<?xml version="1.0" encoding = "iso-8859-1" standalone="no"?>
<!--
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * 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.
-->

<!DOCTYPE faqs SYSTEM "sbk:/style/dtd/faqs.dtd">

<faqs title="Building / Running FAQs">

  <faq title="Why do I get compilation error saying undeclared identifier or class undefined?">

    <q>Why do I get compilation error saying undeclared identifier or class undefined?</q>

    <a>

      <p>&XercesCName; &XercesCVersion; now supports C++ Namespace.</p>
      
      <p>If C++ Namespace is ENABLED, users' applications must
         namespace qualify all the &XercesCName; classes, data, and
         variables with <code>XERCES_CPP_NAMESPACE_QUALIFIER </code>
         or add the <code>XERCES_CPP_NAMESPACE_USE</code> clause.
         Users also need to ensure all forward declarations are
         properly qualified or scoped.
      </p>
      
      <p>See the Programming Guide <jump href="program-others.html#CPPNamespace">
         Using C++ Namespace</jump> for details.
      </p>

    </a>
  </faq>

  <faq title="Why do I get compilation error saying DOMDocument was declared twice using
              Microsoft Visual C++.Net?">

    <q>Why do I get compilation error saying DOMDocument was declared twice using
              Microsoft Visual C++.Net?</q>

    <a>

      <p>Your application somehow has picked up the Microsoft SDK header <code>Msxml.h</code>
         which has its own typedef of <code>DOMDocument</code>.   This confuses
         with the &XercesCName; &XercesCVersion; <code>&XercesCNamespace;::DOMDocument</code>
         and thus lead to the compilation errors.</p>

      <p> Qualifier the use of DOMDocument in your application explicitly e.g.
         <br/><br/><code>XERCES_CPP_NAMESPACE_QUALIFIER DOMDocument * fDoc;</code><br/><br/>
         will eliminate these compilation problems.
      </p>

    </a>
  </faq>

  <faq title="Why can't the compiler find the include files?">

    <q>Why can't the compiler find the include files?</q>

    <a><p>A common cause for this problem is setting build environment
       variable XERCESROOT instead of setting variable XERCESCROOT.
       Note the C before ROOT.</p>
    </a>
  </faq>

  <faq title="Why do I get Internal Compiler Error when compiling &XercesCName; for a 64bit target with gcc?">
    <q>Why do I get Internal Compiler Error when compiling &XercesCName; for a 64bit target with gcc?</q>
    <a>
      <p>This is a compiler problem.  Try turning off optimization to bypass the problem.</p>
    </a>
  </faq>


  <faq title="Why do I get compilation error when compiling &XercesCName; on FreeBSD with native transcoder?">

    <q>Why do I get compilation error when compiling &XercesCName; on FreeBSD with native transcoder?</q>

    <a>
       <p>Please make sure you configure with "-t IconvFBSD" to use FreeBSD specific native transcoder.
       </p>

       <p>Or you can use ICU transcoder (configure with -t icu) instead of the native transcoder.
       </p>

    </a>
  </faq>

  <faq title="Building &XercesCName; with compiler GCC 2.7.x or 2.8.x gives problem, what's wrong?">

    <q>Building &XercesCName; with compiler GCC 2.7.x or 2.8.x gives problem, what's wrong?</q>

    <a>
       <p>Users using GCC 2.7.x or 2.8.x may have unsuccessful compile/link/run experience with
          &XercesCName;.  There were issues related to templates and multi threaded exception
          handling with this old version GCC compiler.
       </p>

       <p>Please upgrade to at least GCC 2.95.2.
       </p>

    </a>
  </faq>

  <faq title="Why does my application give unresolved linking errors?">

    <q>Why does my application give unresolved linking errors?</q>

    <a>

      <p>Please check the following:</p>
      <ol>
        <li>If you're using the binary build of &XercesCName;, make sure that the OS and compiler are
            the same version as the ones used to build the binary &faq-build-faq-distrib1;.  Different OS and
            compiler versions might cause unresolved linking problems or compilation
            errors. If the versions are different, rebuild the &XercesCName; library on
            your system before building your application. If you're using ICU (which is
            packaged with XML4C) you need to rebuild the compatible version of ICU
            first.</li>
        <li>Check that the library path is set properly and that the correct
            versions of <code>gmake</code> and <code>autoconf</code> are on your system.</li>
        <li>If C++ Namespace support is ENABLED (all the binary distributions of &XercesCName;
            &XercesCVersion; are built with C++ Namespace enabled), users' applications
            must namespace qualify all the &XercesCName; classes, data and variables.  
            See the Programming Guide <jump href="program-others.html#CPPNamespace">
            Using C++ Namespace</jump> for details.</li>
      </ol>
    </a>
  </faq>

