Error loading custom node (tempModule[nodeName] is not a constructor)

Questions
,
1

Describe the issue/error/question

I have a custom node that I’ve created with n8n-node-dev, the node compiles just fine but when I start n8n I get an error message.

What is the error message (if any)?

Error loading node "PDF" from: "/home/user/.n8n/custom/PDF.node.js" - tempModule[nodeName] is not a constructor
 ›   Error: There was an error: tempModule[nodeName] is not a constructor

Please share the workflow

No workflow but here’s the node definition.

import { IExecuteFunctions } from 'n8n-core';
import { INodeExecutionData, INodeType, INodeTypeDescription } from 'n8n-workflow';

export class MPdf implements INodeType {
	description: INodeTypeDescription = {
		displayName: 'PDF Fill',
		name: 'pdf',
		group: ['transform'],
		version: 1,
		description: 'Fills input PDF based on the JSON payload.',
		defaults: {
			name: 'PDF Fill',
			color: '#772244',
		},
		inputs: ['main', 'main'],
		outputs: ['main'],
		properties: [
			{
				displayName: 'My String',
				name: 'myString',
				type: 'string',
				default: '',
				placeholder: 'Placeholder value',
				description: 'The description text',
			},
		],
	};

	async execute(this: IExecuteFunctions): Promise<INodeExecutionData[][]> {
		const items = this.getInputData(0);
		const pdf = this.getInputData(1);

		console.log(items, pdf)

		let item: INodeExecutionData;

		for (let itemIndex = 0; itemIndex < items.length; itemIndex++) {
			item = items[itemIndex];

			const payload = JSON.parse(item.json['fields'] as string);

			Object.entries(payload).forEach(
				([key, value]) => console.log(key, value)
			);

			item = items[itemIndex];
		}

		return this.prepareOutputData(items);
	}
}

Share the output returned by the last node

Information on your n8n setup

  • n8n version: 0.189.1
  • Database you’re using (default: SQLite): SQLite
  • Running n8n with the execution process [own(default), main]: default
  • Running n8n via [Docker, npm, n8n.cloud, desktop app]: npm
2

Hi sne,
it looks to me like n8n cannot resolve the node name correctly. Could you try setting the classname and description name like this.

export class PdfFill implements INodeType {
	description: INodeTypeDescription = {
		displayName: 'PDF Fill',
		name: 'pdfFill',
	}
}
1 Like
3

Hi marcus,

I tried changing the classname and description but unfortunately I’m getting the same error as before. Any other ideas? Thanks

4

Hey @sne,
i tried to reproduce your problem but wasn’t really able to. Instead of using the n8n-nodes-dev approach you could follow this tutorial about building a node based on using our n8n-nodes-starter repo.

I also did a free online webinar yesterday about Learn how to build your own nodes. You can rewatch the stream on Youtube or Twitch.

2 Likes
5

Hi @marcus

I compared my node to the starter node that you posted and the issue was with naming of the class and n8n being unable to resolve it. After some refactoring I got the problem sorted out.

Thanks for your support!

1 Like
6

Hey sne, glad to hear you could fix it. Thanks for confirming.

7

I was the same problem. it was a file named wrong.
but don’t forget to delete the /dist folder and update npm link or the problem error will stay