Add support for Schema.org/Recipe

java/org/chromium/distiller/SchemaOrgParser.java

Index: java/org/chromium/distiller/SchemaOrgParser.java
diff --git a/java/org/chromium/distiller/SchemaOrgParser.java b/java/org/chromium/distiller/SchemaOrgParser.java
index 89c09f5f187e2d5345242a86a6b7ef4ca77cb389..df5899abff50ba18c21ce8fac7f52451c210b6ad 100644
--- a/java/org/chromium/distiller/SchemaOrgParser.java
+++ b/java/org/chromium/distiller/SchemaOrgParser.java
@@ -37,6 +37,8 @@ public class SchemaOrgParser {
     static final String DESCRIPTION_PROP = "description";
     static final String IMAGE_PROP = "image";
     static final String HEADLINE_PROP = "headline";
+    static final String MAIN_ENTITY_OF_PAGE = "mainEntityOfPage";
+    static final String MAIN_ENTITY = "mainEntity";
     static final String PUBLISHER_PROP = "publisher";
     static final String COPYRIGHT_HOLDER_PROP = "copyrightHolder";
     static final String COPYRIGHT_YEAR_PROP = "copyrightYear";
@@ -57,35 +59,51 @@ public class SchemaOrgParser {
     static final String GIVEN_NAME_PROP = "givenName";
     static final String LEGAL_NAME_PROP = "legalName";
     static final String AUTHOR_REL = "author";
+    static final String COOK_TIME = "cookTime";
+    static final String COOKING_METHOD = "cookingMethod";
+    static final String NUTRITION = "nutrition";
+    static final String PREP_TIME = "prepTime";
+    static final String RECIPE_CATEGORY = "recipeCategory";
+    static final String RECIPE_CUISINE = "recipeCuisine";
+    static final String RECIPE_INGREDIENT = "recipeIngredient";
+    static final String INGREDIENTS = "ingredients";
+    static final String RECIPE_INSTRUCTIONS = "recipeInstructions";
+    static final String RECIPE_YIELD = "recipeYield";
+    static final String TOTAL_TIME = "totalTime";
 
     enum Type {  // All these types are extended from Thing, directly or indirectly.
         IMAGE,
         ARTICLE,
         PERSON,
         ORGANIZATION,
+        RECIPE,
         UNSUPPORTED,
     }
 
-    static class ThingItem {
+    static abstract class ThingItem {
         private final Element mElement;
         private final Type mType;
-        private final Map<String, String> mStringProperties;
+        private final Map<String, List<String>> mStringProperties;
         private final Map<String, ThingItem> mItemProperties;
 
         ThingItem(Type type, Element element) {
             mElement = element;
             mType = type;
-            mStringProperties = new HashMap<String, String>();
+            mStringProperties = new HashMap<String, List<String>>();
             mItemProperties = new HashMap<String, ThingItem>();
 
-           addStringPropertyName(NAME_PROP);
-           addStringPropertyName(URL_PROP);
-           addStringPropertyName(DESCRIPTION_PROP);
-           addStringPropertyName(IMAGE_PROP);
+            addStringPropertyName(NAME_PROP);
+            addStringPropertyName(URL_PROP);
+            addStringPropertyName(DESCRIPTION_PROP);
+            addStringPropertyName(IMAGE_PROP);
+            addStringPropertyName(MAIN_ENTITY_OF_PAGE);
+            addStringPropertyName(MAIN_ENTITY);
         }
 
         final void addStringPropertyName(String name) {
-            mStringProperties.put(name, "");
+            if (mStringProperties.get(name) == null) {
+                mStringProperties.put(name, new ArrayList<String>());
+            }
         }
 
         final void addItemPropertyName(String name) {
@@ -93,7 +111,11 @@ public class SchemaOrgParser {
         }
 
         final String getStringProperty(String name) {
-            return !mStringProperties.containsKey(name) ? "" : mStringProperties.get(name);
+            return !mStringProperties.containsKey(name) ? "" : DomUtil.join(mStringProperties.get(name).toArray(), ", ");
+        }
+
+        final List<String> getProperty(String name) {
+            return mStringProperties.get(name);
         }
 