  <faq title="Why do I get link error saying icudata library not found when building with ICU?">

    <q>Why do I get link error saying icudata library not found when building with ICU?</q>

    <a>
       <p>There is a bug in the Makefile of ICU 1.7, 1.8 and 1.8.1.  The link created during
          ICU installation in $ICUROOT is, for example,
       </p>

       <p>icudata.so@ -> icudt17l.so
       </p>

       <p>instead of
       </p>

       <p>libicudata.so@ -> libicudt17l.so <br/>
       </p>

       <p>Therefore the -licudata doesn't work.  To bypass the problem, please manually create the
          following link:
       </p>

       <p>libicudata.so@ -> libicudt17l.so
       </p>

       <p>This problem has been fixed in ICU 2.0.
       </p>


    </a>
  </faq>

  <faq title="I cannot run the sample applications. What is wrong?">

    <q>I cannot run the sample applications. What is wrong?</q>

    <a>

      <p>In order to run an application built using &XercesCProjectName; you must
        set up your path and library search path properly. In the stand-alone version
        from Apache, you must have the &XercesCName; runtime library available from
        your path settings.
      </p>
      <p>On Windows this library is called <code>&XercesCWindowsDLL;.dll</code>
        which must be available from your <code>PATH</code> settings. (Note that there are
        separate debug and release dlls for Windows.  The release dll is named
        <code>&XercesCWindowsDLL;.dll</code>, and the debug dll
        is named <code>&XercesCWindowsDLL;d.dll)</code>.
      </p>
      <p>On UNIX platforms the library is called &XercesCUnixLib;.so.&XercesCUnixSoName; (or
         &XercesCUnixLib;&XercesCUnixSoName;.so or &XercesCUnixLib;.sl.&XercesCUnixSoName;)
         which must be available from your <code>LD_LIBRARY_PATH</code>
         (or <code>LIBPATH</code> or <code>SHLIB_PATH</code>) environment variable.</p>

      <p>Thus, if you installed your binaries under <code>$HOME/fastxmlparser</code>, you need to point your library path to that directory.</p>

<source>export LIBPATH=$LIBPATH:$HOME/fastxmlparser/lib # (AIX)
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/fastxmlparser/lib # (Solaris, Linux)
export SHLIB_PATH=$SHLIB_PATH:$HOME/fastxmlparser/lib # (HP-UX)</source>

      <p>If you are using the XML4C parser from IBM, you will
        need to put in two additional DLLs. In the Windows build these are <code>icuuc*.dll</code> and <code>icudt*.dll</code> which must be available from your PATH settings. On UNIX, these
        libraries are called <code>libicuuc*.so</code> and <code>libicudt*.so</code> (or <code>.sl</code> for HP-UX or <code>.a</code> for AIX) which must be available from your library search path.</p>

      <p>If the parser is built with icu message loader (as mentioned above), or message
        catalog loader, you need an environment variable, XERCESC_NLS_HOME to point to
        the directory, $XERCESCROOT/msg, where the message files reside.
      </p>

    </a>
  </faq>

  <faq title="Why does my application crash on AIX when I run it under a
         multi-threaded environment?">

    <q>Why does my application crash on AIX when I run it under a
      multi-threaded environment?</q>

    <a>

      <p>AIX maintains two kinds of libraries on the system, thread-safe and
        non-thread safe. Multi-threaded libraries on AIX follow a different naming
        convention, Usually the multi-threaded library names are followed with "_r".
        For example, libc.a is single threaded whereas libc_r.a is multi-threaded.</p>

      <p>To make your multi-threaded application run on AIX, you <em>must</em>
        ensure that you do not have a "system library path" in your <code>LIBPATH</code>
        environment variable when you run the application. The appropriate
        libraries (threaded or non-threaded) are automatically picked up at runtime. An
        application usually crashes when you build your application for multi-threaded
        operation but don't point to the thread-safe version of the system libraries.
        For example, LIBPATH can be simply set as:</p>

<source>LIBPATH=$HOME/&lt;&XercesCProjectName;&gt;/lib</source>

      <p>Where &lt;&XercesCProjectName;&gt; points to the directory where the
        &XercesCProjectName; application resides.</p>

