= [GenshiRecipes Genshi Recipes]: XInclude scanner for SCons =

== Motivation ==

You need to integrate Genshi sources into an [http://www.scons.org/ SCons] based build system and you would like implicit dependencies for `xi:include` directives.

== Code ==

{{{
#!python
import sys
from genshi.filters import IncludeFilter
from genshi.template import Template,TemplateLoader

def genshi_xinclude_scan(node, env, path, arg):
    t = Template(node.get_contents())
    loader = TemplateLoader('.'.split())
    t.filters.insert(0, IncludeFilter(loader))
    t.generate().render()
    return loader._cache.keys()

markup_scanner = Scanner(
    name='genshi',
    function=genshi_xinclude_scan,
    argument=None,
    skeys = '.xhtml .html .xml'.split())
scanners = Environment().Dictionary('SCANNERS')
env = Environment(SCANNERS = scanners + [genshi_scanner])

env.Command('page-out', 'page.html', './render $SOURCES $TARGET')
}}}

So, assuming `page.html` references another file, say `base.html`, using the XInclude recipe, any edit to `base.html` will cause scons to consider `page-out` to be out of date. After an edit of either `page.html` or `base.html` `scons -f SConscript` will be sufficient to bring `page-out` up to date.

`render` is a trivial wrapper script that renders the final output using Genshi for a single source file. Mine looks like this::

{{{
#!python
#!/usr/bin/python
import sys
try:
    import wingdbstub
except ImportError:
    pass
from genshi.filters import IncludeFilter
from genshi.template import Template, TemplateLoader

t = Template(file(sys.argv[1]).read())
t.filters.insert(0, IncludeFilter(TemplateLoader('.'.split())))
outf = sys.stdout
if len(sys.argv) > 2:
    outf = file(sys.argv[2], 'w')
print >> outf, t.generate()
}}}

There may be slicker ways of doing this. If you know them then please update this recipe.

----
See also: GenshiRecipes, GenshiRecipes/RecursiveIncludeScanner