browser-feature-detection

I actually have an issue im trying to solve since 3 weeks. Im trying to test support for vw units and serve a seperate stylesheet when the browser doesnt support the unit I read the modernizr tutorials and am familiar with modernizr css detects but testing for vh units (viewport relative units) is something I didnt find on the net. So basically: Scenario 1: Browser supports vw unit then serve stylesheet A. Scenario 2: Browser doesnt support it then serve stylesheet B. I did find out that there is a non-core detect called Modernizr.cssvwunit but I honestly have no idea where to start or how to

When researching JavaScript conditional comments for IE, I stumbled upon @cc_on. This seems to work. However, the wikipedia entry on conditional comments provides the following code for more robust IE detections, specifically IE6: /*@cc_on @if (@_jscript_version > 5.7) document.write("You are using IE8+"); @elif (@_jscript_version == 5.7 && window.XMLHttpRequest) document.write("You are using IE7"); @elif (@_jscript_version == 5.6 || (@_jscript_version == 5.7 && !window.XMLHttpRequest)) document.write("You are using IE6"); @elif (@_jscript_version == 5.5) document.write("You are using IE5.5");

What's concept of detecting support of any css pseudo-class in browser through JavaScript? Exactly, I want to check if user's browser supports :checked pseudo-class or not, because I've made some CSS-popups with checkboxes and needs to do fallbacks for old browsers. ANSWER: I'm found already implemented method of testing css selectors in a Modernizr "Additional Tests" . You can simply check if your style with pseudo-class was applied. Something like this: http://jsfiddle.net/qPmT2/1/ stylesheet.insertRule(rule, index) method will throw error if the rule is invalid. so we can use it. var

I'm really enjoying ES6 generators. Is there a way I can detect generator support in browsers? I know generators might not be in a lot of browsers (or possible no browsers at all) at the moment, but that's OK for my purposes. I tried: try { function *(){} } catch(err) { console.log("No generators"); } But it doesn't seem to work. How can I detect support for ES6 generators in browsers? Jeremy J Starcher One of the few times that eval is actually the right solution. For language construct changes, you need something like this: try { eval("(function *(){})"); } catch(err) { console.log(err);