         final ThingItem getItemProperty(String name) {
@@ -104,11 +126,14 @@ public class SchemaOrgParser {
 
         final boolean isSupported() { return mType != Type.UNSUPPORTED; }
 
-        // Store |value| for property with |name|, unless the property already has a non-empty
-        // value, in which case |value| will be ignored.  This means we only keep the first value.
+        // Store |value| for property with |name|. Values are added
+        // into a list indexed by |name|. Using a list of values is
+        // necessary in order to support duplicated properties like
+        // 'recipeIngredient' which appears frequently more than once
+        // in a Recipe.
         final void putStringValue(String name, String value) {
-            if (mStringProperties.containsKey(name) && mStringProperties.get(name).isEmpty()) {
-                mStringProperties.put(name, value);
+            if (mStringProperties.containsKey(name)) {
+                mStringProperties.get(name).add(value);
             }
         }
 
@@ -118,6 +143,13 @@ public class SchemaOrgParser {
             if (mItemProperties.containsKey(name)) mItemProperties.put(name, value);
         }
 
+        /**
+         * Derived items should provide their own implementations.
+         *
+         * @return HTML output.
+         */
+        public abstract String generateOutput();
+
         final Element getElement() {
             return mElement;
         }
@@ -142,6 +174,7 @@ public class SchemaOrgParser {
         sTypeUrls.put("http://schema.org/EducationalOrganization", Type.ORGANIZATION);
         sTypeUrls.put("http://schema.org/GovernmentOrganization", Type.ORGANIZATION);
         sTypeUrls.put("http://schema.org/NGO", Type.ORGANIZATION);
+        sTypeUrls.put("http://schema.org/Recipe", Type.RECIPE);
     }
 
     private final TimingInfo mTimingInfo;
@@ -174,6 +207,43 @@ public class SchemaOrgParser {
         return images;
     }
 
+    /**
+     * Get the main entity of a page if any.
+     *
+     * Main entity of a page is retrieved by the mainEntityOfPage
+     * or by its inverse property mainEntity.
+     *
+     * @return ThingItem which is the main entity of this page.
+     */
+    final ThingItem getMainEntity() {
+        for (ThingItem mItemScope : mItemScopes) {
+            if(!mItemScope.getStringProperty(MAIN_ENTITY).isEmpty() ||
+                    !mItemScope.getStringProperty(MAIN_ENTITY_OF_PAGE).isEmpty()) {
+                return mItemScope;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Look for all top level entities on the page. As we are
+     * representing the graph hierarchy by having a set of
+     * children in every node, the top level entities (roots) are those
+     * nodes that do not appear as children in any other node.
+     *
+     * @return List<ThingItem> which are considered top level entities.
+     */
+    final List<ThingItem> getTopLevelEntities() {
+        List<ThingItem> candidates = new ArrayList<>(mItemScopes);
+        for (ThingItem mItemScope : mItemScopes) {
+            for (Map.Entry<String, ThingItem> entry :
+                    mItemScope.mItemProperties.entrySet()) {
+                candidates.remove(entry.getValue());
+            }
+        }
+        return candidates;
+    }
+
     final String getAuthorFromRel() { return mAuthorFromRel; }
 
     private void parse(Element root) {
@@ -278,6 +348,9 @@ public class SchemaOrgParser {
             case ORGANIZATION:
                 newItem = new OrganizationItem(e);
                 break;
+            case RECIPE:
+                newItem = new RecipeItem(e);
+                break;
             case UNSUPPORTED:
                 newItem = new UnsupportedItem(e);
                 break;
@@ -313,6 +386,11 @@ public class SchemaOrgParser {
             image.height = JavaScript.parseInt(getStringProperty(HEIGHT_PROP), 10);
             return image;
         }
+
+        @Override
+        public String generateOutput() {
+            return "";
+        }
     }
 
     static class ArticleItem extends ThingItem {
@@ -389,9 +467,14 @@ public class SchemaOrgParser {
             image.url = imageUrl;
             return image;
         }
+
+        @Override
+        public String generateOutput() {
+            return "";
+        }
     }
 
-    private static class PersonItem extends ThingItem {
+    static class PersonItem extends ThingItem {
         PersonItem(Element element) {
             super(Type.PERSON, element);
 
