[xml-model] XML Completion based on DTD/XML Schema by using xml-model

Fixes #698

Signed-off-by: azerr <azerr@redhat.com>

org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/dom/DOMDocument.java

@@ -43,18 +43,17 @@
 import org.w3c.dom.DocumentFragment;
 import org.w3c.dom.EntityReference;
 import org.w3c.dom.NodeList;
-import org.w3c.dom.ProcessingInstruction;
 
 /**
  * XML document.
  *
  */
 public class DOMDocument extends DOMNode implements Document {
 
-	private static final String XML_MODEL_PI = "xml-model";
-
 	private SchemaLocation schemaLocation;
 	private NoNamespaceSchemaLocation noNamespaceSchemaLocation;
+	private List<XMLModel> xmlModels;
+
 	private boolean referencedExternalGrammarInitialized;
 	private boolean referencedSchemaInitialized;
 	private final URIResolverExtensionManager resolverExtensionManager;
@@ -255,13 +254,13 @@ private void initializeReferencedSchemaIfNeeded() {
 
 	/**
 	 * Initialize namespaces and schema location declaration .
-	 * 
-	 * @return
 	 */
 	private synchronized void initializeReferencedSchema() {
 		if (referencedSchemaInitialized) {
 			return;
 		}
+		// xml-model
+		xmlModels = XMLModel.createXMLModels(this);
 		// Get root element
 		DOMElement documentElement = getDocumentElement();
 		if (documentElement == null) {
@@ -308,15 +307,16 @@ public boolean hasProlog() {
 		return (children != null && !children.isEmpty() && children.get(0).isProlog());
 	}
 
-	private SchemaLocation createSchemaLocation(DOMNode root, String schemaInstancePrefix) {
+	private static SchemaLocation createSchemaLocation(DOMNode root, String schemaInstancePrefix) {
 		DOMAttr attr = root.getAttributeNode(getPrefixedName(schemaInstancePrefix, "schemaLocation"));
 		if (attr == null) {
 			return null;
 		}
 		return new SchemaLocation(root.getOwnerDocument().getDocumentURI(), attr);
 	}
 
-	private NoNamespaceSchemaLocation createNoNamespaceSchemaLocation(DOMNode root, String schemaInstancePrefix) {
+	private static NoNamespaceSchemaLocation createNoNamespaceSchemaLocation(DOMNode root,
+			String schemaInstancePrefix) {
 		DOMAttr attr = root.getAttributeNode(getPrefixedName(schemaInstancePrefix, "noNamespaceSchemaLocation"));
 		if (attr == null || attr.getValue() == null) {
 			return null;
@@ -344,18 +344,20 @@ public boolean hasDTD() {
 	 * @return true if XML document has a xml-model processing declaration and false
 	 *         otherwise.
 	 */
-	private boolean hasXMLModel() {
-		List<DOMNode> children = getChildren();
-		if (children != null && !children.isEmpty()) {
-			return children.stream().anyMatch(child -> {
-				return isXMLModel(child);
-			});
-		}
-		return false;
+	public boolean hasXMLModel() {
+		return !getXMLModels().isEmpty();
 	}
 
-	private static boolean isXMLModel(DOMNode node) {
-		return node.isProcessingInstruction() && XML_MODEL_PI.equals(((ProcessingInstruction) node).getTarget());
+	/**
+	 * Returns the list of xml-model processing instruction declared in the
+	 * document.
+	 * 
+	 * @return the list of xml-model processing instruction declared in the
+	 *         document.
+	 */
+	public List<XMLModel> getXMLModels() {
+		initializeReferencedSchemaIfNeeded();
+		return xmlModels;
 	}
 
