Support for compilation on the server (much like JSP)

README.markdown

@@ -18,6 +18,26 @@ from the command prompt:
 ####command line options:  
 >    __--bare__   - compile the javascript without top-level function safety wrapper.  
 
+####In a Web Application:
+Add the following filter in your web.xml:
+
+<pre>
+	&lt;filter&gt;
+		&lt;filter-name&gt;jcoffeescript&lt;/filter-name&gt;
+		&lt;filter-class&gt;org.jcoffeescript.web.CoffeeScriptFilter&lt;/filter-class&gt;
+	&lt;/filter&gt;
+	&lt;filter-mapping&gt;
+		&lt;filter-name&gt;jcoffeescript&lt;/filter-name&gt;
+		&lt;url-pattern&gt;*.js&lt;/url-pattern&gt;
+	&lt;/filter-mapping&gt;
+</pre>
+
+Write your CoffeeScript files inside:
+> /WEB-INF/coffee
+
+and access from the server using the following URL:
+> http://&lt;your host&gt;/&lt;your context&gt;/js/&lt;coffeescript file name&gt;.js
+
 ####From java:
 >    String javascript = new org.jcoffeescript.JCoffeeScriptCompiler().compile("a = 1");
 

build.xml

@@ -28,11 +28,17 @@
     <import file="${basedir}/conf/build/build-jar.xml"/>
 
     <target name="dependencies">
-        <path id="compile.classpath">
+        <path id="inline.classpath">
             <fileset dir="${basedir}/lib">
                 <include name="js.jar"/>
             </fileset>
         </path>
+        <path id="compile.classpath">
+            <path refid="inline.classpath"/>
+            <fileset dir="${basedir}/lib">
+                <include name="servlet-api-2.5.jar"/>
+            </fileset>
+        </path>
         <path id="runtime.classpath">
         <fileset dir="${basedir}/lib">
             <include name="js.jar"/>
@@ -44,6 +50,11 @@
             <fileset dir="${basedir}/lib">
                 <include name="hamcrest-all-1.3RC0.jar"/>
                 <include name="junit-dep-4.8.2.jar"/>
+                <include name="commons-httpclient-3.1.jar"/>
+                <include name="commons-codec-1.4.jar"/>
+                <include name="commons-logging-1.1.1.jar"/>
+                <include name="jetty-*.jar"/>
+
             </fileset>
         </path>
     </target>

conf/build/build-jar.xml

@@ -19,7 +19,7 @@
 <project>
     <target name="jar" depends="test">
         <mkdir dir="${basedir}/target/dist"/>
-        <pathtofileset name="jars" pathrefid="compile.classpath" dir="${basedir}/lib"/>
+        <pathtofileset name="jars" pathrefid="inline.classpath" dir="${basedir}/lib"/>
 
         <jar destfile="${basedir}/target/dist/${artifact.name}.jar">
             <manifest><attribute name="Main-Class" value="org.jcoffeescript.Main"/></manifest>

src/main/java/org/jcoffeescript/web/Binary.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2011 Leonardo Verissimo
+ *
+ * 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.jcoffeescript.web;
+
+import java.io.File;
+import java.net.URL;
+
+/*default*/ class Binary {
+
+	private String content;
+	private long lastModified;
+
+	public Binary(URL coffeeURL, String content) {
+		this.lastModified = lastModified(coffeeURL);
+		this.content = content;
+	}
+
+	public boolean isOlderThan(URL coffeeURL) {
+		return this.lastModified < lastModified(coffeeURL);
+	}
+
+	public String getContent() {
+		return content;
+	}
+
+	public long getLastModified() {
+		return lastModified;
+	}
+
+	private long lastModified(URL coffeeURL) {
+		File file = new File(coffeeURL.getFile());
+		// when resource is inside WAR, file doesn't exist and
+		// lastModified equals zero
+		return file.lastModified();
+	}
+}

