Moved import resolving logic to resolvers (#11776)

* made resolvers style sheet specific

Change-Id: Iab7e755d9e3214896c100dfde10727a1353c4354

6 files changed, 124 insertions, 56 deletions

diff --git a/theme-compiler/src/com/vaadin/sass/internal/ScssStylesheet.java b/theme-compiler/src/com/vaadin/sass/internal/ScssStylesheet.java
index 704425e300..7213553e18 100644
--- a/theme-compiler/src/com/vaadin/sass/internal/ScssStylesheet.java
+++ b/theme-compiler/src/com/vaadin/sass/internal/ScssStylesheet.java
@@ -19,10 +19,10 @@ package com.vaadin.sass.internal;
 import java.io.File;
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.logging.Logger;
 
@@ -35,8 +35,9 @@ import com.vaadin.sass.internal.handler.SCSSErrorHandler;
 import com.vaadin.sass.internal.parser.ParseException;
 import com.vaadin.sass.internal.parser.Parser;
 import com.vaadin.sass.internal.parser.SCSSParseException;
+import com.vaadin.sass.internal.resolver.ClassloaderResolver;
+import com.vaadin.sass.internal.resolver.FilesystemResolver;
 import com.vaadin.sass.internal.resolver.ScssStylesheetResolver;
-import com.vaadin.sass.internal.resolver.VaadinResolver;
 import com.vaadin.sass.internal.tree.BlockNode;
 import com.vaadin.sass.internal.tree.MixinDefNode;
 import com.vaadin.sass.internal.tree.Node;
@@ -63,6 +64,8 @@ public class ScssStylesheet extends Node {
 
     private String charset;
 
+    private List<ScssStylesheetResolver> resolvers = new ArrayList<ScssStylesheetResolver>();
+
     /**
      * Read in a file SCSS and parse it into a ScssStylesheet
      * 
@@ -101,8 +104,8 @@ public class ScssStylesheet extends Node {
      * @throws CSSException
      * @throws IOException
      */
-    public static ScssStylesheet get(String identifier, String encoding)
-            throws CSSException, IOException {
+    public static ScssStylesheet get(String identifier,
+            ScssStylesheet parentStylesheet) throws CSSException, IOException {
         /*
          * The encoding to be used is passed through "encoding" parameter. the
          * imported children scss node will have the same encoding as their
@@ -122,12 +125,22 @@ public class ScssStylesheet extends Node {
 
         SCSSDocumentHandler handler = new SCSSDocumentHandlerImpl();
         ScssStylesheet stylesheet = handler.getStyleSheet();
-
-        InputSource source = stylesheet.resolveStylesheet(identifier);
+        if (parentStylesheet == null) {
+            // Use default resolvers
+            stylesheet.addResolver(new FilesystemResolver());
+            stylesheet.addResolver(new ClassloaderResolver());
+        } else {
+            // Use parent resolvers
+            stylesheet.setResolvers(parentStylesheet.getResolvers());
+        }
+        InputSource source = stylesheet.resolveStylesheet(identifier,
+                parentStylesheet);
         if (source == null) {
             return null;
         }
-        source.setEncoding(encoding);
+        if (parentStylesheet != null) {
+            source.setEncoding(parentStylesheet.getCharset());
+        }
 
         Parser parser = new Parser();
         parser.setErrorHandler(new SCSSErrorHandler());
@@ -145,21 +158,10 @@ public class ScssStylesheet extends Node {
         return stylesheet;
     }
 
-    private static ScssStylesheetResolver[] resolvers = null;
-
-    public static void setStylesheetResolvers(
-            ScssStylesheetResolver... styleSheetResolvers) {
-        resolvers = Arrays.copyOf(styleSheetResolvers,
-                styleSheetResolvers.length);
-    }
-
-    public InputSource resolveStylesheet(String identifier) {
-        if (resolvers == null) {
-            setStylesheetResolvers(new VaadinResolver());
-        }
-
-        for (ScssStylesheetResolver resolver : resolvers) {
-            InputSource source = resolver.resolve(identifier);
+    public InputSource resolveStylesheet(String identifier,
+            ScssStylesheet parentStylesheet) {
+        for (ScssStylesheetResolver resolver : getResolvers()) {
+            InputSource source = resolver.resolve(parentStylesheet, identifier);
             if (source != null) {
                 File f = new File(source.getURI());
                 setFile(f);
@@ -171,6 +173,38 @@ public class ScssStylesheet extends Node {
     }
 