 	// -------------------------- External Grammar (XML file associations, catalog)

org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/dom/XMLModel.java

@@ -0,0 +1,86 @@
+/*******************************************************************************
+* Copyright (c) 2020 Red Hat Inc. and others.
+* All rights reserved. This program and the accompanying materials
+* which accompanies this distribution, and is available at
+* http://www.eclipse.org/legal/epl-v20.html
+*
+* SPDX-License-Identifier: EPL-2.0
+*
+* Contributors:
+*     Red Hat Inc. - initial API and implementation
+*******************************************************************************/
+package org.eclipse.lemminx.dom;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.eclipse.lemminx.extensions.xerces.xmlmodel.XMLModelDeclaration;
+import org.w3c.dom.ProcessingInstruction;
+
+/**
+ * XML model processing instruction.
+ * 
+ * <pre>
+ * 	&lt;?xml-model href="http://www.docbook.org/xml/5.0/xsd/docbook.xsd"?&gt;
+ * </pre>
+ * 
+ * 
+ * @see https://www.w3.org/TR/xml-model/
+ */
+public class XMLModel {
+
+	private static final String XML_MODEL_PI = "xml-model";
+
+	private final DOMProcessingInstruction processingInstruction;
+	private XMLModelDeclaration declaration;
+
+	public XMLModel(DOMProcessingInstruction processingInstruction) {
+		this.processingInstruction = processingInstruction;
+	}
+
+	/**
+	 * Returns the location of the referenced schema
+	 * 
+	 * @return the location of the referenced schema
+	 */
+	public String getHref() {
+		String data = processingInstruction.getData();
+		if (data == null) {
+			return null;
+		}
+		if (declaration == null) {
+			declaration = XMLModelDeclaration.parse(data.toCharArray(), 0, data.length());
+		}
+		return declaration.getHref();
+	}
+
+	/**
+	 * Returns the declared xml-model list.
+	 * 
+	 * @param document the DOM document.
+	 * 
+	 * @return the declared xml-model list.
+	 */
+	static List<XMLModel> createXMLModels(DOMDocument document) {
+		List<DOMNode> children = document.getChildren();
+		if (children != null && !children.isEmpty()) {
+			return children.stream().filter(XMLModel::isXMLModel)
+					.map(node -> new XMLModel((DOMProcessingInstruction) node)).collect(Collectors.toList());
+		}
+		return Collections.emptyList();
+	}
+
+	/**
+	 * Returns true if the given node is a xml-model processing instruction and
+	 * false otherwise.
+	 * 
+	 * @param node the DOM node.
+	 * @return true if the given node is a xml-model processing instruction and
+	 *         false otherwise.
+	 */
+	public static boolean isXMLModel(DOMNode node) {
+		return node.isProcessingInstruction() && XML_MODEL_PI.equals(((ProcessingInstruction) node).getTarget());
+	}
+
+}

org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/contentmodel/model/CMDocument.java

@@ -52,14 +52,25 @@ public interface CMDocument {
 	 * @return the declared element which matches the given XML element and null
 	 *         otherwise.
 	 */
-	CMElementDeclaration findCMElement(DOMElement element, String namespace);
+	default CMElementDeclaration findCMElement(DOMElement element) {
+		return findCMElement(element, element.getNamespaceURI());
+	}
 
 	/**
-	 * Returns the root URI of the model document.
+	 * Returns the declared element which matches the given XML element and null
+	 * otherwise.
 	 * 
-	 * @return the root URI of the model document.
+	 * @param element   the XML element
+	 * @param namespace the given namespace
+	 * @return the declared element which matches the given XML element and null
+	 *         otherwise.
 	 */
-	String getURI();
+	CMElementDeclaration findCMElement(DOMElement element, String namespace);
+
+	default CMAttributeDeclaration findCMAttribute(DOMElement element, String attributeName) {
+		CMElementDeclaration elementDeclaration = findCMElement(element);
+		return elementDeclaration != null ? elementDeclaration.findCMAttribute(attributeName) : null;
+	}
 
 	/**
 	 * Returns the location of the type definition of the given node.

org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/contentmodel/model/ContentModelManager.java