      <p>If, for any reason unrelated to &XercesCProjectName;, you need to keep a
        "system library path" in your LIBPATH environment variable, you must make sure
        that you have placed the thread-safe path before you specify the normal system
        path. For example, you must place <ref>/lib/threads</ref> before
        <ref>/lib</ref> in your LIBPATH variable. That is to say your LIBPATH may look
        like this:</p>

<source>export LIBPATH=$HOME/&lt;&XercesCProjectName;&gt;/lib:/usr/lib/threads:/usr/lib</source>

      <p>Where /usr/lib is where your system libraries are.</p>

    </a>
  </faq>

  <faq title="Why does my multi-threaded application crash on Solaris 2.6?">

    <q>Why does my multi-threaded application crash on Solaris 2.6?</q>

    <a>

      <p>The problem appears because the throw call on Solaris 2.6 is not
        multi-thread safe. Sun Microsystems provides a patch to solve this problem. To
        get the latest patch for solving this problem, go to
        <jump href="http://sunsolve.sun.com">SunSolve.sun.com</jump> and get the
        appropriate patch for your operating system. For Intel machines running
        Solaris, you need to get Patch ID 104678. For SPARC machines you need to get
        Patch ID #105591.</p>

    </a>
  </faq>

  <faq title="I just built my own application using the &XercesCName; parser. Why does it crash?">

    <q>I just built my own application using the &XercesCName; parser. Why does
      it crash?</q>

    <a>

      <p>In order to work with the &XercesCName; parser, you have to first
        initialize the XML subsystem. The most common mistake is to forget this
        initialization. Before you make any calls to &XercesCName; APIs, you must
        call XMLPlatformUtils::Initialize(): </p>

<source>
try {
   XMLPlatformUtils::Initialize();
}
catch (const XMLException&amp; toCatch) {
   // Do your failure processing here
}</source>

      <p>This initializes the &XercesCProjectName; system and sets its internal
        variables. Note that you must the include <code>xercesc/util/PlatformUtils.hpp</code> file for this to work.</p>

    </a>
  </faq>

  <faq title="Why does deleting a transcoded string result in assertion on windows?">
    <q>Why does deleting a transcoded string result in assertion on windows?</q>
    <a>
      <p>Both your application program and the &XercesCName; DLL must use the same *DLL* version of the
         runtime library.  If either statically links to the runtime library, the
		 problem will still occur.</p>

      <p>For example, for a Win32/VC6 build, the runtime library build setting MUST
		 be "Multithreaded DLL" for release builds and "Debug Multithreaded DLL" for
		 debug builds.</p>

      <p>Or for example for a Win32/BCB6 build, application need to switch to Multithreaded
         runtime to avoid such memory access violation.</p>

      <p>To bypass such problem, instead of calling operator delete[] directly, you can use the
         provided function XMLString::release to delete any string that was allocated by the parser.
         This will ensure the string is allocated and deleted by the same DLL and such assertion
         problem should be resolved.</p>
    </a>
  </faq>

  <faq title="Can't debug into the &XercesCName; DLL with the MSVC debugger">

    <q> The libs/dll's I downloaded keep me from using the debugger in VC6.0. I
      am using the 'D', debug versions of them. "no symbolic information found" is
      what it says. Do I have to compile everything from source to make it work?</q>

    <a>

      <p>Unless you have the .pdb files, all you are getting with the debug
        library is that it uses the debug heap manager, so that you can compile your
        stuff in debug mode and not be dangerous. If you want full symbolic info for
        the &XercesCName; library, you'll need the .pdb files, and to get those, you'll
        need to rebuild the &XercesCName; library.</p>

    </a>
  </faq>

  <faq title="First-chance exception in Microsoft debugger">

    <q>"First-chance exception in DOMPrint.exe (KERNEL32.DLL): 0xE06D7363:
      Microsoft C++ Exception." I am always getting this message when I am using the
      parser. My programs are terminating abnormally. Even the samples are giving
      this exception. I am using Visual C++ 6.0 with latest service pack
      installed.</q>

    <a>

      <p>&XercesCName; uses C++ exceptions internally, as part of its normal
        operation. By default, the MSVC debugger will stop on each of these with the
        "First-chance exception ..." message.</p>

      <p>To stop this from happening do this:</p>

      <ul>
        <li>start debugging (so the debug menu appears)</li>
        <li>from the debug menu select "Exceptions"</li>
        <li>from the box that opens select "Microsoft C++ Exception" and set it
          to "Stop if not handled" instead of "stop always".</li>
      </ul>

