001/*
002 * Copyright 2002-2012 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.ui;
018
019import java.util.Collection;
020import java.util.Map;
021
022/**
023 * Java-5-specific interface that defines a holder for model attributes.
024 * Primarily designed for adding attributes to the model.
025 * Allows for accessing the overall model as a {@code java.util.Map}.
026 *
027 * @author Juergen Hoeller
028 * @since 2.5.1
029 */
030public interface Model {
031
032        /**
033         * Add the supplied attribute under the supplied name.
034         * @param attributeName the name of the model attribute (never {@code null})
035         * @param attributeValue the model attribute value (can be {@code null})
036         */
037        Model addAttribute(String attributeName, Object attributeValue);
038
039        /**
040         * Add the supplied attribute to this {@code Map} using a
041         * {@link org.springframework.core.Conventions#getVariableName generated name}.
042         * <p><emphasis>Note: Empty {@link java.util.Collection Collections} are not added to
043         * the model when using this method because we cannot correctly determine
044         * the true convention name. View code should check for {@code null} rather
045         * than for empty collections as is already done by JSTL tags.</emphasis>
046         * @param attributeValue the model attribute value (never {@code null})
047         */
048        Model addAttribute(Object attributeValue);
049
050        /**
051         * Copy all attributes in the supplied {@code Collection} into this
052         * {@code Map}, using attribute name generation for each element.
053         * @see #addAttribute(Object)
054         */
055        Model addAllAttributes(Collection<?> attributeValues);
056
057        /**
058         * Copy all attributes in the supplied {@code Map} into this {@code Map}.
059         * @see #addAttribute(String, Object)
060         */
061        Model addAllAttributes(Map<String, ?> attributes);
062
063        /**
064         * Copy all attributes in the supplied {@code Map} into this {@code Map},
065         * with existing objects of the same name taking precedence (i.e. not getting
066         * replaced).
067         */
068        Model mergeAttributes(Map<String, ?> attributes);
069
070        /**
071         * Does this model contain an attribute of the given name?
072         * @param attributeName the name of the model attribute (never {@code null})
073         * @return whether this model contains a corresponding attribute
074         */
075        boolean containsAttribute(String attributeName);
076
077        /**
078         * Return the current set of model attributes as a Map.
079         */
080        Map<String, Object> asMap();
081
082}