001 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 The Apache Software Foundation
002 //
003 // Licensed under the Apache License, Version 2.0 (the "License");
004 // you may not use this file except in compliance with the License.
005 // You may obtain a copy of the License at
006 //
007 // http://www.apache.org/licenses/LICENSE-2.0
008 //
009 // Unless required by applicable law or agreed to in writing, software
010 // distributed under the License is distributed on an "AS IS" BASIS,
011 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012 // See the License for the specific language governing permissions and
013 // limitations under the License.
014
015 package org.apache.tapestry5.model;
016
017 import org.apache.tapestry5.annotations.MixinAfter;
018 import org.apache.tapestry5.annotations.Persist;
019 import org.apache.tapestry5.annotations.SupportsInformalParameters;
020 import org.apache.tapestry5.ioc.Resource;
021 import org.slf4j.Logger;
022
023 import java.util.List;
024 import java.util.Set;
025
026 /**
027 * Defines a component in terms of its capabilities, parameters, sub-components, etc. During <em>runtime</em>, the
028 * component model is immutable. During <em>construction</em> time, when the class is being transformed and loaded, the
029 * model is mutable.
030 *
031 * @see org.apache.tapestry5.model.MutableComponentModel
032 */
033 public interface ComponentModel
034 {
035 /**
036 * Is this a model of a page (rather than a component, mixin, or base-class)?
037 *
038 * @return true if a page
039 * @since 5.3
040 */
041 boolean isPage();
042
043 /**
044 * Returns the resource corresponding to the class file for this component. This is used to find related resources,
045 * such as the component's template and message catalog.
046 */
047 Resource getBaseResource();
048
049 /**
050 * The fully qualified class name of the component.
051 */
052 String getComponentClassName();
053
054 /**
055 * Returns the ids of all embedded components defined within the component class (via the {@link
056 * org.apache.tapestry5.annotations.Component} annotation), including those defined by any super-class.
057 */
058 List<String> getEmbeddedComponentIds();
059
060 /**
061 * Returns an embedded component defined by this component or by a super-class.
062 *
063 * @param componentId the id of the embedded component
064 * @return the embedded component model, or null if no component exists with that id
065 */
066 EmbeddedComponentModel getEmbeddedComponentModel(String componentId);
067
068 /**
069 * Returns the persistent strategy associated with the field.
070 *
071 * @param fieldName
072 * @return the corresponding strategy, or the empty string
073 * @throws IllegalArgumentException if the named field is not marked as persistent
074 */
075 String getFieldPersistenceStrategy(String fieldName);
076
077 /**
078 * Returns object that will be used to log warnings and errors related to this component.
079 *
080 * @see org.apache.tapestry5.annotations.Log
081 */
082 Logger getLogger();
083
084 /**
085 * Returns a list of the class names of mixins that are part of the component's implementation.
086 */
087 List<String> getMixinClassNames();
088
089 /**
090 * Return a single parameter model by parameter name, or null if the parameter is not defined (is not
091 * a formal parameter). This may be a parameter defined by this component, or from a base class.
092 *
093 * @param parameterName the name of the parameter (case is ignored)
094 * @return the parameter model if found in this model or a parent model, or null if not found
095 */
096 ParameterModel getParameterModel(String parameterName);
097
098 /**
099 * Returns true if the named parameter is formally defined (there's a ParameterModel).
100 *
101 * @param parameterName name of the parameter (case is ignored)
102 * @since 5.2.0
103 */
104 boolean isFormalParameter(String parameterName);
105
106 /**
107 * Returns an alphabetically sorted list of the names of all formal parameters. This includes parameters defined by
108 * a base class.
109 */
110
111 List<String> getParameterNames();
112
113 /**
114 * Returns an alphabetically sorted list of the names of all formal parameters defined by this specific class
115 * (parameters inherited from base classes are not identified).
116 */
117 List<String> getDeclaredParameterNames();
118
119 /**
120 * Returns a list of the names of all persistent fields (within this class, or any super-class). The names are
121 * sorted alphabetically.
122 *
123 * @see Persist
124 */
125 List<String> getPersistentFieldNames();
126
127 /**
128 * Returns true if the modeled component is a root class, a component class whose parent class is not a component
129 * class. We may in the future require that components only extend from Object.
130 *
131 * @return true if a root class, false if a subclass
132 */
133 boolean isRootClass();
134
135 /**
136 * Returns true if the model indicates that informal parameters, additional parameters beyond the formal parameter
137 * defined for the component, are supported. This is false in most cases, but may be set to true for specific
138 * classes (when the {@link SupportsInformalParameters} annotation is present, or inherited from a super-class).
139 *
140 * @return true if this component model supports informal parameters
141 */
142 boolean getSupportsInformalParameters();
143
144 /**
145 * Returns the component model for this component's super-class, if it exists. Remember that only classes in the
146 * correct packages, are considered component classes.
147 *
148 * @return the parent class model, or null if this component's super class is not itself a component class
149 */
150 ComponentModel getParentModel();
151
152 /**
153 * Relevant for component mixins only. Indicates that the mixin behavior should occur <em>after</em> (not before)
154 * the component. Normally, this flag is set by the presence of the {@link MixinAfter} annotation.
155 *
156 * @return true if the mixin should operate after, not before, the component
157 */
158 boolean isMixinAfter();
159
160 /**
161 * Gets a meta value identified by the given key. If the current model does not provide a value for the key, then
162 * the parent component model (if any) is searched.
163 *
164 * @param key identifies the value to be accessed
165 * @return the value for the key (possibly inherited from a parent model), or null
166 */
167 String getMeta(String key);
168
169 /**
170 * Returns a set of all the render phases that this model (including parent models) that are handled. Render phases
171 * are represented by the corresponding annotation ({@link org.apache.tapestry5.annotations.BeginRender}, {@link
172 * org.apache.tapestry5.annotations.AfterRender}, etc.).
173 *
174 * @return set of classes
175 * @since 5.0.19, 5.1.0.0
176 */
177 Set<Class> getHandledRenderPhases();
178
179 /**
180 * Determines if the component has an event handler for the indicated event name (case insensitive). This includes
181 * handles in the component class itself, or its super-classes, but does not include event handles supplied by
182 * implementation or instance mixins.
183 *
184 * @param eventType name of event to check (case insensitive)
185 * @return true if event handler present
186 */
187 boolean handlesEvent(String eventType);
188
189 /**
190 * @param mixinClassName class name of the mixin for which the ordering is desired
191 * @return the ordering constraint(s) for the mixin, potentially null.
192 * @since 5.2.0
193 */
194 String[] getOrderForMixin(String mixinClassName);
195 }