fix JSON sample (for #899)

website/playground/new-samples/extending-language-services/configure-json-defaults/sample.js

@@ -1,12 +1,20 @@
 // Configures two JSON schemas, with references.
 
-var id = "foo.json";
+var jsonCode = [
+    '{',
+    '    "p1": "v3",',
+    '    "p2": false',
+    "}"
+].join('\n');
+var modelUri = monaco.Uri.parse("a://b/foo.json"); // a made up unique URI for our model
+var model = monaco.editor.createModel(jsonCode, "json", modelUri);
 
+// configure the JSON language support with schemas and schema associations
 monaco.languages.json.jsonDefaults.setDiagnosticsOptions({
     validate: true,
     schemas: [{
-        uri: "http://myserver/foo-schema.json",
-        fileMatch: [id],
+        uri: "http://myserver/foo-schema.json", // id of the first schema
+        fileMatch: [modelUri.toString()], // associate with our model
         schema: {
             type: "object",
             properties: {
@@ -14,13 +22,12 @@ monaco.languages.json.jsonDefaults.setDiagnosticsOptions({
                     enum: ["v1", "v2"]
                 },
                 p2: {
-                    $ref: "http://myserver/bar-schema.json"
+                    $ref: "http://myserver/bar-schema.json" // reference the second schema
                 }
             }
         }
     }, {
-        uri: "http://myserver/bar-schema.json",
-        fileMatch: [id],
+        uri: "http://myserver/bar-schema.json", // id of the first schema
         schema: {
             type: "object",
             properties: {
@@ -32,16 +39,6 @@ monaco.languages.json.jsonDefaults.setDiagnosticsOptions({
     }]
 });
 
-
-var jsonCode = [
-	'{',
-	'    "p1": "v3",',
-	'    "p2": false',
-	"}"
-].join('\n');
-
-var model = monaco.editor.createModel(jsonCode, "json", id);
-
 monaco.editor.create(document.getElementById("container"), {
     model: model
 });