Source Code Cross Referenced for BnfTask.java in  » Database-ORM » transformica-2.3.0 » biz » hammurapi » transformica » bnf » Java Source Code / Java DocumentationJava Source Code and Java Documentation

001:        /*
002:         * transformica 2
003:         * Code generator 
004:         * Copyright (C) 2004  Hammurapi Group
005:         *
006:         * This program is free software; you can redistribute it and/or
007:         * modify it under the terms of the GNU Lesser General Public
008:         * License as published by the Free Software Foundation; either
009:         * version 2 of the License, or (at your option) any later version.
010:         *
011:         * This program is distributed in the hope that it will be useful,
012:         * but WITHOUT ANY WARRANTY; without even the implied warranty of
013:         * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014:         * Lesser General Public License for more details.
015:         *
016:         * You should have received a copy of the GNU Lesser General Public
017:         * License along with this library; if not, write to the Free Software
018:         * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
019:         *
020:         * URL: http://www.pavelvlasov.com/pv/content/menu.show@id=products.transformica.html
021:         * e-Mail: support@hammurapi.biz
022:         */
023:        package biz.hammurapi.transformica.bnf;
024:
025:        import java.io.File;
026:        import java.io.FileNotFoundException;
027:        import java.io.FileReader;
028:
029:        import org.apache.tools.ant.BuildException;
030:        import org.apache.tools.ant.types.Path;
031:        import org.mesopotamia.MesopotamiaException;
032:        import org.mesopotamia.util.BnfModel;
033:
034:        import biz.hammurapi.transformica.TransformSession;
035:        import biz.hammurapi.transformica.TransformTask;
036:        import biz.hammurapi.util.Visitable;
037:
038:        /**
039:         * Transforms BNF file into multiple files. Transformations are defined by nested channel elements.
040:         * Velocity template engine is used for code generation. Current bnf element (model or rule definition) is accessible through 'element' context object, 
041:         * 'session' context object of type biz.hammurapi.transformica.TransformSession gives access to current Ant project and provides
042:         * methods to include other templates or channels and to store information.   
043:         * <section name="Example" suppress-description="yes">
044:         <pre>
045:         &lt;taskdef name="bnftransform" classname="biz.hammurapi.transformica.bnf.BnfTask"&gt;<br/>
046:         <tab/>&lt;classpath&gt;<br/>
047:         <tab/><tab/>&lt;fileset dir="lib" includes="*.jar"/&gt;<br/>
048:         <tab/>&lt;/classpath&gt;<br/>
049:         &lt;/taskdef&gt;<br/>
050:         <br/>
051:         &lt;bnftransform file="java.bnf"&gt;<br/>
052:         <tab/>&lt;channel <br/>
053:         <tab/><tab/>outputDir="generated"<br/> 
054:         <tab/><tab/>type="RuleDefinition" <br/>
055:         <tab/><tab/>template="templates/LanguageElement.java"<br/>
056:         <tab/><tab/>fileNameTemplate='$${element.name}.java'	<br/>
057:         <tab/>&gt;<br/>
058:         <tab/>&lt;/channel&gt;<br/>
059:         &lt;/bnftransform&gt;<br/>
060:         </pre></section>
061:         * @ant.element name="jseltransform"
062:         * @author Pavel Vlasov
063:         */
064:        public class BnfTask extends TransformTask {
065:
066:            /**
067:             * Defines transformation channel.
068:             * @ant.required
069:             * @return
070:             */
071:            public BnfChannel createBnfChannel() {
072:                BnfChannel ret = new BnfChannel(session);
073:                channels.add(ret);
074:                return ret;
075:            }
076:
077:            protected Visitable getModel(TransformSession session)
078:                    throws BuildException {
079:                try {
080:                    return new BnfModel(new FileReader(file),
081:                            className == null ? null : Class.forName(className));
082:                } catch (MesopotamiaException e) {
083:                    throw new BuildException("Can't load file: "
084:                            + file.getAbsolutePath() + ", " + e, e);
085:                } catch (FileNotFoundException e) {
086:                    throw new BuildException("Can't load file: "
087:                            + file.getAbsolutePath() + ", " + e, e);
088:                } catch (ClassNotFoundException e) {
089:                    throw new BuildException("Can't load class: " + className
090:                            + ", " + e, e);
091:                }
092:            }
093:
094:            /**
095:             * Classpath for loading classes
096:             * @ant:non-required 
097:             */
098:            private Path classPath;
099:            private File file;
100:            private String className;
101:
102:            public void setClassPath(Path classPath) {
103:                if (this .classPath == null) {
104:                    this .classPath = classPath;
105:                } else {
106:                    this .classPath.append(classPath);
107:                }
108:            }
109:
110:            /**
111:             * Maybe creates a nested classpath element.
112:             * @ant:non-required
113:             */
114:            public Path createClasspath() {
115:                if (classPath == null) {
116:                    classPath = new Path(project);
117:                }
118:                return classPath.createPath();
119:            }
120:
121:            /**
122:             * Source file.
123:             * @ant.required
124:             */
125:            public void setFile(File file) {
126:                this .file = file;
127:            }
128:
129:            /**
130:             * Token types class to validate token names
131:             * @param className
132:             * @ant.non-required
133:             */
134:            public void setTokenTypesClass(String className) {
135:                this.className = className;
136:            }
137:        }