views:

18

answers:

2

I am experimenting with changing some stylesheets from javascript I have come across a strange issue:

When I set an attribute on a style rule it silently fails in Firefox if the property is one of their proprietary ones. I have made an example demonstrating the issue (live example):

<html>
<head>
<style type="text/css">
div {
    margin: 5px;
    padding: 3px;
    color: white;
}
#el1 {
    -moz-box-shadow: 2px 2px 2px red;
    -webkit-box-shadow: 2px 2px 2px red;
    -moz-border-radius: 5px;
    -webkit-border-radius: 5px;
    background: maroon;
    height: 20px;
}
#el2 {
    height: 20px;
    background:navy;
}
​
</style>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/prototype/1.6.1.0/prototype.js"&gt;&lt;/script&gt;
<script type="text/javascript">
    document.observe("dom:loaded", function() {
        var myStyles = $A(document.styleSheets).last();
        var rules = myStyles.cssRules || myStyles.rules;

        var el1 = rules[rules.length-2],
            el2 = rules[rules.length-1];

        //works
        el1.style["background"] = "#030";

        if (Prototype.Browser.WebKit) {
            //works
            console.log("setting webkit proprietaries");
            el2.style["-webkit-box-shadow"] = "2px 2px 2px blue";
            el2.style["-webkit-border-radius"] = "5px";

        } else if (Prototype.Browser.Gecko) {
            // does not work?!
            console.log("setting moz box-shadow");
            el2.style["-moz-box-shadow"] = "2px 2px 2px blue";
            el2.style["-moz-border-radius"] = "5px";
        }
    });
</script>
</head>
<body>
  <div id="el1">Element 1<div>  
  <div id="el2">Element 2<div>
</body>
</html>

I am running Fx 3.6.10 and it has no problem changing the background of el1 to green but I see nothing of the drop-shadow and border-radius on el2 in Fx although it works fine on webkit (at least in chrome and safari here).

So it seems like the rule.style[propName] = value works on standard-options but not on -moz-options. Why is that, and is there any way around it?

+2  A: 

For -moz- options, it seems you need to remove the dashes and capitalise the first letter of each word:

    } else if (Prototype.Browser.Gecko) {
        // Works now?
        console.log("setting moz box-shadow");
        // Changed colour to red for contrast
        el2.style["MozBoxShadow"] = "2px 2px 2px red";
        el2.style["MozBorderRadius"] = "5px";
    }

I worked this out by looping through all elements of el2.style and outputting them:

for(var i in el2.style) {
    console.log('el2.style[' + i + ']: ' + el2.style[i]) ;
}
Gus
A: 

Alternatively, if you want to use the CSS property names instead of their DOM equivalents, you can use:

el2.style.setProperty("-moz-box-shadow", "2px 2px 2px red", "");

instead of:

el2.style.MozBoxShadow = "2px 2px 2px red";

or:

el2.style["MozBoxShadow"] = "2px 2px 2px red";
David Baron