digitalbazaar · davidlehn · Sep 10, 2019 · Aug 28, 2019 · Sep 4, 2019 · Sep 4, 2019
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # jsonld ChangeLog
 
+### Added
+- Support literal JSON.
+  - **NOTE**: The JSON serialization is based on the JSON Canonicalization
+    Scheme (JCS) drafts. Changes in the JCS algorithm could cause changes in
+    the `toRdf` output.
+
 ## 1.7.0 - 2019-08-30
 
 ### Added

diff --git a/lib/constants.js b/lib/constants.js
@@ -17,6 +17,7 @@ module.exports = {
   RDF_TYPE: RDF + 'type',
   RDF_PLAIN_LITERAL: RDF + 'PlainLiteral',
   RDF_XML_LITERAL: RDF + 'XMLLiteral',
+  RDF_JSON_LITERAL: RDF + 'JSON',
   RDF_OBJECT: RDF + 'object',
   RDF_LANGSTRING: RDF + 'langString',
 

diff --git a/lib/context.js b/lib/context.js
@@ -499,7 +499,7 @@ api.createTermDefinition = (
         {code: 'invalid type mapping', context: localCtx});
     }
 
-    if(type !== '@id' && type !== '@vocab') {
+    if(type !== '@id' && type !== '@vocab' && type !== '@json') {
       // expand @type to full IRI
       type = _expandIri(
         activeCtx, type, {vocab: true, base: false}, localCtx, defined,
@@ -1114,6 +1114,7 @@ api.isKeyword = v => {
     case '@graph':
     case '@id':
     case '@index':
+    case '@json':
     case '@language':
     case '@list':
     case '@nest':

diff --git a/lib/expand.js b/lib/expand.js
@@ -23,7 +23,8 @@ const {
   expandIri: _expandIri,
   getContextValue: _getContextValue,
   isKeyword: _isKeyword,
-  process: _processContext
+  process: _processContext,
+  processingMode: _processingMode
 } = require('./context');
 
 const {
@@ -289,6 +290,8 @@ api.expand = ({
         'Invalid JSON-LD syntax; only strings may be language-tagged.',
         'jsonld.SyntaxError',
         {code: 'invalid language-tagged value', element: rval});
+    } else if(_processingMode(activeCtx, 1.1) && types.includes('@json') && types.length === 1) {
+      // Any value of @value is okay if @type: @json
     } else if(!types.every(t =>
       (_isAbsoluteIri(t) && !(_isString(t) && t.indexOf('_:') === 0) ||
       _isEmptyObject(t)))) {
@@ -494,16 +497,7 @@ function _expandObject({
         'jsonld.SyntaxError', {code: 'invalid @graph value', value});
     }
 
-    // @value must not be an object or an array (unless framing)
     if(expandedProperty === '@value') {
-      if((_isObject(value) || _isArray(value)) && !options.isFrame) {
-        throw new JsonLdError(
-          'Invalid JSON-LD syntax; "@value" value must not be an ' +
-          'object or an array.',
-          'jsonld.SyntaxError',
-          {code: 'invalid value object value', value});
-      }
-
       _addValue(
         expandedParent, '@value', value, {propertyIsArray: options.isFrame});
       continue;
@@ -669,6 +663,12 @@ function _expandObject({
           insideList: isList,
           expansionMap
         });
+      } else if(
+        _getContextValue(activeCtx, key, '@type') === '@json') {
+        expandedValue = {
+          '@type': '@json',
+          '@value': value
+        };
       } else {
         // recursively expand value with key as new active property
         expandedValue = api.expand({
@@ -747,6 +747,20 @@ function _expandObject({
     });
   }
 
