iOS: Launching Messages app with multiple recipients

Question

I'm trying to set it up so my user can send a text to a group of people. Now with email it's simple, the URL scheme is just mailto://[email protected],[email protected] which can then be used with the openURL method.

Naturally when it came to SMS I decided to try sms://2065555555,2061234567 however this doesn't work (it only adds the first number). After browsing Google a bit, I found some older threads claiming that texting to multiple recipients isn't possible using the URL method.

In order to send a message to multiple people, I've gone ahead and added MessageUI to my application, hooked up the MFMessageComposeViewControllerDelegate, and now I can send indeed send messages to multiple people at once. However only from within my own application, which is not what I want. I was hoping there'd be something in the framework that would allow me to take advantage of the multiple recipients functionality and then launch it in the default messenger, but I can't find anything that allows that.

So, in short, is there any possible way I can code my app to populate the default Messages app with multiple recipients?

Edit

Actually I'm certain there must be a way to do it, I just checked the app Cobook and they allow the user to select contacts then launch the Messages app sending a "New Group MMS".

Answer 1

I realize this is a very old question - but I discovered the way to do it recently, and posted about it here:

SMS WatchKit multiple number delimiter

While this answer is watchkit specific, the url is really what you are asking about.

ANSWER: I found an obscure page that gave me the answer. Turns out it is not documented by Apple anywhere I could find:

    let urlSafeBody = messageBody.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLHostAllowedCharacterSet())
    if let urlSafeBody = urlSafeBody, url = NSURL(string: "sms:/open?addresses=1-408-555-1212,1-408-555-2121,1-408-555-1221&body=\(urlSafeBody)") {
        WKExtension.sharedExtension().openSystemURL(url)
     }

The above version will open the messages app on the Apple Watch with multiple recipients pre-populated.

There are many pages that state it isn't possible, but it is. Hooray!