jquery animate for element attributes not style

Question

ASAIK jquery animate function accepts style properties only. but i want to animate the attributes of an element. consider a SVG element rectangle

Answer 1

I like the Hoffmann approach, but i think is more elegant without creating a virtual dom object.

This is my coffeescript snippet

$rects.each ->
  that = @
  $({width: 0}).animate
  width: parseInt($(@).attr('width'))
  ,
  duration: 2000
  easing: 'easeIn'
  step: ->
    $(that).attr 'width', Math.round(@.width)
  done: ->
    console.log 'Done'

which compiles into

return $rects.each(function() {
  var that;
  that = this;
  return $({
    width: 0
  }).animate({
    width: parseInt($(this).attr('width'))
  }, {
    duration: 1000,
    easing: 'easeIn',
    step: function() {
      return $(that).attr('width', Math.round(this.width));
    },
    done: function() {
      return console.log('Done');
    }
  });
});

Answer 2

I would try something like this

<svg>
    <rect class="myElement" id="rect1" x="10" y="20" width="100px" height="100px">
</svg>

in the script :

var myElemX = $('.myElement').attr('x');
var myElemY = $('.myElement').attr('y');
$("#rect1").animate({
    left: myElemX+'px',
    top:  myElemY+'px'
}, 1500 );

Answer 3

Alright all answers here are either specific to SVG or reimplement the .animate() jQuery call, I found a way to use the jQuery call without running into the problem that the attribute gets reset to 0 when the animation starts:

Lets say we want to animate the width and height attribute of an img tag element with id image. To animate it from its current value to 300 we could do this:

var animationDiv= $("<div></div>"); //we don't add this div to the DOM
var image= $("img#image");
//could use any property besides "top" and "left", but the value must be valid, that means concatenating a "px" to numerical attributes if they don't have it already (and removing them in the step callback if they do)
animationDiv.css("left", image.attr("width")); 
animationDiv.css("top", image.attr("height")); 
animationDiv.animate(
    {
        left: 300,
        top: 300
    },
    {
        duration: 2500,
        step: function(value, properties) {
            if (properties.prop == "left")
                 image.attr("width", value + "px")
            else
                 image.attr("height", value + "px")
        }
    }
)

In this approach we use a div that is not inside the DOM and animate values in it, we then use the div CSS values to animate our element. Not very pretty but gets the job done, if you need to stop the animation you can call .stop() on animationDiv.

jsfiddle

Answer 4

just animate the old fashioned way:

you can call animate in a jquery like fashion.

http://jsfiddle.net/wVv9P/7/

function animate($el, attrs, speed) {

    // duration in ms
    speed = speed || 400;

    var start = {}, // object to store initial state of attributes
        timeout = 20, // interval between rendering loop in ms
        steps = Math.floor(speed/timeout), // number of cycles required
        cycles = steps; // counter for cycles left

    // populate the object with the initial state
    $.each(attrs, function(k,v) {
        start[k] = $el.attr(k);
    });

    (function loop() {
        $.each(attrs, function(k,v) {  // cycle each attribute
            var pst = (v - start[k])/steps;  // how much to add at each step
            $el.attr(k, function(i, old) {
                return +old + pst;  // add value do the old one
            });
        });

        if (--cycles) // call the loop if counter is not exhausted
            setTimeout(loop, timeout);
        else // otherwise set final state to avoid floating point values
            $el.attr(attrs);

    })(); // start the loop
}

$('button').on('click', function() {       
    animate(
        $('#rect1'), // target jQuery element
        { x:100, y:300, width:50, height:100 }, // target attributes
        2000 // optional duration in ms, defaults to 400
    );
});

Answer 5

this may fits you simple

$("your div id").css("position", "absolute").animate({
    left: 159,
    top:  430
});