      <p>You'll still land in the debugger if your program is terminating
        abnormally, but it will be at your problem, not from the internal &XercesCName;
        exceptions.</p>

    </a>
  </faq>

  <faq title="Fatal Error: Cannot open include file: XXX: No such file or directory">
    <q>"Fatal Error: Cannot open include file: XXX: No such file or directory"?</q>
    <a>
      <p>
	      Due to the recent directory change, you may need to either update your
		  project file, makefile, or your source/header file, for details,
          please refer to <jump href="migrate.html#DirChange">Directory Change. </jump></p>
    </a>
  </faq>

  <faq title="Cannot load message domain, Xerces Panic Error">
    <q>"Cannot load message domain, Xerces Panic Error"?</q>
    <a>
      <p>If the parser is built with icu message loader (like IBM XML4C binaries), 
         you need to make sure that the message library &faq-build-faq-distrib3;
         is located in a directory which is on the library search path.
         Or the message resource file, XercesMessages_en_US.res, is in the directory given at the call to        
         XMLPlatformUtils::Initialize(), or is located in the directory pointed to by the environment variable 
         XERCESC_NLS_HOME, or at $XERCESCROOT/msg.
      </p>
      <p>If the parser is built with message catalog loader, you need to make sure that the message
         catalog file, XercesMessages_en_US.cat, is in the directory given at the call to XMLPlatformUtils::Initialize(),
         or is located in the directory pointed to by the environment variable XERCESC_NLS_HOME, or  
         at $XERCESCROOT/msg.
      </p>      

    </a>
  </faq>

  <faq title="Why my document is valid on some platforms while invalid on others">
    <q>"Why my document is valid on some platform while invalid on others"?</q>
    <a>
      <p>The parser relies on the system call, strtod(), to parse a string representation 
         of a double/float data. In the case of no invalid characters found, the strtod()
         returns a double/float value if it is representable on that platform, or raises 
         ERANGE to indicate either underflow or underflow occurs. And the parser assigns 
         zero to the said data if underflow is found.        
      </p>
      <p>The threshold, where the strtod() decides if an underflow occurs, varies on 
         platforms. On windows, it is roughly the order of e-308, on Linux, e-325, and 
         on AIX, HP and Solaris, e-324.
      </p>      
      <p>So in an instance document, a data of value 1.0e-310 from a type with minExclusive 0, 
         is considered invalid on windows (since it is converted to 0 and therefore violates
         the minExclusive constraint), but valid on other unix platforms (since it remains 
         the original value).          
      </p>
      <p>The discussion above applies to data in xsd file as well.
      </p>            
    </a>
  </faq>
 
  <faq title='Regenerating (API) documention?'>
    <q>How do I regenerate the (API) documentation?</q>
    <a>
     <p>To use the internal XML based application that creates the
        documentation, you must have a Java Virtual machine installed
        on your system. The application itself, written in Java, is
        part of Xerces.</p>

     <p>To regenerate the documentation, go to directory <code>$XERCESCROOT</code>
        and start <code>createDocs.sh</code> (for Unix) or
        <code>createdocs.bat</code> (for Windows). The result can be
        found in directory <code>$XERCESCROOT/doc/html</code>.</p>

     <p>
      To regenerate the API documentation, you need to have at least
      <jump href="http://www.stack.nl/~dimitri/doxygen/">Doxygen</jump>
      installed on your system.</p>

      <p>If you want the API documentation to
      contain dependency graphs, you also need to have <jump
      href="http://www.research.att.com/sw/tools/graphviz/">GraphViz</jump> installed on
      your system. (Note that some people object to the 
      <jump
      href="http://www.research.att.com/sw/tools/graphviz/license/index.html">GraphViz
      license</jump>, so there are Linux distributions that do not
      include it.)</p>

      <p>If you do not have GraphViz, or do not want to use it, you
      have to edit file <code>$XERCESCROOT/doc/Doxyfile</code> and change <code>HAVE_DOT =
      YES</code> into <code>HAVE_DOT = NO</code>.</p>

      <p>To actually regenerate the API documentation, go to directory
      <code>$XERCESCROOT/doc/</code> and start Doxygen. The result can be
        found in directory <code>$XERCESCROOT/doc/html/apiDocs</code>.</p>
    </a>
   </faq>

</faqs>
