I need to dynamically load banner images into a HTML5 app and would like a couple of different versions to suit the screen widths. I can't correctly determine the phone's screen width, so the only way I can think of doing this is to add background images of a div and use @media to determine the screen width and display the correct image.

For example:

 <span style="background-image:particular_ad.png; @media (max-width:300px){background-image:particular_ad_small.png;}"></span>

Is this possible, or does anyone have any other suggestions?

Solution 1

@media at-rules and media queries cannot exist in inline style attributes as they can only contain property: value declarations. As the spec puts it:

The value of the style attribute must match the syntax of the contents of a CSS declaration block

The only way to apply styles to one specific element only in certain media is with a separate rule in your stylesheet (be it linked externally or internally in a <style> element), which means you'll need to come up with a selector for it. You can grab one using your browser's dev tools, or figure out a class and/or ID combination that isolates this element:

#myelement { background-image: url(particular_ad.png); }

@media (max-width: 300px) {
    #myelement { background-image: url(particular_ad_small.png); }
}

If you're unable to find a selector that will reliably match this element alone due to the nature of your page, you can use a custom property, provided you don't need to worry about specificity or Internet Explorer:

:root { --particular-ad: url(particular_ad.png); }

@media (max-width: 300px) {
    :root { --particular-ad: url(particular_ad_small.png); }
}
<span style="background-image: var(--particular-ad);"></span>

Solution 2

Problem

No, Media Queries cannot be used in this way

<span style="@media (...) { ... }"></span>

Solution

But if you want provided a specific behavior usable on the fly AND responsive, you can use the style markup and not the attribute.

e.i.

<style scoped>
.on-the-fly-behavior {
    background-image: url('particular_ad.png'); 
}
@media (max-width: 300px) {
    .on-the-fly-behavior {
        background-image: url('particular_ad_small.png');
    }
}
</style>
<span class="on-the-fly-behavior"></span>

See the code working in live on CodePen

In my Blog for example, I inject a <style> markup in <head> just after <link> declaration for CSS and it's contain the content of a textarea provided beside of real content textarea for create extra-class on the fly when I wrote an artitle.

Note : the scoped attribute is a part of HTML5 specification. If you do not use it, the validator will blame you but browsers currently not support the real purpose : scoped the content of <style> only on immediatly parent element and that element's child elements. Scoped is not mandatory if the <style> element is in <head> markup.


UPDATE: I advice to always use rules in the mobile first way so previous code should be:

<style scoped>
/* 0 to 299 */
.on-the-fly-behavior {
    background-image: url('particular_ad_small.png'); 
}
/* 300 to X */
@media (min-width: 300px) { /* or 301 if you want really the same as previously.  */
    .on-the-fly-behavior {   
        background-image: url('particular_ad.png');
    }
}
</style>
<span class="on-the-fly-behavior"></span>

Solution 3

Inline styles cannot currently contain anything other than declarations (property: value pairs).

You can use style elements with appropriate media attributes in head section of your document.

Solution 4

Yes, you can write media query in inline-css if you are using a picture tag. For different device sizes you can get different images.

<picture>
    <source media="(min-width: 650px)" srcset="img_pink_flowers.jpg">
    <source media="(min-width: 465px)" srcset="img_white_flower.jpg">
    <img src="img_orange_flowers.jpg" alt="Flowers" style="width:auto;">
</picture>

Solution 5

Hey I just wrote it.

Now you can use <div style="color: red; @media (max-width: 200px) { color: green }"> or so.

Enjoy.

Solution 6

If you are using Bootstrap Responsive Utilities or similar alternative that allows to hide / show divs depending on the break points, it may be possible to use several elements and show the most appropriate. i.e.

 <span class="hidden-xs" style="background: url(particular_ad.png)"></span>
 <span class="visible-xs" style="background: url(particular_ad_small.png)"></span>

Solution 7

Media Queries in style-Attributes are not possible right now. But if you have to set this dynamically via Javascript. You could insert that rule via JS aswell.

document.styleSheets[0].insertRule("@media only screen and (max-width : 300px) { span { background-image:particular_ad_small.png; } }","");

This is as if the style was there in the stylesheet. So be aware of specificity.

Solution 8

I tried to test this and it did not seem to work but I'm curious why Apple is using it. I was just on https://linkmaker.itunes.apple.com/us/ and noticed in the generated code it provides if you select the 'Large Button' radio button, they are using an inline media query.

<a href="#" 
    target="itunes_store" 
    style="
        display:inline-block;
        overflow:hidden;
        background:url(#.png) no-repeat;
        width:135px;
        height:40px;
        @media only screen{
            background-image:url(#);
        }
"></a>

note: added line-breaks for readability, original generated code is minified

Solution 9

yes,you can do with javascript by the window.matchMedia

  1. desktop for red colour text

  2. tablet for green colour text

  3. mobile for blue colour text

//isat_style_media_query_for_desktop_mobile_tablets
var tablets = window.matchMedia("(max-width:  768px)");//for tablet devices
var mobiles = window.matchMedia("(max-width: 480px)");//for mobile devices
var desktops = window.matchMedia("(min-width: 992px)");//for desktop devices



isat_find_device_tablets(tablets);//apply style for tablets
isat_find_device_mobile(mobiles);//apply style for mobiles
isat_find_device_desktops(desktops);//apply style for desktops
// isat_find_device_desktops(desktops,tablets,mobiles);// Call listener function at run time
tablets.addListener(isat_find_device_tablets);//listen untill detect tablet screen size
desktops.addListener(isat_find_device_desktops);//listen untill detect desktop screen size
mobiles.addListener(isat_find_device_mobile);//listen untill detect mobile devices
// desktops.addListener(isat_find_device_desktops);

 // Attach listener function on state changes

function isat_find_device_mobile(mob)
{
  
// isat mobile style here
var daynight=document.getElementById("daynight");
daynight.style.color="blue";

// isat mobile style here

}

function isat_find_device_desktops(des)
{

// isat mobile style here

var daynight=document.getElementById("daynight");
daynight.style.color="red";
 
//  isat mobile style here
}

function isat_find_device_tablets(tab)
{

// isat mobile style here
var daynight=document.getElementById("daynight");
daynight.style.color="green";

//  isat mobile style here
}


//isat_style_media_query_for_desktop_mobile_tablets
    <div id="daynight">tricky style for mobile,desktop and tablet</div>

Solution 10

You can use image-set()

<div style="
  background-image: url(icon1x.png);
  background-image: -webkit-image-set(  
    url(icon1x.png) 1x,  
    url(icon2x.png) 2x);  
  background-image: image-set(  
    url(icon1x.png) 1x,  
    url(icon2x.png) 2x);">

Solution 11

Inline media queries are possible by using something like Breakpoint for Sass

This blog post does a good job explaining how inline media queries are more manageable than separate blocks: There Is No Breakpoint

Related to inline media queries is the idea of "element queries", a few interesting reads are:

  1. Thoughts on Media Queries for Elements
  2. Media Queries are a Hack
  3. Media Queries Are Not The Answer: Element Query Polyfill
  4. if else blocks

Solution 12

if you add the rule to the print.css file you don't have to use @media.

I uncluded it in the smarty foreach i use to give some elements a background color.

<script type='text/javascript'>
  document.styleSheets[3].insertRule(" #caldiv_<?smarty $item.calendar_id ?> { border-color:<?smarty $item.color ?> }", 1);
</script>