GXml provides a GObject API for manipulating XML and a Serializable
framework from GObject to XML.

GXml provide a DOM level 4 API for XML with multiple backends.

* A backend wrapping around libxml2 for read/write, the GNode class series
* A GObject based tree backend, a more closed DOM4 implementation support is present,
  the GomNode class series.

There is a GObject based tree backend, using libxml2 just to read XML files,
the TNode [Unmaintained], offering just DOM leve 1 API.

Compile:
  Requirements:
   * vala
   * libxml2

  Optional Requirements:
    * valadoc: we generate documentation using valadoc.  If it's not
      packaged for your distro (like Fedora) follow the instructions
      at:

      https://live.gnome.org/Valadoc

  Autotools build system:

  $ ./configure
  $ make
  $ make install

  Meson build system:

  $ meson _build
  $ cd _build
  $ ninja
  $ ninja install

  You can use some common ./configure options like --prefix=$SOMEPATH to specify
  where to install it.

Test: You can run the test suite, which is gxml_test, which you may
  have installed into your $PATH.  You should actually run it from
  test/, though, as it requires .xml files that are currently just
  relatively referenced.

  $ cd test/
  $ ./gxml_test

  Autotools build system:

  $ make test

  Meson build system:

  $ meson test



Writing documentation

  We use Valadoc, http://www.valadoc.org/, which is probably the best
  solution to generate both valadoc documentation and HTML gtk-doc
  documentation.

  Installation for DevHelp:

  Make sure you have valadoc installed, documentation is automatically
  generated, then install it, your documentation will be available in
  DevHelp.

  Some notes:

  - Documentation for overriding functions/methods is shown in
    valadoc, but not in gtkdoc.  For gtkdoc, you can only go up to the
    original superclass to see what's been available, even if it's
    been overriden.  (Would we want this to be any different for
    gtkdoc?)

  - We don't get an Object Hierarchy in our gtkdoc with valadoc :(
    TODO: write a patch to valadoc :D

  - We can't highlight special macro values like NULL/null, TRUE/true,
    or FALSE/false consistently.  For gtkdoc, you can use #NULL, but
    then in the vala code, we see "#NULL" instead of "null", and the
    reverse.
    TODO: write a patch to valadoc :D

  - Multiline descriptions will only have the first line appear in
    valadoc.

  - For the gtkdoc or valadoc to be visible in devhelp and you're installing into
    an abnormal prefix, consider placing a symlink to your prefix
    installed gtk-doc in /usr/share/gtk-doc/html/.  For example,
    $ ln -s ~/.local/share/gtk-doc/html/gxml /usr/share/gtk-doc/html

  - Valadoc's documentation use JavaScript to naviate over inherited
    methods and properties, but DevHelp have no support for that.
    TODO: write a patch to DevHelp to support Valadoc's JavaScript