Ionic Platform Backbutton firing multiple times.

[nomanshahsyed]

Bug Report

Ionic version:

[x] 5.5.2

Current behavior:

The back button fires multiple times.

Expected behavior:

It should only fire once.

Steps to reproduce:

In app.components.ts put the back button code in the constructor.

this.platform.backButton.subscribe((clicked) => {
    console.log("back clicked", clicked);
});

Ionic info:

Ionic:

   Ionic CLI                     : 6.12.2 (C:\Users\noman.shah\AppData\Roaming\npm\node_modules\@ionic\cli)
   Ionic Framework               : @ionic/angular 5.5.2
[native-run] Installing platforms\android\app\build\outputs\apk\debug\app-debug.apk...
[native-run] Starting application activity com.linkdesign.linkeazy/com.linkdesign.linkeazy.MainActivity...
[native-run] Run Successful
PS C:\Users\noman.shah\Documents\LinkEazy\Nomi\LinkEazy> ionic info

Ionic:

   Ionic CLI                     : 6.12.2 (C:\Users\username\AppData\Roaming\npm\node_modules\@ionic\cli)
   Ionic Framework               : @ionic/angular 5.5.2
   @angular-devkit/build-angular : 0.1002.0
   @angular-devkit/schematics    : 10.0.8
   @angular/cli                  : 10.0.8
   @ionic/angular-toolkit        : 2.3.3

Cordova:

   Cordova CLI       : 10.0.0
   Cordova Platforms : 6.0.0, android 8.1.0, browser
   Cordova Plugins   : cordova-plugin-ionic-keyboard 2.2.0, cordova-plugin-ionic-webview 4.2.1, (and 6 other plugins)

Utility:

   cordova-res                          : not installed
   native-run (update available: 1.3.0) : 0.2.7

System:

   NodeJS : v10.15.2 (C:\Program Files\nodejs\node.exe)
   npm    : 4.6.1
   OS     : Windows 10```

[ionitron-bot]

Thanks for the issue! This issue has been labeled as needs reproduction. This label is added to issues that need a code reproduction.

Please reproduce this issue in an Ionic starter application and provide a way for us to access it (GitHub repo, StackBlitz, etc). Without a reliable code reproduction, it is unlikely we will be able to resolve the issue, leading to it being closed.

If you have already provided a code snippet and are seeing this message, it is likely that the code snippet was not enough for our team to reproduce the issue.

For a guide on how to create a good reproduction, see our Contributing Guide.

[nomanshahsyed]

@liamdebeasi I cant simulate this issue as it is only Android hardware back button issue.

[liamdebeasi]

Can you reproduce the issue in an Ionic starter application? I have an Android device I can test it on.

[nomanshahsyed]

Hi, ok i started a new Ionic project and added the platform button code and i only see it firing once. I wonder why is it firing multiple times in my app. I just checked that in my app, on the first page it fires twice. If i navigate to page two it fires thrice and so on. Do you have any idea as to why it is happening?

[liamdebeasi]

It's hard to say without seeing your application code. It sounds like you are re-subscribing to the hardware back button event every time you navigate, which would explain why the callback fires multiple times.

I am going to close this as this is more of a support question, but if you are still trying to figure out why this is happening I recommend opening an issue on our forums: http://forum.ionicframework.com/. Thanks!

[ionitron-bot]

Thanks for the issue! This issue is being locked to prevent comments that are not relevant to the original issue. If this is still an issue with the latest version of Ionic, please create a new issue and ensure the template is fully filled out.