| /* |
| * Copyright (C) 2010 Google Inc. |
| * |
| * Licensed 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 com.google.clearsilver.jsilver.functions; |
| |
| import com.google.clearsilver.jsilver.autoescape.EscapeMode; |
| |
| import com.google.clearsilver.jsilver.exceptions.JSilverInterpreterException; |
| import com.google.clearsilver.jsilver.values.Value; |
| |
| import java.io.IOException; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| /** |
| * Simple implementation of FunctionFinder that you can register your own functions with. |
| * |
| * @see FunctionExecutor |
| */ |
| public class FunctionRegistry implements FunctionExecutor { |
| |
| protected Map<String, Function> functions = new HashMap<String, Function>(); |
| protected Map<String, TextFilter> escapers = new HashMap<String, TextFilter>(); |
| |
| public FunctionRegistry() { |
| setupDefaultFunctions(); |
| } |
| |
| @Override |
| public Value executeFunction(String name, Value... args) { |
| Function function = functions.get(name); |
| if (function == null) { |
| throw new JSilverInterpreterException("Function not found " + name); |
| } |
| Value result = function.execute(args); |
| if (result == null) { |
| throw new JSilverInterpreterException("Function " + name + " did not return value"); |
| } |
| return result; |
| } |
| |
| @Override |
| public void escape(String name, String input, Appendable output) throws IOException { |
| if (name == null || name.isEmpty() || name.equals("none")) { |
| output.append(input); |
| } else { |
| TextFilter escaper = escapers.get(name); |
| if (escaper == null) { |
| throw new JSilverInterpreterException("Unknown escaper: " + name); |
| } |
| escaper.filter(input, output); |
| } |
| } |
| |
| @Override |
| public boolean isEscapingFunction(String name) { |
| Function function = functions.get(name); |
| if (function == null) { |
| throw new JSilverInterpreterException("Function not found " + name); |
| } |
| return function.isEscapingFunction(); |
| } |
| |
| /** |
| * Subclasses can override this to register their own functions. |
| */ |
| protected void setupDefaultFunctions() {} |
| |
| /** |
| * Register a Function with a given name. |
| */ |
| public void registerFunction(String name, Function function) { |
| functions.put(name, function); |
| } |
| |
| /** |
| * Register a TextFilter as a Function that takes a single String argument and returns the |
| * filtered value. |
| */ |
| public void registerFunction(String name, final TextFilter textFilter) { |
| registerFunction(name, textFilter, false); |
| } |
| |
| public void registerFunction(String name, final TextFilter textFilter, final boolean isEscaper) { |
| |
| // Adapt a TextFilter to the Function interface. |
| registerFunction(name, new Function() { |
| @Override |
| public Value execute(Value... args) { |
| if (args.length != 1) { |
| throw new IllegalArgumentException("Expected 1 argument"); |
| } |
| String in = args[0].asString(); |
| StringBuilder out = new StringBuilder(in.length()); |
| try { |
| textFilter.filter(in, out); |
| } catch (IOException e) { |
| throw new JSilverInterpreterException(e.getMessage()); |
| } |
| |
| EscapeMode mode; |
| boolean isPartiallyEscaped; |
| if (isEscaper) { |
| // This function escapes its input. Hence the output is |
| // partiallyEscaped. |
| mode = EscapeMode.ESCAPE_IS_CONSTANT; |
| isPartiallyEscaped = true; |
| } else { |
| mode = EscapeMode.ESCAPE_NONE; |
| isPartiallyEscaped = false; |
| for (Value arg : args) { |
| if (arg.isPartiallyEscaped()) { |
| isPartiallyEscaped = true; |
| break; |
| } |
| } |
| } |
| return Value.literalValue(out.toString(), mode, isPartiallyEscaped); |
| } |
| |
| public boolean isEscapingFunction() { |
| return isEscaper; |
| } |
| }); |
| } |
| |
| /** |
| * Registers an escaper, that is called when executing a <?cs escape ?> command. |
| * |
| * @param name The name with which <?cs escape ?> will invoke this escaper. |
| * @param escaper A TextFilter that implements the escaping functionality. |
| */ |
| public void registerEscapeMode(String name, TextFilter escaper) { |
| |
| escapers.put(name, escaper); |
| } |
| |
| } |