SetInterval is not working in Kindle and Kobo Browsers - javascript

I want do stream images to my e-ink reader's browser. I have a Kobo Aura H2O and a Kindle Paperwhite.
I have tried multiple mechanics but nothing seems to work, because the browser ignores half of the javascript.
Websockets do not work, setInterval to update the image regularly does not work neither
Are there any Specs of this Browsers to be found? What other alternatives within Javascript are there to test?

The Kindle browser does technically support WebSockets (even on the very first Kindle Touch), however because it's based on a very old version of Webkit, it's the very first version (or one of the first versions, I'm not exactly sure) of the WebSocket spec which is very different from the current one and isn't supported in the majority of Websocket libraries.
I made a very bad patch for the Node ws library here: https://github.com/HimbeersaftLP/ws
Google's pywebsocket also supports it: https://github.com/google/pywebsocket/wiki/WebSocketProtocolSpec

setInterval actually works, the problem was that I have used es6 instead of es5 js syntax.
Websockets also work with Kobo Browser but not on Kindle

Related

Force Employee To Use Firefox + Specified Version For Company Intranet

Please not not turn this into a discussion about which browser is better and the ethics of forcing a browser. It's an intranet, and it's what I am required to do so everyone calm down =o)
I need to prevent employees from trying to bypass the check to not use their preferred browser instead of the company mandated one + version. The decision was made based on security, compatibility, costs, and the use of company made Firefox extensions.
I came across this Force users to use Chrome/FireFox instead of IE which I can do easily in PHP to force use of Firefox, however it relies on the useragent which can easily be changed in numerous browsers and with the use of plugins.
Is there a JavaScript solution that I can use that DOES NOT check the useragent or any value that can be 'easily' modified by a user/plugin? It would need to detect if the browser is Firefox and what version it is. Site uses jQuery so if it can be done using that, however not required then by all means yes. I just am not aware of what ways to detect a browser and it's version that there are without checking useragent.
I remember way back in the day for detecting Netscape or some browser checking for document.all was used instead of useragent, so I'm guessing something similar, which only Firefox will have.
Thank you very much in advance!
Try this: http://jsfiddle.net/DerekL/62exH/
Because Firefox handles onpopstate differently than other browsers, you can then use this to detect if it is Firefox or not. This can not be changed by user or script. But the disadvantage is you can only get the version number by doing navigator.appVersion.
You can only try but cannot succeed in forcing a browser. That being said you can strip down the CSS in other browsers which may completely make your site close to unusable in other browsers.
To make your CSS only work with Firefox you can try approaches given # Targeting only Firefox with CSS

Is there a plugin to make ActiveX Code cross browser compatible

I'm currently working on a web application I didn't build. My current mission is to make it cross browser compatible. It has certain requests written in ActiveX. My question is, is there a plug in, or short cut (per se) to make this application work in all modern browsers.
FireBreath is a C++ wrapper which gives you the possiblity to create a wrapper over an ActiveX, so they can be supported in other browsers.
Checkout http://www.firebreath.org/display/documentation/About+FireBreath
Ziv
It is not possible. ActiveX is a MSIE-only technique. You can safely assume that it will never be supported in any other browsers.
No, there isn't. It isn't really a feasible project anyway since ActiveX involves binary code that depends on Windows APIs. It would be difficult to get it to work on non-Windows platforms (WINE is far from perfect) and require architecture emulation to get it to work on non-x86 compatible platforms.

