializationUtils.primaryTypePredicate;
import static org.fcrepo.http.commons.responses.RdfSerializationUtils.setCachingHeaders;
import static org.slf4j.LoggerFactory.getLogger;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.net.URL;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import javax.annotation.PostConstruct;
import javax.jcr.RepositoryException;
import javax.jcr.Session;
import javax.jcr.nodetype.NodeTypeIterator;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.UriInfo;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.ext.Provider;
import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.VelocityEngine;
import org.apache.velocity.context.Context;
import org.apache.velocity.tools.generic.EscapeTool;
import org.apache.velocity.tools.generic.FieldTool;
import org.fcrepo.kernel.RdfLexicon;
import org.fcrepo.http.commons.session.SessionFactory;
import org.slf4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap.Builder;
import com.hp.hpl.jena.graph.Node;
import com.hp.hpl.jena.query.Dataset;
import com.hp.hpl.jena.rdf.model.Model;
/**
* A simple JAX-RS Entity Provider that can accept RDF datasets that represent
* Fedora resources and merge them into templates chosen based on the primary
* node type of the backing JCR node for that Fedora resource.
*
* @author ajs6f
* @date May 19, 2013
*/
@Provider
public class BaseHtmlProvider implements MessageBodyWriter<Dataset> {
@Autowired
SessionFactory sessionFactory;
@javax.ws.rs.core.Context
UriInfo uriInfo;
private static EscapeTool escapeTool = new EscapeTool();
protected VelocityEngine velocity = new VelocityEngine();
/**
* Location in the classpath where Velocity templates are to be found.
*/
public static final String templatesLocation = "/views";
/**
* A map from String names for primary node types to the Velocity templates
* that should be used for those node types.
*/
protected Map<String, Template> templatesMap;
public static final String templateFilenameExtension = ".vsl";
private static final Logger LOGGER = getLogger(BaseHtmlProvider.class);
public static final String velocityPropertiesLocation =
"/velocity.properties";
@PostConstruct
void init() throws IOException, RepositoryException {
LOGGER.trace("Velocity engine initializing...");
final Properties properties = new Properties();
final URL propertiesUrl =
getClass().getResource(velocityPropertiesLocation);
LOGGER.debug("Using Velocity configuration from {}", propertiesUrl);
try (final InputStream propertiesStream = propertiesUrl.openStream()) {
properties.load(propertiesStream);
}
velocity.init(properties);
LOGGER.trace("Velocity engine initialized.");
LOGGER.trace("Assembling a map of node primary types -> templates...");
final Builder<String, Template> templatesMapBuilder = builder();
final Session session = sessionFactory.getSession();
try {
// we search all of the possible node primary types
for (final NodeTypeIterator primaryNodeTypes =
session.getWorkspace().getNodeTypeManager()
.getPrimaryNodeTypes(); primaryNodeTypes.hasNext();) {
final String primaryNodeTypeName =
primaryNodeTypes.nextNodeType().getName();
// for each node primary type, we try to find a template
final String templateLocation =
templatesLocation + "/" +
primaryNodeTypeName.replace(':', '-') +
templateFilenameExtension;
if (velocity.resourceExists(templateLocation)) {
final Template template =
velocity.getTemplate(templateLocation);
template.setName(templateLocation);
LOGGER.debug("Found template: {}", templateLocation);
templatesMapBuilder.put(primaryNodeTypeName, template);
LOGGER.debug("which we will use for nodes with primary type: {}",
primaryNodeTypeName);
} else {
// No HTML representation available for that kind of node
LOGGER.debug("Didn't find template for nodes with primary type: {} in location: {}",
primaryNodeTypeName, templateLocation);
}
}
List<String> otherTemplates =
ImmutableList.of("search:results", "jcr:namespaces",
"jcr:workspaces", "node");
for (String key : otherTemplates) {
final Template template =
velocity.getTemplate(templatesLocation + "/" +
key.replace(':', '-') +
templateFilenameExtension);
templatesMapBuilder.put(key, template);
}
templatesMap = templatesMapBuilder.build();
} finally {
session.logout();
}
LOGGER.trace("Assembled template map.");
LOGGER.trace("HtmlProvider initialization complete.");
}
@Override
public void writeTo(final Dataset rdf, final Class<?> type,
final Type genericType, final Annotation[] annotations,
final MediaType mediaType,
final MultivaluedMap<String, Object> httpHeaders,
final OutputStream entityStream) throws IOException,
WebApplicationException {
LOGGER.debug("Writing an HTML response for: {}", rdf);
LOGGER.trace("Attempting to discover our subject");
Node subject = getDatasetSubject(rdf);
// add standard headers
httpHeaders.put("Content-type", of((Object) TEXT_HTML));
setCachingHeaders(httpHeaders, rdf);
final Template nodeTypeTemplate =
getTemplate(rdf, subject, annotations);
final Context context = getContext(rdf, subject);
// the contract of MessageBodyWriter<T> is _not_ to close the stream
// after writing to it
final Writer outWriter = new OutputStreamWriter(entityStream);
nodeTypeTemplate.merge(context, outWriter);
outWriter.flush();
}
protected Context getContext(Dataset rdf, Node subject) {
final FieldTool fieldTool = new FieldTool();
final Context context = new VelocityContext();
context.put("rdfLexicon", fieldTool.in(RdfLexicon.class));
context.put("helpers", ViewHelpers.getInstance());
context.put("esc", escapeTool);
context.put("rdf", rdf.asDatasetGraph());
Model model = unifyDatasetModel(rdf);
context.put("model", model);
context.put("subjects", model.listSubjects());
context.put("nodeany", Node.ANY);
context.put("topic", subject);
context.put("uriInfo", uriInfo);
return context;
}
private Template getTemplate(final Dataset rdf, final Node subject,
final Annotation[] annotations) {
Template template = null;
for (Annotation a : annotations) {
if (a instanceof HtmlTemplate) {
final String value = ((HtmlTemplate) a).value();
LOGGER.debug("Found an HtmlTemplate annotation {}", value);
template = templatesMap.get(value);
break;
}
}
if (template == null) {
LOGGER.trace("Attempting to discover the primary type of the node for the resource in question...");
final String nodeType =
getFirstValueForPredicate(rdf, subject,
primaryTypePredicate);
LOGGER.debug("Found primary node type: {}", nodeType);
template = templatesMap.get(nodeType);
}
if (template == null) {
LOGGER.debug("Falling back on default node template");
template = templatesMap.get("node");
}
LOGGER.debug("Choosing template: {}", template.getName());
return template;
}
@Override
public boolean isWriteable(final Class<?> type, final Type genericType,
final Annotation[] annotations, final MediaType mediaType) {
return mediaType.equals(TEXT_HTML_TYPE) &&
(Dataset.class.isAssignableFrom(type) || Dataset.class
.isAssignableFrom(genericType.getClass()));
}
@Override
public long getSize(final Dataset t, final Class<?> type,
final Type genericType, final Annotation[] annotations,
final MediaType mediaType) {
// we don't know in advance how large the result might be
return -1;
}
}