Added blank node get support.

Author: mcollina

index.js

@@ -1,7 +1,9 @@
 
 var jsonld = require("jsonld")
   , uuid   = require("uuid")
-  , IRI = /(ftp|http|https):\/\/(\w+:{0,1}\w*@)?(\S+)(:[0-9]+)?(\/|\/([\w#!:.?+=&%@!\-\/]))?/i;
+  , IRI = /(ftp|http|https):\/\/(\w+:{0,1}\w*@)?(\S+)(:[0-9]+)?(\/|\/([\w#!:.?+=&%@!\-\/]))?/i
+  , RDFTYPE = "http://www.w3.org/1999/02/22-rdf-syntax-ns#type"
+  , async = require("async");
 
 function levelgraphJSONLD(db, jsonldOpts) {
 
@@ -43,59 +45,108 @@ function levelgraphJSONLD(db, jsonldOpts) {
         callback(null, obj);
       });
 
-      expanded.forEach(function(triples) {
+      var writeTriples = function(triples) {
         var subject = triples["@id"];
         delete triples["@id"];
 
         if (!subject) {
-          subject = (options.base || graphdb.jsond.options.base) + uuid.v1();
+          subject = "_:" + uuid.v1();
         }
 
         Object.keys(triples).forEach(function(predicate) {
+          if (predicate === "@type") {
+            if (!triples[predicate].forEach) {
+              triples[predicate] = [triples[predicate]];
+            }
+
+            triples[RDFTYPE] = triples[predicate];
+            delete triples[predicate];
+            predicate = RDFTYPE;
+          }
+
           triples[predicate].forEach(function(object) {
             var triple = {
                 subject: subject
               , predicate: predicate
-              , object: object["@id"] || object["@value"]
+              , object: (typeof object === 'string') ? object : object["@id"] || object["@value"]
             };
+            
+            if (!triple.object) {
+              // the object should be a blank node that points
+              // to a another triple
+              writeTriples(object);
+              triple.object = object["@id"];
+            }
+
             stream.write(triple);
           });
         });
-      });
+
+        triples["@id"] = subject;
+      };
+
+      expanded.forEach(writeTriples);
 
       stream.end();
     });
   };
 
-  graphdb.jsonld.get = function(iri, context, options, callback) {
-
-    if (typeof options === 'function') {
-      callback = options;
-      options = {};
+  var fetchExpandedTriples = function(iri, memo, callback) {
+    if (typeof memo === "function") {
+      callback = memo;
+      memo = {};
     }
 
     graphdb.get({ subject: iri }, function(err, triples) {
       if (err || triples.length === 0) {
         return callback(err, null);
       }
 
-      var triples   = triples.reduce(function(acc, triple) {
-                        var key;
+      async.reduce(triples, memo, function(acc, triple, cb) {
+        var key;
 
-                        if (!acc[triple.subject]) {
-                          acc[triple.subject] = { "@id": triple.subject };
-                        }
-                        acc[triple.subject][triple.predicate] = {};
-                        key = triple.object.match(IRI) ? "@id" : "@value";
-                        acc[triple.subject][triple.predicate][key] = triple.object;
+        if (!acc[triple.subject]) {
+          acc[triple.subject] = { "@id": triple.subject };
+        }
+        
+        if (triple.predicate === RDFTYPE) {
+          if (acc[triple.subject]["@type"]) {
+            acc[triple.subject]["@type"] = [acc[triple.subject]["@type"]];
+            acc[triple.subject]["@type"].push(triple.object);
+          } else {
+            acc[triple.subject]["@type"] = triple.object;
+          }
+          cb(null, acc);
+        } else if (triple.object.indexOf("_:") !== 0) {
+          acc[triple.subject][triple.predicate] = {};
+          key = (triple.object.match(IRI) || triple.object.indexOf("_:") === 0) ? "@id" : "@value";
+          acc[triple.subject][triple.predicate][key] = triple.object;
+          cb(null, acc);
+        } else {
+          fetchExpandedTriples(triple.object, function(err, expanded) {
+            acc[triple.subject][triple.predicate] = expanded[triple.object];
+            cb(err, acc);
+          });
+        }
+      }, callback);
+    });
+  };
 
-                        return acc;
-                      }, {})
+  graphdb.jsonld.get = function(iri, context, options, callback) {
 
-        , expanded  = Object.keys(triples).reduce(function(acc, key) {
-                        acc.push(triples[key]);
-                        return acc;
-                      }, []);
+    if (typeof options === 'function') {
+      callback = options;
+      options = {};
+    }
+
+    fetchExpandedTriples(iri, function(err, expanded) {
+      if (err || expanded === null) {
+        return callback(err, expanded);
+      }
+      expanded = Object.keys(expanded).reduce(function(acc, key) {
+        acc.push(expanded[key]);
+        return acc;
+      }, []);
 
       jsonld.compact(expanded, context, options, callback);
     });

package.json

@@ -24,7 +24,8 @@
   "license": "MIT",
   "dependencies": {
     "jsonld": "0.0.62",
-    "uuid": "~1.4.1"
+    "uuid": "~1.4.1",
+    "async": "~0.2.9"
   },
   "peerDependencies": {
     "levelgraph": "~0.6.1"

test/common.js

@@ -2,3 +2,13 @@
 
 global.chai = require("chai");
 global.expect = require("chai").expect;
+
+var fs       = require("fs")
+  , fixtures = {};
+
+global.fixture = function(name) {
+  if (!fixtures[name]) {
+    fixtures[name] = fs.readFileSync(__dirname + "/fixture/" + name);
+  }
+  return JSON.parse(fixtures[name]);
+};

test/fixture/john.jsonld

@@ -1,26 +1,16 @@
 
-var level = require("level-test")()
-  , graph = require("levelgraph")
+var level  = require("level-test")()
+  , graph  = require("levelgraph")
   , jsonld = require("../")
+  , fs     = require("fs")
+  , JSONLD = require("jsonld");
 
 describe("jsonld.get", function() {
 
-  var db
-    , manu = {
-          "@context": {
-              "name": "http://xmlns.com/foaf/0.1/name"
-            , "homepage": {
-                  "@id": "http://xmlns.com/foaf/0.1/homepage"
-                , "@type": "@id"
-              }
-          }
-        , "@id": "http://manu.sporny.org#person"
-        , "name": "Manu Sporny"
-        , "homepage": "http://manu.sporny.org/"
-      };
+  var db, manu = fixture("manu.json");
 
   beforeEach(function() {
-    db = jsonld(graph(level()));
+    db = jsonld(graph(level()), { base: "http://levelgraph.io/get" } );
   });
 
   afterEach(function(done) {
@@ -46,4 +36,22 @@ describe("jsonld.get", function() {
       });
     });
   });
+
+  describe("with an object with blank nodes", function() {
+    var tesla;
+
+    beforeEach(function(done) {
+      tesla = fixture("tesla.json")
+      db.jsonld.put(tesla, done);
+    });
+
+    it("should load it properly", function(done) {
+      db.jsonld.get(tesla["@id"], { "@context": tesla["@context"] }, function(err, obj) {
+        tesla["gr:hasPriceSpecification"]["@id"] = obj["gr:hasPriceSpecification"]["@id"];
+        tesla["gr:includes"]["@id"] = obj["gr:includes"]["@id"];
+        expect(obj).to.eql(tesla);
+        done();
+      });
+    });
+  });
 });