|  | | | | Table of Content: 
Licensing Terms for libxml
    libxml is released under the MIT
    License, see the file Copyright in the distribution for the precise
    wording
Can I embed libxml in a proprietary application ?
    Yes. The MIT License allows you to also keep proprietary the changes
    you made to libxml, but it would be graceful to provide back bug fixes
    and improvements as patches for possible incorporation in the main
    development tree 
Unless you are forced to because your application links with a Gnome
    library requiring it,  Do
    Not Use libxml1, use libxml2
Where can I get libxml ?
    The original distribution comes from rpmfind.net or gnome.org
 Most Linux and BSD distributions include libxml, this is probably the
    safer way for end-users David Doolin provides precompiled Windows versions at http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/
I see libxml and libxml2 releases, which one should I install ?
    
If you are not concerned by any existing backward compatibility
        with existing application, install libxml2 onlyIf you are not doing development, you can safely install both.
        usually the packages libxml and libxml2 are
        compatible (this is not the case for development packages)If you are a developer and your system provides separate packaging
        for shared libraries and the development components, it is possible
        to install libxml and libxml2, and also libxml-devel
        and libxml2-devel
        too for libxml2 >= 2.3.0If you are developing a new application, please develop against
        libxml2(-devel)
I can't install the libxml package it conflicts with libxml0
    You probably have an old libxml0 package used to provide the shared
    library for libxml.so.0, you can probably safely remove it. Anyway the
    libxml packages provided on rpmfind.net provides
    libxml.so.0
I can't install the libxml(2) RPM package due to failed
    dependencies
    The most generic solution is to re-fetch the latest src.rpm , and
    rebuild it locally with rpm --rebuild libxml(2)-xxx.src.rpm
 if everything goes well it will generate two binary rpm (one providing
    the shared libs and xmllint, and the other one, the -devel package
    providing includes, static libraries and scripts needed to build
    applications with libxml(2)) that you can install locally. 
What is the process to compile libxml ?
    As most UNIX libraries libxml follows the "standard": gunzip -c xxx.tar.gz | tar xvf -
 cd libxml-xxxx
 ./configure --help
 to see the options, then the compilation/installation proper ./configure [possible options]
 make
 make install
 At that point you may have to rerun ldconfig or similar utility to
    update your list of installed shared libs.
What other libraries are needed to compile/install libxml ?
    Libxml does not requires any other library, the normal C ANSI API
    should be sufficient (please report any violation to this rule you may
    find). However if found at configuration time libxml will detect and use the
    following libs: 
libz : a
        highly portable and available widely compression libraryiconv: a powerful character encoding conversion library. It's
        included by default on recent glibc libraries, so it doesn't need to
        be installed specifically on Linux. It seems it's now part
        of the official UNIX specification. Here is one implementation
        of the library which source can be found here.
make check fails on some platforms
    Sometime the regression tests results don't completely match the value
    produced by the parser, and the makefile uses diff to print the delta. On
    some platforms the diff return breaks the compilation process, if the
    diff is small this is probably not a serious problem. Sometimes (especially on Solaris) make checks fails due to limitations
    in make. Try using GNU-make instead.
I use the CVS version and there is no configure script
    The configure (and other Makefiles) are generated. Use the autogen.sh
    script to regenerate the configure and Makefiles, like: ./autogen.sh --prefix=/usr --disable-shared
I have troubles when running make tests with gcc-3.0
    It seems the initial release of gcc-3.0 has a problem with the
    optimizer which miscompiles the URI module. Please use another
    compiler 
xmlDocDump() generates output on one line
    libxml will not invent spaces in the content of a
    document since all spaces in the content of a document are
    significant. If you build a tree from the API and want
    indentation: 
the correct way is to generate those yourself toothe dangerous way is to ask libxml to add those blanks to your
        content modifying the content of your document in the
        process. The result may not be what you expect. There is
        NO way to guarantee that such a modification won't
        impact other part of the content of your document. See xmlKeepBlanksDefault
        () and xmlSaveFormatFile
        ()
Extra nodes in the document:
    For a XML file as below: <?xml version="1.0"?>
<PLAN xmlns="http://www.argus.ca/autotest/1.0/">
<NODE CommFlag="0"/>
<NODE CommFlag="1"/>
</PLAN> after parsing it with the function
    pxmlDoc=xmlParseFile(...); I want to the get the content of the first node (node with the
    CommFlag="0") so I did it as following; xmlNodePtr pnode;
pnode=pxmlDoc->children->children; but it does not work. If I change it to pnode=pxmlDoc->children->children->next; then it works.  Can someone explain it to me. 
 In XML all characters in the content of the document are significant
    including blanks and formatting line breaks. The extra nodes you are wondering about are just that, text nodes with
    the formatting spaces which are part of the document but that people tend
    to forget. There is a function xmlKeepBlanksDefault
    ()  to remove those at parse time, but that's an heuristic, and its
    use should be limited to case where you are sure there is no
    mixed-content in the document.
I get compilation errors of existing code like when accessing
    root or childs fields of nodes
    You are compiling code developed for libxml version 1 and using a
    libxml2 development environment. Either switch back to libxml v1 devel or
    even better fix the code to compile with libxml2 (or both) by following the instructions.
I get compilation errors about non existing
    xmlRootNode or xmlChildrenNode
    fields
    The source code you are using has been upgraded to be able to compile with both libxml
    and libxml2, but you need to install a more recent version:
    libxml(-devel) >= 1.8.8 or libxml2(-devel) >= 2.1.0
XPath implementation looks seriously broken
    XPath implementation prior to 2.3.0 was really incomplete, upgrade to
    a recent version, there is no known bug in the current version.
The example provided in the web page does not compile
    It's hard to maintain the documentation in sync with the code
    <grin/> ... Check the previous points 1/ and 2/ raised before, and send
    patches.
Where can I get more examples and informations than in the web
    page
    Ideally a libxml book would be nice. I have no such plan ... But you
    can: 
check more deeply the existing
        generated doc
looks for examples of use for libxml function using the Gnome code
        for example the following will query the full Gnome CVS base for the
        use of the xmlAddChild() function:
        http://cvs.gnome.org/lxr/search?string=xmlAddChild This may be slow, a large hardware donation to the gnome project
        could cure this :-)
Browse
        the libxml source , I try to write code as clean and documented
        as possible, so looking at it may be helpful. Especially the code of
        xmllint.c and of the various testXXX.c tests programs should provide
        good example on how to do things with the library.What about C++ ?
    libxml is written in pure C in order to allow easy reuse on a number
    of platforms, including embedded systems. I don't intend to convert to
    C++. There is however a few C++ wrappers which may fulfill your needs:How to validate a document a posteriori ?
    It is possible to validate documents which had not been validated at
    initial parsing time or documents who have been built from scratch using
    the API. Use the xmlValidateDtd()
    function. It is also possible to simply add a DTD to an existing
    document: xmlDocPtr doc; /* your existing document */
        xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */
        dtd->name = xmlStrDup((xmlChar*)"root_name"); /* use the given root */
        doc->intSubset = dtd;
        if (doc->children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
        else xmlAddPrevSibling(doc->children, (xmlNodePtr)dtd);
          etc ... 
 Daniel Veillard | 
 | 
 | 
 |