running different JavaScript based on browser

Canvas clearing gets vastly different perfomance on different browsers. See http://jsperf.com/canvas-clearing2 .
I need to clear a canvas every frame and how I do it has a huge impact on mobile safari vs Desktop safari performance. Desktop Safari likes canvas.width = width but mobile safari prefers canvas.drawRect() .
Is there a way to detect what browser is what an run different JavaScript based on it? I would prefer to do this through JavaScript rather than server side.
Also, I've found that jQuery's $.browser doesn't help because it doesn't distinguish between mobile safari and desktop safari. the navigator object has similar problems.
Targeting specific browsers is always a bit of a problem. While there are certainly ways to do it, it's not a particularly maintainable way to do it because there are lots of different browsers and versions of each browser and those browsers change over time, thus which browsers are optimized by which code can be changing all the time. This creates quite a maintenance headache. For example, mobile Safari on an iPod Touch has very different performance characteristics than mobile Safari on each different generation of iPhone or iPad.
So ... instead of trying to detect the type of browser, it's much better to either do feature detection or performance detection and dynamically adjust based on how any given browser reacts. Done right, this can work equally well for all browsers, even browsers you've never seen or that aren't even released yet.
In your case, you could devise a quick performance test that tests the performance of each of your two methods. If there's really a big performance difference between the two methods, then you could probably tell the difference in a matter of a few hundred milliseconds, set a cookie on the local browser indicating the method that works best and then just use the preferred method in that browser from then on. If you wanted to, you could let the cookie expire every few months (so it would get retested every once in a while) or you could put the exact browser version into the cookie too and reruns the tests and set a new cookie if the browser version every changed (software upgrades).
In this way, your code would always be using the fastest version of your code in all browsers, now and forever without you ever having to maintain/test zillions of browsers to know which should be used for each.
I'm with jfriend00 on this if you're looking at longer-lasting, closer-to-sure-proof solutions. However, you can still pull quite a bit of information with certain functions in Javascript and use that to your advantage.
Check this out:
http://notnotmobile.appspot.com/
Other Resources
Navigator Object: http://www.w3schools.com/js/js_browser.asp
Browser Detect: http://www.quirksmode.org/js/detect.html

Best way to display warning message to "untested" browsers?

I have an app that I have fully tested in Safari 5, IE 9, FF6, and Chrome 14. I'm not looking to block or exclude any browsers from the experience. But I want to warn/inform users that there may be a better experience in another browser, and if they choose to continue, there may be features not working or broken.
I have looked at jQuery browser detection, but it seems to be a bit quirky. I know the best solution would be to warn based on feature detection, but we are currently in beta and I am not completely sure what features make or break. Such as web workers, its known that web workers not working breaks our app, but it works in IE lower versions. But then there is an issue with Opera that web workers is available, but not functioning correctly.
Ultimately I am looking for an easy way to say Browser X Version y and up don't show warning, and those and under show warning.
What is the best way to approach this?
Browser detection is indeed "a bit quirky", in pretty much any scenario. The jQuery route is probably as good as you're going to get, but as you say it's not great.
A better solution is generally to do feature detection, especially in cases like the one you describe where your site relies on specific features.
The best feature detection library is Modernizr. This will give you an bunch of Javascript flags which are set to true or false according to whether the browser supports a given feature. It detects support for a whole bunch of stuff, including Web Workers.
Check out this: http://www.w3schools.com/js/js_browser.asp
-Easy way of detecting the user's browser with javascript. From there I'd just use a switch statement or something to display the messages for browsers that aren't tested yet. If you want the exact browser version you'll have to parse it from the "navigator.userAgent" field.
If the goal is full validation, you need to be even more specific about versions. Keep in mind that some browser upgrades are not 100% backwards compatible with previous versions. (Look at how IE8 mode in IE9 is not the same as native IE8 rendering, for instance.) You're going to have to retest with every new browser version, and sooner or later there's going to be a "Fully tested with browser version X, not tested with version X+1 that was released yesterday" problem. Feature detection, graceful degradation, and a warning non-intrusively displayed to the user if their experience is being significantly downgraded is a better way to go.
To directly answer your question, if you must implement what you are asking for just parse the user agent. This could be useful specifically watching out for a browser you know doesn't work right and warning, or as a bandaid for a badly written intranet app that is very picky about the exact browser version it will run on. For a newly developed app where you have control over the requirements, I would not recommend warning on browser version since there are better ways to do it.

