I have built a website that uses some simple JavaScript. I make use of many events throughout the website such as the input and submit event for validating and processing a contact form, the focus event for some form-related things and a dynamically-created tab interface, etc. I register all of these handlers using element.addEventListener("event", handler).
My JavaScript works wonderfully everywhere that I have been able to test (Firefox and Chrome on Ubuntu; Firefox and Chrome on Android), except for on iOS devices (regardless of what browser is used), where it seems that very few events are being fired.
It has been difficult for me to debug what the issue is on iOS devices because I do not have an OSX computer to connect an iOS device to so that I can use the remote console. I have come to the conclusion that the events are not firing for a few reasons:
The contact form on the website is being submitted even though I make a call to event.preventDefault() in the form's submit event handler, and do not explicitly submit the form anywhere after that.
I have tried catching any errors and displaying them in an alert like so:
window.onerror(function(err) { alert(err) })
to no avail (i.e. no errors were caught).
I have adapted all my functions to make use of only the click event, and then they work perfectly!
The last point is a possible solution to the problem, but I think it is bad practice to adapt all my work to one specific platform and rely only on a single event when there are so many purpose-built events that can be used and that are supposedly supported by iOS in the first place.
Why are so many events not being fired on iOS devices?
The problem was actually that I had made a const declaration in strict mode, which is, according to caniuse, not recognized in the current versions of both Safari and iOS Safari (9.1 and 9.3, respectively, as of writing).
I have better documented this problem in another question and answer.
Related
I have some js code to record outbound link click events in Google Analytics, which effectively adds a delay to the click event before allowing the normal click behaviour to go through.
This applies to both http as well as tel: links. I trigger a specific "phone number has been clicked" event in GA so we know the user intended to make a call (whether or not they go through with it is a different issue entirely).
The number of events being tracked into GA seems strangely low and with anecdotal testing, many deliberately triggered events don't seem to show up in GA (I.e. I sit on my phone and press the link a few times).
I wonder why this could be.
Does iOS do something weird to immediately halt or bypass my javascript when a tel: link is clicked? If not, what could explain the lack of event tracking going on here?
For context, I'm talking about tracking the click event before the call prompt comes up:
i had the same issue (working with jquery) and found out that it occurs when i tried to recognize the tap with jquery click handler.
i found a solution with adding
jquery.on("click touchstart", function(e){...});
now it works fine again on desktop and mobile/touch browsers (tested on newer ios and android devices) and the call-prompt is displayed immediately.
I have a Rails app that has a closed back-end. On certain pages, I want to auto-select a text input so I can use an external bluetooth scanner to scan a barcode without selecting it with a mouse/touchscreen every time. This works perfectly on non-mobile devices. However, on mobile devices (mostly tablets), I want the keyboard to popup (as the scanners are viewed as "keyboards" by the system). I know this is prevented by iOS, because it could be annoying. However, I want to know:
Can I have the keyboard auto-appear on Android and/or Windows tablets?
On iOS, can I change this default behavior so the keyboard DOES auto-appear? I have access to all the devices this behavior would be needed.
Edit: I know that I can use a click event to make the keyboard appear (that is how it appears now). However, I do not want to touch the tablet every time I want to scan.
There are some workarounds except using great prompt().
Wrap the web application into Phonegap and do the following way.
Keeping in mind that bluetooth scanner needs a first click to enable listening to keyboard events, you can slightly change js-code to perform first click manually (say, fullscreen textarea) and then deal with scanner. It can be a textarea that hides right after a first click and everything is done with javascript without textarea in view.
Looks like Windows smartphones can help you, can't find any issue concerning a problem.
I've tested autofocus fiddle in Chrome56 with Windows 8.1, Windows10 and an old Windows Mobile 8.1 at Nokia Lumia. In first two cases it does listen to keyboard after focusing. The latter one doesn't.
