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JavaScript

Posted by Chase Lester
Chase Lester
10,972 Points

Writing CSS with JavaScript

Currently this is what my css looks like in JavaScript:

  $('body').css({
    'background-image' : "url('" + backgrounds[currentBackground] + "')"
  });

I want to add a few more in there so it looks like this css:

body{
background-image: url('') no-repeat center center fixed;                 background-size: cover;
}

So how would I write all that in the javascript css I have already written?

3 Answers

Kevin Korte
Kevin Korte
28,149 Points

You could do something like this:]

$('body').css({"background": "url('http://www.worldswallpapers.org/wp-content/uploads/2014/02/Nature-Wallpapers-2014-1.jpg') no-repeat center center fixed", "background-size": "cover"});

You just have to put in whatever dynamic way it looks like you're generating a background image. I just used a static one.

I will say this though, I'd set as many of these CSS elements in CSS as possible for maintainability reasons. I get to do dynamic backgrounds you have to use Javascript/Jquery, but the rest I'd at least considered limiting your inline CSS to as few as possible.

http://jsfiddle.net/eA6Ek/ (Codepen is broken right now )

Jason Anello
Jason Anello
Courses Plus Student 94,610 Points

As Kevin noted, you have to switch to the shorthand background property.

I agree with Kevin that if the other properties aren't dynamic then move those styles to your css file.

To integrate with your existing code you could do:

$('body').css({'background' : "url('" + backgrounds[currentBackground] + "') center center / cover no-repeat fixed"
  });

You can also include the background-size property in the shorthand but it must come after the position and the two have to be separated with a forward slash.

Dino Paškvan
PLUS
Dino Paškvan
Courses Plus Student 44,108 Points
Dino Paškvan
Dino Paškvan
Courses Plus Student 44,108 Points

The jQuery css method accepts an object of property-value pairs as its parameter:

$('body').css({
   'background' : "url('" + backgrounds[currentBackground] + "') no-repeat center center fixed",
   'background-size': 'cover'
});

You can even expand it to something like this, if you want to define every property separately:

$('body').css({
   'background-image' : "url('" + backgrounds[currentBackground] + "')",
   'background-position': "center center",
   'background-repeat': "no-repeat",
   'background-attachment': 'fixed',
   'background-size': 'cover'
});
Jason Anello
Jason Anello
Courses Plus Student 94,610 Points

Hi Dino,

I think your first code sample wouldn't be valid since you're using background-image instead of background

Dino Paškvan
Dino Paškvan
Courses Plus Student 44,108 Points

Right you are. Serves me right for pasting instead of typing. :)

Chase Lester
Chase Lester
10,972 Points
Chase Lester
Chase Lester
10,972 Points

Thanks Kevin! That worked. I generally would write this in my css for the background, but I am having the body background image loop through images, so I needed it set in the JS. Though I probably could put the background-size in the css since that stays the same through each bg image. Thanks again!