PhoneGap and WhatsApp

Edit for newer cordova versions:

Use <allow-intent href="whatsapp:*" />

Old answer:

Add this line to your config.xml

<access origin="whatsapp:*" launch-external="yes" />

Or use the social sharing plugin

https://github.com/EddyVerbruggen/SocialSharing-PhoneGap-Plugin

<button onclick="window.plugins.socialsharing.shareViaWhatsApp('Message via WhatsApp', null /* img */, null /* url */, function() {console.log('share ok')}, function(errormsg){alert(errormsg)})">msg via WhatsApp (with errcallback)</button>

First and more important, add this line to your config.xml

<allow-intent href="whatsapp:*" />

after use the code:

<a href="whatsapp://send?text=Hello%20World!">Hello, world!</a>

window.location.href = 'whatsapp://send?text=hello world';

this worked for phonegap IOS

window.open("'whatsapp://send?text=hello world'", "_system");

for android.