Bonus. HTC One M8 emulator with Android 4.4 listens to keyboard without a click. Tested with browserstack service. What if there are some android examples without need to click?
Bonus2 - autodetect scanner library.
Based on thoses answers you have to try some workarounds
You can't, at least not in iOS (iPhone), and I believe Android as well. It's a usability issue that the keyboard should not be allowed to be triggered except by user input (it's just annoying if it's automatic).
There are a couple of ways I know of to get around this:
prompt() opens the keyboard
If you trigger the .focus() from within a .click() event (e.g. from >opening your dialog), the keyboard shows up
In your case at the openning of your page ?
At least maybe this JS fiddle can help you or this one
You can use JavaScript in built functions for event handling such as focus(), prompt() to initiate bar code scanning function. Also changing some of the usability would also be helpful in this case. For building hybrid apps try some reading on Cordova Keyboard Plugin at https://github.com/cjpearson/cordova-plugin-keyboard
Happy Coding.
try below code. It might work
// div is some selected element
var f = function(event) {
$timeout(function() { // angular way, setTimeout is OK
input[0].focus();
event.preventDefault();
})
};
var mobile = false;
div.on('click', function(event) {
if(mobile) return;
f(event);
});
div.on('touchstart', function(event) {
mobile = true;
f(event);
});
div.on('touchend', function(event) {
event.preventDefault();
event.stopPropagation();
});
My best bet is using offsite input and focusing there. It will help you to control -
the timing of keyboard appearance(setTimeOut)
Check and reopen the keyboard
You will need to do something like this-
<input type="text" style="visibility: hidden; position: fixed; left: -200px" >
With jQuery-
$("#theOffViewBox").focus();
This will work equally on iOS/Android/Windows/Linux as being base JavaScript jugad.
In past mobile apps that I developed, I found that the click event did not work as expected in all devices (for example: in games in which the user had to tap/click quickly on the screen, instead of triggering the click event, the double click was triggered), and using touchstart gave better results for what I wanted.
Since then, I started listening to the touchstart event instead of click; but testing on Chrome, I got the following warning message in the JS console:
Performing operations that require explicit user interaction on touchstart events is deprecated and will be removed in M54, around October 2016. See https://www.chromestatus.com/features/5649871251963904 for more details.
I visited the linked page (and the links inside it) and it seems that this new behavior is to avoid certain unwanted actions, and in particular to avoid third-party iframes or ads (my app has none) from opening pop-ups. I tried changing the event to touchend (as one of the links stated "The touchend event will continue to behave as before"), but got a similar warning message.
And my questions:
Is this something that only affects Chrome, or will it affect my web apps (with Cordova/Phonegap) for Android and iOS?
What event should I use to replace touchstart and avoid the issues I faced in the past? I could go back to click, but fast clicking/tapping would still be a problem.
When creating Cordova app, you target different OS versions, Android 5 and up has auto updating webview based on Chromium, so that problem will probably affect your apps.
But since Chrome 32, when using this viewport <meta name="viewport" content="width=device-width">, the click delay should go away (see this article), so you could safely use click event. Latest webviews on android 5 and 6 are based on Chromium 52.
You can also use fastclick library that will "fix" the click delay only where it's necessary
I have a simple query:
My web application allows users to use keyboard shortcuts like Ctrl-X etc. to invoke events that require fast input and action e.g Aborting an action that was just carried out quickly.
I am aware of the events to bind to in js for desktops.
However, while I am aware of the tap events and events available for both desktop and mobile browsers (keypress etc.), I would like to ask your opinion on what events could be bound to specifically in mobile browsers, such as muting, volume up/down. The answers I found in Google were archaic and not very cross-browser compliant
So simply put, are there any events, for actions by the user, specifically for browsers on mobile devices that can be bound to, in the event that using click and tap events are too slow or cumbersome?
JQM by itself cannot access the buttons on the phone, if you want to do that you'll have to write additional Java code to access the buttons through the original Android API.
