Assembly paging prototype

pantheon-bundle/src/main/java/com/redhat/pantheon/asciidoctor/extension/SlingResourceIncludeProcessor.java

@@ -61,10 +61,20 @@ public void process(Document document, PreprocessorReader reader, String target,
             // Included resource might be a plain file or another module
             if( includedResourceAsModel.getProperty(JCR_PRIMARYTYPE, String.class).equals("pant:module") ) {
                 Module module = includedResourceAsModel.adaptTo(Module.class);
+                StringBuilder moduleContent = new StringBuilder()
+                        .append("\n")
+                        .append("pass:[<!--pantheon-module-start-->]")
+                        .append("\n");
                 // TODO, right now only default locale and latest (draft) version of the module are used
-                content = module.getDraftContent(GlobalConfig.DEFAULT_MODULE_LOCALE)
+                moduleContent.append(
+                        module.getDraftContent(GlobalConfig.DEFAULT_MODULE_LOCALE)
                             .get()
-                            .asciidocContent().get();
+                            .asciidocContent().get()
+                )
+                .append("\n")
+                .append("pass:[<!--pantheon-module-end-->]");
+
+                content = moduleContent.toString();
             } else {
                 // It's a plain file
                 // TODO Resources (assets) will be versioned too, and module versions will have a record of their
@@ -77,7 +87,8 @@ public void process(Document document, PreprocessorReader reader, String target,
             log.warn("Could not find include for {}", target);
         }
 
-        reader.push_include(content, target, target, 1, attributes);
+        String includedFilePath = includeResource != null ? includeResource.getPath() : target;
+        reader.push_include(content, includedFilePath, includedFilePath, 1, attributes);
     }
 
     private Resource resolveWithSymlinks(String path, Resource pathParent) {

pantheon-bundle/src/main/java/com/redhat/pantheon/jcr/JcrQueryHelper.java

@@ -4,6 +4,8 @@
 import org.apache.sling.api.resource.Resource;
 import org.apache.sling.api.resource.ResourceResolver;
 
+import javax.jcr.ItemNotFoundException;
+import javax.jcr.Node;
 import javax.jcr.RepositoryException;
 import javax.jcr.Session;
 import javax.jcr.query.Query;
@@ -28,6 +30,18 @@ public JcrQueryHelper(ResourceResolver resourceResolver) {
         this.resourceResolver = resourceResolver;
     }
 
+    public Resource findById(String id) throws RepositoryException {
+        Session session = resourceResolver.adaptTo(Session.class);
+        Node node;
+        try {
+            node = session.getNodeByIdentifier(id);
+        } catch (ItemNotFoundException infe) {
+            return null;
+        }
+        // Transform to a sling resource
+        return resourceResolver.getResource(node.getPath());
+    }
+
     /**
      * A convenience method to run a query in any supported language against the JCR Repository,
      * adding limit and offset values useful for pagination.

pantheon-bundle/src/main/java/com/redhat/pantheon/servlet/assembly/AssemblyPageRenderingServlet.java

