1. /*
  2. * The Apache Software License, Version 1.1
  3. *
  4. * Copyright (c) 1999 The Apache Software Foundation. All rights
  5. * reserved.
  6. *
  7. * Redistribution and use in source and binary forms, with or without
  8. * modification, are permitted provided that the following conditions
  9. * are met:
  10. *
  11. * 1. Redistributions of source code must retain the above copyright
  12. * notice, this list of conditions and the following disclaimer.
  13. *
  14. * 2. Redistributions in binary form must reproduce the above copyright
  15. * notice, this list of conditions and the following disclaimer in
  16. * the documentation and/or other materials provided with the
  17. * distribution.
  18. *
  19. * 3. The end-user documentation included with the redistribution, if
  20. * any, must include the following acknowlegement:
  21. * "This product includes software developed by the
  22. * Apache Software Foundation (http://www.apache.org/)."
  23. * Alternately, this acknowlegement may appear in the software itself,
  24. * if and wherever such third-party acknowlegements normally appear.
  25. *
  26. * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
  27. * Foundation" must not be used to endorse or promote products derived
  28. * from this software without prior written permission. For written
  29. * permission, please contact apache@apache.org.
  30. *
  31. * 5. Products derived from this software may not be called "Apache"
  32. * nor may "Apache" appear in their names without prior written
  33. * permission of the Apache Group.
  34. *
  35. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
  36. * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  37. * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  38. * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
  39. * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  40. * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  41. * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  42. * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  43. * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  44. * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  45. * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  46. * SUCH DAMAGE.
  47. * ====================================================================
  48. *
  49. * This software consists of voluntary contributions made by many
  50. * individuals on behalf of the Apache Software Foundation. For more
  51. * information on the Apache Software Foundation, please see
  52. * <http://www.apache.org/>.
  53. *
  54. */
  55. package javax.servlet.jsp.tagext;
  56. /**
  57. * Optional class provided by the tag library author to describe additional
  58. * translation-time information not described in the TLD.
  59. * The TagExtraInfo class is mentioned in the Tag Library Descriptor file (TLD).
  60. *
  61. * <p>
  62. * This class can be used:
  63. * <ul>
  64. * <li> to indicate that the tag defines scripting variables
  65. * <li> to perform translation-time validation of the tag attributes.
  66. * </ul>
  67. *
  68. * <p>
  69. * It is the responsibility of the JSP translator that the initial value
  70. * to be returned by calls to getTagInfo() corresponds to a TagInfo
  71. * object for the tag being translated. If an explicit call to
  72. * setTagInfo() is done, then the object passed will be returned in
  73. * subsequent calls to getTagInfo().
  74. *
  75. * <p>
  76. * The only way to affect the value returned by getTagInfo()
  77. * is through a setTagInfo() call, and thus, TagExtraInfo.setTagInfo() is
  78. * to be called by the JSP translator, with a TagInfo object that
  79. * corresponds to the tag being translated. The call should happen before
  80. * any invocation on isValid() and before any invocation on
  81. * getVariableInfo().
  82. */
  83. public abstract class TagExtraInfo {
  84. /**
  85. * information on scripting variables defined by the tag associated with
  86. * this TagExtraInfo instance.
  87. * Request-time attributes are indicated as such in the TagData parameter.
  88. *
  89. * @param data The TagData instance.
  90. * @return An array of VariableInfo data.
  91. */
  92. public VariableInfo[] getVariableInfo(TagData data) {
  93. return new VariableInfo[0];
  94. }
  95. /**
  96. * Translation-time validation of the attributes.
  97. * Request-time attributes are indicated as such in the TagData parameter.
  98. *
  99. * @param data The TagData instance.
  100. * @return Whether this tag instance is valid.
  101. */
  102. public boolean isValid(TagData data) {
  103. return true;
  104. }
  105. /**
  106. * Set the TagInfo for this class.
  107. *
  108. * @param tagInfo The TagInfo this instance is extending
  109. */
  110. public final void setTagInfo(TagInfo tagInfo) {
  111. this.tagInfo = tagInfo;
  112. }
  113. /**
  114. * Get the TagInfo for this class.
  115. *
  116. * @return the taginfo instance this instance is extending
  117. */
  118. public final TagInfo getTagInfo() {
  119. return tagInfo;
  120. }
  121. // private data
  122. private TagInfo tagInfo;
  123. }