diff options
Diffstat (limited to 'libxml2-2.9.10/doc/upgrade.html')
| -rw-r--r-- | libxml2-2.9.10/doc/upgrade.html | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/libxml2-2.9.10/doc/upgrade.html b/libxml2-2.9.10/doc/upgrade.html new file mode 100644 index 0000000..f2f22af --- /dev/null +++ b/libxml2-2.9.10/doc/upgrade.html @@ -0,0 +1,112 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><link rel="SHORTCUT ICON" href="/favicon.ico" /><style type="text/css"> +TD {font-family: Verdana,Arial,Helvetica} +BODY {font-family: Verdana,Arial,Helvetica; margin-top: 2em; margin-left: 0em; margin-right: 0em} +H1 {font-family: Verdana,Arial,Helvetica} +H2 {font-family: Verdana,Arial,Helvetica} +H3 {font-family: Verdana,Arial,Helvetica} +A:link, A:visited, A:active { text-decoration: underline } +</style><title>Upgrading 1.x code</title></head><body bgcolor="#8b7765" text="#000000" link="#a06060" vlink="#000000"><table border="0" width="100%" cellpadding="5" cellspacing="0" align="center"><tr><td width="120"><a href="http://swpat.ffii.org/"><img src="epatents.png" alt="Action against software patents" /></a></td><td width="180"><a href="http://www.gnome.org/"><img src="gnome2.png" alt="Gnome2 Logo" /></a><a href="http://www.w3.org/Status"><img src="w3c.png" alt="W3C Logo" /></a><a href="http://www.redhat.com/"><img src="redhat.gif" alt="Red Hat Logo" /></a><div align="left"><a href="http://xmlsoft.org/"><img src="Libxml2-Logo-180x168.gif" alt="Made with Libxml2 Logo" /></a></div></td><td><table border="0" width="90%" cellpadding="2" cellspacing="0" align="center" bgcolor="#000000"><tr><td><table width="100%" border="0" cellspacing="1" cellpadding="3" bgcolor="#fffacd"><tr><td align="center"><h1>The XML C parser and toolkit of Gnome</h1><h2>Upgrading 1.x code</h2></td></tr></table></td></tr></table></td></tr></table><table border="0" cellpadding="4" cellspacing="0" width="100%" align="center"><tr><td bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td valign="top" width="200" bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="1" width="100%" bgcolor="#000000"><tr><td><table width="100%" border="0" cellspacing="1" cellpadding="3"><tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>Developer Menu</b></center></td></tr><tr><td bgcolor="#fffacd"><form action="search.php" enctype="application/x-www-form-urlencoded" method="get"><input name="query" type="text" size="20" value="" /><input name="submit" type="submit" value="Search ..." /></form><ul><li><a href="index.html" style="font-weight:bold">Main Menu</a></li><li><a href="html/index.html" style="font-weight:bold">Reference Manual</a></li><li><a href="examples/index.html" style="font-weight:bold">Code Examples</a></li><li><a href="guidelines.html">XML Guidelines</a></li><li><a href="tutorial/index.html">Tutorial</a></li><li><a href="xmlreader.html">The Reader Interface</a></li><li><a href="ChangeLog.html">ChangeLog</a></li><li><a href="XSLT.html">XSLT</a></li><li><a href="python.html">Python and bindings</a></li><li><a href="architecture.html">libxml2 architecture</a></li><li><a href="tree.html">The tree output</a></li><li><a href="interface.html">The SAX interface</a></li><li><a href="xmlmem.html">Memory Management</a></li><li><a href="xmlio.html">I/O Interfaces</a></li><li><a href="library.html">The parser interfaces</a></li><li><a href="entities.html">Entities or no entities</a></li><li><a href="namespaces.html">Namespaces</a></li><li><a href="upgrade.html">Upgrading 1.x code</a></li><li><a href="threads.html">Thread safety</a></li><li><a href="DOM.html">DOM Principles</a></li><li><a href="example.html">A real example</a></li><li><a href="xml.html">flat page</a>, <a href="site.xsl">stylesheet</a></li></ul></td></tr></table><table width="100%" border="0" cellspacing="1" cellpadding="3"><tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>API Indexes</b></center></td></tr><tr><td bgcolor="#fffacd"><ul><li><a href="APIchunk0.html">Alphabetic</a></li><li><a href="APIconstructors.html">Constructors</a></li><li><a href="APIfunctions.html">Functions/Types</a></li><li><a href="APIfiles.html">Modules</a></li><li><a