Merge pull request #5 from olivergondza/namespaces

Add support for XML namespaces

src/main/java/com/github/olivergondza/saxeed/Saxeed.java

@@ -155,6 +155,7 @@ private SAXParser getSaxParser() {
             factory.setFeature("http://xml.org/sax/features/external-general-entities", false);
             factory.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
             factory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
+            factory.setNamespaceAware(true);
             return factory.newSAXParser();
         } catch (ParserConfigurationException | SAXException e) {
             throw new AssertionError("SAX or its essential features are not supported", e);

src/main/java/com/github/olivergondza/saxeed/Subscribed.java

@@ -1,57 +1,107 @@
 package com.github.olivergondza.saxeed;
 
+import java.util.Arrays;
+import java.util.List;
+
 /**
  * Criteria for Visitor-to-tags subscription.
  */
-public abstract class Subscribed {
+@FunctionalInterface
+public interface Subscribed {
+
+    /**
+     * Subscribe to all tags in the document.
+     */
+    static Subscribed toAll() {
+        return Builder.ALL;
+    }
+
+    /**
+     * Build subscription criteria.
+     */
+    static Subscribed.Builder to() {
+        return new Subscribed.Builder();
+    }
+
+    boolean isSubscribed(TagName tagName);
 
-    private static final Subscribed ALL = new Subscribed() {
-        @Override
-        public boolean isSubscribed(String tagName) {
-            return true;
+    final class Builder {
+        private static final Subscribed ALL = tagName -> true;
+
+        private Subscribed nsFilter = ALL;
+        private Subscribed tagFilter = ALL;
+
+        Builder() {
         }
-    };
 
-    private static final Subscribed NONE = new Subscribed() {
-        @Override
-        public boolean isSubscribed(String tagName) {
-            return false;
+        /**
+         * Match tags regardless of namespace status.
+         */
+        public Builder anyNamespace() {
+            nsFilter = ALL;
+            return this;
         }
-    };
 
-    public static Subscribed toAll() {
-        return ALL;
-    }
+        /**
+         * Match tags in default, not overridden namespace.
+         */
+        public Builder noNamespace() {
+            nsFilter = name -> name.getNsUri().isEmpty();
+            return this;
+        }
 
-    public static Subscribed to(String... tagNames) {
-        return tagNames.length == 0
-                ? NONE
-                : new Tags(tagNames)
-        ;
-    }
+        /**
+         * Match tags in default namespace, named or not.
+         */
+        public Builder defaultNamespace() {
+            nsFilter = name -> name.getNsPrefix().isEmpty();
+            return this;
+        }
 
-    public abstract boolean isSubscribed(String tagName);
+        /**
+         * Match tags in namespace its uri is in the arguments.
+         */
+        public Builder namespaceUris(String... uris) {
+            List<String> namespaces = list("namespace", uris);
+            nsFilter = name -> namespaces.contains(name.getNsUri());
+            return this;
+        }
 
-    private static final class Tags extends Subscribed {
+        /**
+         * Match any local tag name.
+         */
+        public Builder anyTag() {
+            tagFilter = ALL;
+            return this;
+        }
 
-        private final String[] tagNames;
+        /**
+         * Match local tag names specified in arguments.
+         */
+        public Builder tagNames(String... locals) {
+            List<String> tags = list("tag", locals);
+            tagFilter = name -> tags.contains(name.getLocal());
+            return this;
+        }
 
-        public Tags(String... tagNames) {
-            this.tagNames = tagNames;
-            for (String name: tagNames) {
-                if (name == null || name.isEmpty()) {
-                    throw new IllegalArgumentException("Empty tag name specified for subscription");
-                }
-            }
+        public Subscribed build() {
+            assert nsFilter != null;
+            assert tagFilter != null;
+
+            return name -> tagFilter.isSubscribed(name) && nsFilter.isSubscribed(name);
         }
 
-        @Override
-        public boolean isSubscribed(String tagName) {
-            for (String name: tagNames) {
-                if (name.equals(tagName)) return true;
+        private static List<String> list(String type, String[] vals) {
+            if (vals.length == 0) {
+                throw new IllegalArgumentException("Subscribing to 0 " + type + "s means no subscription at all");
             }
 
-            return false;
+            for (String name: vals) {
+                if (name == null || name.isEmpty()) {
+                    throw new IllegalArgumentException("Empty " + type + " name specified for subscription in: " + Arrays.toString(vals));
+                }
+            }
+            return List.of(vals);
         }
     }
 }

src/main/java/com/github/olivergondza/saxeed/Tag.java

@@ -13,12 +13,13 @@ public interface Tag {
     /**
      * Get element name.
      */
-    String getName();
+    TagName getName();
 
     /**
      * Determine if current tag's name is @name.
      */
     boolean isNamed(String name);
+    boolean isNamed(TagName name);
 