     /**
+     * Retrieves a list of resolvers to use when resolving imports
+     * 
+     * @since 7.2
+     * @return the resolvers used to resolving imports
+     */
+    public List<ScssStylesheetResolver> getResolvers() {
+        return Collections.unmodifiableList(resolvers);
+    }
+
+    /**
+     * Sets the list of resolvers to use when resolving imports
+     * 
+     * @since 7.2
+     * @param resolvers
+     *            the resolvers to set
+     */
+    public void setResolvers(List<ScssStylesheetResolver> resolvers) {
+        this.resolvers = new ArrayList<ScssStylesheetResolver>(resolvers);
+    }
+
+    /**
+     * Adds the given resolver to the resolver list
+     * 
+     * @since 7.2
+     * @param resolver
+     *            The resolver to add
+     */
+    public void addResolver(ScssStylesheetResolver resolver) {
+        resolvers.add(resolver);
+    }
+
+    /**
      * Applies all the visitors and compiles SCSS into Css.
      * 
      * @throws Exception
diff --git a/theme-compiler/src/com/vaadin/sass/internal/resolver/VaadinResolver.java b/theme-compiler/src/com/vaadin/sass/internal/resolver/AbstractResolver.java
index fec16a54c8..ac11f1fa0e 100644
--- a/theme-compiler/src/com/vaadin/sass/internal/resolver/VaadinResolver.java
+++ b/theme-compiler/src/com/vaadin/sass/internal/resolver/AbstractResolver.java
@@ -13,45 +13,87 @@
  * License for the specific language governing permissions and limitations under
  * the License.
  */
+
 package com.vaadin.sass.internal.resolver;
 
 import java.io.File;
+import java.io.Serializable;
 import java.util.Stack;
 
 import org.w3c.css.sac.InputSource;
 
-public class VaadinResolver implements ScssStylesheetResolver {
+import com.vaadin.sass.internal.ScssStylesheet;
 
+/**
+ * Base class for resolvers. Implements functionality for locating paths which
+ * an import can be relative to and helpers for extracting path information from
+ * the identifier.
+ * 
+ * @since 7.2
+ * @author Vaadin Ltd
+ */
+public abstract class AbstractResolver implements ScssStylesheetResolver,
+        Serializable {
+    /*
+     * (non-Javadoc)
+     * 
+     * @see
+     * com.vaadin.sass.internal.resolver.ScssStylesheetResolver#resolve(java
+     * .lang.String)
+     */
     @Override
-    public InputSource resolve(String identifier) {
-
-        // Remove extra "." and ".."
-        identifier = normalize(identifier);
-
+    public InputSource resolve(ScssStylesheet parentStylesheet,
+            String identifier) {
         InputSource source = null;
-
-        // Can we find the scss from the file system?
-        ScssStylesheetResolver resolver = new FilesystemResolver();
-        source = resolver.resolve(identifier);
+        if (parentStylesheet != null) {
+            StringBuilder filePathBuilder = new StringBuilder(
+                    parentStylesheet.getFileName());
+            filePathBuilder.append(File.separatorChar).append(identifier);
+            if (!filePathBuilder.toString().endsWith(".scss")) {
+                filePathBuilder.append(".scss");
+            }
+            source = normalizeAndResolve(filePathBuilder.toString());
+        }
 
         if (source == null) {
-            // How about the classpath?
-            resolver = new ClassloaderResolver();
-            source = resolver.resolve(identifier);
+            source = normalizeAndResolve(identifier);
         }
 
         return source;
     }
 
     /**
+     * Resolves the normalized version of the given identifier
+     * 
+     * @param identifier
+     *            The identifier to resolve
+     * @return An input source if the resolver found one or null otherwise
+     */
+    protected InputSource normalizeAndResolve(String identifier) {
+        String normalized = normalize(identifier);
+        return resolveNormalized(normalized);
+    }
+
+    /**
+     * Resolves the identifier after it has been normalized using
+     * {@link #normalize(String)}.
+     * 
+     * @param identifier
+     *            The normalized identifier
+     * @return an InputSource if the resolver found a source or null otherwise
+     */
+    protected abstract InputSource resolveNormalized(String identifier);
+
+    /**
      * Normalizes "." and ".." from the path string where parent path segments
-     * can be removed. Preserve leading "..".
+     * can be removed. Preserve leading "..". Also ensure / is used instead of \
+     * in all places.
      * 
      * @param path
      *            A relative or absolute file path
      * @return The normalized path
      */
-    private static String normalize(String path) {
+    protected String normalize(String path) {
 
