[javascript] Padding or margin value in pixels as integer using jQuery

jQuery has height() en width() functions that returns the height or width in pixels as integer...

How can I get a padding or margin value of an element in pixels and as integer using jQuery?

My first idea was to do the following:

var padding = parseInt(jQuery("myId").css("padding-top"));

But if padding is given in ems for example, how can I get the value in pixels?

Looking into the JSizes plugin suggested by Chris Pebble i realized that my own version was the right one :). jQuery returns always value in pixels, so just parsing it to integer was the solution.

Thanks to Chris Pebble and Ian Robinson

The parseInt function has a "radix" parameter which defines the numeral system used on the conversion, so calling parseInt(jQuery('#something').css('margin-left'), 10); returns the left margin as an Integer.

This is what JSizes use.

Compare outer and inner height/widths to get the total margin and padding:

var that = $("#myId");
alert(that.outerHeight(true) - that.innerHeight());

Don't use string.replace("px", ""));

Use parseInt or parseFloat!

You can just grab them as with any CSS attribute:

alert($("#mybox").css("padding-right"));
alert($("#mybox").css("margin-bottom"));

You can set them with a second attribute in the css method:

$("#mybox").css("padding-right", "20px");

EDIT: If you need just the pixel value, use parseInt(val, 10):

parseInt($("#mybox").css("padding-right", "20px"), 10);

Parse int

parseInt(canvas.css("margin-left")); 

returns 0 for 0px

You should be able to use CSS (http://docs.jquery.com/CSS/css#name). You may have to be more specific such as "padding-left" or "margin-top".

Example:

CSS

a, a:link, a:hover, a:visited, a:active {color:black;margin-top:10px;text-decoration: none;}

JS

$("a").css("margin-top");

The result is 10px.

If you want to get the integer value, you can do the following:

parseInt($("a").css("margin-top"))

I probably use github.com/bramstein/jsizes jquery plugin for paddings and margins in very comfortable way, Thanks...

You could also extend the jquery framework yourself with something like:

jQuery.fn.margin = function() {
var marginTop = this.outerHeight(true) - this.outerHeight();
var marginLeft = this.outerWidth(true) - this.outerWidth();

return {
    top: marginTop,
    left: marginLeft
}};

Thereby adding a function on your jquery objects called margin(), which returns a collection like the offset function.

fx.

$("#myObject").margin().top

Not to necro but I made this which can determine pixels based on a variety of values:

$.fn.extend({
  pixels: function (property, base) {
    var value = $(this).css(property);
    var original = value;
    var outer = property.indexOf('left') != -1 || property.indexOf('right') != -1 
      ? $(this).parent().outerWidth()
      : $(this).parent().outerHeight();

    // EM Conversion Factor
    base = base || 16;

    if (value == 'auto' || value == 'inherit') 
        return outer || 0;

    value = value.replace('rem', '');
    value = value.replace('em', '');

    if (value !== original) {
       value = parseFloat(value);
       return value ? base * value : 0;
    }

    value = value.replace('pt', '');

    if (value !== original) {
       value = parseFloat(value);
       return value ? value * 1.333333 : 0; // 1pt = 1.333px
    }

    value = value.replace('%', '');

    if (value !== original) {
      value = parseFloat(value);
      return value ? (outer * value / 100) : 0;
    }

    value = value.replace('px', '');
    return parseFloat(value) || 0;
  }
});

This way, we take into account for sizing, and auto / inherit.

This simple function will do it:

$.fn.pixels = function(property) {
    return parseInt(this.css(property).slice(0,-2));
};

Usage:

var padding = $('#myId').pixels('paddingTop');

Shamelessly adopted from Quickredfox.

jQuersy.fn.cssNum = function(){
    return parseInt(jQuery.fn.css.apply(this, arguments), 10);
};

update

Changed to parseInt(val, 10) since it is faster than parseFloat.

http://jsperf.com/number-vs-plus-vs-toint-vs-tofloat/20

PLEASE don't go loading another library just to do something that's already natively available!

jQuery's .css() converts %'s and em's to their pixel equivalent to begin with, and parseInt() will remove the 'px' from the end of the returned string and convert it to an integer:

http://jsfiddle.net/BXnXJ/

$(document).ready(function () {
    var $h1 = $('h1');
    console.log($h1);
    $h1.after($('<div>Padding-top: ' + parseInt($h1.css('padding-top')) + '</div>'));
    $h1.after($('<div>Margin-top: ' + parseInt($h1.css('margin-top')) + '</div>'));
});

Here's how you can get the surrounding dimentions:

var elem = $('#myId');

var marginTopBottom  = elem.outerHeight(true) - elem.outerHeight();
var marginLeftRight  = elem.outerWidth(true)  - elem.outerWidth();

var borderTopBottom  = elem.outerHeight() - elem.innerHeight();
var borderLeftRight  = elem.outerWidth()  - elem.innerWidth();

var paddingTopBottom  = elem.innerHeight() - elem.height();
var paddingLeftRight  = elem.innerWidth()  - elem.width();

Pay attention that each variable, paddingTopBottom for example, contains the sum of the margins on the both sides of the element; i.e., paddingTopBottom == paddingTop + paddingBottom. I wonder if there is a way to get them separately. Of course, if they are equal you can divide by 2 :)

ok just to answer the original question:

you can get the padding as a usable integer like this:

var padding = parseInt($("myId").css("padding-top").replace("ems",""));

If you have defined another measurement like px just replace "ems" with "px". parseInt interprets the stringpart as a wrong value so its important to replace it with ... nothing.