Web App is the big trend since SaaS grow these years.
But local hardware access for browsers is always major headache compared to traditional apps.
Especially direct print, a essential function for any traditional app is always missing piece of Web App.
COM port access is another missing feature, you need it to open drawer from POS, get readings from a digital scale… etc
I have researched and found four major possible directions
- Tweak browser to support it
- Enhance existing browser to support it
- Build a browser that support it
- Use/Create external service that handle it
A. Tweak browser to support it
A1. Outdated methods
Use <object>, <embed>, VB Script, this.print(true) that have very bad to non-existing compatibility
Feasibility: NO, @2016
Functionality: Direct print to default printer
Simplicity: Extremely easy
A2. Chrome Kiosk Print
Require to close Chrome completely and launch it again with --kiosk-printing
http://www.shoptill-e.com/support/48
Feasibility: Yes
Functionality: Direct print to default printer
Simplicity: Easy
A3. Firefox “Always print slient
about:config and enable print.always_print_silent
https://support.mozilla.org/en-US/questions/1021071
Feasibility: Yes
Functionality: Direct print to default printer
Simplicity: Easy
B. Enhance existing browser to support it
B1. NSAPI / ActiveX
NSAPI have had its day… but now all major browser are removing support of it.
So for new project, there are no reason to use it again
ActiveX is Internet Explorer only and have bad reputation nowaways
Feasibility: Almost No, @2016
Functionality: Full access to system resources
Simplicity: Hard
B2. Other Web Plugins (Java Applet / Flash / Silverlight…etc)
Java Applet and Flash are fading out too…
Sliverlight have poor support for non-Windows OS
Feasibility: Maybe? @2016
Functionality: Full access to system resources
Simplicity: Medium to Hard
B3. Firefox + Extension
Enhance Firefox to print directly.
There are extension that suppress print dialog to just by toggling print.always_print_silent config by white-listing
https://addons.mozilla.org/en-US/firefox/addon/seamless-print/
XUL seems capable for more power.
But Firefox is removing XUL extension support soon so I gave up.
Feasibility: Yes
Functionality: Direct print to default printer
Simplicity: Very Easy
4. Chrome + Extension
Enhance Chrome to print directly.
Unfortunately Chrome Platform API do not provide enough privilege to print directly.
There are a Native Messaging API that allow to invoke local process (i.e. .exe)
So it’s possible but rather complicated.
Feasibility: Yes
Functionality: Full access to system resources
Simplicity: Very Hard
C. Build a browser that support it
C1. JavaFX + WebView
Create a enhanced browser that have access to local resources
WebView in JavaFX support modern HTML5 web features well.
It’s possible to create JS-to-Java bridge that allow JavaScript to share Java’s privilege
I have made test implementation on this approach.
But found that WebView itself lack of many common functionality that user may complain.
Example: HTTP digest authentication, File download, back/next mouse button
Feasibility: Yes
Functionality: Full access to system resources
Simplicity: Hard to Very Hard
C2. .NET + WebView
Similar to JavaFX but for .NET.
I am not a fan of Microsoft stuff haven’t dig into it.
Feasibility: Yes
Functionality: Full access to system resources
Simplicity: Hard to Very Hard
D. Use/Create external service that handle it
D1. Any Browser + Google Cloud Print
Install Google Cloud Print on local machine.
Then the Web App use JavaScript to submit print job to Google Cloud Print
http://stackoverflow.com/questions/31888183/chrome-extensions-for-silent-print
Feasibility: Yes
Functionality: Able to select printers
Simplicity: Easy
D2. Any Browser + Custom Local Service
Use any language able to access local resources, create a Service/Daemon listening on local port as REST API.
Then the Web App call the API using Cross-Origin AJAX / JSONP
Feasibility: Yes
Functionality: Full access to system resources
Simplicity: Hard to Very Hard
E. Other tweaks
E1. Acrobat Reader with JavaScript
http://londonwebdev.com/2010/09/14/silent-pdf-printing-from-a-php-based-web-application/
Feasibility: Unknown (Not tested)
Functionality: Able to select printers
Simplicity: Medium
E2. Execute print command / Write print job directly to local printer
http://stackoverflow.com/questions/13415948/how-to-silent-print-with-fpdf-and-php
Feasibility: Only if server and client on same place
Functionality: Able to select printers
Simplicity: Easy
Any other ideas? Please comment 🙂