Android Question Check if app exists on device

JohnC

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• Jul 15, 2020

• #2

If I understand you correctly, you would like user to be able to scan a QR Code, and if they have your app already installed on their phone, and if so, run it.

But if your app is not already installed on their device, you would like their device to navigate to your app's page in the play store?

If so, (and I have not done this myself) but I think that can be accomplished with "deep linking":

Using App Deeplinking in your app (based on json Config file)

In this tutorial i will show a way of using MobileDeepLinking in your app. To use App deeplinking in your app to you need to setup your manifet to do so Lets start with it: Edit your manifest and add AddApplicationText( ) to it. mydeep in this case is the...

www.b4x.com

App Deeplinks

Google now supports App Deeplinking from Google search. How can we handle this with b4a? https://developers.google.com/app-indexing/webmasters/server

www.b4x.com

 

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Colin Evans

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• Jul 15, 2020

• #3

Hi JohnC, thanks for the reply, yes basically I want the user to scan a QR Code and check if the app is installed if so run it, this is step one but unfortunately I'm not sure how to implement it and the second issue would be, if it isn't installed, install it from a url (not google play store) which I think I may understand how to do.

It's the first step I'm totally at a loss with

 

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JohnC

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• Jul 16, 2020

• #4

I have not done any work with deep linking, so I unfortunately can't offer any more help.

But I do think you might be able to redirect to another URL so the user can sideload your app.

 

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Colin Evans

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• Jul 16, 2020

• #5

I'm not sure if it is possible to do what I want, basically from the scanning of the QR Code run a program held on a server to check if the app is installed on the phone, or just check if it is via some other means, I think that's my stumbling block... but thanks for replying anyway

 

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Douglas Farias

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• Jul 16, 2020

• #6

I have not tested...
but try

B4X:

Sub App_Exist(package As String) As Boolean
    Private appExist As Boolean = False
    Dim pm As PackageManager
    Dim packages As List
    packages = pm.GetInstalledPackages
    For i = 0 To packages.Size - 1
        If package = packages.Get(i) Then appExist = True
    Next
    Return appExist
End Sub


Sub Download_App(package As String)
    Try
        Private withGooglePlay As Intent
        withGooglePlay.Initialize (withGooglePlay.ACTION_VIEW, "market://details?id=" & package)
        StartActivity (withGooglePlay)
   
    Catch
        Private withoutGooglePlay As Intent
        withoutGooglePlay.Initialize (withoutGooglePlay.ACTION_VIEW, "https://play.google.com/store/apps/details?id=" & package)
        StartActivity (withoutGooglePlay)
    End Try
End Sub

to use...

B4X:

Log(App_Exist("com.facebook.katana"))
'Download_App("com.facebook.katana")

Requires Phone lib!

 

Last edited: Jul 16, 2020

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DonManfred

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• Jul 16, 2020

• #7

You are not expected to download a App from any url.
Google expect you using GooglePlayStore.

Deeplinking is the correct solution as already pointed out by @JohnC

But even here, the App MUST be installed by GooglePlayStore.

 

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JohnC

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• Jul 16, 2020

• #8

DonManfred said:

But even here, the App MUST be installed by GooglePlayStore.

Click to expand...

Hey Don,

Not trying to contradict in any way....but I thought maybe deep linking can work with links other then with the play store.

I'm thinking this because often if I click on a youtube video link, it will prompt me to view the video in the browser or using the youtube app.

So, I was thinking that this guy could designate his URL to be the location of an APK on his website (that the user would side-load), but in the manifest he would "register" that particular URL as a deep link so that if the app is already installed on the users device, it will launch the app instead of navigating to that url (his website).

But again, I never did deep linking before, so my quick impression of how it works could be totally off-base.

 

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DonManfred

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• Jul 16, 2020

• #9

Deeplinking does use GooglePlay as per Documentation.


You invite a User using Deeplinking:
- The user gets an email from google with a invitationLink.
- The User clicks on this link and is pointed to GooglePlay.
- If the app is not installed on the Device he get the chance to install it.
- He install the app and then open it. Google give your app the deeplink you defined on the first run. Do whatever you want to do with the Data (link, values) in the deeplink.

If the app already is installed on his device the app gets started when clicking the invitelink.
Google give your app the deeplink you defined when starting your app. Do whatever you want to do with the Data (link, values) in the deeplink.

 

Last edited: Jul 16, 2020

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JohnC

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• Jul 16, 2020

• #10

OK - understood.

 

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Colin Evans

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• Jul 16, 2020

• #11

Hi, thanks for all the input greatly appreciated,
I don't want to use Google play store, the app would reside on my network and when a visitor activates the QR Code and the checks show the app doesn't exist on their phone or device it would load the apk via an http address. So I'm still not sure whether doing it through a QR Code would be feasible as they wouldn't have the code to check if it was installed or not on their device.

Hope I'm making sense

 

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DonManfred

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• Jul 16, 2020

• #12

Colin Evans said:

Hope I'm making sense

Click to expand...

Not really. The User needs an App which reads the QRCode, analize the content and then uses Code to check if the app exists or not, download it and then install it.
No one QRCode Reader app is able to do that.

You need to write your own Reader with this functionality.

 

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Colin Evans

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• Jul 16, 2020

• #13

Okay, many thanks to everyone who responded, I may have a look at Deeplinking and see if it offers a solution

 

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Colin Evans

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• Jul 19, 2020

• #14

Thanks again to all who contributed, I figured it out in the end using a QR Code which invoked a web form which did what i needed, thanks again

 

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BugNot

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• Aug 8, 2020

• #15

(Sorry it's off topic)

Hi Colin Evans,

You have create an fishing log app?

 

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