         // Ensure only "/" is used, also in Windows
         path = path.replace(File.separatorChar, '/');
diff --git a/theme-compiler/src/com/vaadin/sass/internal/resolver/ClassloaderResolver.java b/theme-compiler/src/com/vaadin/sass/internal/resolver/ClassloaderResolver.java
index 8711a0a3e9..68752b459a 100644
--- a/theme-compiler/src/com/vaadin/sass/internal/resolver/ClassloaderResolver.java
+++ b/theme-compiler/src/com/vaadin/sass/internal/resolver/ClassloaderResolver.java
@@ -20,10 +20,10 @@ import java.io.InputStream;
 
 import org.w3c.css.sac.InputSource;
 
-public class ClassloaderResolver implements ScssStylesheetResolver {
+public class ClassloaderResolver extends AbstractResolver {
 
     @Override
-    public InputSource resolve(String identifier) {
+    public InputSource resolveNormalized(String identifier) {
         // identifier should not have .scss, fileName should
         String ext = ".scss";
         if (identifier.endsWith(".css")) {
diff --git a/theme-compiler/src/com/vaadin/sass/internal/resolver/FilesystemResolver.java b/theme-compiler/src/com/vaadin/sass/internal/resolver/FilesystemResolver.java
index 9bb1969ab1..3fec33ae13 100644
--- a/theme-compiler/src/com/vaadin/sass/internal/resolver/FilesystemResolver.java
+++ b/theme-compiler/src/com/vaadin/sass/internal/resolver/FilesystemResolver.java
@@ -21,10 +21,10 @@ import java.io.InputStream;
 
 import org.w3c.css.sac.InputSource;
 
-public class FilesystemResolver implements ScssStylesheetResolver {
+public class FilesystemResolver extends AbstractResolver {
 
     @Override
-    public InputSource resolve(String identifier) {
+    public InputSource resolveNormalized(String identifier) {
         // identifier should not have .scss, fileName should
         String ext = ".scss";
         if (identifier.endsWith(".css")) {
diff --git a/theme-compiler/src/com/vaadin/sass/internal/resolver/ScssStylesheetResolver.java b/theme-compiler/src/com/vaadin/sass/internal/resolver/ScssStylesheetResolver.java
index 45f10836a3..64b3d10d88 100644
--- a/theme-compiler/src/com/vaadin/sass/internal/resolver/ScssStylesheetResolver.java
+++ b/theme-compiler/src/com/vaadin/sass/internal/resolver/ScssStylesheetResolver.java
@@ -17,6 +17,8 @@ package com.vaadin.sass.internal.resolver;
 
 import org.w3c.css.sac.InputSource;
 
+import com.vaadin.sass.internal.ScssStylesheet;
+
 public interface ScssStylesheetResolver {
     /**
      * Called with the "identifier" of a stylesheet that the resolver should try
@@ -26,9 +28,12 @@ public interface ScssStylesheetResolver {
      * stylesheet was found, e.g "runo.scss" might result in a URI like
      * "VAADIN/themes/runo/runo.scss".
      * 
+     * @param parentStylesheet
+     *            The parent style sheet
      * @param identifier
      *            used fo find stylesheet
      * @return InputSource for stylesheet (with URI set) or null if not found
      */
-    public InputSource resolve(String identifier);
+    public InputSource resolve(ScssStylesheet parentStylesheet,
+            String identifier);
 }
\ No newline at end of file
diff --git a/theme-compiler/src/com/vaadin/sass/internal/visitor/ImportNodeHandler.java b/theme-compiler/src/com/vaadin/sass/internal/visitor/ImportNodeHandler.java
index 87c7cadcf8..e52767bb5a 100644
--- a/theme-compiler/src/com/vaadin/sass/internal/visitor/ImportNodeHandler.java
+++ b/theme-compiler/src/com/vaadin/sass/internal/visitor/ImportNodeHandler.java
@@ -16,7 +16,6 @@
 
 package com.vaadin.sass.internal.visitor;
 
-import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -57,21 +56,9 @@ public class ImportNodeHandler {
                 ImportNode importNode = (ImportNode) n;
                 if (!importNode.isPureCssImport()) {
                     try {
-                        StringBuilder filePathBuilder = new StringBuilder(
-                                styleSheet.getDirectory());
-                        filePathBuilder.append(File.separatorChar).append(
-                                importNode.getUri());
-                        if (!filePathBuilder.toString().endsWith(".scss")) {
-                            filePathBuilder.append(".scss");
-                        }
-
                         // set parent's charset to imported node.
                         ScssStylesheet imported = ScssStylesheet.get(
-                                filePathBuilder.toString(),
-                                styleSheet.getCharset());
-                        if (imported == null) {
-                            imported = ScssStylesheet.get(importNode.getUri());
-                        }
+                                importNode.getUri(), styleSheet);
                         if (imported == null) {
                             throw new FileNotFoundException("Import '"
                                     + importNode.getUri() + "' in '"