QuicklyFilter.java

/*
 * #%L
 * ACS AEM Commons Bundle
 * %%
 * Copyright (C) 2013 Adobe
 * %%
 * 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.
 * #L%
 */

package com.adobe.acs.commons.quickly.impl;

import com.adobe.acs.commons.quickly.QuicklyEngine;
import com.adobe.acs.commons.util.BufferingResponse;
import com.adobe.acs.commons.util.ResourceDataUtil;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.felix.scr.annotations.Activate;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.ConfigurationPolicy;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.Service;
import org.apache.sling.api.resource.LoginException;
import org.apache.sling.api.resource.ResourceResolver;
import org.apache.sling.api.resource.ResourceResolverFactory;

import javax.jcr.RepositoryException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Map;

/**
 * ACS AEM Commons - Quickly - App HTML Injection Filter
 * Injects the necessary HTML into the Request page.
 */
@Component(policy = ConfigurationPolicy.OPTIONAL)
@Property(name = "pattern",
          value = ".*")
@Service

public class QuicklyFilter implements Filter {
    private static final String[] REJECT_PATH_PREFIXES = new String[]{
            "/libs/granite/core/content/login",
    };

    private static final String HTML_FILE = "/quickly/inject.html";

    private static String appHTML = "";

    @Reference
    private QuicklyEngine quicklyEngine;

    @Override
    public void init(final FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(final ServletRequest servletRequest,
                         final ServletResponse servletResponse,
                         final FilterChain filterChain) throws IOException, ServletException {

        final HttpServletRequest request = (HttpServletRequest) servletRequest;
        final HttpServletResponse response = (HttpServletResponse) servletResponse;

        if(!accepts(request)) {
            filterChain.doFilter(servletRequest, servletResponse);
            return;
        }

        final BufferingResponse capturedResponse = new BufferingResponse(response);

        filterChain.doFilter(request, capturedResponse);

        // Get contents
        final String contents = capturedResponse.getContents();

        if (contents != null && StringUtils.contains(response.getContentType(), "html")) {

            final int bodyIndex = contents.indexOf("</body>");
            if (bodyIndex != -1) {

                final PrintWriter printWriter = response.getWriter();

                printWriter.write(contents.substring(0, bodyIndex));
                printWriter.write(appHTML);
                printWriter.write(contents.substring(bodyIndex));

                return;
            }
        }

        if (contents != null) {
            response.getWriter().write(contents);
        }
    }

    @Override
    public void destroy() {

    }

    private boolean accepts(final HttpServletRequest request) {
        if (!StringUtils.equalsIgnoreCase("get", request.getMethod())) {
            // Only inject on GET requests
            return false;
        } else if (StringUtils.startsWithAny(request.getRequestURI(), REJECT_PATH_PREFIXES)) {
            return false;
        } else if (StringUtils.equals(request.getHeader("X-Requested-With"), "XMLHttpRequest")) {
            // Do not inject into XHR requests
            return false;
        } else if (StringUtils.endsWith(request.getHeader("Referer"), "/editor.html" + request.getRequestURI())) {
            // Do not apply to pages loaded in the TouchUI editor.html
            return false;
        } else if (StringUtils.endsWith(request.getHeader("Referer"), "/cf")) {
            // Do not apply to pages loaded in the Content Finder
            return false;
        }
        return true;
    }

    @Activate
    protected final void activate(final Map<String, String> config) throws IOException {
        InputStream inputStream = null;
        try {
            inputStream = getClass().getResourceAsStream(HTML_FILE);
            appHTML = IOUtils.toString(inputStream, "UTF-8");
        } finally {
            IOUtils.closeQuietly(inputStream);
        }
    }
}