Useage of contrib-npm

[smitterer]

Hi!

I'd like to use the npm node (node-red-contrib-npm (node) - Node-RED) to be able to use pdf-merger-js (pdf-merger-js - npm).

Unfortunately, I always get errors like TypeError: func is not a function or similar, depending on how I connect the individual nodes in the following flow:

[{"id":"ae6cb40ae0efa2ed","type":"npm","z":"4b453fb457938d95","name":"pdf-merger-js","func":"const PDFMerger = require('pdf-merger-js');\n\nvar merger = new PDFMerger();\n\n(async () => {\n  await merger.add('pdf1.pdf');  //merge all pages. parameter is the path to file and filename.\n  await merger.add('pdf2.pdf');\n\n  await merger.save('merged.pdf'); //save under given name and reset the internal document\n})();\nreturn npm_module(msg.payload);","npm_module":"pdf-merger-js","module_style":"custom","msg_payload":"return_val","function_name":"","x":470,"y":600,"wires":[["07e72953e011a95c"]]},{"id":"24b90b147213d017","type":"inject","z":"4b453fb457938d95","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":200,"y":600,"wires":[["ed2cb1df163e8109"]]},{"id":"07e72953e011a95c","type":"debug","z":"4b453fb457938d95","name":"debug 36","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":660,"y":560,"wires":[]},{"id":"ed2cb1df163e8109","type":"npm","z":"4b453fb457938d95","name":"pdf-lib","func":"// NPM module exposed as variable, npm_module\nreturn npm_module(msg.payload);","npm_module":"pdf-lib","module_style":"cstr","msg_payload":"callback_error","function_name":"","x":230,"y":540,"wires":[["102cd5d700f07c78"]]},{"id":"102cd5d700f07c78","type":"npm","z":"4b453fb457938d95","name":"pdf-merger-js install","func":"// NPM module exposed as variable, npm_module\nreturn npm_module(msg.payload);","npm_module":"pdf-merger-js","module_style":"cstr","msg_payload":"return_val","function_name":"","x":430,"y":540,"wires":[["ae6cb40ae0efa2ed"]]}]

Any idea how I am able to get this to work?

I'd also appreciate another solution on how I would be able to generate a template output per injected payload to store each output as a page in one file using node-red-contrib-pdf (node) - Node-RED instead of the approach of combining the resulting pdfs.

Thanks!

[bakman2]

I'd like to use the npm node

You don't have to use that node anymore, it has been integrated into the function node into the setup tab.

[smitterer]

Thanks, but this still requires me to add it to settings.js or am I wrong? (Writing Functions : Node-RED)

[bakman2]

It needs to be enabled in settings.js:

setting functionExternalModules to true in you settings.js file

restart node-red and you should be able to use any npm package within the function node.

[smitterer]

hm this is already set to true.

I added the modules:

On message now looks:

const PDFMerger = require('pdfMergerJs');

var merger = new PDFMerger();

(async () => {
  await merger.add('pdf1.pdf');  //merge all pages. parameter is the path to file and filename.
  await merger.add('pdf2.pdf');

  await merger.save('merged.pdf'); //save under given name and reset the internal document
})();
return msg.payload;

Getting the error:

ReferenceError: require is not defined (line 1, col 19)

Should it be requrire('pdf-merger-js'); (original node name) or requrie('pdfMergerJs') from "Import as" in module settings?
Or what am I missing here?

Thanks

[bakman2]

You can remove the require, as that is what the setup tab invokes.

const merger = new pdfMergerJs()

[smitterer]

You are my absolute hero.

Her is the final, working code:

const merger = new pdfMergerJs();

(async () => {
  await merger.add('/media/file1.pdf');  //merge all pages. parameter is the path to file and filename.
  await merger.add('/media/file2.pdf');

  await merger.save('/media/merged.pdf'); //save under given name and reset the internal document
})();
return msg

As I need to change the function based on a list of files in a folder (and I need support with that but it has nothing to do with contrib-npm), I'll create a new topic on that.

Thanks!