lakesuperior_legacy/lakesuperior/util/translator.py

from flask import request
from rdflib.term import URIRef

from lakesuperior.dictionaries.namespaces import ns_collection as nsc
from lakesuperior.store_layouts.rdf.base_rdf_layout import BaseRdfLayout


class Translator:
    '''
    Utility class to perform translations of strings and their wrappers.
    All static methods.
    '''

    @staticmethod
    def camelcase(word):
        '''
        Convert a string with underscores with a camel-cased one.

        Ripped from https://stackoverflow.com/a/6425628
        '''
        return ''.join(x.capitalize() or '_' for x in word.split('_'))


    @staticmethod
    def uuid_to_uri(uuid):
        '''Convert a UUID to a URI.

        @return URIRef
        '''
        return URIRef('{}rest/{}'.format(request.host_url, uuid))


    @staticmethod
    def localize_string(s):
        '''Convert URIs into URNs in a string using the application base URI.

        @param string s Input string.

        @return string
        '''
        return s.replace(
            request.host_url + 'rest/',
            str(nsc['fcres'])
        )


    @staticmethod
    def globalize_string(s):
        '''Convert URNs into URIs in a string using the application base URI.

        @param string s Input string.

        @return string
        '''
        return s.replace(
            str(nsc['fcres']),
            request.host_url + 'rest/'
        )


    @staticmethod
    def globalize_term(urn):
        '''
        Convert an URN into an URI using the application base URI.

        @param rdflib.term.URIRef urn Input URN.

        @return rdflib.term.URIRef
        '''
        if urn == BaseRdfLayout.ROOT_NODE_URN:
            urn = nsc['fcres']
        return URIRef(Translator.globalize_string(str(urn)))


    @staticmethod
    def globalize_graph(g):
        '''
        Globalize a graph.
        '''
        from lakesuperior.model.ldpr import Ldpr
        q = '''
        CONSTRUCT {{ ?s ?p ?o . }} WHERE {{
          {{
            ?s ?p ?o .
            FILTER (
              STRSTARTS(str(?s), "{0}")
              ||
              STRSTARTS(str(?o), "{0}")
              ||
              STRSTARTS(str(?s), "{1}")
              ||
              STRSTARTS(str(?o), "{1}")
            ) .
          }}
        }}'''.format(nsc['fcres'], BaseRdfLayout.ROOT_NODE_URN)
        flt_g = g.query(q)

        for t in flt_g:
            global_s = Translator.globalize_term(t[0])
            global_o = Translator.globalize_term(t[2]) \
                    if isinstance(t[2], URIRef) \
                    else t[2]
            g.remove(t)
            g.add((global_s, t[1], global_o))

        return g


    @staticmethod
    def globalize_rsrc(rsrc):
        '''
        Globalize a resource.
        '''
        g = rsrc.graph
        urn = rsrc.identifier

        global_g = Translator.globalize_graph(g)
        global_uri = Translator.globalize_term(urn)

        return global_g.resource(global_uri)