jQuery detect Bootstrap 3 state

Question

In Bootstrap 3, there are 4 states; extra small devices, small devices, medium devices, and large devices. How can I know the website is currently at which state with jQuery? So that I can do some processing like when it is in extra small devices, then run this function.

Thanks.

Solution 1

I made some changes to this for bootstrap 3, try this"

function findBootstrapEnvironment() {
    var envs = ["ExtraSmall", "Small", "Medium", "Large"];
    var envValues = ["xs", "sm", "md", "lg"];

    var $el = $('<div>');
    $el.appendTo($('body'));

    for (var i = envValues.length - 1; i >= 0; i--) {
        var envVal = envValues[i];

        $el.addClass('hidden-'+envVal);
        if ($el.is(':hidden')) {
            $el.remove();
            return envs[i]
        }
    };
}

Solution 2

Following @Khurshid's answer (which works perfectly well) I've written a native JavaScript implementation which is significantly faster:

function findBootstrapEnvironment() {
    var envs = ["xs", "sm", "md", "lg"],    
        doc = window.document,
        temp = doc.createElement("div");

    doc.body.appendChild(temp);

    for (var i = envs.length - 1; i >= 0; i--) {
        var env = envs[i];

        temp.className = "hidden-" + env;

        if (temp.offsetParent === null) {
            doc.body.removeChild(temp);
            return env;
        }
    }
    return "";
}

Solution 3

I had to do something similiar for the medium size.

The media query for the extra small is up to 480px;

so you can say something like:

if($(document).width > 480)
{

  //Do Something
}

Comments

[carter]

You should declare the $el and not pollute the global scope.

[Scott Smith]

I have to admit that I generally dismissed replacing simply jQuery calls with native as an unnecessary micro-optimization. Definitely didn't anticipate this comparison would show a 90+% difference in performance.

[Simon Arnold]

Work great, but on IE it seems to always return "xs" :S

[Simon Arnold]

For IE support, I used if($(this.dom.temp).is(':hidden')) { $(this.dom.temp).remove(); return env; } instead of if (temp.offsetParent === null) { doc.body.removeChild(temp); return env; }

[dburdan]

To make this code Bootstrap v4 compatible, add "xl" to the 'envs' array and change temp.className = "hidden-" + env; to temp.className = "hidden-" + env + "-up";

[awj]

@dburdan Without sounding lazy, I'm quite happy for you to edit my solution and attach your name to it.

[Subrata Sarkar]

This is by far the best and to the point solution I have come across. The main reason for this is nobody except a developer is going to switch browser width to test responsive behavior! A site user will use one device at a time, either a desktop or a tablet or a handheld. I presume this solution was suggested keeping above in mind!

[Angry 84]

You will still get users changing the browser side, eg dragging it to a second screen or changing its size so they can see windows underneath and other user cases.. But its a simple example which simply reminds people.. Check the width..

[user2502479]

Great answer! Thank you.