+  // @value must not be an object or an array (unless framing) or if @type is @json
+  if('@value' in element) {
+    const value = element['@value'];
+    if(element['@type'] === '@json' && _processingMode(activeCtx, 1.1)) {
+      // allow any value, to be verified when the object is fully expanded and the @type is @json.
+    } else if((_isObject(value) || _isArray(value)) && !options.isFrame) {
+      throw new JsonLdError(
+        'Invalid JSON-LD syntax; "@value" value must not be an ' +
+        'object or an array.',
+        'jsonld.SyntaxError',
+        {code: 'invalid value object value', value});
+    }
+  }
+
   // expand each nested key
   for(const key of nests) {
     const nestedValues = _isArray(element[key]) ? element[key] : [element[key]];

diff --git a/lib/fromRdf.js b/lib/fromRdf.js
@@ -3,6 +3,7 @@
  */
 'use strict';
 
+const JsonLdError = require('./JsonLdError');
 const graphTypes = require('./graphTypes');
 const types = require('./types');
 const util = require('./util');
@@ -17,6 +18,7 @@ const {
   RDF_TYPE,
   // RDF_PLAIN_LITERAL,
   // RDF_XML_LITERAL,
+  RDF_JSON_LITERAL,
   // RDF_OBJECT,
   // RDF_LANGSTRING,
 
@@ -285,6 +287,17 @@ function _RDFToObject(o, useNativeTypes) {
     if(!type) {
       type = XSD_STRING;
     }
+    if(type === RDF_JSON_LITERAL) {
+      type = '@json';
+      try {
+        rval['@value'] = JSON.parse(rval['@value']);
+      } catch(e) {
+        throw new JsonLdError(
+          'JSON literal could not be parsed.',
+          'jsonld.InvalidJsonLiteral',
+          {code: 'invalid JSON literal', value: rval['@value'], cause: e});
+      }
+    }
     // use native types for certain xsd types
     if(useNativeTypes) {
       if(type === XSD_BOOLEAN) {

diff --git a/lib/toRdf.js b/lib/toRdf.js
@@ -6,6 +6,7 @@
 const {createNodeMap} = require('./nodeMap');
 const {isKeyword} = require('./context');
 const graphTypes = require('./graphTypes');
+const jsonCanonicalize = require('canonicalize');
 const types = require('./types');
 const util = require('./util');
 
@@ -18,6 +19,7 @@ const {
   RDF_TYPE,
   // RDF_PLAIN_LITERAL,
   // RDF_XML_LITERAL,
+  RDF_JSON_LITERAL,
   // RDF_OBJECT,
   RDF_LANGSTRING,
 
@@ -224,8 +226,11 @@ function _objectToRDF(item, issuer, dataset, graphTerm) {
     let value = item['@value'];
     const datatype = item['@type'] || null;
 
-    // convert to XSD datatypes as appropriate
-    if(types.isBoolean(value)) {
+    // convert to XSD/JSON datatypes as appropriate
+    if(datatype === '@json') {
+      object.value = jsonCanonicalize(value);
+      object.datatype.value = RDF_JSON_LITERAL;
+    } else if(types.isBoolean(value)) {
       object.value = value.toString();
       object.datatype.value = datatype || XSD_BOOLEAN;
     } else if(types.isDouble(value) || datatype === XSD_DOUBLE) {

diff --git a/package.json b/package.json
@@ -30,6 +30,7 @@
     "lib/**/*.js"
   ],
   "dependencies": {
+    "canonicalize": "^1.0.1",
     "rdf-canonize": "^1.0.2",
     "request": "^2.88.0",
     "semver": "^5.6.0",

