init

java/org/apache/jasper/compiler/ScriptingVariabler.java

@@ -0,0 +1,157 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.jasper.compiler;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import javax.servlet.jsp.tagext.TagVariableInfo;
+import javax.servlet.jsp.tagext.VariableInfo;
+
+import org.apache.jasper.JasperException;
+
+/**
+ * Class responsible for determining the scripting variables that every
+ * custom action needs to declare.
+ *
+ * @author Jan Luehe
+ */
+class ScriptingVariabler {
+
+    private static final Integer MAX_SCOPE = Integer.valueOf(Integer.MAX_VALUE);
+
+    /*
+     * Assigns an identifier (of type integer) to every custom tag, in order
+     * to help identify, for every custom tag, the scripting variables that it
+     * needs to declare.
+     */
+    private static class CustomTagCounter extends Node.Visitor {
+
+        private int count;
+        private Node.CustomTag parent;
+
+        @Override
+        public void visit(Node.CustomTag n) throws JasperException {
+            n.setCustomTagParent(parent);
+            Node.CustomTag tmpParent = parent;
+            parent = n;
+            visitBody(n);
+            parent = tmpParent;
+            n.setNumCount(Integer.valueOf(count++));
+        }
+    }
+
+    /*
+     * For every custom tag, determines the scripting variables it needs to
+     * declare.
+     */
+    private static class ScriptingVariableVisitor extends Node.Visitor {
+
+        private final ErrorDispatcher err;
+        private final Map<String, Integer> scriptVars;
+
+        public ScriptingVariableVisitor(ErrorDispatcher err) {
+            this.err = err;
+            scriptVars = new HashMap<>();
+        }
+
+        @Override
+        public void visit(Node.CustomTag n) throws JasperException {
+            setScriptingVars(n, VariableInfo.AT_BEGIN);
+            setScriptingVars(n, VariableInfo.NESTED);
+            visitBody(n);
+            setScriptingVars(n, VariableInfo.AT_END);
+        }
+
+        private void setScriptingVars(Node.CustomTag n, int scope)
+                throws JasperException {
+
+            TagVariableInfo[] tagVarInfos = n.getTagVariableInfos();
+            VariableInfo[] varInfos = n.getVariableInfos();
+            if (tagVarInfos.length == 0 && varInfos.length == 0) {
+                return;
+            }
+
+            List<Object> vec = new ArrayList<>();
+
+            Integer ownRange = null;
+            Node.CustomTag parent = n.getCustomTagParent();
+            if (scope == VariableInfo.AT_BEGIN
+                    || scope == VariableInfo.AT_END) {
+                if (parent == null)
+                    ownRange = MAX_SCOPE;
+                else
+                    ownRange = parent.getNumCount();
+            } else {
+                // NESTED
+                ownRange = n.getNumCount();
+            }
+
+            if (varInfos.length > 0) {
+                for (int i=0; i<varInfos.length; i++) {
+                    if (varInfos[i].getScope() != scope
+                            || !varInfos[i].getDeclare()) {
+                        continue;
+                    }
+                    String varName = varInfos[i].getVarName();
+
+                    Integer currentRange = scriptVars.get(varName);
+                    if (currentRange == null ||
+                            ownRange.compareTo(currentRange) > 0) {
+                        scriptVars.put(varName, ownRange);
+                        vec.add(varInfos[i]);
+                    }
+                }
+            } else {
+                for (int i=0; i<tagVarInfos.length; i++) {
+                    if (tagVarInfos[i].getScope() != scope
+                            || !tagVarInfos[i].getDeclare()) {
+                        continue;
+                    }
+                    String varName = tagVarInfos[i].getNameGiven();
+                    if (varName == null) {
+                        varName = n.getTagData().getAttributeString(
+                                        tagVarInfos[i].getNameFromAttribute());
+                        if (varName == null) {
+                            err.jspError(n,
+                                    "jsp.error.scripting.variable.missing_name",
+                                    tagVarInfos[i].getNameFromAttribute());
+                        }
+                    }
+
+                    Integer currentRange = scriptVars.get(varName);
+                    if (currentRange == null ||
+                            ownRange.compareTo(currentRange) > 0) {
+                        scriptVars.put(varName, ownRange);
+                        vec.add(tagVarInfos[i]);
+                    }
+                }
+            }
+
+            n.setScriptingVars(vec, scope);
+        }
+    }
+
+    public static void set(Node.Nodes page, ErrorDispatcher err)
+            throws JasperException {
+        page.visit(new CustomTagCounter());
+        page.visit(new ScriptingVariableVisitor(err));
+    }
+}