@@ -14,6 +14,7 @@
 
 import java.nio.file.Path;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -63,31 +64,78 @@ public ContentModelManager(URIResolverExtensionManager resolverManager) {
 		setUseCache(true);
 	}
 
-	public CMElementDeclaration findCMElement(DOMElement element) throws Exception {
-		return findCMElement(element, element.getNamespaceURI());
+	/**
+	 * Returns the owner document of the declared element which matches the given
+	 * XML element and null otherwise.
+	 * 
+	 * @param element the XML element
+	 * 
+	 * @return the owner document of the declared element which matches the given
+	 *         XML element and null otherwise.
+	 */
+	public Collection<CMDocument> findCMDocument(DOMElement element) {
+		return findCMDocument(element.getOwnerDocument(), element.getNamespaceURI());
 	}
 
 	/**
-	 * Returns the declared element which matches the given XML element and null
-	 * otherwise.
+	 * Returns the owner document of the declared element which matches the given
+	 * XML element and null otherwise.
 	 * 
 	 * @param element the XML element
-	 * @return the declared element which matches the given XML element and null
-	 *         otherwise.
+	 * 
+	 * @return the owner document of the declared element which matches the given
+	 *         XML element and null otherwise.
 	 */
-	public CMElementDeclaration findCMElement(DOMElement element, String namespaceURI) throws Exception {
-		CMDocument cmDocument = findCMDocument(element, namespaceURI);
-		return cmDocument != null ? cmDocument.findCMElement(element, namespaceURI) : null;
+	public Collection<CMDocument> findCMDocument(DOMElement element, String namespaceURI) {
+		return findCMDocument(element.getOwnerDocument(), namespaceURI);
 	}
 
-	public CMDocument findCMDocument(DOMElement element, String namespaceURI) {
-		return findCMDocument(element.getOwnerDocument(), namespaceURI);
+	public Collection<CMDocument> findCMDocument(DOMDocument xmlDocument, String namespaceURI) {
+		return findCMDocument(xmlDocument, namespaceURI, true);
 	}
 
-	public CMDocument findCMDocument(DOMDocument xmlDocument, String namespaceURI) {
-		ContentModelProvider modelProvider = getModelProviderByStandardAssociation(xmlDocument, false);
-		String systemId = modelProvider != null ? modelProvider.getSystemId(xmlDocument, namespaceURI) : null;
-		return findCMDocument(xmlDocument.getDocumentURI(), namespaceURI, systemId, modelProvider);
+	/**
+	 * Returns the declared documents which match the given DOM document and null
+	 * otherwise.
+	 * 
+	 * @param xmlDocument  the DOM document.
+	 * @param namespaceURI the namespace URI
+	 * @return the declared documents which match the given DOM document and null
+	 *         otherwise.
+	 */
+	public Collection<CMDocument> findCMDocument(DOMDocument xmlDocument, String namespaceURI, boolean withInternal) {
+		Collection<CMDocument> documents = new ArrayList<>();
+		for (ContentModelProvider modelProvider : modelProviders) {
+			// internal grammar
+			if (withInternal) {
+				CMDocument internalCMDocument = modelProvider.createInternalCMDocument(xmlDocument);
+				if (internalCMDocument != null) {
+					documents.add(internalCMDocument);
+				}
+			}
+			// external grammar
+			if (modelProvider.adaptFor(xmlDocument, false)) {
+				// The content model provider can collect the system ids
+				// ex for <?xml-model , the model provider which takes care of xml-model returns
+				// the href of xml-model.
+				Collection<String> systemIds = modelProvider.getSystemIds(xmlDocument, namespaceURI);
+				for (String systemId : systemIds) {
+					// get the content model document from the current system id
+					CMDocument cmDocument = findCMDocument(xmlDocument.getDocumentURI(), namespaceURI, systemId,
+							modelProvider);
+					if (cmDocument != null) {
+						documents.add(cmDocument);
+					}
+				}
+			}
+		}
+		if (documents.isEmpty()) {
+			CMDocument cmDocument = findCMDocument(xmlDocument.getDocumentURI(), namespaceURI, null, null);
+			if (cmDocument != null) {
+				documents.add(cmDocument);
+			}
+		}
+		return documents;
 	}
 
