recognize and parse Schema.org Markup

src/com/dom_distiller/client/SchemaOrgParserAccessor.java

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package com.dom_distiller.client;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.google.gwt.dom.client.Element;
+
+/**
+ * This class instantiates SchemaOrgParser and implements MarkupParser.Parser interface to provide
+ * access to properties that SchemaOrgParser has parsed.
+ */
+public class SchemaOrgParserAccessor implements MarkupParser.Parser {
+    private final SchemaOrgParser parser;
+
+    /**
+     * The object that instantiates SchemaOrgParser and implements its MarkupParser.Parser
+     * interface.
+     */
+    public SchemaOrgParserAccessor(Element root) {
+        parser = new SchemaOrgParser(root);
+    }
+
+    @Override
+    public String getTitle() {
+        String title = "";
+        List<SchemaOrgParser.ArticleItem> articles = parser.getArticleItems();
+
+        // Get the "headline" property of the first article that has it.
+        for (int i = 0; i < articles.size() && title.isEmpty(); i++) {
+            title = articles.get(i).getStringProperty(SchemaOrgParser.HEADLINE_PROP);
+        }
+
+        // If there's no "headline" property, use "name" property.
+        for (int i = 0; i < articles.size() && title.isEmpty(); i++) {
+            title = articles.get(i).getStringProperty(SchemaOrgParser.NAME_PROP);
+        }
+
+        return title;
+    }
+
+    @Override
+    public String getType() {
+        // TODO(kuan): consolidate/standardize types returned from all 3 parsers in MarkupParser.
+        // Returns ARTICLe if there's an article.
+        return parser.getArticleItems().isEmpty() ? "" : SchemaOrgParser.Type.ARTICLE.toString();
+    }
+
+    @Override
+    public String getUrl() {
+        List<SchemaOrgParser.ArticleItem> articles = parser.getArticleItems();
+        return articles.isEmpty() ? "" :
+                articles.get(0).getStringProperty(SchemaOrgParser.URL_PROP);
+    }
+
+    @Override
+    public MarkupParser.Image[] getImages() {
+        List<MarkupParser.Image> images = new ArrayList<MarkupParser.Image>();
+
+        // First, get images from ArticleItem's.
+        List<SchemaOrgParser.ArticleItem> articleItems = parser.getArticleItems();
+        MarkupParser.Image imageOfArticle = null;
+        SchemaOrgParser.ImageItem associatedImageOfArticle = null;
+
+        for (int i = 0; i < articleItems.size(); i++) {
+            SchemaOrgParser.ArticleItem articleItem = articleItems.get(i);
+            // If article has an associated image or the "image" property, remember them for now;
+            // they'll be added to the list later when the position in the list can be determined.
+            if (associatedImageOfArticle == null) {
+                associatedImageOfArticle = articleItem.getRepresentativeImageItem();
+                if (associatedImageOfArticle != null) continue;
+            }
+            MarkupParser.Image image = articleItem.getImage();
+            if (image == null) continue;
+            if (imageOfArticle == null) {
+                imageOfArticle = image;
+            } else {
+                images.add(image);
+            }
+        }
+
+        // Then, get images from ImageItem's.
+        List<SchemaOrgParser.ImageItem> imageItems = parser.getImageItems();
+        boolean hasRepresentativeImage = false;
+
+        for (int i = 0; i < imageItems.size(); i++) {
+            SchemaOrgParser.ImageItem imageItem = imageItems.get(i);
+            MarkupParser.Image image = imageItem.getImage();
+            // Insert |image| at beginning of list if it's the first image that's representative of
+            // page or it's the associated image of the first article.
+            if (!hasRepresentativeImage && (imageItem == associatedImageOfArticle ||
+                                            imageItem.isRepresentativeOfPage())) {
+                hasRepresentativeImage = true;
+                images.add(0, image);
+            } else {
+                images.add(image);
+            }
+        }
+
+        // Prepend |imageOfArticle| to list if there's no image representative of page; append it
+        // otherwise.
+        if (imageOfArticle != null) {
+            if (!hasRepresentativeImage) images.add(0, imageOfArticle);
+            else images.add(imageOfArticle);
+        }
+
+        if (images.isEmpty()) return null;
+
+        return images.toArray(new MarkupParser.Image[images.size()]);
+    }
+
+    @Override
+    public String getDescription() {
+        List<SchemaOrgParser.ArticleItem> articles = parser.getArticleItems();
+        return articles.isEmpty() ?  "" :
+                articles.get(0).getStringProperty(SchemaOrgParser.DESCRIPTION_PROP);
+    }
+
+    @Override
+    public String getPublisher() {
+        // Returns either the "publisher" or "copyrightHolder" property of the first article.
+        String publisher = "";
+        List<SchemaOrgParser.ArticleItem> articles = parser.getArticleItems();
+        if (!articles.isEmpty()) {
+            SchemaOrgParser.ArticleItem article = articles.get(0);
+            publisher = article.getPersonOrOrganizationName(SchemaOrgParser.PUBLISHER_PROP);
+            if (publisher.isEmpty()) {
+                publisher = article.getPersonOrOrganizationName(
+                        SchemaOrgParser.COPYRIGHT_HOLDER_PROP);
+            }
+        }
+        return publisher;
+    }
+
+    @Override
+    public String getCopyright() {
+        List<SchemaOrgParser.ArticleItem> articles = parser.getArticleItems();
+        return articles.isEmpty() ? "" : articles.get(0).getCopyright();
+    }
+
+    @Override
+    public String getAuthor() {
+        String author = "";
+        List<SchemaOrgParser.ArticleItem> articles = parser.getArticleItems();
+        if (!articles.isEmpty()) {
+             SchemaOrgParser.ArticleItem article = articles.get(0);
+             author = article.getPersonOrOrganizationName(SchemaOrgParser.AUTHOR_PROP);
+             // If there's no "author" property, use "creator" property.
+             if (author.isEmpty()) {
+                 author = article.getPersonOrOrganizationName(SchemaOrgParser.CREATOR_PROP);
+             }
+        }
+        // Otherwise, use "rel=author" tag.
+        return author.isEmpty() ? parser.getAuthorFromRel() : author;
+    }
+
+    @Override
+    public MarkupParser.Article getArticle() {
+        List<SchemaOrgParser.ArticleItem> articles = parser.getArticleItems();
+        return articles.isEmpty() ? null : articles.get(0).getArticle();
+    }
+
+    @Override
+    public boolean optOut() {
+        return false;
+    }
+}