Simplified flow

Author: Alkarex

README.md

@@ -30,7 +30,7 @@ Here is an example of full Node-RED flow: [Node-RED_example_of_flow.json](exampl
 * *Purpose*: Ability to determine the URL of the JSON Schema (e.g. FIWARE NGSI) or JSONata expression to use for a given JSON payload received.
 * *Configuration*: A Node-RED `mappingsUrl` property to indicate the URL of a file listing which JSON Schema or JSONata expression to use for which data input. (See examples below).
 * *Input*: A JSON observation (e.g. one of the FIWARE NGSI types) in the `msg.payload` property.
-* *Output*: The unmodified JSON observation in the `msg.payload` property, and the resolved schema URL in the `msg.schemaUrl` property.
+* *Output*: The unmodified JSON observation in the `msg.payload` property, and the resolved schema URL in the `msg.schemaUrl` property (if any match was found).
 
 ### Example of input data
 This is an example of [standard payload](https://fiware-datamodels.readthedocs.io/en/latest/Transportation/Vehicle/Vehicle/doc/spec/index.html), for which we need to look-up the [corresponding JSON Schema](https://smart-data-models.github.io/data-models/specs/Transportation/Vehicle/VehicleModel/schema.json).
@@ -166,7 +166,8 @@ Output:
 * *Context*: Node-RED node, or command line with `index.js multi-schema-transformer`
 * *Purpose*: Ability to transform a JSON observation on the fly from whichever format to another format (e.g. one of the FIWARE NGSI types) using a specified JSONata URL. Schemas are automatically downloaded and cached the first time they are needed.
 * *Input*: A JSON observation in whichever format in the `msg.payload` property, and the corresponding JSONata URL on the `msg.schemaUrl` property (coming from json-multi-schema-resolver).
-* *Output*: The transformed JSON observation in the `msg.payload` property, and potential validation errors in the `msg.error` property.
+  * If no `msg.schemaUrl` is provided, no transformation is performed.
+* *Output*: The transformed JSON observation in the `msg.payload` property, the used JSONata in the `msg.transformUrl` (if any transformation was performed), and potential validation errors in the `msg.error` property.
 * *Implementation*: Based on [JSONata](https://github.com/jsonata-js/jsonata).
 
 It is typically used with a *json-multi-schema-resolver* node in front.
@@ -261,7 +262,8 @@ Output:
 * *Context*: Node-RED node, or command line with `./index.js json-multi-schema-validator`
 * *Purpose*: Ability to validate a JSON observation (e.g. one of the FIWARE NGSI types) on the fly against a specified JSON Schema URL. Schemas are automatically downloaded and cached the first time they are needed.
 * *Input*: A JSON observation (e.g. one of the FIWARE NGSI types) in the `msg.payload` property, and the corresponding JSON Schema URL on the `msg.schemaUrl` property (coming from json-multi-schema-resolver).
-* *Output*: The unmodified JSON observation in the `msg.payload` property, and potential validation errors in the `msg.error` property.
+  * If no `msg.schemaUrl` is provided, no validation is performed.
+* *Output*: The unmodified JSON observation in the `msg.payload` property, the used schema in the `msg.validUrl` (if any validation was performed), and potential validation errors in the `msg.error` property.
 * *Implementation*: Based on [AJV](https://ajv.js.org).
 
 It is typically used with a *json-multi-schema-resolver* node in front.

json-multi-schema-resolver.js

@@ -54,8 +54,6 @@ module.exports = RED => {
 				if (schemaUrl != '') {
 					msg.schemaUrl = schemaUrl;
 					msg.error = msg.error != '';
-				} else {
-					msg.error += util.format('Failed resolving schema using "%s"', mappingsUrl);
 				}
 				if (lastStatusError) {
 					node.status({ fill:'green', shape:'dot', text:'OK', });

json-multi-schema-transformer.html

@@ -25,8 +25,8 @@
 	<p>Node to transform a JSON observation to another format using a configurable set of JSONata rules.</p>
 	<ul>
 		<li>The node will transform a given JSON payload received in <code>msg.payload</code> using some JSONata rules, which URL is given in <code>msg.schemaUrl</code></li>
-		<li>The URL of the corresponding JSONata file is returned in <code>msg.transformUrl</code>.</li>
-		<li>The transformed payload is returned in <code>msg.payload</code>.</li>
+		<li>If any transformation is actually performed, the URL of the corresponding JSONata file is returned in <code>msg.transformUrl</code>.</li>
+		<li>The transformed payload is returned in <code>msg.payload</code>. If no <code>msg.schemaUrl</code> is provided, no transformation is performed.</li>
 		<li>Errors are returned on <code>msg.error</code></li>
 	</ul>
 	<p>Example of file containing the list of transformations:</p>

json-multi-schema-transformer.js

@@ -66,9 +66,7 @@ module.exports = RED => {
 
 		node.on('input', async msg => {
 			msg.error = msg.error ? msg.error + ' ; ' : '';
-			if (msg.schemaUrl == '') {
-				msg.error += 'Unknown schema!';
-			} else {
+			if (msg.schemaUrl != '') {
 				msg.transformUrl = msg.schemaUrl;
 				try {
 					const result = await transformAsync(msg.payload, msg.schemaUrl);

json-multi-schema-validator.html

@@ -24,8 +24,8 @@
 <script type="text/x-red" data-help-name="json-multi-schema-validator">
 	<ul>
 		<li>The node will validate the JSON data given in <code>msg.payload</code> against the JSON Schema URL given in <code>msg.schemaUrl</code></li>
-		<li>The URL of the corresponding JSON Schema file is returned in <code>msg.validUrl</code>.</li>
-		<li>The content of <code>msg.payload</code> is unchanged.</li>
+		<li>If any validation was actually performed, the URL of the corresponding JSON Schema file is returned in <code>msg.validUrl</code>.</li>
+		<li>The content of <code>msg.payload</code> is unchanged. If no <code>msg.schemaUrl</code> is provided, no validation is performed.</li>
 		<li>Errors are returned on <code>msg.error</code></li>
 	</ul>
 </script>

json-multi-schema-validator.js

@@ -90,9 +90,7 @@ module.exports = RED => {
 
 		node.on('input', async msg => {
 			msg.error = msg.error ? msg.error + ' ; ' : '';
-			if (msg.schemaUrl == '') {
-				msg.error += 'Unknown schema!';
-			} else {
+			if (msg.schemaUrl != '') {
 				msg.validUrl = msg.schemaUrl;
 				try {
 					const result = await validateAsync(msg.payload, msg.schemaUrl);

package-lock.json

@@ -1,6 +1,6 @@
 {
 	"name": "node-red-contrib-json-multi-schema",
-	"version": "0.5.0",
+	"version": "0.5.1",
 	"description": "Generic JSON data pipeline tools, with dynamic transformation (using JSONata rules), resolving JSON Schema (using JSONata rules), and then validation (using JSON Schema). For Node-RED and for command-line.",
 	"main": "index.js",
 	"readmeFilename": "readme.md",