src/main/java/org/jcoffeescript/web/CoffeeScriptFilter.java

@@ -0,0 +1,178 @@
+package org.jcoffeescript.web;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.net.URL;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.jcoffeescript.JCoffeeScriptCompileException;
+import org.jcoffeescript.JCoffeeScriptCompiler;
+
+public class CoffeeScriptFilter implements Filter {
+
+	private static final String DEFAULT_JS_PREFIX = "/js";
+	private static final String DEFAULT_COFFEE_PREFIX = "/WEB-INF/coffee";
+	private static final int BUFFER_SIZE = 4096;
+	private static final int MAX_COMPILED_JS = 100;
+
+	private String javascriptResourcePrefix;
+	private String coffeescriptFilenamePrefix;
+
+	private long startupTime = new java.util.Date().getTime() / 1000 * 1000;
+
+	@SuppressWarnings("serial")
+	@Override
+	public void init(FilterConfig config) throws ServletException {
+		// prefixes
+		String jsPrefix = config.getInitParameter("javascriptResourcePrefix");
+		if (jsPrefix == null || jsPrefix.equals("")) {
+			jsPrefix = DEFAULT_JS_PREFIX;
+		}
+		this.javascriptResourcePrefix = jsPrefix;
+
+		String csPrefix = config.getInitParameter("coffeescriptFilenamePrefix");
+		if (csPrefix == null || csPrefix.equals("")) {
+			csPrefix = DEFAULT_COFFEE_PREFIX;
+		}
+		this.coffeescriptFilenamePrefix = csPrefix;
+
+		// coffeescript compiler
+		JCoffeeScriptCompiler compiler = new JCoffeeScriptCompiler();
+		config.getServletContext().setAttribute("compiler", compiler);
+
+		// hashmap
+		LinkedHashMap<String, Binary> previousBinaries = new LinkedHashMap<String, Binary>() {
+
+			@Override
+			protected boolean removeEldestEntry(Entry<String, Binary> eldest) {
+				return size() > MAX_COMPILED_JS;
+			}
+		};
+		config.getServletContext().setAttribute("previousBinaries", Collections.synchronizedMap(previousBinaries));
+	}
+
+
+	@Override
+	public void destroy() {
+	}
+
+	@SuppressWarnings("unchecked")
+	@Override
+	public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain)
+			throws IOException, ServletException {
+
+		HttpServletRequest request = (HttpServletRequest) req;
+		HttpServletResponse response = (HttpServletResponse) resp;
+		ServletContext servletContext = request.getSession().getServletContext();
+
+		JCoffeeScriptCompiler compiler = (JCoffeeScriptCompiler) servletContext.getAttribute("compiler");
+		Map<String, Binary> previousBinaries = (Map<String, Binary>) servletContext.getAttribute("previousBinaries");
+
+
+		String javascriptURI = getJavascriptURI(request);
+		String coffeeFilename = discoverCoffeeFilename(javascriptURI);
+		if (coffeeFilename == null) {
+			// it's not javascript
+			chain.doFilter(req, resp);
+			return;
+		}
+
+		URL coffeeURL = servletContext.getResource(coffeeFilename);
+
+		if (coffeeURL == null) {
+			// static javascript or coffe filename was deleted
+			previousBinaries.remove(coffeeFilename);
+			chain.doFilter(req, resp);
+			return;
+		}
+
+		Binary binary;
+		if ((binary = previousBinaries.get(coffeeFilename)) == null
+				|| binary.isOlderThan(coffeeURL)) {
+
+			InputStream coffeeStream = coffeeURL.openStream();
+			String source = getContent(coffeeStream);
+
+			try {
+				synchronized (compiler) {
+					binary = new Binary(coffeeURL, compiler.compile(source));
+				}
+			} catch (JCoffeeScriptCompileException e) {
+				throw new ServletException("Compilation error on file: " + coffeeFilename + " " + e.getMessage(), e);
+			}
+		}
+
+		// write in all cases to put value at the end of the linked list
+		previousBinaries.put(coffeeFilename, binary);
+
+		// optimizing response
+		long lastModified = binary.getLastModified() == 0 ? this.startupTime : (binary.getLastModified() / 1000 * 1000);
+		long ifModifiedSince = request.getDateHeader("If-Modified-Since");
+
+		if (lastModified > ifModifiedSince) {
+
+			// write last modified info
+			response.setDateHeader("Last-Modified", lastModified);
+			response.setContentType("text/javascript");
+			PrintWriter writer = resp.getWriter();
+			writer.write(binary.getContent());
+		} else {
+			response.setContentLength(0);
+			response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
+		}
+	}
+
+	private String getJavascriptURI(HttpServletRequest request) {
+		String javascriptURI = request.getServletPath();
+		if (request.getPathInfo() != null) {
+			javascriptURI += request.getPathInfo();
+		}
+		return javascriptURI;
+	}
+
+	private String discoverCoffeeFilename(String javascriptResource) {
+
+		Pattern pattern = Pattern.compile(javascriptResourcePrefix + "/(.*).js");
+		Matcher matcher = pattern.matcher(javascriptResource);
+		if (!matcher.matches()) {
+			return null;
+		}
+		return coffeescriptFilenamePrefix + "/" + matcher.group(1) + ".coffee";
+	}
+
+	private String getContent(InputStream coffeeStream) throws IOException {
+		InputStreamReader reader = new InputStreamReader(coffeeStream);
+		try {
+			StringWriter writer = new StringWriter();
+
+			char[] buffer = new char[BUFFER_SIZE];
+			int n = 0;
+			while (-1 != (n = reader.read(buffer))) {
+				writer.write(buffer, 0, n);
+			}
+			String source = writer.toString();
+			return source;
+		} finally {
+			reader.close();
+		}
+	}
+
+}

src/unit-tests/java/app/WEB-INF/coffee/error.coffee

@@ -0,0 +1,2 @@
+list = [1,2
+

src/unit-tests/java/app/WEB-INF/coffee/simple.coffee

@@ -0,0 +1 @@
+a = 1

src/unit-tests/java/app/index.html

@@ -0,0 +1 @@
+<h1>It Works!</h1>

src/unit-tests/java/app/javascript/static.js

@@ -0,0 +1 @@
+var test = 0;