Added document links for xsi:schemaLocation

Every second token for the value of xsi:schemaLocation is turned into a
document link to the referenced schema file.

Closes #666

Signed-off-by: David Thompson <[email protected]>

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

@@ -12,40 +12,62 @@
  */
 package org.eclipse.lemminx.dom;
 
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.StringTokenizer;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 /**
- * 
+ *
  * The declared "xsi:schemaLocation"
  */
 public class SchemaLocation {
 
-	private final Map<String, String> schemaLocationValuePairs;
+	private final Map<String, SchemaLocationHint> schemaLocationValuePairs;
 
 	private final DOMAttr attr;
 
+	// The text to match is of the form:
+	// http://example.org root.xsd http://example.org bison.xsd http://example.org potato.xsd
+	private static final Pattern SCHEMA_LOCATION_PAIR_PATTERN = Pattern.compile("\\s*([^\\s]+)\\s+([^\\s]+)\\s*");
+
 	public SchemaLocation(String base, DOMAttr attr) {
 		this.attr = attr;
 		this.schemaLocationValuePairs = new HashMap<>();
 		String value = attr.getValue();
-		StringTokenizer st = new StringTokenizer(value);
-		do {
-			String namespaceURI = st.hasMoreTokens() ? st.nextToken() : null;
-			String locationHint = st.hasMoreTokens() ? st.nextToken() : null;
+		Matcher locPairMatcher = SCHEMA_LOCATION_PAIR_PATTERN.matcher(value);
+		while (locPairMatcher.find()) {
+			String namespaceURI = locPairMatcher.group(1);
+			String locationHint = locPairMatcher.group(2);
 			if (namespaceURI == null || locationHint == null)
 				break;
-			schemaLocationValuePairs.put(namespaceURI, locationHint);
-		} while (true);
+			DOMNode valNode = attr.getNodeAttrValue();
+			// matcher matches 1 char ahead, but valNode's start is at beginning of "
+			int start = valNode.getStart() + locPairMatcher.start(2);
+			// matcher matches end correctly, but range needs to be one past end
+			// to highlight the end, and one to make up for "
+			int end = valNode.getStart() + locPairMatcher.end(2) + 2;
+			schemaLocationValuePairs.put(namespaceURI,
+					new SchemaLocationHint(start, end, locationHint, this));
+		}
 	}
 
 	public String getLocationHint(String namespaceURI) {
-		return schemaLocationValuePairs.get(namespaceURI);
+		return schemaLocationValuePairs.get(namespaceURI).getHint();
 	}
 
 	public DOMAttr getAttr() {
 		return attr;
 	}
 
+	/**
+	 * Gets all the location hints given in this xsi:schemaLocation attribute
+	 *
+	 * @return A Collection of all the location hints as <code>SchemaLocationHint</code>
+	 */
+	public Collection<SchemaLocationHint> getSchemaLocationHints() {
+		return schemaLocationValuePairs.values();
+	}
+
 }

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

@@ -0,0 +1,70 @@
+/**
+ * Copyright (c) 2018 Red Hat Inc.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v2.0
+ * 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;
+
+/**
+ * Represents one of the location hints provided in an xsi:schemaLocation attribute.
+ */
+public class SchemaLocationHint implements DOMRange {
+
+	private final int start, end;
+
+	private final String hint;
+
+	private final SchemaLocation parent;
+
+	/**
+	 *
+	 * @param start The offset from the beginning of the document where this location hint starts
+	 * @param end The offset from the beginning of the document where this location hint ends
+	 * @param hint The hint to the location of a schema (A URI that points to a schema)
+	 * @param parent The SchemaLocation in which this hint was given
+	 */
+	public SchemaLocationHint(int start, int end, String hint, SchemaLocation parent) {
+		this.start = start;
+		this.end = end;
+		this.hint = hint;
+		this.parent = parent;
+	}
+
+	/**
+	 * Get the location hint that this SchemaLocationHint represents
+	 *
+	 * @return The location hint, a URI to a schema, as a String
+	 */
+	public String getHint() {
+		return this.hint;
+	}
+
+	/**
+	 * @return The offset from the beginning of the document where this location hint starts
+	 */
+	@Override
+	public int getStart() {
+		return this.start;
+	}
+
+	/**
+	 * @return The offset from the beginning of the document where this location hint ends
+	 */
+	@Override
+	public int getEnd() {
+		return this.end;
+	}
+
+	@Override
+	public DOMDocument getOwnerDocument() {
+		return parent.getAttr().getOwnerDocument();
+	}
+
+}

org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/contentmodel/participants/ContentModelDocumentLinkParticipant.java

@@ -14,6 +14,7 @@
 
 import static org.eclipse.lemminx.utils.XMLPositionUtility.createDocumentLink;
 
+import java.util.Collection;
 import java.util.List;
 
 import org.apache.xerces.impl.XMLEntityManager;
@@ -23,18 +24,21 @@
 import org.eclipse.lemminx.dom.DOMDocumentType;
 import org.eclipse.lemminx.dom.DOMRange;
 import org.eclipse.lemminx.dom.NoNamespaceSchemaLocation;
+import org.eclipse.lemminx.dom.SchemaLocation;
+import org.eclipse.lemminx.dom.SchemaLocationHint;
 import org.eclipse.lemminx.dom.XMLModel;
 import org.eclipse.lemminx.services.extensions.IDocumentLinkParticipant;
 import org.eclipse.lsp4j.DocumentLink;
 
 /**
  * Document link for :
- * 
+ *
  * <ul>
  * <li>XML Schema xsi:noNamespaceSchemaLocation</li>
  * <li>DTD SYSTEM (ex : <!DOCTYPE root-element SYSTEM "./extended.dtd" )</li>
+ * <li>XML Schema xsi:schemaLocation</li>
  * </ul>
- * 
+ *
  * @author Angelo ZERR
  *
  */
@@ -88,11 +92,27 @@ public void findDocumentLinks(DOMDocument document, List<DocumentLink> links) {
 				}
 			}
 		}
+		// Doc link for xsi:schemaLocation
+		SchemaLocation schemaLocation = document.getSchemaLocation();
+		if (schemaLocation != null) {
+			try {
+				Collection<SchemaLocationHint> schemaLocationHints = schemaLocation.getSchemaLocationHints();
+				String location;
+				for (SchemaLocationHint schemaLocationHint : schemaLocationHints) {
+					location = getResolvedLocation(document.getDocumentURI(), schemaLocationHint.getHint());
+					if (location != null) {
+						links.add(createDocumentLink(schemaLocationHint, location));
+					}
+				}
+			} catch (BadLocationException e) {
+				// Do nothing
+			}
+		}
 	}
 
 	/**
 	 * Returns the expanded system location
-	 * 
+	 *
 	 * @return the expanded system location
 	 */
 	private static String getResolvedLocation(String documentURI, String location) {