href="APIsymbols.html">Symbols</a></li></ul></td></tr></table><table width="100%" border="0" cellspacing="1" cellpadding="3"><tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>Related links</b></center></td></tr><tr><td bgcolor="#fffacd"><ul><li><a href="http://mail.gnome.org/archives/xml/">Mail archive</a></li><li><a href="http://xmlsoft.org/XSLT/">XSLT libxslt</a></li><li><a href="http://phd.cs.unibo.it/gdome2/">DOM gdome2</a></li><li><a href="http://www.aleksey.com/xmlsec/">XML-DSig xmlsec</a></li><li><a href="ftp://xmlsoft.org/">FTP</a></li><li><a href="http://www.zlatkovic.com/projects/libxml/">Windows binaries</a></li><li><a href="http://opencsw.org/packages/libxml2">Solaris binaries</a></li><li><a href="http://www.explain.com.au/oss/libxml2xslt.html">MacOsX binaries</a></li><li><a href="http://lxml.de/">lxml Python bindings</a></li><li><a href="http://cpan.uwinnipeg.ca/dist/XML-LibXML">Perl bindings</a></li><li><a href="http://libxmlplusplus.sourceforge.net/">C++ bindings</a></li><li><a href="http://www.zend.com/php5/articles/php5-xmlphp.php#Heading4">PHP bindings</a></li><li><a href="http://sourceforge.net/projects/libxml2-pas/">Pascal bindings</a></li><li><a href="http://libxml.rubyforge.org/">Ruby bindings</a></li><li><a href="http://tclxml.sourceforge.net/">Tcl bindings</a></li><li><a href="https://gitlab.gnome.org/GNOME/libxml2/issues">Bug Tracker</a></li></ul></td></tr></table></td></tr></table></td><td valign="top" bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="1" width="100%"><tr><td><table border="0" cellspacing="0" cellpadding="1" width="100%" bgcolor="#000000"><tr><td><table border="0" cellpadding="3" cellspacing="1" width="100%"><tr><td bgcolor="#fffacd"><p>Incompatible changes:</p><p>Version 2 of libxml2 is the first version introducing serious backward +incompatible changes. The main goals were:</p><ul> + <li>a general cleanup. A number of mistakes inherited from the very early + versions couldn't be changed due to compatibility constraints. Example + the "childs" element in the nodes.</li> + <li>Uniformization of the various nodes, at least for their header and link + parts (doc, parent, children, prev, next), the goal is a simpler + programming model and simplifying the task of the DOM implementors.</li> + <li>better conformances to the XML specification, for example version 1.x + had an heuristic to try to detect ignorable white spaces. As a result the + SAX event generated were ignorableWhitespace() while the spec requires + character() in that case. This also mean that a number of DOM node + containing blank text may populate the DOM tree which were not present + before.</li> +</ul><h3>How to fix libxml-1.x code:</h3><p>So client code of libxml designed to run with version 1.x may have to be +changed to compile against version 2.x of libxml. Here is a list of changes +that I have collected, they may not be sufficient, so in case you find other +change which are required, <a href="mailto:Daniel.Veillard@w3.org">drop me a +mail</a>:</p><ol> + <li>The package name have changed from libxml to libxml2, the library name + is now -lxml2 . There is a new xml2-config script which should be used to + select the right parameters libxml2</li> + <li>Node <strong>childs</strong> field has been renamed + <strong>children</strong> so s/childs/children/g should be applied + (probability of having "childs" anywhere else is close to 0+</li> + <li>The document don't have anymore a <strong>root</strong> element it has + been replaced by <strong>children</strong> and usually you will get a + list of element here. For example a Dtd element for the internal subset + and it's declaration may be found in that list, as well as processing + instructions or comments found before or after the document root element. + Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of + a document. Alternatively if you are sure to not reference DTDs nor have + PIs or comments before or after the root element + s/->root/->children/g will probably do it.