Reputation: 1246
I have an input text field where the user provides the source url of the image ,
for example http://mysite/images/STARTPAGE_LOGO.gif
is a valid value.
I dont have any img
tag or something else in my html document. How can i determine the dimensions of the image which is present at the URL the user has entered .
Upvotes: 0
Views: 331
Reputation: 6916
There is no method to find out the width and height of the image without loading it so you will have to dynamically load it , and to do so you can use
function getDimensions(_src,_callback){
/* create a new image , not linked anywhere in document */
var img = document.createElement('img');
/* set the source of the image to what u want */
img.src=_src;
/* Wait the image to load and when its so call the callback function */
/* If you want the actual natural dimensions of the image use naturalWidth and natural height instead */
img.onload = function () { _callback(img.width,img.height) };
}
After declaring the above function in pure javascript spirit you can do something like
getDimensions('http://mysite/images/STARTPAGE_LOGO.gif',function(w,h){
console.log( "Height : ",h,"Width:",w);
});
Upvotes: 12
Reputation: 5042
HTML:
<input id="src" type="text" value="https://www.google.pl/images/srpr/logo3w.png"/>
JAVASCRIPT:
var img = new Image; // create tmp image element
// is equal to document.createElement('img');
Bind function on onload event, it will be called automatically when image is loaded.
img.onload = function(){
alert( this.width +" : " + this.height );
};
Set the source of image;
img.src = document.getElementById('src').value // get the value of input element;
for curiosity in jQuery:
$('<img/>').attr('src',$('#src').val()).bind('load',function(){
alert( this.width +' x ' + this.height );
});
Upvotes: -3