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https://github.com/fraserxu/electron-pdf

📄 A command line tool to generate PDF from URL, HTML or Markdown files.
https://github.com/fraserxu/electron-pdf

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📄 A command line tool to generate PDF from URL, HTML or Markdown files.

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README 

        
## Electron-PDF



[![NPM version][npm-image]][npm-url]

[![Build status][travis-image]][travis-url]

[![Downloads][downloads-image]][downloads-url]

[![js-standard-style][standard-image]][standard-url]



Electron-PDF is a powerful command-line tool that leverages [Electron](https://www.electronjs.org/) to generate PDF files from URLs, HTML, or Markdown files.



## Table of Contents



- [Electron-PDF](#electron-pdf)

- [Version Compatibility](#version-compatibility)

- [Installation](#installation)

- [Node.js Usage](#nodejs-usage)

  - [Application Setup](#application-setup)

  - [Using Electron-PDF](#using-electron-pdf)

  - [Handling Multiple Export Jobs](#handling-multiple-export-jobs)

  - [Using In-Memory Buffer](#using-in-memory-buffer)

- [Events](#events)

- [Environment Variables](#environment-variables)

- [Command Line Usage](#command-line-usage)

- [Rendering Options](#rendering-options)

  - [To specify browser options](#to-specify-browser-options)

  - [Observing your own event](#observing-your-own-event)

- [All Available Options](#all-available-options)

- [Debugging](#debugging)

  - [Sentry](#sentry)

  - [CLI Usage](#cli-usage)

  - [Other Formats](#other-formats)

  - [Extensions](#extensions)

- [License](#license)



### Version Compatibility



Starting from version 4.0.x, the master branch of Electron-PDF will always align with the latest Electron version.



Semantic Versioning is followed, and the version numbers correspond to Electron versions as follows:



- electron-pdf 25.0.x (master) => electron=25.4.0, node=16.15.0, chrome=114.0.5735.248

- electron-pdf 20.0.x => electron=20.0.2, node=16.15.0, chrome=104.0.5112.81

- electron-pdf 15.0.x => electron=15.1.1, node=16.5.0, chrome=94.0.4606.61

- electron-pdf 10.0.x =>  electron=10.1.3, node=12.16.3, chrome=85.0.4183.121

- electron-pdf 7.0.x  =>  electron 7.x (Chromium 78, Node 12.8.1)

- electron-pdf 4.0.x  =>  electron 4.x (Chromium 69, Node 10.11.0)

- electron-pdf 1.3.x  =>  electron 1.6.x (Chromium 56, Node 7.4)

- electron-pdf 1.2.x  =>  electron 1.4.x (Chromium 53, Node 6.5)



Please note that the choice of Chromium version affects the functionality you can utilize. Choose the version that aligns with your needs.



### Installation



Install Electron-PDF via npm:



```bash

npm install electron-pdf

```



If you're installing as root using system-level npm (rather than a user-level install like with NVM), use the following command:



```bash

sudo npm install electron-pdf -g --unsafe-perm

```

Please see [the npm docs](https://docs.npmjs.com/misc/config#unsafe-perm) for more information.



For GNU/Linux installations without a graphical environment, you need to install xvfb and set up a virtual display:



```bash

sudo apt-get install xvfb # or equivalent

export DISPLAY=':99.0'

Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &

electron-pdf ...

```



A Docker machine example is available [here](https://github.com/fraserxu/docker-tape-run).



### Node.js Usage



Electron-PDF can be integrated into your application or used as a rendering engine for a PDF service. Below are examples of usage.



#### Application Setup



In your `package.json`:



```json

"scripts": {

  "start": "DEBUG=electronpdf:* electron index.js",

  "watch": "DEBUG=electronpdf:* nodemon --exec electron index.js"

}

```



#### Using Electron-PDF



```javascript

const ElectronPDF = require('electron-pdf')

const express = require('express')

const bodyParser = require('body-parser')

const app = express()

app.use(bodyParser.json())



const exporter = new ElectronPDF()

exporter.on('charged', () => {

  app.listen(port, hostname, () => {

    console.log(`Export Server running at http://${hostname}:${port}`)

  })

})

exporter.start()

```



#### Handling Multiple Export Jobs



```javascript

app.post('/pdfexport', (req, res) => {

  const jobOptions = {

  /*

    r.results[] will contain the following based on inMemory

    false: the fully qualified path to a PDF file on disk

    true: The Buffer Object as returned by Electron

    Note: the default is false, this can not be set using the CLI

  */

    inMemory: false // Set inMemory to true for Buffer export

  }

  const options = {

    pageSize: "A4"

  }

  

  exporter.createJob(source, target, options, jobOptions).then(job => {

    job.on('job-complete', r => {

      console.log('pdf files:', r.results)

      // Process the PDF file(s) here

    })

    job.render()

  })

})

```



#### Using In-Memory Buffer



If you set the `inMemory` setting to true, you must also set `closeWindow=false`

or you will get a segmentation fault anytime the window is closed before the buffer 

is sent on the response.  You then need to invoke `job.destroy` to close the window.



```javascript

const jobOptions = { inMemory: true, closeWindow: false }

exporter.createJob(source, target, options, jobOptions).then(job => {

  job.on('job-complete', r => {

    // Send the Buffer here

    process.nextTick(() => { job.destroy() })

  })

})

```



### Events



Electron-PDF emits events to provide insights into its operations. A full documentation of events is a work in progress.



