STGroupDir.java

package nebula.simpletemplate;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;

import org.antlr.runtime.ANTLRInputStream;
import org.antlr.runtime.Token;
import org.stringtemplate.v4.compiler.STException;

/**
 * A directory or directory tree full of templates and/or group files. We load
 * files on-demand. Dir search path: current working dir then CLASSPATH (as a
 * resource). Do not look for templates outside of this dir subtree (except via
 * imports).
 */
public class STGroupDir extends STGroup {
	public String groupDirName;
	public URL root;

	public STGroupDir(String dirName) {
		this(dirName, '<', '>');
	}

	public STGroupDir(String dirName, char delimiterStartChar, char delimiterStopChar) {
		super(delimiterStartChar, delimiterStopChar);
		this.groupDirName = dirName;
		File dir = new File(dirName);
		if (dir.exists() && dir.isDirectory()) {
			// we found the directory and it'll be file based
			try {
				root = dir.toURI().toURL();
			} catch (MalformedURLException e) {
				throw new STException("can't load dir " + dirName, e);
			}
			if (verbose) System.out.println("STGroupDir(" + dirName + ") found at " + root);
		} else {
			ClassLoader cl = Thread.currentThread().getContextClassLoader();
			root = cl.getResource(dirName);
			if (root == null) {
				cl = this.getClass().getClassLoader();
				root = cl.getResource(dirName);
			}
			if (verbose) System.out.println("STGroupDir(" + dirName + ") found via CLASSPATH at " + root);
			if (root == null) {
				throw new IllegalArgumentException("No such directory: " + dirName);
			}
		}
	}

	public STGroupDir(String dirName, String encoding) {
		this(dirName, encoding, '<', '>');
	}

	public STGroupDir(String dirName, String encoding, char delimiterStartChar, char delimiterStopChar) {
		this(dirName, delimiterStartChar, delimiterStopChar);
		this.encoding = encoding;
	}

	public STGroupDir(URL root, String encoding, char delimiterStartChar, char delimiterStopChar) {
		super(delimiterStartChar, delimiterStopChar);
		this.groupDirName = new File(root.getFile()).getName();
		this.root = root;
		this.encoding = encoding;
	}

	@Override
	public void importTemplates(Token fileNameToken) {
		String msg = "import illegal in group files embedded in STGroupDirs; " + "import " + fileNameToken.getText() + " in STGroupDir " + this.getName();
		throw new UnsupportedOperationException(msg);
	}

	/**
	 * Load a template from directory or group file. Group file is given
	 * precedence over directory with same name. {@code name} is always
	 * fully-qualified.
	 */
	@Override
	protected CompiledST load(String name) {
		if (verbose) System.out.println("STGroupDir.load(" + name + ")");
		String parent = Misc.getParent(name); // must have parent; it's
												// fully-qualified
		String prefix = Misc.getPrefix(name);
		// if (parent.isEmpty()) {
		// // no need to check for a group file as name has no parent
		// return loadTemplateFile("/", name+TEMPLATE_FILE_EXTENSION); // load
		// t.st file
		// }

		URL groupFileURL = null;
		try { // see if parent of template name is a group file
			groupFileURL = new URL(root + parent + GROUP_FILE_EXTENSION);
		} catch (MalformedURLException e) {
			errMgr.internalError(null, "bad URL: " + root + parent + GROUP_FILE_EXTENSION, e);
			return null;
		}

		InputStream is = null;
		try {
			is = groupFileURL.openStream();
		} catch (IOException ioe) {
			// must not be in a group file
			String unqualifiedName = Misc.getFileName(name);
			return loadTemplateFile(prefix, unqualifiedName + TEMPLATE_FILE_EXTENSION); // load
																						// t.st
																						// file
		} finally { // clean up
			try {
				if (is != null) is.close();
			} catch (IOException ioe) {
				errMgr.internalError(null, "can't close template file stream " + name, ioe);
			}
		}

		loadGroupFile(prefix, root + parent + GROUP_FILE_EXTENSION);
		return rawGetTemplate(name);
	}

	/** Load .st as relative file name relative to root by {@code prefix}. */
	public CompiledST loadTemplateFile(String prefix, String unqualifiedFileName) {
		if (verbose) System.out.println("loadTemplateFile(" + unqualifiedFileName + ") in groupdir " + "from " + root + " prefix=" + prefix);
		URL f = null;
		try {
			f = new URL(root + prefix + unqualifiedFileName);
		} catch (MalformedURLException me) {
			// errMgr.runTimeError(null, null, ErrorType.INVALID_TEMPLATE_NAME,
			// me, root + unqualifiedFileName);
			return null;
		}

		ANTLRInputStream fs;
		try {
			fs = new ANTLRInputStream(f.openStream(), encoding);
			fs.name = unqualifiedFileName;
		} catch (IOException ioe) {
			if (verbose) System.out.println(root + "/" + unqualifiedFileName + " doesn't exist");
			// errMgr.IOError(null, ErrorType.NO_SUCH_TEMPLATE, ioe,
			// unqualifiedFileName);
			return null;
		}

		return loadTemplateFile(prefix, unqualifiedFileName, fs);
	}

	@Override
	public String getName() {
		return groupDirName;
	}

	@Override
	public String getFileName() {
		return root.getFile();
	}

	@Override
	public URL getRootDirURL() {
		return root;
	}
}