Coverage Report - org.apache.tapestry.IBinding
 
Classes in this File Line Coverage Branch Coverage Complexity
IBinding
N/A
N/A
1
 
 1  
 // Copyright 2004, 2005 The Apache Software Foundation
 2  
 //
 3  
 // Licensed under the Apache License, Version 2.0 (the "License");
 4  
 // you may not use this file except in compliance with the License.
 5  
 // You may obtain a copy of the License at
 6  
 //
 7  
 //     http://www.apache.org/licenses/LICENSE-2.0
 8  
 //
 9  
 // Unless required by applicable law or agreed to in writing, software
 10  
 // distributed under the License is distributed on an "AS IS" BASIS,
 11  
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 12  
 // See the License for the specific language governing permissions and
 13  
 // limitations under the License.
 14  
 
 15  
 package org.apache.tapestry;
 16  
 
 17  
 import org.apache.hivemind.Locatable;
 18  
 
 19  
 /**
 20  
  * A binding is the mechanism used to provide values for parameters of specific {@link IComponent}
 21  
  * instances. The component doesn't care where the required value comes from, it simply requires
 22  
  * that a value be provided when needed.
 23  
  * <p>
 24  
  * Bindings are set inside the containing component's specification or template. Bindings may be
 25  
  * invariant or dynamic (though that is irrelevant to the component). Components may also use a
 26  
  * binding to write a value back through a property to some other object (typically, another
 27  
  * component).
 28  
  * 
 29  
  * @author Howard Lewis Ship
 30  
  */
 31  
 
 32  
 public interface IBinding extends Locatable
 33  
 {
 34  
     /**
 35  
      * Returns the value of this binding. This is the essential method.
 36  
      */
 37  
 
 38  
     Object getObject();
 39  
 
 40  
     /**
 41  
      * Returns the value for the binding after performing some basic checks.
 42  
      * <p>
 43  
      * Note: In release 4.0, the parameterName parameter was removed.
 44  
      * 
 45  
      * @param type
 46  
      *            if not null, the value must be assignable to the specific class
 47  
      * @throws BindingException
 48  
      *             if the value is not assignable to the specified type
 49  
      * @since 0.2.9
 50  
      */
 51  
 
 52  
     Object getObject(Class type);
 53  
 
 54  
     /**
 55  
      * Returns true if the value is invariant (not changing; the same value returned each time).
 56  
      * Static and message bindings are always invariant, and
 57  
      * {@link org.apache.tapestry.binding.ExpressionBinding}s may be marked invariant (as an
 58  
      * optimization).
 59  
      * 
 60  
      * @since 2.0.3
 61  
      */
 62  
 
 63  
     boolean isInvariant();
 64  
 
 65  
     /**
 66  
      * Updates the value of the binding, if possible.
 67  
      * 
 68  
      * @exception BindingException
 69  
      *                If the binding is read only.
 70  
      */
 71  
 
 72  
     void setObject(Object value);
 73  
 
 74  
     /**
 75  
      * Returns a description of how the binding is used; this description
 76  
      * is localized and incorporated into some exception messages.
 77  
      * 
 78  
      * @since 4.0
 79  
      */
 80  
     
 81  
     String getDescription();
 82  
 }