### Environment Variables



- `ELECTRONPDF_RENDERER_MAX_MEMORY`: Specify the `--max-old-space-size` option for each Electron renderer process (browser window) default: `75% of total system memory up to 8GB`

- `ELECTRONPDF_WINDOW_CLEANUP_INTERVAL`: Interval to check for hung windows, in milliseconds default: `30 seconds`

- `ELECTRONPDF_WINDOW_LIFE_THRESHOLD`: How long a window can remain open before it is terminated, in milliseconds default: `5 minutes`

- `ELECTRONPDF_PNG_CAPTURE_DELAY`: Delay before invoking `WebContents.capturePage` for PNG exports default: `100ms`



### Command Line Usage



Electron-PDF provides a versatile command-line interface (CLI) for various conversions and exports.



#### Generate a PDF from an HTML file



```bash

$ electron-pdf index.html ~/Desktop/index.pdf

```



#### Generate a PDF from a Markdown file



```bash

$ electron-pdf index.md ~/Desktop/index.pdf

```



#### Generate a PDF from a Markdown file with custom CSS



```bash

$ electron-pdf index.html ~/Desktop/index.pdf -c my-awesome-css.css

```



#### Generate a PDF from a URL



```bash

$ electron-pdf https://fraserxu.me ~/Desktop/fraserxu.pdf

```



Rendering Options

-----

Electron PDF gives you complete control of how the BrowserWindow should be configured, and when 

the window contents should be captured.



### To specify browser options



The [BrowserWindow supports many options](https://github.com/electron/electron/blob/master/docs/api/browser-window.md#new-browserwindowoptions) which you

 may define by passing a JSON Object to the `--browserConfig` option.

 

Some common use cases may include:



* `height` and `width` - electron-pdf calculates the browser height and width based off of the 

dimensions of PDF page size multiplied by the HTML standard of 96 pixels/inch.  So only set these

 values if you need to override this behavior

* `show` - to display the browser window during generation



```

$ electron-pdf https://fraserxu.me ~/Desktop/fraserxu.pdf --browserConfig '{"show":true}'

```



### To generate a PDF after the an async task in the HTML



```

electron-pdf ./index.html ~/Desktop/README.pdf -e

```



In your application, at the point which the view is ready for rendering



```javascript

document.body.dispatchEvent(new Event('view-ready'))

```



**Warning:** It is possible that your application will be ready and emit the event before the main electron process has had a chance execute the javascript in the renderer process which listens for this event.  



If you are finding that the [event is not effective](https://github.com/fraserxu/electron-pdf/issues/169) and your page waits until the full timeout has occurred, then you should use `setInterval` to emit the event until it is acknowledged like so:



```javascript

  var eventEmitInterval = setInterval(function () {

    document.body.dispatchEvent(new Event('view-ready'))

  }, 25)



  document.body.addEventListener('view-ready-acknowledged', function(){

    clearInterval(eventEmitInterval)

  })

```



When the main process first receives your ready event it will emit a single acknowlegement on `document.body` with whatever event name you are using suffixed with `-acknowledged`.  So the default would be `view-ready-acknowledged`



#### Observing your own event



If the page you are rending is under your control, and you wish to modify the behavior

of the rendering process you can use a [CustomEvent](https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent/CustomEvent)

and an observer that will be triggered after the view is ready but before it is captured.



##### your-page.html



```javascript

document.body.dispatchEvent(new CustomEvent('view-ready', { detail: {layout: landscape} }))

```



##### your-exporter.js

You are required to provide a function that accepts the `detail` object from 

the CustomEvent and returns a Promise.  You may optionally fulfill the promise with 

and object that will amend/override any of the contextual attributes assigned to resource (url)

currently being exported.



As an example, suppose you wanted to change the orientation of the PDF,

and capture the output as PNG instead of a PDF.



```javascript

job.observeReadyEvent( (detail) => {

    return new Promise( (resolve,reject) => {

      const context = {}

      if( detail && detail.landscape ){

        job.changeArgValue('landscape', true)

        context.type = 'png'

      }

      resolve(context)

    })

})

```



Note: Future versions of the library will only allow you to provide context overrides, 

and not allow you to change job level attributes.



