PostCompileProcessProviderImpl.java

package org.apache.sling.webresource.postprocessors.impl;

import javax.jcr.Node;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.ReferenceCardinality;
import org.apache.felix.scr.annotations.ReferencePolicy;
import org.apache.felix.scr.annotations.Service;

import org.apache.sling.webresource.postprocessors.PostCompileProcess;
import org.apache.sling.webresource.postprocessors.PostCompileProcessProvider;

@Component(label = "Web Resource Post Compiler Process Provider Service", immediate = true)
@Service
@Reference(name = "WebResourcePostCompilerProcessProvider", referenceInterface = PostCompileProcess.class, cardinality = ReferenceCardinality.OPTIONAL_MULTIPLE, policy = ReferencePolicy.DYNAMIC)
public class PostCompileProcessProviderImpl implements
		PostCompileProcessProvider {

	private List<PostCompileProcess> webResourcePostCompileProcessList = new ArrayList<PostCompileProcess>();

	private PostCompileProcess[] webResourcePostCompileProcesses;

	@Override
	public InputStream applyPostCompileProcesses(Node sourceNode,
			InputStream compiledSource) {

		InputStream result = compiledSource;

		PostCompileProcess[] postCompileProcesses = getWebResourcePostCompilerProcessProviders();

		if (postCompileProcesses != null) {
			for (PostCompileProcess currentProcess : postCompileProcesses) {
				if (currentProcess.shouldProcess(sourceNode)) {
					result = currentProcess.processCompiledStream(result);
				}
			}
		}
		return result;
	}

	/**
	 * 
	 * 
	 * @param webResourcePostCompileProcessService
	 */
	protected void bindWebResourcePostCompilerProcessProvider(
			PostCompileProcess webResourcePostCompileProcessService) {
		synchronized (this.webResourcePostCompileProcessList) {
			this.webResourcePostCompileProcessList
					.add(webResourcePostCompileProcessService);
			this.webResourcePostCompileProcesses = null;
		}
	}

	/**
	 * 
	 * @param webResourcePostCompileProcessService
	 */
	protected void unbindWebResourcePostCompilerProcessProvider(
			PostCompileProcess webResourcePostCompileProcessService) {
		synchronized (this.webResourcePostCompileProcessList) {
			this.webResourcePostCompileProcessList
					.remove(webResourcePostCompileProcessService);
			this.webResourcePostCompileProcesses = null;
		}
	}

	/**
	 * 
	 * Return list of available compilers
	 * 
	 * @return
	 */
	private PostCompileProcess[] getWebResourcePostCompilerProcessProviders() {
		PostCompileProcess[] list = this.webResourcePostCompileProcesses;

		if (list == null) {
			synchronized (this.webResourcePostCompileProcessList) {
				this.webResourcePostCompileProcesses = this.webResourcePostCompileProcessList
						.toArray(new PostCompileProcess[this.webResourcePostCompileProcessList
								.size()]);
				list = this.webResourcePostCompileProcesses;
			}
		}

		return list;
	}

}