 	/**
@@ -103,10 +151,18 @@ public boolean dependsOnGrammar(DOMDocument document, String grammarURI) {
 		if (StringUtils.isEmpty(grammarURI)) {
 			return false;
 		}
-		ContentModelProvider modelProvider = getModelProviderByStandardAssociation(document, false);
-		String systemId = modelProvider != null ? modelProvider.getSystemId(document, document.getNamespaceURI())
-				: null;
-		String key = resolverManager.resolve(document.getDocumentURI(), null, systemId);
+		for (ContentModelProvider modelProvider : modelProviders) {
+			if (modelProvider.adaptFor(document, false)) {
+				Collection<String> systemIds = modelProvider.getSystemIds(document, document.getNamespaceURI());
+				for (String systemId : systemIds) {
+					String key = resolverManager.resolve(document.getDocumentURI(), null, systemId);
+					if (grammarURI.equals(key)) {
+						return true;
+					}
+				}
+			}
+		}
+		String key = resolverManager.resolve(document.getDocumentURI(), null, null);
 		return grammarURI.equals(key);
 	}
 
@@ -187,55 +243,14 @@ private void cache(String key, CMDocument cmDocument) {
 		}
 	}
 
-	public CMElementDeclaration findInternalCMElement(DOMElement element) throws Exception {
-		return findInternalCMElement(element, element.getNamespaceURI());
-	}
-
 	/**
-	 * Returns the declared element which matches the given XML element and null
-	 * otherwise.
+	 * Returns the model provider by the given uri and null otherwise.
 	 * 
-	 * @param element the XML element
-	 * @return the declared element which matches the given XML element and null
-	 *         otherwise.
-	 */
-	public CMElementDeclaration findInternalCMElement(DOMElement element, String namespaceURI) throws Exception {
-		CMDocument cmDocument = findInternalCMDocument(element, namespaceURI);
-		return cmDocument != null ? cmDocument.findCMElement(element, namespaceURI) : null;
-	}
-
-	public CMDocument findInternalCMDocument(DOMElement element, String namespaceURI) {
-		return findInternalCMDocument(element.getOwnerDocument(), namespaceURI);
-	}
-
-	public CMDocument findInternalCMDocument(DOMDocument xmlDocument, String namespaceURI) {
-		ContentModelProvider modelProvider = getModelProviderByStandardAssociation(xmlDocument, true);
-		if (modelProvider != null) {
-			return modelProvider.createInternalCMDocument(xmlDocument);
-		}
-		return null;
-	}
-
-	/**
-	 * Returns the content model provider by using standard association
-	 * (xsi:schemaLocation, xsi:noNamespaceSchemaLocation, doctype) an dnull
-	 * otherwise.
+	 * @param uri the grammar URI
 	 * 
-	 * @param xmlDocument
-	 * @return the content model provider by using standard association
-	 *         (xsi:schemaLocation, xsi:noNamespaceSchemaLocation, doctype) an dnull
-	 *         otherwise.
+	 * @return the model provider by the given uri and null otherwise.
 	 */
-	private ContentModelProvider getModelProviderByStandardAssociation(DOMDocument xmlDocument, boolean internal) {
-		for (ContentModelProvider modelProvider : modelProviders) {
-			if (modelProvider.adaptFor(xmlDocument, internal)) {
-				return modelProvider;
-			}
-		}
-		return null;
-	}
-
-	private ContentModelProvider getModelProviderByURI(String uri) {
+	public ContentModelProvider getModelProviderByURI(String uri) {
 		for (ContentModelProvider modelProvider : modelProviders) {
 			if (modelProvider.adaptFor(uri)) {
 				return modelProvider;