Cannot read property 'once' of undefined

[Lxxyx]

When start the project by express.

/Users/lxxyx/Desktop/own/yun-type/node_modules/electron-pdf/lib/index.js:32
electronApp.once('ready', () => {
^

TypeError: Cannot read property 'once' of undefined
at PDFExporter.start (/Users/lxxyx/Desktop/own/yun-type/node_modules/electron-pdf/lib/index.js:32:16)
at Object. (/Users/lxxyx/Desktop/own/yun-type/js_server/app.js:22:10)
at Module._compile (module.js:570:32)
at Object.Module._extensions..js (module.js:579:10)
at Module.load (module.js:487:32)
at tryModuleLoad (module.js:446:12)
at Function.Module._load (module.js:438:3)
at Module.runMain (module.js:604:10)
at run (bootstrap_node.js:394:7)
at startup (bootstrap_node.js:149:9)
at bootstrap_node.js:509:3

import * as express from 'express'
import * as bodyParser from 'body-parser'
const ElectronPDF = require('electron-pdf')

const app = express()
app.use(bodyParser.json())

const exporter = new ElectronPDF()

app.post('/pdfexport', (req, res) => {
    const source:string = req.body.source
    exporter.createJob(source, './')
    .then((job) => {
        job.render()
        job.on('job-complete', (r) => {
            console.log('pdf files:', r.results)
        })
    })
})

exporter.on('charged', () => {
    //Only start the express server once the exporter is ready
    app.listen(3000)
})

exporter.start()

[codecounselor]

Can you post your scripts from package.json? I suspect that you are running your server with node, and you need to run it with electron.

[Lxxyx]

@codecounselor Thank you. I run it at Node but not electron.

[javy1103]

I get the same error when using electron to run the app. What am I doing wrong?

Here is my package.json

  "name": "pdfgenerator",
  "version": "1.0.0",
  "description": "",
  "main": "app.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "body-parser": "^1.17.2",
    "electron": "^1.7.5",
    "electron-pdf": "^1.3.0",
    "express": "^4.15.4"
  }
}

[codecounselor]

You should have a script that looks like this "start": "electron app.js"

[codecounselor]

Probably unrelated, but I see that you have electron 1.7.5 specified. You don't really need that, and in your case it could potentially cause problems because electron-pdf 1.3.0 uses 1.6.x

[javy1103]

I tried both those suggestions.

Changed my package.json to look like:

{
  "name": "pdfgenerator",
  "version": "1.0.0",
  "description": "",
  "main": "app.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "electron app.js"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "body-parser": "^1.17.2",
    "electron-pdf": "^1.3.0",
    "electron": "1.6.5",
    "express": "^4.15.4"
  }
}

and my app.js like this:

var ElectronPDF = require('electron-pdf')
var express = require('express')
var bodyParser = require('body-parser')
var app = express()
app.use(bodyParser.json())

var exporter = new ElectronPDF()

exporter.on('charged', () => {
    //Only start the express server once the exporter is ready
    app.listen(4000, function() {
        console.log(`Export Server running at http://${port}`);
    })
})
exporter.start()

Do I need to install electron globally in a specific way, dont know what is going wrong here since Im starting the app with electron.

I was debugging your lib/index.js file and logged the electron variable and got this path to a .exe
(\PDFGenerator\node_modules\electron-pdf\node_modules\electron\dist\electron.exe). Is that supposed to give me that path?

BTW thank you for your help

[javy1103]

Do you have a working example somewhere?

[codecounselor]

That looks right to me, you are running npm start?
electron will be installed as a transitive dependency of electron-pdf and be available in ./node_modules/.bin. That is how your start script is able to execute it - you do not need it installed globally.

Which version of npm are you using? I think 3+ should dedup dependencies and electron should be in ./node_modules/electron and not nested under ./node_modules/electron-pdf/electron. Atleast that is what I am observing with NPM 4.x

Perhaps that is your problem.

[codecounselor]

And I don't have a public example of an API server, but perhaps I will publish one.

[javy1103]

Is this package compatible with windows?

[codecounselor]

Yes it runs on windows, but you have to run npm install from the target OS or you won't get the right binaries