🔀 Merge master

nodes/ExampleNode/ExampleNode.node.ts

@@ -1,5 +1,10 @@
 import { IExecuteFunctions } from 'n8n-core';
-import { INodeExecutionData, INodeType, INodeTypeDescription } from 'n8n-workflow';
+import {
+	INodeExecutionData,
+	INodeType,
+	INodeTypeDescription,
+	NodeOperationError,
+} from 'n8n-workflow';
 
 export class ExampleNode implements INodeType {
 	description: INodeTypeDescription = {
@@ -14,29 +19,56 @@ export class ExampleNode implements INodeType {
 		inputs: ['main'],
 		outputs: ['main'],
 		properties: [
-			// Node properties that the user can see and change on the node.
+			// Node properties which the user gets displayed and
+			// can change on the node.
 			{
 				displayName: 'My String',
 				name: 'myString',
 				type: 'string',
 				default: '',
 				placeholder: 'Placeholder value',
-				description: 'This is a description',
+				description: 'The description text',
 			},
 		],
 	};
 
+	// The function below is responsible for actually doing whatever this node
+	// is supposed to do. In this case, we're just appending the `myString` property
+	// with whatever the user has entered.
+	// You can make async calls and use `await`.
 	async execute(this: IExecuteFunctions): Promise<INodeExecutionData[][]> {
 		const items = this.getInputData();
 
-		// The node iterates over all input items and adds the key "myString" with the
-		// value the parameter "myString" resolves to. (This could be a different value
-		// for each item in case it contains an expression.)
-		for (let itemIndex = 0; itemIndex < items.length; itemIndex++) {
-			const myString = this.getNodeParameter('myString', itemIndex, '') as string;
-			const item = items[itemIndex];
+		let item: INodeExecutionData;
+		let myString: string;
 
-			item.json['myString'] = myString;
+		// Iterates over all input items and add the key "myString" with the
+		// value the parameter "myString" resolves to.
+		// (This could be a different value for each item in case it contains an expression)
+		for (let itemIndex = 0; itemIndex < items.length; itemIndex++) {
+			try {
+				myString = this.getNodeParameter('myString', itemIndex, '') as string;
+				item = items[itemIndex];
+
+				item.json['myString'] = myString;
+			} catch (error) {
+				// This node should never fail but we want to showcase how
+				// to handle errors.
+				if (this.continueOnFail()) {
+					items.push({ json: this.getInputData(itemIndex)[0].json, error });
+				} else {
+					// Adding `itemIndex` allows other workflows to handle this error
+					if (error.context) {
+						// If the error thrown already contains the context property,
+						// only append the itemIndex
+						error.context.itemIndex = itemIndex;
+						throw error;
+					}
+					throw new NodeOperationError(this.getNode(), error, {
+						itemIndex,
+					});
+				}
+			}
 		}
 
 		return this.prepareOutputData(items);