know-sparql-render

#!/usr/bin/python3

import argparse
from sys import stdin, stdout, stderr
import os.path
from subprocess import Popen, PIPE

from rdflib import Graph, URIRef, Literal
from lxml import etree
from RDFFresnel import Context, ContainerBox

from PKB4Unix import endpoint

argparser = argparse.ArgumentParser(
    description=('Render Resources with Fresnel'))
argparser.add_argument('resources', nargs='+', metavar='URI',
                    help=('Resource to be rendered. Use - to read the URIs from standard input'))
argparser.add_argument('-i', '--instance-graph', metavar='GRAPH', dest='instance_graph',
                    help=('Restrict instance data to this graph'))
argparser.add_argument('-l', '--lens-graph', metavar='GRAPH', dest='lens_graph',
                    help=('Graph containing Fresnel Lenses (if not given, all available graphs are searched for lenses)'))
argparser.add_argument('-t', '--transform', metavar='FILE', dest='transform',
                    help=('The location of a XSL transformation to be applied (using xsltproc) after rendering'))
argparser.add_argument('-T', '--default-transform', dest='default_transform', action='store_true',
                    help=('Like -t with fresneltoxhtml5.xsl from ~/.local/share/RDFFresnel, /usr/local/share/RDFFresnel or /usr/share/RDFFresnel, depending on which one exists'))

args = argparser.parse_args()

kb = endpoint.kbConnect()

if args.instance_graph:
    instances = kb.get_context(URIRef(args.instance_graph))
else:
    instances = kb

if args.lens_graph:
    lenses = kb.get_context(URIRef(args.lens_graph))
else:
    lenses = kb

if args.default_transform:
    for p in (
        "~/.local/share/RDFFresnel/fresneltoxhtml5.xsl",
        "/usr/local/share/RDFFresnel/fresneltoxhtml5.xsl",
        "/usr/share/RDFFresnel/fresneltoxhtml5.xsl",
    ):
        os.path.expanduser(p)
        if os.path.exists(p):
            args.transform = p
            break
    print("Couldn't find default transformation", file=stderr)
    exit(1)

ctx = Context(fresnelGraph=lenses, instanceGraph=instances)
box = ContainerBox(ctx)
for r in args.resources:
    if r == '-':
        for line in iter(stdin.readline, ''):
            r = line.strip()
            if line:
                box.append(URIRef(r))
    else:
        box.append(URIRef(r))

box.select()
box.portray()
tree = box.transform()

if args.transform:
    pipe = Popen(['xsltproc', args.transform, '-'], stdin=PIPE)
    dest = pipe.stdin
else:
    dest = stdout.buffer

dest.write(etree.tostring(tree,encoding="UTF-8",xml_declaration=True))