     /**
      * Get Tag's parent
@@ -33,13 +34,15 @@ public interface Tag {
      * @return null for root tag, or when parent name differs, parent otherwise.
      */
     Tag getParent(String name);
+    Tag getParent(TagName name);
 
     /**
      * Get the closest ancestor (wrapping tag) its name is @name.
      *
      * @return null if there is no such ancestor, ancestor otherwise.
      */
     Tag getAncestor(String name);
+    Tag getAncestor(TagName name);
 
     /**
      * Get modifiable attribute map.
@@ -98,6 +101,8 @@ interface Start extends Tag {
          */
         Tag.Start addChild(String name);
 
+        Tag.Start addChild(TagName name);
+
         /**
          * Add new parent element for the current tag.
          *
@@ -107,10 +112,22 @@ interface Start extends Tag {
          */
         Tag.Start wrapWith(String name);
 
+        Tag.Start wrapWith(TagName name);
+
         /**
          * Set text to write after opening tag.
          */
         void addText(String text);
+
+        /**
+         * Declare new namespace on this tag.
+         *
+         * Note that tag name will not be converted to us this prefix
+         *
+         * @param uri Namespace URI
+         * @param prefix Namespace prefix, can be "" for default namespace.
+         */
+        void declareNamespace(String uri, String prefix);
     }
 
     interface Chars extends Tag {
@@ -124,6 +141,8 @@ interface Chars extends Tag {
          */
         Tag.Start addChild(String name);
 
+        Tag.Start addChild(TagName name);
+
         /**
          * Set text to write before closing tag.
          */
@@ -145,6 +164,8 @@ interface End extends Tag {
          */
         Tag.Start addChild(String name);
 
+        Tag.Start addChild(TagName name);
+
         /**
          * Set text to write before closing tag.
          */

src/main/java/com/github/olivergondza/saxeed/TagName.java

@@ -0,0 +1,86 @@
+package com.github.olivergondza.saxeed;
+
+import java.util.Objects;
+
+/**
+ * Namespace aware tag name.
+ */
+public class TagName {
+
+    private final String local;
+    private final String qName;
+
+    private final String uri;
+    private final String prefix;
+
+    public static TagName fromSaxArgs(String uri, String localName, String qName) {
+        boolean noNsInTagName = Objects.equals(localName, qName);
+        if (uri.isEmpty()) {
+            assert noNsInTagName;
+            return new TagName("", "", localName);
+        }
+
+        assert qName.endsWith(localName): String.format("Tag name ('%s') does not start with local name ('%s')", qName, localName);
+
+        if (noNsInTagName) {
+            return new TagName(uri, "", localName);
+        }
+
+        return new TagName(uri, qName.replaceFirst(":.*", ""), localName);
+    }
+
+    public static TagName noNs(String local) {
+        return new TagName("", "", local);
+    }
+
+    public static TagName withNs(String uri, String local) {
+        return new TagName(uri, "", local);
+    }
+
+    public static TagName withNs(String uri, String prefix, String local) {
+        return new TagName(uri, prefix, local);
+    }
+
+    /**
+     * Create tag in specified namespace.
+     */
+    public TagName(String uri, String prefix, String local) {
+        this.uri = Objects.requireNonNull(uri);
+        this.prefix = Objects.requireNonNull(prefix);
+        this.local = Objects.requireNonNull(local);
+
+        if (local.isEmpty()) throw new IllegalArgumentException("Tag cannot have local name an empty string");
+
+        if (uri.isEmpty() && !prefix.isEmpty()) throw new IllegalArgumentException("Tag cannot have NS name, but no NS URI");
+
+        qName = prefix.isEmpty()
+                ? local
+                : prefix + ":" + local
+        ;
+    }
+
+    @Override
+    public String toString() {
+        return String.format("TagName{local='%s', uri='%s', ns='%s'}", local, uri, prefix);
+    }
+
+    public String getNsUri() {
+        return uri;
+    }
+
+    public String getNsPrefix() {
+        return prefix;
+    }
+
+    public String getLocal() {
+        return local;
+    }
+
+    public String getQualifiedName() {
+        return qName;
+    }
+
+    public TagName inheritNamespace(String name) {
+        return new TagName(uri, prefix, name);
+    }
+}

src/main/java/com/github/olivergondza/saxeed/TransformationBuilder.java

@@ -14,11 +14,11 @@ public TransformationBuilder() {
     }
 
     public TransformationBuilder add(String tagName, List<UpdatingVisitor> visitors) {
-        return add(Subscribed.to(tagName), visitors);
+        return add(Subscribed.to().tagNames(tagName).build(), visitors);
     }
 
     public TransformationBuilder add(String tagName, UpdatingVisitor visitor) {
-        return add(Subscribed.to(tagName), visitor);
+        return add(Subscribed.to().tagNames(tagName).build(), visitor);
     }
 
     public TransformationBuilder add(Subscribed subs, UpdatingVisitor visitor) {