diff --git a/tests/misc.js b/tests/misc.js
@@ -519,3 +519,20 @@ describe('js keywords', () => {
     assert.deepStrictEqual(e, ex);
   });
 });
+
+describe('literal JSON', () => {
+  it('handles error', done => {
+    const d =
+'_:b0 <ex:p> "bogus"^^<http://www.w3.org/1999/02/22-rdf-syntax-ns#JSON> .'
+;
+    const p = jsonld.fromRDF(d);
+    assert(p instanceof Promise);
+    p.then(() => {
+      assert.fail();
+    }).catch(e => {
+      assert(e);
+      assert.equal(e.name, 'jsonld.InvalidJsonLiteral');
+      done();
+    });
+  });
+});
diff --git a/tests/test-common.js b/tests/test-common.js
@@ -60,16 +60,6 @@ const TEST_TYPES = {
         /compact-manifest.jsonld#tpi04$/,
         /compact-manifest.jsonld#tpi05$/,
         /compact-manifest.jsonld#tpi06$/,
-        // JSON literals
-        /compact-manifest.jsonld#tjs01$/,
-        /compact-manifest.jsonld#tjs02$/,
-        /compact-manifest.jsonld#tjs03$/,
-        /compact-manifest.jsonld#tjs04$/,
-        /compact-manifest.jsonld#tjs05$/,
-        /compact-manifest.jsonld#tjs06$/,
-        /compact-manifest.jsonld#tjs07$/,
-        /compact-manifest.jsonld#tjs08$/,
-        /compact-manifest.jsonld#tjs09$/,
         // IRI confusion
         /compact-manifest.jsonld#te002$/,
         // @propogate
@@ -171,18 +161,6 @@ const TEST_TYPES = {
         /expand-manifest.jsonld#tpi09$/,
         /expand-manifest.jsonld#tpi10$/,
         /expand-manifest.jsonld#tpi11$/,
-        // JSON literals
-        /expand-manifest.jsonld#tjs01$/,
-        /expand-manifest.jsonld#tjs02$/,
-        /expand-manifest.jsonld#tjs03$/,
-        /expand-manifest.jsonld#tjs04$/,
-        /expand-manifest.jsonld#tjs05$/,
-        /expand-manifest.jsonld#tjs06$/,
-        /expand-manifest.jsonld#tjs07$/,
-        /expand-manifest.jsonld#tjs08$/,
-        /expand-manifest.jsonld#tjs09$/,
-        /expand-manifest.jsonld#tjs10$/,
-        /expand-manifest.jsonld#tjs11$/,
         // misc
         /expand-manifest.jsonld#te043$/,
         /expand-manifest.jsonld#te044$/,
@@ -336,14 +314,6 @@ const TEST_TYPES = {
       specVersion: ['json-ld-1.0'],
       // FIXME
       idRegex: [
-        // JSON literals
-        /fromRdf-manifest.jsonld#tjs01$/,
-        /fromRdf-manifest.jsonld#tjs02$/,
-        /fromRdf-manifest.jsonld#tjs03$/,
-        /fromRdf-manifest.jsonld#tjs04$/,
-        /fromRdf-manifest.jsonld#tjs05$/,
-        /fromRdf-manifest.jsonld#tjs06$/,
-        /fromRdf-manifest.jsonld#tjs07$/,
       ]
     },
     fn: 'fromRDF',
@@ -406,20 +376,6 @@ const TEST_TYPES = {
         /html-manifest.jsonld#tr020$/,
         /html-manifest.jsonld#tr021$/,
         /html-manifest.jsonld#tr022$/,
-        // JSON literal
-        /toRdf-manifest.jsonld#tjs01$/,
-        /toRdf-manifest.jsonld#tjs02$/,
-        /toRdf-manifest.jsonld#tjs03$/,
-        /toRdf-manifest.jsonld#tjs04$/,
-        /toRdf-manifest.jsonld#tjs05$/,
-        /toRdf-manifest.jsonld#tjs06$/,
-        /toRdf-manifest.jsonld#tjs07$/,
-        /toRdf-manifest.jsonld#tjs08$/,
-        /toRdf-manifest.jsonld#tjs09$/,
-        /toRdf-manifest.jsonld#tjs10$/,
-        /toRdf-manifest.jsonld#tjs11$/,
-        /toRdf-manifest.jsonld#tjs12$/,
-        /toRdf-manifest.jsonld#tjs13$/,
         // number fixes
         /toRdf-manifest.jsonld#trt01$/,
         // IRI resolution