| /* |
| * 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 com.opensymphony.xwork2.util; |
| |
| import java.util.Map; |
| |
| /** |
| * ValueStack allows multiple beans to be pushed in and dynamic EL expressions to be evaluated against it. When |
| * evaluating an expression, the stack will be searched down the stack, from the latest objects pushed in to the |
| * earliest, looking for a bean with a getter or setter for the given property or a method of the given name (depending |
| * on the expression being evaluated). |
| */ |
| public interface ValueStack { |
| |
| public static final String VALUE_STACK = "com.opensymphony.xwork2.util.ValueStack.ValueStack"; |
| |
| public static final String REPORT_ERRORS_ON_NO_PROP = "com.opensymphony.xwork2.util.ValueStack.ReportErrorsOnNoProp"; |
| |
| /** |
| * Gets the context for this value stack. The context holds all the information in the value stack and it's surroundings. |
| * |
| * @return the context. |
| */ |
| public abstract Map<String, Object> getContext(); |
| |
| /** |
| * Sets the default type to convert to if no type is provided when getting a value. |
| * |
| * @param defaultType the new default type |
| */ |
| public abstract void setDefaultType(Class defaultType); |
| |
| /** |
| * Set a override map containing <code> key -> values </code> that takes precedent when doing find operations on the ValueStack. |
| * <p> |
| * See the unit test for ValueStackTest for examples. |
| * </p> |
| * |
| * @param overrides overrides map. |
| */ |
| public abstract void setExprOverrides(Map<Object, Object> overrides); |
| |
| /** |
| * Gets the override map if anyone exists. |
| * |
| * @return the override map, <tt>null</tt> if not set. |
| */ |
| public abstract Map<Object, Object> getExprOverrides(); |
| |
| /** |
| * Get the CompoundRoot which holds the objects pushed onto the stack |
| * |
| * @return the root |
| */ |
| public abstract CompoundRoot getRoot(); |
| |
| /** |
| * Attempts to set a property on a bean in the stack with the given expression using the default search order. |
| * |
| * @param expr the expression defining the path to the property to be set. |
| * @param value the value to be set into the named property |
| */ |
| public abstract void setValue(String expr, Object value); |
| |
| /** |
| * Attempts to set a property on a bean in the stack with the given expression using the default search order. |
| * N.B.: unlike #setValue(String,Object) it doesn't allow eval expression. |
| * @param expr the expression defining the path to the property to be set. |
| * @param value the value to be set into the named property |
| */ |
| void setParameter(String expr, Object value); |
| |
| /** |
| * Attempts to set a property on a bean in the stack with the given expression using the default search order. |
| * |
| * @param expr the expression defining the path to the property to be set. |
| * @param value the value to be set into the named property |
| * @param throwExceptionOnFailure a flag to tell whether an exception should be thrown if there is no property with |
| * the given name. |
| */ |
| public abstract void setValue(String expr, Object value, boolean throwExceptionOnFailure); |
| |
| public abstract String findString(String expr); |
| public abstract String findString(String expr, boolean throwExceptionOnFailure); |
| |
| /** |
| * Find a value by evaluating the given expression against the stack in the default search order. |
| * |
| * @param expr the expression giving the path of properties to navigate to find the property value to return |
| * @return the result of evaluating the expression |
| */ |
| public abstract Object findValue(String expr); |
| |
| public abstract Object findValue(String expr, boolean throwExceptionOnFailure); |
| |
| /** |
| * Find a value by evaluating the given expression against the stack in the default search order. |
| * |
| * @param expr the expression giving the path of properties to navigate to find the property value to return |
| * @param asType the type to convert the return value to |
| * @return the result of evaluating the expression |
| */ |
| public abstract Object findValue(String expr, Class asType); |
| public abstract Object findValue(String expr, Class asType, boolean throwExceptionOnFailure); |
| |
| /** |
| * Get the object on the top of the stack <b>without</b> changing the stack. |
| * |
| * @return the object on the top. |
| * @see CompoundRoot#peek() |
| */ |
| public abstract Object peek(); |
| |
| /** |
| * Get the object on the top of the stack and <b>remove</b> it from the stack. |
| * |
| * @return the object on the top of the stack |
| * @see CompoundRoot#pop() |
| */ |
| public abstract Object pop(); |
| |
| /** |
| * Put this object onto the top of the stack |
| * |
| * @param o the object to be pushed onto the stack |
| * @see CompoundRoot#push(Object) |
| */ |
| public abstract void push(Object o); |
| |
| /** |
| * Sets an object on the stack with the given key |
| * so it is retrievable by {@link #findValue(String)}, {@link #findValue(String, Class)} |
| * |
| * @param key the key |
| * @param o the object |
| */ |
| public abstract void set(String key, Object o); |
| |
| /** |
| * Get the number of objects in the stack |
| * |
| * @return the number of objects in the stack |
| */ |
| public abstract int size(); |
| |
| } |