Cons of using Internet Explorer's Compatibility Mode

What are cons of force a web site viewed in IE to compatible mode? Say we force IE9 to IE8 compatiblity mode?
Performance drawbacks
Can't use any new IE9 specific features like HTML5/CSS3/SVG
Why?
We run legacy web app which is developed since 2000 so it's a mess ball fighting to be compatible with Chrome, Opera, Firefox, IE6/7/8 and now we decide to add IE9 to the list. But with IE9 we run in issues with printing, "Permission deniend" JavaScript errors (probably something about cross-frame JavaScript calls) and next issues - the easy workaround is to force IE9 to behave as a IE8 and then everything works fine. But I am still not sure if it's way to go...
first our app is public site (for our clients)
You have a public website developed in 2000 and it doesn't work on modern browsers? Deprecate it or re-write it.
Don't hack your code to support modern browsers, the website is clearly poorly written and doesn't apply to standards. You can't get away with this.
The only place where you can get away with this level of incompatibility is intranet applications and even then you should simply state "it works on browser X, live with it"
You can't say that to public facing clients. I mean you can try, but have fun losing business to your competitors.
Re-develop your website to match the W3C HTML/CSS standards and the ES5 standards and it will be completely future facing (for some years).
Alas, the way the web works is that anything more then 5 years old is deprecated. So either re-write it every 5 years or get out of the web business.
In terms of actually using compatibility mode, don't. IE6-8 are horrible engines and should be avoided like the plague. If you use them then you can't write future facing standards compliant code.
Your code needs to match the standards and you should fix / shim / patch any browser specific bugs where those browsers don't implement the standards.
You cannot say you have tested in IE6/7/8/9 until you have tested in those different versions. Emulating the test environment is not the same as using the test environment. To my knowledge IE7/8 compatibility modes are the older render engines, not the underlying browser as a whole, bugs and all. It is closed source so you will never know.
Convert Microsoft's free to download virtual disk images for cross-browser testing to Virtualbox images and put them on a machine that just runs Virtualbox. An old machine will do, run the VMs headless and access them with remote desktop. In that way you will be able to test in all browsers without burdening your machine with MS/Spyware.
I believe your system admins can set IE to compatibility mode for all intranet traffic using the Group Policy Editor. Any site you create will from this point forward, you can add a meta tag to force IE9 to render natively and use all the newer features...
I'm having to do that on my current project using the following doctype and meta tag in my header:
<!DOCTYPE HTML >
<meta http-equiv="X-UA-Compatible" content="IE=100" />
Compatability mode is something that MS introduced to give people some chance to upgrade their applications, not for long term use. AFAIU.
If you want your application to be compatible with IE9, then you will have to change it. If you are trying to maintain IE6-9 compatibility then you have a real challenge, and you should consider whether this is really practical - in essence, you need at least 2 distinct sets of html. Is this practical for you?
IE9 compatibility mode is different form IE9 and IE8 - it draws bits from both. So you need to do a full test agaisnt the compatibility mode version, and ensure that it remains working against this.
So in answer to the question, the cons are that you are not being IE9 compatible, and there is a danger that when IE10 comes out, your code will not run against that in any mode. You are putting the effort into compatibilty testing without providing for future changes. You would do better, in the longer term, to make your code IE9 compatible. Also, the message you are giving your clients is that your code base is not going to be compatible for much longer. Unless you are talking to them about a re-work, this is a real negative.
However, it sounds like your entire code needs a re-work, to forget about IE6 and be written for modern working browsers. Using compatibility mode until that happens is probably OK. If you do this - and tell your clients - then staying in compatibility mode is viable.
Using compatibility mode will NOT cause the browser to use the JavaScript engine that was present in the old version of IE.
By that I mean it will run any JavaScript code using the IE9 engine. Which was a problem for us when debugging an old product that had a problem with IE7/8.

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