Injecting extra data into the XSLT

If you want to have some extra data passed to the xslt, which can not be obtained by the serializer you can make some view helpers that create xml and pass it as a stringparam to the xslt.

Reasons why you would need this:

• You’ve got a model that has a foreign key to itself. You need this if you want some kind of hierarchical page tree or something. You might want to put the self referencing ForeignKey to serialize=False. This way it can not mess up the serializer, but you don’t have a hierarchic structure in your xml.
• You pull data from an external source.
• You have to do some processing on the models before they get turned into xml.
• You have some data not coming from models that needs to be passed to the xslt.

In all these cases you can use XmlPrinter to make some well formed unicode safe xml you can feed to the xslt.

Here is an example where some static strings get passed to the xslt. These strings are translatable using django’s regular i18n mechanism, but they are not in the database:

from django.utils.translation import ugettext as _

stringlib = dict(
    close_button = _('Close'),
    next_button = _('Next'),
    the_end = _("That's all folks")
)

def render_stringlib_xml():
    """Renders the stringlib xml"""
    stream = StringIO()
    xml = XmlPrinter(stream, settings.DEFAULT_CHARSET)
    xml.startElement('stringlib', {'id':'stringlib'})
    for (key, value) in stringlib.iteritems():
        xml.startElement(key, {})
        xml.characters(value)
        xml.endElement(key)
    xml.endElement('stringlib')

    byte_string = stream.getvalue()
    return byte_string.decode('utf-8')

Before you pass the rendered xml string, you should prepare it using prepare_string_param():

from easymode.xslt import prepare_string_param as q
from easymode.xslt.response import render_to_response

params = {
    'stringlib' : q(render_stringlib_xml()),
}

qs = Foo.objects.all()

return render_to_response('xslt/model-to-xml.xsl', qs, params)