@@ -0,0 +1,114 @@
+package com.redhat.pantheon.servlet.assembly;
+
+import com.google.common.base.Charsets;
+import com.redhat.pantheon.conf.GlobalConfig;
+import com.redhat.pantheon.html.Html;
+import com.redhat.pantheon.jcr.JcrQueryHelper;
+import com.redhat.pantheon.model.api.SlingModels;
+import com.redhat.pantheon.model.module.Module;
+import com.redhat.pantheon.model.module.ModuleVersion;
+import com.redhat.pantheon.servlet.ServletUtils;
+import org.apache.sling.api.SlingHttpServletRequest;
+import org.apache.sling.api.SlingHttpServletResponse;
+import org.apache.sling.api.resource.Resource;
+import org.apache.sling.api.servlets.SlingSafeMethodsServlet;
+import org.apache.sling.servlets.annotations.SlingServletPaths;
+import org.jetbrains.annotations.NotNull;
+import org.jsoup.nodes.Document;
+import org.jsoup.nodes.Element;
+import org.jsoup.nodes.Node;
+import org.osgi.framework.Constants;
+import org.osgi.service.component.annotations.Component;
+
+import javax.jcr.RepositoryException;
+import javax.servlet.Servlet;
+import javax.servlet.ServletException;
+import java.io.IOException;
+import java.io.Writer;
+import java.util.Optional;
+import java.util.StringTokenizer;
+
+/**
+ * @author Carlos Munoz
+ */
+@Component(
+        service = Servlet.class,
+        property = {
+                Constants.SERVICE_DESCRIPTION + "=Renders an assembly page in html",
+                Constants.SERVICE_VENDOR + "=Red Hat Content Tooling team"
+        })
+@SlingServletPaths(value = "/api/assembly")
+public class AssemblyPageRenderingServlet extends SlingSafeMethodsServlet {
+
+    private static final String SPLIT_TAG = "\\<\\!\\-\\-pantheon\\-module\\-start\\-\\-\\>";
+
+    @Override
+    protected void doGet(@NotNull SlingHttpServletRequest request, @NotNull SlingHttpServletResponse response) throws ServletException, IOException {
+        String assemblyId = ServletUtils.paramValue(request, "id");
+        Long pageNum = ServletUtils.paramValueAsLong(request, "page", 1L);
+
+        try {
+            // First get the assembly
+            // Since there are no assemblies yet, we will get modules
+            JcrQueryHelper helper = new JcrQueryHelper(request.getResourceResolver());
+            Resource assemblyResource = helper.findById(assemblyId);
+            Module assembly = SlingModels.getModel(assemblyResource, Module.class);
+
+            // Get the page content
+            // Split by sections with class 'sect1' as they seem to be the top level sections
+            // Assuming latest draft or released version, and only in English for now
+            Optional<ModuleVersion> versionOpt = assembly.getReleasedVersion(GlobalConfig.DEFAULT_MODULE_LOCALE);
+            ModuleVersion version = versionOpt.orElse( assembly.getDraftVersion(GlobalConfig.DEFAULT_MODULE_LOCALE).get() );
+            String fullHtmlContent = version.content().get().cachedHtml().get().data().get();
+            // Now split it into the right page
+            String pageHtml =
+                    //new TopSectionSplittingStrategy().split(fullHtmlContent, pageNum.intValue());
+                    new CustomTagBasedSplittingStrategy().split(fullHtmlContent, pageNum.intValue());
+
+            // Render the page as html
+            response.setContentType("text/html");
+            Writer w = response.getWriter();
+            w.write(pageHtml);
+        } catch (RepositoryException e) {
+            throw new ServletException(e);
+        }
+    }
+
+    private interface HtmlSplittingStrategy {
+        String split(String html, int page);
+    }
+
+    private class TopSectionSplittingStrategy implements HtmlSplittingStrategy {
+
+        @Override
+        public String split(String html, int pageNum) {
+            return Html.parse(Charsets.UTF_8.name())
+                    .andThen(Document::body)
+                    .andThen(element -> element.select("section.sect1"))
+                    .andThen(elements -> elements.listIterator(pageNum-1).next())
+                    .andThen(element -> element.outerHtml())
+                    .apply(html);
+        }
+    }
+
+    private class CustomTagBasedSplittingStrategy implements HtmlSplittingStrategy {
+
+        @Override
+        public String split(String html, int page) {
+            // extract just the body
+            String fullBodyHtml = Html.parse(Charsets.UTF_8.name())
+                    .andThen(Document::body)
+                    .andThen(Element::html)
+                    .apply(html);
+
+            // TODO this is very rudimentary, the system could do a more scalable split and could also
+            // TODO cache the pages after generation
+            String[] pages = fullBodyHtml.split(SPLIT_TAG);
+
+            // Send the html through Jsoup again so it's cleaned up
+            return Html.parse(Charsets.UTF_8.name())
+                    .andThen(Document::outerHtml)
+                    .apply(pages[page-1]);
+        }
+    }
+}