Is App Installed?

[cactuscraig]

I think I have asked this before - but did not get any where with it.
I need to check if an App is installed.
ie: reserve://opentable.com/18910?partySize=2 will open the Open Table App.

My plan is that is the App is not installed, then I would goto the Website instead (www). I am sure this might be simple, using some Objective C code using "canOpenURL"

Can anyone help?

[blazeman]

Check the Objective-C blueprint. Look at the jailbreak check. Might be able to use similar code

The way you have it. Unless each app will have shortcode defined in the plist... it will be hard to tell for sure

[cactuscraig]

After some long hard Googling... I figured it out.
See attached.

I have submitted request to make this part of NimbleKit as I think it could be pretty useful.

I have tested with several schemes on my iPad:
fb (facebook)
youtube
tel (False on iPad)
reserve (OpenTable)
http (Safari mobile)
imdb
tweetie (twitter client)


see http://wiki.akosma.com/IPhone_URL_Schemes

I hope you enjoy!

[HalfMoon]

Nice one Craig - adding this to nK Blueprint Obj-C

[carroll.megs]

Okay, so I'm still very new to all of this and I cannot figure out how to implement this code. I have two buttons that I want to set so that when the user taps the button it either opens the app or takes them to a website. It seems like that is what the code above should do, but I don't know how to get it to work with my app. I copied the myscheme.m and myscheme.h directly and pasted this code into my .html file.

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   // Register Class
   NKRegisterClass("myscheme");
   
   // Check for scheme
   function isInstalled()
   {
      myScheme = textField.getString() + ":";
      var canWeOpenScheme = CallNKitAction('canOpenScheme?className=myscheme&sync=yes&scheme=' + myScheme);
      NKLog (canWeOpenScheme);
      NKAlert ("Can we open " + myScheme + "?",canWeOpenScheme);
      
   }

What do I change in the code above to get it to look at the buttons rather than a text field? And where do I put the alternate site urls (for the websites to go to if the user doesn't have the app)? If it helps you, this is what my buttons look like:

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 var twitterButton = new NKButton();
            twitterButton.init(20, 20, 80, 80, "twitterLink");
            twitterButton.setImage('twitter-128x128.png');
            twitterButton.show();
            
            function twitterLink() {
                NKOpenURLInSafari('twitter://user?screen_name=kind_post');
            }
            
            var fbButton = new NKButton();
            fbButton.init(120, 20, 80, 80, "fbLink");
            fbButton.setImage('facebook-128x128.png');
            fbButton.show();
            
            function fbLink() {
                NKOpenURLInSafari('fb://page/306311346061753');
            }

Sorry, I know this must be pretty basic but it's all very new to me. I would really appreciate any help. Thanks.

[cactuscraig]

Button calls a function

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myButton.init(l,t,w,h,"functionFB()");

Function checks if app is installed. If TRUE then open app, else open www page.

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function functionFB()
{
If (isInstalled("fb")==TRUE)
  {
    Nkopenurlinsafari("fb://etc")
   } else {
   nkopenurlinsafari("http://www.facebook.com/etc")
   }
}

And change the isinstalled function to read a variable

Code: Select all

function isInstalled(myurl)
{
// check it here
var canWeOpenScheme = CallNKitAction('canOpenScheme?className=myscheme&sync=yes&scheme=' +  myurl + ':');
}

I am doing this from iPad so code may have errors but should be close for you.
I would recommend learning about JavaScript as this is pretty basic changes.

[carroll.megs]

Thank you, cactuscraig. I knew it would be something simple, but I just started learning Javascript and I wasn't sure exactly what to do. Thanks for taking the time to help me. I appreciate it!

[carroll.megs]

Cactuscraig, your code was missing a couple of quotes and a return statement. Once I added those, it worked perfectly. I thought I would share what my final code looks like in case anyone else wants to do the same thing. Here's what you do:

First save the myscheme.m and myscheme.h files from the example above and set a function in your HTML to register the class.

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NKRegisterClass("myscheme");

Then create the button and call a function to either open the app or open the website if the app is not installed.

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var fbButton = new NKButton();
            fbButton.init(c_x-b_w/2+space, c_y-b_h/2 , b_w , b_h, "functionFB()");
            fbButton.setImage('facebook.png');
            fbButton.show();
            
            function functionFB() {
                if (isInstalled("fb")=="TRUE")
                {
                    NKOpenURLInSafari("fb://page/306311346061753")
                } 
                else {
                    NKOpenURLInSafari("http://www.facebook.com/kindpost")
                }
            }

Next, create the isInstalled function and set it to check if the app is installed. Don't forget to include the return statement.

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 function isInstalled(myurl)
            {
                // check it here
                var canWeOpenScheme = CallNKitAction('canOpenScheme?className=myscheme&sync=yes&scheme=' +  myurl + ':');
                return canWeOpenScheme;
            }

I left in my specific URLs so you can see exactly where you need to edit the code to get it to work for you. Thanks again to cactuscraig for his invaluable help in getting this to work.

[cactuscraig]

Yep - not easy debugging from an iPad Glad you got it working ok. I have asked them (the "devs") to include this as an NK function... so maybe they will.
Seems like an important function have. Took me a long time to get it up and running.

[HalfMoon]

This website has a great list of available URL Schemes:
handleopenurl.com