Merge pull request #15 from dan-f/native-field-values

Convert rdf types to native JS types in field values

package.json

@@ -15,7 +15,7 @@
     "pretest": "npm run lint",
     "posttest": "npm run coverage:check",
     "test": "nyc mocha --compilers js:babel-core/register test/**.spec.js",
-    "test:develop": "mocha -d -w --compilers js:babel-core/register test/*.spec.js",
+    "test:develop": "mocha -d -w -G --compilers js:babel-core/register test/*.spec.js",
     "coverage:check": "nyc check-coverage --lines 98",
     "coverage:report": "nyc report --repoprter=text-lcov --reporter=html",
     "coverage:coveralls": "nyc report --reporter=text-lcov | coveralls",
@@ -50,7 +50,7 @@
     "expect": "^1.20.2",
     "mocha": "^3.0.2",
     "nyc": "^8.1.0",
-    "rdflib": "^0.9.0",
+    "rdflib": "^0.12.3",
     "sinon": "^1.17.5",
     "solid-namespace": "^0.1.0",
     "standard": "^7.1.2",
@@ -60,7 +60,6 @@
     "immutable": "^3.8.1",
     "lodash": "^4.14.2",
     "node-uuid": "^1.4.7",
-    "rdflib": "^0.9.0",
     "valid-url": "^1.0.9"
   }
 }

src/field.js

@@ -119,7 +119,7 @@ export class Field {
     // 'value' and 'listed'.
     if (isDefined(originalObject)) {
       this.originalObject = originalObject
-      this.value = originalObject.value
+      this.value = rdfToJs(originalObject)
     }
     if (isDefined(originalSource)) {
       this.originalSource = originalSource
@@ -164,7 +164,7 @@ export class Field {
     } else {
       sourceURI = this.listed ? defaultSources.listed : defaultSources.unlisted
     }
-    return rdf.namedNode(sourceURI)
+    return rdf.NamedNode.fromValue(sourceURI)
   }
 
   /**
@@ -179,13 +179,14 @@ export class Field {
     let object
     if (isDefined(this.originalObject)) {
       object = clone(this.originalObject)
-      object.value = this.value
+      // Convert the native JS value back to the corresponding RDF string value
+      object.value = this.originalObject.constructor.fromValue(this.value).value
       if (isDefined(object.uri)) {
         object.uri = this.value
       }
     } else {
       object = isUri(this.value)
-        ? rdf.namedNode(this.value)
+        ? rdf.NamedNode.fromValue(this.value)
         : rdf.Literal.fromValue(this.value)
     }
 
@@ -277,3 +278,56 @@ export class Field {
     })
   }
 }
+
+/**
+ * Extracts the value of an rdf node into the native JS representation of that
+ * node's type/value.  For example, it will extract booleans from a node with a
+ * datatype of xsd:boolean and a value of '0' or '1'.
+ *
+ * @param {Object} node - The rdf node object.
+ * @returns The value of that node.
+ */
+function rdfToJs (node) {
+  let value
+  const rdfVal = node.value
+  const datatype = node.datatype
+  const throwError = () => {
+    throw new Error(
+      `Cannot parse rdf type/value to JS value.  Given value [${rdfVal}] of type [${datatype}].`
+    )
+  }
+  if (datatype) {
+    const XMLSchema = 'http://www.w3.org/2001/XMLSchema#'
+    switch (datatype.value) {
+      case `${XMLSchema}boolean`:
+        if (rdfVal === '1') {
+          value = true
+        } else if (rdfVal === '0') {
+          value = false
+        } else {
+          throwError()
+        }
+        break
+      case `${XMLSchema}dateTime`:
+        // Format of date string can be found at: http://books.xmlschemata.org/relaxng/ch19-77049.html
+        value = new Date(rdfVal)
+        break
+      case `${XMLSchema}decimal`:
+      case `${XMLSchema}double`:
+        value = Number.parseFloat(rdfVal)
+        break
+      case `${XMLSchema}integer`:
+        value = Number.parseInt(rdfVal)
+        break
+      case 'http://www.w3.org/1999/02/22-rdf-syntax-ns#langString':
+      case `${XMLSchema}string`:
+      default:
+        value = rdfVal
+        break
+    }
+  } else {
+    // Assume string if there's no provided datatype
+    value = rdfVal
+  }
+  return value
+}

src/model.js

@@ -43,7 +43,7 @@ export function modelFactory (rdf, sourceConfig, fieldMap) {
   const factory = fieldFactory(sourceConfig)
   return (graph, subjectStr) => {
     const fieldCreators = {}
-    const subject = rdf.namedNode(subjectStr)
+    const subject = rdf.NamedNode.fromValue(subjectStr)
     const fields = Immutable.Map(
       Object.keys(fieldMap).reduce((prevFields, fieldName) => {
         const fieldPredicate = fieldMap[fieldName]