|
1
9
10 package org.jboss.portal.format.template;
11
12 import java.io.Writer  ;
13 import java.util.Iterator ;
14 import java.util.LinkedList ;
15 import java.util.Set ;
16
17 import javassist.CannotCompileException;
18 import javassist.ClassPool;
19 import javassist.CtClass;
20 import javassist.CtConstructor;
21 import javassist.CtField;
22 import javassist.CtMethod;
23 import javassist.CtNewMethod;
24 import javassist.LoaderClassPath;
25 import javassist.Modifier;
26 import javassist.NotFoundException;
27
28 import org.apache.log4j.Logger;
29 import org.dom4j.Document;
30 import org.dom4j.Element;
31 import org.dom4j.Node;
32 import org.dom4j.Text;
33
34
37 public class TemplateBuilder
38 {
39
40 private static final String CONTEXT = Context.class.getName();
41 private static final String ITERATOR = Iterator .class.getName();
42
43 private final ClassPool pool;
44 private final Element node;
45 private final int index;
46 private final Logger log;
47 private final Set propertyNames;
48 private CtClass cc;
49
50 public static int classNameCounter = 0;
51
52 public TemplateBuilder(Document doc, Set propertyNames)
53 {
54 this(doc.getRootElement(), propertyNames);
55 }
56
57 public TemplateBuilder(Element node, Set propertyNames)
58 {
59 this(new ClassPool(null), node, propertyNames);
60 pool.appendClassPath(new LoaderClassPath(Thread.currentThread().getContextClassLoader()));
61 }
62
63 public TemplateBuilder(ClassPool pool, Document doc, Set names)
64 {
65 this(pool, doc.getRootElement(), names);
66 }
67
68 public TemplateBuilder(ClassPool pool, Element node, Set names)
69 {
70 this.index = classNameCounter++;
71 this.pool = pool;
72 this.node = node;
73 this.propertyNames = names;
74 this.log = Logger.getLogger(getClass() + "." + index);
75 }
76
77 public CtClass getGeneratedClass()
78 {
79 return cc;
80 }
81
82 public void build() throws BuildException
83 {
84 try
85 {
86 cc = pool.makeClass("org.jboss.nukes.common.template.Generated" + index);
87 cc.setSuperclass(pool.get(Template.class.getName()));
88 cc.setModifiers(Modifier.PUBLIC);
89
90 addConstructor();
91 implementRender();
92 }
93 catch(CannotCompileException e)
94 {
95 throw new BuildException("Unexpected error, cannot build template", e);
96 }
97 catch(NotFoundException e)
98 {
99 throw new BuildException("Unexpected error, cannot build template", e);
100 }
101 }
102
103 private void addConstructor() throws CannotCompileException, NotFoundException
104 {
105 CtConstructor ctor = new CtConstructor(new CtClass[]{pool.get(CONTEXT)}, cc);
106 ctor.setBody("{ super($1); }");
107 cc.addConstructor(ctor);
108 log.debug("Added constructor on template " + cc.getName());
109 }
110
111 private void implementRender() throws CannotCompileException, NotFoundException
112 {
113 LinkedList stack = new LinkedList ();
114 stack.add("");
115 StringBuffer buffer = new StringBuffer ();
116 buffer.append("public void render(").append(Context.class.getName()).append(" ctx, ").append(Writer .class.getName()).append(" writer)\n").
117 append("{\n").
118 append(" ").append(CONTEXT).append(" ctx_ = $1;\n");
119 generateRender(stack, buffer, " ", node);
120 buffer.append("}\n");
121 String code = buffer.toString();
122 CtMethod method = CtNewMethod.make(code, cc);
123 cc.addMethod(method);
124 CtField gc = new CtField(pool.get(String .class.getName()), "_generated_code", cc);
125 gc.setModifiers(Modifier.PUBLIC | Modifier.STATIC);
126 CtField.Initializer initializer = CtField.Initializer.constant(code);
127 cc.addField(gc, initializer);
128 log.debug("Created render method on template " + cc.getName() + " with body " + code);
129 }
130
131 private void generateRender(LinkedList stack, StringBuffer buffer, String indent, Element node)
132 {
133 buffer.append(indent).append("String s_").append(stack.size()).append(" = null;\n");
134 for (Iterator i = node.content().iterator();i.hasNext();)
135 {
136 Node item = (Node)i.next();
137 if (item instanceof Text)
138 {
139 String text = item.getText().trim();
140 text = org.jboss.portal.common.util.Tools.replace(text, "\n", "\\n");
141 text = org.jboss.portal.common.util.Tools.replace(text, "\"", "\\\"");
142 buffer.append(indent).append("$2.write(\"").append(text).append("\");\n");
143 }
144 else if (item instanceof Element)
145 {
146 Element elt = (Element)item;
147 if ("loop".equals(elt.getName()))
148 {
149 String name = elt.attributeValue("name");
150 String iterator = "it_" + name;
151 String context = "ctx_" + name;
152 buffer.append(indent).append("for (").append(ITERATOR).append(" ").append(iterator).append(" = ").append("ctx_").append(stack.getLast()).append(".childIterator(\"").append(name).append("\");").
153 append(iterator).append(".hasNext();").
154 append(")\n").
155 append(indent).append("{\n").
156 append(indent).append(" ").append(CONTEXT).append(" ").append(context).append(" = (").append(CONTEXT).append(")").append(iterator).append(".next();\n");
157 stack.add(name);
158 generateRender(stack, buffer, indent + " ", elt.element("node"));
159 stack.removeLast();
160 buffer.append(indent).append("}\n");
161 }
162 else if ("ref".equals(elt.getName()))
163 {
164 String name = elt.attributeValue("name");
165 int depth = Integer.parseInt(elt.attributeValue("depth"));
166 String target = null;
167 if (depth == 0)
168 {
169 target = propertyNames.contains(name) ? "$0.local" : "ctx_";
170 }
171 else
172 {
173 target = "ctx_" + (String )stack.get(depth);
174 }
175 if (target != null)
176 {
177 buffer.append(indent).append("s_").append(stack.size()).append(" = (java.lang.String)").append(target).append(".get(\"").append(name).append("\");\n").
178 append(indent).append("if (s_").append(stack.size()).append(" != null)\n").
179 append(indent).append("{\n").
180 append(indent).append(" $2.write(s_").append(stack.size()).append(");\n").
181 append(indent).append("}\n").
182 append(indent).append("else if (log.isDebugEnabled())\n").
183 append(indent).append("{\n").
184 append(indent).append(" log.debug(\"field ").append(name).append(" is null\");\n").
185 append(indent).append("}\n");
186 }
187 else
188 {
189 }
191 }
192 }
193 }
194 }
195
196 }
197 |
Popular Tags |
Java API By Example, From Geeks To Geeks.