Rails: Mainpulate Image After Upload - ruby-on-rails

Question

In a Rails environment, I want to manipulate an image after it has been uploaded. I do not need to change the image, but I want to present it to the user based on parameters in the URL.
Any suggestions?

Answer 1

It means after uploading completed you need to show image, you can show imaged using javascript and jquery, i have done this in sample project like following way
function showThumbnail(files){
for(var i=0;i< files.length;i++){
var file = files[i];
var imageType = /image.*/
if(!file.type.match(imageType)){
alert("Not an image");
}
var image = document.createElement("img");
var thumbnail = document.getElementById("thumbnail");
image.file = file;
if(file.type.match(imageType)) {
if((thumbnail.hasChildNodes() == true)){
thumbnail.removeChild(thumbnail.firstChild);
thumbnail.appendChild(image);
}else
{
thumbnail.appendChild(image);
}
}
var reader = new FileReader()
reader.onload = (function(aImg){
return function(e){
aImg.src = e.target.result;
};
}(image))
var ret = reader.readAsDataURL(file);
var canvas = document.createElement("canvas");
ctx = canvas.getContext("2d");
image.onload= function(){
ctx.drawImage(image,75,75);
$(".uploadedPhoto").addClass('whiteBG');
$(".uploadtxt").html(file.name);
}
}
}