All Available Options

-----



Electron PDF exposes the printToPDF settings (i.e. pageSize, orientation, margins, etc.) 

available from the Electron API.  See the following options for usage.



```



  A command line tool to generate PDF from URL, HTML or Markdown files



  Options

    --help                     Show this help

    --version                  Current version of package

    

    -i | --input               String - The path to the HTML file or url

    -o | --output              String - The path of the output PDF

    

    -b | --printBackground     Boolean - Whether to print CSS backgrounds.

    

    --acceptLanguage           String - A valid value for the 'Accept-Language' http request header

    

    --browserConfig            String - A valid JSON String that will be parsed into the options passed to electron.BrowserWindow

    

    -c | --css                 String - The path to custom CSS (can be specified more than once)

    

    -d | --disableCache        Boolean - Disable HTTP caching

                                 false - default

    

    -e | --waitForJSEvent      String - The name of the event to wait before PDF creation

                                 'view-ready' - default

    

    -l | --landscape           Boolean - true for landscape, false for portrait (don't pass a string on the CLI, just the `-l` flag)

                                 false - default

    

    -m | --marginsType         Integer - Specify the type of margins to use

                                 0 - default margins

                                 1 - no margins (electron-pdf default setting)

                                 2 - minimum margins

    

    --noprint                  Boolean - Do not run printToPDF, useful if the page downloads a file that needs captured instead of a PDF.  

                                         The Electron `win.webContents.session.on('will-download')` event will be implemented 

                                         and the file saved to the location provided in `--output`.

                                         Currently only supports a single import url.

                                         The page is responsible for initiating the download itself.

    

    -p | --pageSize            String - Can be A3, A4, A5, Legal, Letter, Tabloid or an Object containing height and width in microns

                                 "A4" - default

    

    -r | --requestHeaders      String - A valid JSON String that will be parsed into an Object where each key/value pair is: : 

                                 Example: '{"Authorization": "Bearer token", "X-Custom-Header": "Hello World"}'  

    

    -s | --printSelectionOnly  Boolean - Whether to print selection only

                                 false - default

                                 

    -t | --trustRemoteContent  Boolean - Whether to trust remote content loaded in the Electron webview.  False by default.

    --type                     String - The type of export, will dictate the output file type.  'png': PNG image, anything else: PDF File

    

    -w | --outputWait          Integer – Time to wait (in MS) between page load and PDF creation.  

                                         If used in conjunction with -e this will override the default timeout of 10 seconds    

    --ignoreCertificateErrors  Boolean - If true, all certificate errors thrown by Electron will be ignored.  This can be used to accept self-signed and untrusted certificates.  You should be aware of the security implications of setting this flag.

                             false - default

```



Find more information on [Electron Security here](https://github.com/electron/electron/blob/master/docs/tutorial/security.md).



Debugging

-----



## Sentry

If you have a [Sentry](https://sentry.io) account and setup a new app to get a new DSN, you can set a `SENTRY_DSN` environment variable which will activate sentry logs.

See `lib/sentry.js` for implementation details.



This will allow you to easily see/monitor errors that are occuring inside of the Chromium renderer (browser window).

It also automatically integrates with Electron's [Crash Reporter](https://electronjs.org/docs/api/crash-reporter)



CLI Usage

-----    



You can see some additional logging (if you're getting errors or unexpected output) by setting `DEBUG=electron*`

For example: `DEBUG=electron* electron-pdf   -l`



```

  Usage

    $ electron-pdf  

    $ electron-pdf   -l



  Examples

    $ electron-pdf http://fraserxu.me ~/Desktop/fraserxu.pdf

    $ electron-pdf ./index.html ~/Desktop/index.pdf

    $ electron-pdf ./README.md ~/Desktop/README.pdf -l

    $ electron-pdf ./README.md ~/Desktop/README.pdf -l -c my-awesome-css.css

```



Inspired by [electron-mocha](https://github.com/jprichardson/electron-mocha)



### Other Formats



Want to use the same options, but export to PNG or snapshot the rendered HTML?

Just set the output filename to end in .png or .html instead!



```

  Examples

    $ electron-pdf http://fraserxu.me ~/Desktop/fraserxu.pdf

    $ electron-pdf http://fraserxu.me ~/Desktop/fraserxu.html

    $ electron-pdf http://fraserxu.me ~/Desktop/fraserxu.png

```



### Extensions



If you need powerpoint support, [pdf-powerpoint](https://www.npmjs.com/package/pdf-powerpoint) 

picks up where Electron PDF leaves off by converting each page in the PDF to a PNG and placing 

them on individual slides.



### License



MIT



[npm-image]: https://img.shields.io/npm/v/electron-pdf.svg?style=flat-square

[npm-url]: https://npmjs.org/package/electron-pdf

[travis-image]: https://img.shields.io/travis/fraserxu/electron-pdf/master.svg?style=flat-square

[travis-url]: https://travis-ci.org/fraserxu/electron-pdf

[downloads-image]: https://img.shields.io/npm/dm/electron-pdf.svg?style=flat-square

[downloads-url]: https://npmjs.org/package/electron-pdf

[standard-image]: https://img.shields.io/badge/code%20style-standard-brightgreen.svg?style=flat-square

[standard-url]: https://github.com/feross/standard