Or, you could use Phonegap: http://docs.phonegap.com/en/2.0.0/cordova_events_events.md.html#Events
Check it out, you can use the "volumeup" or "volumedown" events.
As far as I know, the best you can get is the touch events.
Take a look at http://developer.apple.com/library/ios/#documentation/AppleApplications/Reference/SafariWebContent/Introduction/Introduction.html for iOS, not sure if the same documentation exists for android/BB.
It seems odd for a web app to override the default behavior of heavily OS involved physical buttons on the device, like volume/power/home buttons, as the user would experience abnormal behavior which would be confusing to the average user. I doubt it is possible to intercept them in a web app.
EDIT: This specific link has a list of iOS web events you can listen for in a table at the bottom:
http://developer.apple.com/library/ios/#documentation/AppleApplications/Reference/SafariWebContent/HandlingEvents/HandlingEvents.html#//apple_ref/doc/uid/TP40006511-SW1
I'm writing an iPhone web app, and I want to automatically focus a text field when the page is loaded, bringing up the keyboard. The usual Javascript:
input.focus();
doesn't seem to be working. Any ideas?
It will only show the keyboard if you fire focus from a click event, so put a button on the page with a onclick that does the focus and it will show the keyboard. Completely useless except for validation (on click of submit validation code focuses on invalid element)
Edit: The following no longer works on iOS - UIWebView did allow autofocus and home screen links used to autofocus but they disabled that many versions ago.
The autofocus (see below) property doesn't work from a url in Mobile Safari but does work if you are:
using a UIWebView
using a home screen link
The fontsize of the input needs to be large enough to avoid the iOS10 zoom on double-tap (now that viewport is always zoomable) and to design the page to be sized so that it fits the screen (otherwise on page loading you get strange timing/race bugs in zoom, or if scrollable the field sometimes doesn't center to the screen properly).
autofocus: The HTML5 spec for doing this is the autofocus property of the input tag. But iOS ignores that, presumably for a cleaner UI that doesn't pop up the touch keyboard when navigating to a page. Here is a page that demonstrates the autofocus property. Before HTML5 you would call element.focus() in the window.onload event. However focus() calls are not supported on iOS except during the handler of an onclick event.
Note: this answer is old and may not be relevant to newer versions out there...
It comes as no help to you but the last poster in this thread wrote that its a bug of the webkit engine.
I can't tell if its a verified bug or not...
Last post from way back machine (as original seems to not work):
I am developing my app in pure XHTML MP / Ecmascript MP / WCSS. So
using native platform browser control api is really not an option for
me. Yes the behaviour u mention is the same as mine. I searched his
topic in the bugzilla at webkit.org and found that this indeed is a
reported bug. focus() to a text box does highlight the element but
does not provide a carat in it for the user to start entering text.
Using a timer as mentioned by "peppe#peppe.net" does not help either.
This behaviour is common across platforms (s60,iphone,android) which
use the webkit engine.
So as of now i dont see a solution to this problem.
Hope this helps
I have a similar issue, only my issue is that the focus will not occur on a 'touchend' event.
http://jsfiddle.net/milosdakic/FNVm5/
The following code will work in Chrome/Safari etc. but will fail on Mobile Safari. The only way to get it to work is to make the event on 'click', but seeing as the code is made for an iOS device, it would benefit for it to work with touch events.
It seems to be a bug with the Webkit engine.
If you are setting focus with from a click event, you need to preventDefault otherwise the click events default action will set focus on the clicked item.
A bit late maybe but for future person maybe. In our webapp running on iOS iPad (6 and more recent), we do it with a set interval:
startFocusOnTextField: function() {
this.intervalIDForTextFieldFocus = window.setInterval(function() {
document.getElementById(page.textInputFieldObj.id).focus();
}, 150);
},
Which is called on page load (jQuery mobile environment)
This is a workround:
setTimeout(function(){
input.focus();
},500);//milliseconds