sparql

request = require 'request' querystring = require 'querystring' normalize_v = (v) -> return null unless v? if v instanceof Array if v.length is 0 return null else return v else return [v] get_one_key = (obj) -> for own k of obj return k compose_prefix_string = (prefix_map) -> ( "prefix #{k}: <#{v}>" for k, v of prefix_map ).join ' ' does_query_have_prefixes = (query) -> # TODO: should be regex # for now, simple heuristic. "prefix" must happen within the first 10 chars iof = query.toLowerCase().indexOf 'prefix' 0 < iof < 10 ensure_prefixes = (query, prefix_map) -> s = compose_prefix_string prefix_map if s.length is 0 or does_query_have_prefixes query then query else s + ' ' + query generate_set_sparql = ( g, s, p, o, inverted, cb ) -> [e, a, v] = if inverted then [o, p, s] else [s, p, o] v = normalize_v v del = (if inverted then ['?x', a, e] else [e, a, '?x']).join ' ' if v? ins = ((if inverted then [val, a, e] else [e, a, val]).join ' ' for val in v).join ' . ' q = "modify #{g} delete { #{del} } insert { #{ins} } where { optional{ #{del} } }" else q = "delete from #{g} { #{del} } where { #{del} } " generate_mset_sparql = ( g, s, atts, cb ) -> # This method doesn't check on anything, just issues an insert. # If you want something safer (for now), you have to combine with get qSjt = "insert into #{g} { #{s} " # This is my hack to iterate over the atts object! counter = 1 qAtt = for k,v of atts if counter < Object.keys(atts).length x = ";" else x = "" counter = counter + 1 k + " '" + v + "' "+ x q = qSjt + qAtt.join(" ") + ". }" exports.ensure_prefixes = ensure_prefixes exports.does_query_have_prefixes = does_query_have_prefixes exports.compose_prefix_string = compose_prefix_string exports.generate_set_sparql = generate_set_sparql exports.generate_mset_sparql = generate_mset_sparql class Client constructor: ( @url ) -> @prefix_map = {} query : ( query, cb ) -> query = ensure_prefixes query, @prefix_map console?.log query if @log_query is true # quick n' dirty logging option opts = uri: @url headers: 'content-type':'application/x-www-form-urlencoded' 'accept':'application/sparql-results+json' body: querystring.stringify (query:query) encoding: 'utf8' request.post opts, (err, res, body) -> if res?.statusCode is 200 cb? null, JSON.parse body else cb? [err, res, body] rows : ( query, cb ) -> @query query, (err, res) -> if err? cb err return if res? cb null, res.results.bindings else cb null, null cols : ( query, cb ) -> @query query, (err, res) -> if err? cb err return if res? r = {} r[name] = ( row[name] for row in res.results.bindings ) for name in res.head.vars cb null, r else cb null, null cell : ( query, cb ) -> @row query, (err, res) -> if err? cb err return if res? cb null, res[ get_one_key res ] else cb null, null row : ( query, cb ) -> @query query, (err, res) -> if err? cb err return b = res.results.bindings if b.length is 0 cb null, null else cb null, b[0] col : ( query, cb ) -> @query query, (err, res) -> if err? cb err return bs = res.results.bindings if bs.length is 0 cb null, [] else key = get_one_key bs[0] cb null, (b[key] for b in bs) set : ( g, s, p, o, inverted, cb ) -> q = generate_set_sparql g, s, p, o, inverted @query q, (err, res) -> cb? err, res mset : ( g, s, atts, cb ) -> q = generate_mset_sparql g, s, atts @query q, (err, res) -> cb? err, res exports.Client = Client