content: /*
   * TemplateLabel.java July 2009
   *
   * Copyright (C) 2009, Niall Gallagher <niallg@users.sf.net>
   *
   * 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.aliyun.odps.simpleframework.xml.core;
  
  import com.aliyun.odps.simpleframework.xml.strategy.Type;
  
  /**
   * The <code>TemplateLabel</code> object is used to provide stock
   * functions that can be used by all implementations. This ensures
   * there is a consistent set of behaviours for each label. It also
   * reduces the number of methods that need to be maintained for
   * each <void>Label</code> implementation.
   * 
   * @author Niall Gallagher
   */
  abstract class TemplateLabel implements Label {
     
     /**
      * This is the builder that is used to generate label keys.
      */
     private final KeyBuilder builder;
     
     /**
      * Constructor for the <code>TemplateLabel</code> is used to
      * create a template for other labels. If any of the method
      * implementations are not as required or they should be
      * overridden by the subclass.
      */
     protected TemplateLabel() {
        this.builder = new KeyBuilder(this);
     }
     
     /**
      * This is used to acquire the <code>Type</code> that the type
      * provided is represented by. Typically this will return the
      * field or method represented by the label. However, in the 
      * case of unions this will provide an override type.
      * 
      * @param type this is the class to acquire the type for
      * 
      * @return this returns the type represented by this class
      */
     public Type getType(Class type) throws Exception {
        return getContact();
     }
     
     /**
      * This is used to acquire the <code>Label</code> that the type
      * provided is represented by. Typically this will return the
      * same instance. However, in the case of unions this will
      * look for an individual label to match the type provided.
      * 
      * @param type this is the type to acquire the label for
      * 
      * @return this returns the label represented by this type
      */
     public Label getLabel(Class type) throws Exception {
        return this;
     }
     
     /**
      * This returns a <code>Collection</code> of element names. This
      * will typically contain both the name and path of the label. 
      * However, if this is a union it can contain many names and
      * paths. This method should never return null. 
      * 
      * @return this returns the names of each of the elements
      */
     public String[] getNames() throws Exception {
        String path = getPath();
        String name = getName();
        
        return new String[] {path, name};
     }
     
     /**
      * This returns a <code>Collection</code> of element paths. This
      * will typically contain only the path of the label, which is
      * composed using the <code>Path</code> annotation and the name
      * of the label. However, if this is a union it can contain many 
      * paths. This method should never return null.
      * 
      * @return this returns the names of each of the elements
      */
     public String[] getPaths() throws Exception {
        String path = getPath();
        
        return new String[] {path};
     }
     
     /**
      * This is the key used to represent this label. The key is used
      * to store the parameter in hash containers. Typically the
      * key is generated from the paths associated with the label.
      * 
      * @return this is the key used to represent the label
      */
     public Object getKey() throws Exception {
        return builder.getKey();
     }
     
     /**
      * This is typically used to acquire the entry value as acquired
      * from the annotation. However given that the annotation this
      * represents does not have a entry attribute this will always
      * provide a null value for the entry string.
      * 
      * @return this will always return null for the entry value 
      */
     public String getEntry() throws Exception {
        return null;
     }
     
     /**
      * This is used to acquire the dependent class for this label. 
      * This returns null as there are no dependents to the element
      * annotation as it can only hold primitives with no dependents.
      * 
      * @return this is used to return the dependent type of null
      */
     public Type getDependent() throws Exception {
        return null;
     }
     
     /**
      * This method is used to determine if the label represents an
      * attribute. This is used to style the name so that elements
      * are styled as elements and attributes are styled as required.
      * 
      * @return this is used to determine if this is an attribute
      */
     public boolean isAttribute() {
        return false;
     }
     
     /**
      * This is used to determine if the label is a collection. If the
      * label represents a collection then any original assignment to
      * the field or method can be written to without the need to 
      * create a new collection. This allows obscure collections to be
      * used and also allows initial entries to be maintained.
      * 
      * @return true if the label represents a collection value
      */
     public boolean isCollection() {
        return false;
     }
     
     /**
      * This is used to determine whether the label represents an
      * inline XML entity. The <code>ElementList</code> annotation
      * and the <code>Text</code> annotation represent inline 
      * items. This means that they contain no containing element
      * and so can not specify overrides or special attributes.
      * 
      * @return this returns true if the annotation is inline
      */
     public boolean isInline() {
        return false;
     }
     
     /**
      * This is used to determine if the label represents text. If
      * a label represents text it typically does not have a name,
      * instead the empty string represents the name. Also text
      * labels can not exist with other text labels, or elements.
      * 
      * @return this returns true if this label represents text
      */
     public boolean isText() {
        return false;
     }
     
     /**
      * This is used to determine if an annotated list is a text 
      * list. A text list is a list of elements that also accepts
      * free text. Typically this will be an element list union that
      * will allow unstructured XML such as XHTML to be parsed.
      * 
      * @return returns true if the label represents a text list
      */
     public boolean isTextList() {
        return false;
     }
     
     /**
      * This is used to determine if this label is a union. If this
      * is true then this label represents a number of labels and
      * is simply a wrapper for these labels. 
      * 
      * @return this returns true if the label represents a union
      */
     public boolean isUnion() {
        return false;
     }
  }
  