WebResourceTag.java

package org.apache.sling.webresource.taglib;

import java.io.IOException;
import java.util.List;
import java.util.Map;

import javax.jcr.Node;
import javax.jcr.RepositoryException;
import javax.jcr.Session;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.TagSupport;

import org.apache.commons.io.IOUtils;
import org.apache.sling.api.scripting.SlingScriptHelper;
import org.apache.sling.webresource.WebResourceScriptCache;
import org.apache.sling.webresource.util.JCRUtils;

public class WebResourceTag extends TagSupport {

	/**
	 * 
	 */
	private static final long serialVersionUID = -3322071843929377647L;

	private SlingScriptHelper sling;

	private Node currentNode;

	private WebResourceScriptCache webResourceScriptCache;

	private String groupName;

	private boolean inline;

	@Override
	public int doStartTag() throws JspException {
		if (groupName == null) {
			throw new JspException("Either Group Name must be set");
		}

		return super.doStartTag();
	}

	@Override
	public void setPageContext(PageContext pageContext) {

		super.setPageContext(pageContext);
		sling = (SlingScriptHelper) pageContext.findAttribute("sling");
		currentNode = (Node) pageContext.findAttribute("currentNode");
		webResourceScriptCache = sling.getService(WebResourceScriptCache.class);
	}

	@Override
	public int doEndTag() throws JspException {
		JspWriter out = null;
		try {
			out = pageContext.getOut();
			Session currentSession = currentNode.getSession();
			Map<String, List<String>> webResourcePaths = null;
			if (groupName != null) {
				webResourcePaths = webResourceScriptCache
						.getWebResourceCachedInventoryPaths(currentSession,
								groupName);
				for (String currentExtention : webResourcePaths.keySet()) {
					processExtentionList(out, currentSession, webResourcePaths,
							currentExtention);
				}

			}
		} catch (IOException e) {
			try {
				out.write("/*" + e.toString() + "*/");
			} catch (IOException e1) {
				throw new JspException(e1);
			}
		} catch (RepositoryException e) {
			try {
				out.write("/*" + e.toString() + "*/");
			} catch (IOException e1) {
				throw new JspException(e1);
			}
		}

		return super.doEndTag();
	}

	/**
	 * 
	 * Writes out scripts based on extension.
	 * 
	 * @param out
	 * @param currentSession
	 * @param webResourcePathMap
	 * @param extentionName
	 * @throws IOException
	 * @throws RepositoryException
	 */
	protected void processExtentionList(JspWriter out, Session currentSession,
			Map<String, List<String>> webResourcePathMap, String extentionName)
			throws IOException, RepositoryException {
		if (extentionName.equals("js")) {
			for (String currentPath : webResourcePathMap.get(extentionName)) {
				StringBuffer scriptBuffer = createScriptLinks(currentSession,
						currentPath);
				out.write(scriptBuffer.toString());
			}
		} else {
			for (String currentPath : webResourcePathMap.get(extentionName)) {
				StringBuffer scriptBuffer = createStyleSheetLinks(
						currentSession, currentPath);
				out.write(scriptBuffer.toString());
			}
		}
	}

	protected StringBuffer createStyleSheetLinks(Session currentSession,
			String currentPath) throws RepositoryException, IOException {
		StringBuffer scriptBuffer = new StringBuffer();

		scriptBuffer.append("<link rel=\"stylesheet\" ");
		if (inline) {
			scriptBuffer.append(">");
			copyCompiledNodeToBuffer(currentSession, currentPath, scriptBuffer);
			scriptBuffer.append("</link>");
		} else {
			scriptBuffer.append("href=\"" + currentPath + "\"/>");
		}

		return scriptBuffer;
	}

	protected StringBuffer createScriptLinks(Session currentSession,
			String currentPath) throws RepositoryException, IOException {
		StringBuffer scriptBuffer = new StringBuffer();
		scriptBuffer.append("<script");
		if (inline) {
			scriptBuffer.append(">");
			copyCompiledNodeToBuffer(currentSession, currentPath, scriptBuffer);
			scriptBuffer.append("</script>");

		} else {
			scriptBuffer.append(" src=\"" + currentPath + "\"></script>");
		}

		return scriptBuffer;
	}

	/**
	 * 
	 * Copies the full node content to the buffer. Used for inlining
	 * 
	 * @param currentSession
	 * @param currentPath
	 * @param scriptBuffer
	 * @throws RepositoryException
	 * @throws IOException
	 */
	protected void copyCompiledNodeToBuffer(Session currentSession,
			String currentPath, StringBuffer scriptBuffer)
			throws RepositoryException, IOException {
		Node compiledNode = currentSession.getNode(currentPath);
		String compiledScriptString = IOUtils.toString(JCRUtils
				.getFileNodeAsStream(compiledNode));
		scriptBuffer.append(compiledScriptString);
	}

	public void setInline(boolean inline) {
		this.inline = inline;
	}

	public boolean getInline() {
		return inline;
	}

	public void setGroupName(String groupName) {
		this.groupName = groupName;
	}

}