@@ -406,9 +489,98 @@ public class SchemaOrgParser {
             return !name.isEmpty() ? name :
                     concat(getStringProperty(GIVEN_NAME_PROP), getStringProperty(FAMILY_NAME_PROP));
         }
+
+        Person getPerson() {
+            Person person = new Person();
+            person.name = getName();
+            return person;
+        }
+
+        class Person {
+            String name;
+        }
+
+        @Override
+        public String generateOutput() {
+            return MarkupGenerator.generateMarkup(getPerson());
+        }
     }
 
-    private static class OrganizationItem extends ThingItem {
+    static class RecipeItem extends ThingItem {
+
+        RecipeItem(Element element) {
+            super(Type.RECIPE, element);
+
+            addStringPropertyName(AUTHOR_PROP);
+            addStringPropertyName(CREATOR_PROP);
+            addStringPropertyName(COOK_TIME);
+            addStringPropertyName(COOKING_METHOD);
+            addStringPropertyName(NUTRITION);
+            addStringPropertyName(PREP_TIME);
+            addStringPropertyName(RECIPE_CATEGORY);
+            addStringPropertyName(RECIPE_CUISINE);
+            addStringPropertyName(RECIPE_INGREDIENT);
+            addStringPropertyName(INGREDIENTS);
+            addStringPropertyName(RECIPE_INSTRUCTIONS);
+            addStringPropertyName(RECIPE_YIELD);
+            addStringPropertyName(TOTAL_TIME);
+
+            addItemPropertyName(AUTHOR_PROP);
+            addItemPropertyName(CREATOR_PROP);
+        }
+
+        final Recipe getRecipe() {
+            Recipe recipe = new Recipe();
+            recipe.title = getStringProperty(NAME_PROP);
+            recipe.imageSrc = getStringProperty(IMAGE_PROP);
+            recipe.cookTime = DomUtil.formatDuration(
+                    getStringProperty(COOK_TIME));
+            recipe.author = retrieveProperty(AUTHOR_PROP);
+            recipe.creator = retrieveProperty(CREATOR_PROP);
+            recipe.description = getStringProperty(DESCRIPTION_PROP);
+            recipe.recipeYield = getStringProperty(RECIPE_YIELD);
+            recipe.prepTime = DomUtil.formatDuration(
+                    getStringProperty(PREP_TIME));
+            recipe.recipeIngredient = getProperty(RECIPE_INGREDIENT).isEmpty() ?
+                    getProperty(INGREDIENTS) : getProperty(RECIPE_INGREDIENT);
+            recipe.recipeInstructions = getProperty(RECIPE_INSTRUCTIONS);
+            recipe.totalTime = DomUtil.formatDuration(
+                    getStringProperty(TOTAL_TIME));
+            return recipe;
+        }
+
+        String retrieveProperty(String property) {
+            String value = getStringProperty(property);
+            if(value.isEmpty()) {
+                ThingItem itemProperty = getItemProperty(property);
+                if (itemProperty != null) {
+                    value = itemProperty.generateOutput();
+                }
+            }
+            return value;
+        }
+
+        @Override
+        public String generateOutput() {
+            return MarkupGenerator.generateMarkup(getRecipe());
+        }
+
+        class Recipe {
+            String title;
+            String imageSrc;
+            String author;
+            String creator;
+            String description;
+            String recipeYield;
+            String prepTime;
+            String cookTime;
+            String totalTime;
+            List<String> recipeIngredient;
+            List<String> recipeInstructions;
+        }
+    }
+
+    static class OrganizationItem extends ThingItem {
         OrganizationItem(Element element) {
             super(Type.ORGANIZATION, element);
 
@@ -420,12 +592,22 @@ public class SchemaOrgParser {
             String name = getStringProperty(NAME_PROP);
             return !name.isEmpty() ? name : getStringProperty(LEGAL_NAME_PROP);
         }
+
+        @Override
+        public String generateOutput() {
+            return "";
+        }
     }
 
     private static class UnsupportedItem extends ThingItem {
         UnsupportedItem(Element element) {
             super(Type.UNSUPPORTED, element);
         }
+
+        @Override
+        public String generateOutput() {
+            return "";
+        }
     }
 
     private static boolean isItemScope(Element e) {