1. /*
  2. * The Apache Software License, Version 1.1
  3. *
  4. *
  5. * Copyright (c) 2002 The Apache Software Foundation. All rights
  6. * reserved.
  7. *
  8. * Redistribution and use in source and binary forms, with or without
  9. * modification, are permitted provided that the following conditions
  10. * are met:
  11. *
  12. * 1. Redistributions of source code must retain the above copyright
  13. * notice, this list of conditions and the following disclaimer.
  14. *
  15. * 2. Redistributions in binary form must reproduce the above copyright
  16. * notice, this list of conditions and the following disclaimer in
  17. * the documentation and/or other materials provided with the
  18. * distribution.
  19. *
  20. * 3. The end-user documentation included with the redistribution,
  21. * if any, must include the following acknowledgment:
  22. * "This product includes software developed by the
  23. * Apache Software Foundation (http://www.apache.org/)."
  24. * Alternately, this acknowledgment may appear in the software itself,
  25. * if and wherever such third-party acknowledgments normally appear.
  26. *
  27. * 4. The names "Xalan" and "Apache Software Foundation" must
  28. * not be used to endorse or promote products derived from this
  29. * software without prior written permission. For written
  30. * permission, please contact apache@apache.org.
  31. *
  32. * 5. Products derived from this software may not be called "Apache",
  33. * nor may "Apache" appear in their name, without prior written
  34. * permission of the Apache Software Foundation.
  35. *
  36. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
  37. * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  38. * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  39. * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
  40. * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  41. * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  42. * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  43. * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  44. * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  45. * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  46. * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  47. * SUCH DAMAGE.
  48. * ====================================================================
  49. *
  50. * This software consists of voluntary contributions made by many
  51. * individuals on behalf of the Apache Software Foundation and was
  52. * originally based on software copyright (c) 1999, Lotus
  53. * Development Corporation., http://www.lotus.com. For more
  54. * information on the Apache Software Foundation, please see
  55. * <http://www.apache.org/>.
  56. */
  57. package org.apache.xalan.templates;
  58. import org.apache.xpath.ExpressionOwner;
  59. import org.apache.xpath.XPathVisitor;
  60. import org.apache.xpath.axes.LocPathIterator;
  61. import org.apache.xpath.functions.FuncCurrent;
  62. import org.apache.xpath.functions.FuncExtFunction;
  63. import org.apache.xpath.functions.Function;
  64. import org.apache.xpath.operations.Variable;
  65. /**
  66. * This class runs over a path expression that is assumed to be absolute, and
  67. * checks for variables and the like that may make it context dependent.
  68. */
  69. public class AbsPathChecker extends XPathVisitor
  70. {
  71. private boolean m_isAbs = true;
  72. /**
  73. * Process the LocPathIterator to see if it contains variables
  74. * or functions that may make it context dependent.
  75. * @param path LocPathIterator that is assumed to be absolute, but needs checking.
  76. * @return true if the path is confirmed to be absolute, false if it
  77. * may contain context dependencies.
  78. */
  79. public boolean checkAbsolute(LocPathIterator path)
  80. {
  81. m_isAbs = true;
  82. path.callVisitors(null, this);
  83. return m_isAbs;
  84. }
  85. /**
  86. * Visit a function.
  87. * @param owner The owner of the expression, to which the expression can
  88. * be reset if rewriting takes place.
  89. * @param func The function reference object.
  90. * @return true if the sub expressions should be traversed.
  91. */
  92. public boolean visitFunction(ExpressionOwner owner, Function func)
  93. {
  94. if((func instanceof FuncCurrent) ||
  95. (func instanceof FuncExtFunction))
  96. m_isAbs = false;
  97. return true;
  98. }
  99. /**
  100. * Visit a variable reference.
  101. * @param owner The owner of the expression, to which the expression can
  102. * be reset if rewriting takes place.
  103. * @param var The variable reference object.
  104. * @return true if the sub expressions should be traversed.
  105. */
  106. public boolean visitVariableRef(ExpressionOwner owner, Variable var)
  107. {
  108. m_isAbs = false;
  109. return true;
  110. }
  111. }