</li> + <li>The white space issue, this one is more complex, unless special case of + validating parsing, the line breaks and spaces usually used for indenting + and formatting the document content becomes significant. So they are + reported by SAX and if your using the DOM tree, corresponding nodes are + generated. Too approach can be taken: + <ol> + <li>lazy one, use the compatibility call + <strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are + relying on a special (and possibly broken) set of heuristics of + libxml to detect ignorable blanks. Don't complain if it breaks or + make your application not 100% clean w.r.t. to it's input.</li> + <li>the Right Way: change you code to accept possibly insignificant + blanks characters, or have your tree populated with weird blank text + nodes. You can spot them using the commodity function + <strong>xmlIsBlankNode(node)</strong> returning 1 for such blank + nodes.</li> + </ol> + <p>Note also that with the new default the output functions don't add any + extra indentation when saving a tree in order to be able to round trip + (read and save) without inflating the document with extra formatting + chars.</p> + </li> + <li>The include path has changed to $prefix/libxml/ and the includes + themselves uses this new prefix in includes instructions... If you are + using (as expected) the + <pre>xml2-config --cflags</pre> + <p>output to generate you compile commands this will probably work out of + the box</p> + </li> + <li>xmlDetectCharEncoding takes an extra argument indicating the length in + byte of the head of the document available for character detection.</li> +</ol><h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3><p>Two new version of libxml (1.8.11) and libxml2 (2.3.4) have been released +to allow smooth upgrade of existing libxml v1code while retaining +compatibility. They offers the following:</p><ol> + <li>similar include naming, one should use + <strong>#include<libxml/...></strong> in both cases.</li> + <li>similar identifiers defined via macros for the child and root fields: + respectively <strong>xmlChildrenNode</strong> and + <strong>xmlRootNode</strong></li> + <li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be + inserted once in the client code</li> +</ol><p>So the roadmap to upgrade your existing libxml applications is the +following:</p><ol> + <li>install the libxml-1.8.8 (and libxml-devel-1.8.8) packages</li> + <li>find all occurrences where the xmlDoc <strong>root</strong> field is + used and change it to <strong>xmlRootNode</strong></li> + <li>similarly find all occurrences where the xmlNode + <strong>childs</strong> field is used and change it to + <strong>xmlChildrenNode</strong></li> + <li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your + <strong>main()</strong> or in the library init entry point</li> + <li>Recompile, check compatibility, it should still work</li> + <li>Change your configure script to look first for xml2-config and fall + back using xml-config . Use the --cflags and --libs output of the command + as the Include and Linking parameters needed to use libxml.</li> + <li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and + libxml-devel-1.8.y can be kept simultaneously)</li> + <li>remove your config.cache, relaunch your configuration mechanism, and + recompile, if steps 2 and 3 were done right it should compile as-is</li> + <li>Test that your application is still running correctly, if not this may + be due to extra empty nodes due to formatting spaces being kept in libxml2 + contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your + code before calling the parser (next to + <strong>LIBXML_TEST_VERSION</strong> is a fine place).</li> +</ol><p>Following those steps should work. It worked for some of my own code.</p><p>Let me put some emphasis on the fact that there is far more changes from +libxml 1.x to 2.x than the ones you may have to patch for. The overall code +has been considerably cleaned up and the conformance to the XML specification +has been drastically improved too. Don't take those changes as an excuse to +not upgrade, it may cost a lot on the long term ...</p><p><a href="bugs.html">Daniel Veillard</a></p></td></tr></table></td></tr></table></td></tr></table></td></tr></table></td></tr></table></body></html> |