Currently I'm developing a LG webOS application (using Vue.js). Everything works fine, except the fact that when I press the back button on the remote, the back event does not fire. This causes that I'm forced to assign the function to go back to the previous page, to another button (which is not user friendly) instead of the normal return button.

(FYI: I'm using a webOS Signage display)

I've read the documentation about the history API and handling the back event (webOS Back Button) and tried the following, but none of what I tried works:

• SettingdisableBackHistoryAPI to true in appinfo.json and then manually catching the keydown event when the back button is pressed (keycode 461);
• SettingdisableBackHistoryAPI to false in appinfo.json and then adding an eventlistener for the popstate event
• Vice versa (cause you never know)

Even trying to catch the back button press event (so catching keycode 461) doesn't work. The application recognizes all other keycodes, but pressing the back button simply doesn't do anything (fires no event). Anyone has any idea on this?

To be sure the problem is not per se application bound, I installed the following application Back Button Application. The same result: no back event.

Code to catch key event (logs all keycodes except 461):

window.addEventListener('keydown', evt => {
    evt = evt || window.event
    console.log(evt.keyCode)
    if (evt.keyCode === 461) {
        router.go(-1)
    }
  })

The back button is being registered on the LG webOS emulator (v4.0). The framework I'm using as stated earlier, is Vue.js and I use Cordova Toast to pile my projects to LG webOS (and in the future to Samsung Tizen).

-- BOUNTY EXPIRED BUT STILL LOOKING FOR AN ANSWER --

Currently I'm developing a LG webOS application (using Vue.js). Everything works fine, except the fact that when I press the back button on the remote, the back event does not fire. This causes that I'm forced to assign the function to go back to the previous page, to another button (which is not user friendly) instead of the normal return button.

(FYI: I'm using a webOS Signage display)

I've read the documentation about the history API and handling the back event (webOS Back Button) and tried the following, but none of what I tried works:

• SettingdisableBackHistoryAPI to true in appinfo.json and then manually catching the keydown event when the back button is pressed (keycode 461);
• SettingdisableBackHistoryAPI to false in appinfo.json and then adding an eventlistener for the popstate event
• Vice versa (cause you never know)

Even trying to catch the back button press event (so catching keycode 461) doesn't work. The application recognizes all other keycodes, but pressing the back button simply doesn't do anything (fires no event). Anyone has any idea on this?

To be sure the problem is not per se application bound, I installed the following application Back Button Application. The same result: no back event.

Code to catch key event (logs all keycodes except 461):

window.addEventListener('keydown', evt => {
    evt = evt || window.event
    console.log(evt.keyCode)
    if (evt.keyCode === 461) {
        router.go(-1)
    }
  })

The back button is being registered on the LG webOS emulator (v4.0). The framework I'm using as stated earlier, is Vue.js and I use Cordova Toast to pile my projects to LG webOS (and in the future to Samsung Tizen).

-- BOUNTY EXPIRED BUT STILL LOOKING FOR AN ANSWER --

• javascript
• keycode
• webos
• smart-tv

• Can you please post the code where you are trying to catch the "keydown" event? – burakk Commented Aug 26, 2019 at 23:53
• @burakk added the code! – Condor Commented Aug 27, 2019 at 7:07
• Weird question, but is the key working generally ? Maybe there is a hardware issue with the remote if you can catch ANY other key except this one? – noa-dev Commented Aug 27, 2019 at 10:28
• @noa-dev to be sure, I tried a different remote but still the same problem. – Condor Commented Aug 27, 2019 at 10:31

3 Answers 3

Try adding this code into the head section of your index.html, and "disableBackHistoryAPI": true into your appinfo.json:

<script src="webOSTVjs-1.1.0/webOSTV.js" charset="utf-8"></script>
<script src="webOSTVjs-1.1.0/webOSTV-dev.js" charset="utf-8"></script>
<script type="text/javascript">

    window.addEventListener("keydown", function(e) {
        console.log("[keyCode] : " + "[" + e.keyCode + "]");

        switch (e.keyCode) {
            case 461:
                console.log("Back key pressed");
                webOS.platformBack();

                break;
        }
    });

</script>

Please remember that ES6 is not supported in the LG webOS TV. I guess you already know that and use Babel to convert the code.

Please refer to this page for more information.

Were you able to use the BACK button on the remote control? I have the same problem here.

This code see the other buttons, except the back button.

    window.addEventListener("keydown", function(inEvent){   

        if(window.event) {
            keycode = inEvent.keyCode;
        } else if(e.which) {
            keycode = inEvent.which;
        }

        document.getElementById("BtnControle").innerHTML = keycode;

    });  

In my appinfo.json I added this: disableBackHistoryAPI: true;

from there the code below started to work:

<script type = "text / javascript">
         window.addEventListener ("keydown", function (inEvent) {
             if (window.event) {
                 keycode = inEvent.keyCode;
             } else if (e.which) {
                 keycode = inEvent.which;
             }
             switch (keycode) {
                 case 461: history.back (-1); break;
                 case 38: document.getElementById ("TesteTit"). innerHTML = "up"; break;
                 case 40: document.getElementById ("TesteTit"). innerHTML = "down"; break;
             }
         });
</script>

If you can test it on your app, tell me if it worked.