How to alert after paste event in Javascript?
You could put your alert in a setTimeout
.
setTimeout(function() {alert('Pasted');}, 0);
This will delay the code until after the value has updated.
Just keep in mind that this
in the setTimeout
callback will have a different value than that in the enclosing environment.
If you'll need a reference to the outer this
, which will be the element, then reference it in a variable...
var self = this;
setTimeout(function() {alert(self.value);}, 0);
Or use .bind()
(Supported in most browsers that support addEventListener
. Older Safari didn't support it.)...
setTimeout(function() {alert(this.value);}.bind(this), 0);
setTimeout seems the best option and you can use something like this to generalise
// object definition
function PasteMonitor(element)
{
if(typeof element == "string")
{
this.target = document.getElementById(element);
}
else if(typeof element == "object" || typeof element == "function")
{
this.target = element;
}
if(this.target != null && this.target != undefined)
{
this.target.addEventListener('paste',this.inPaste.bind(this),false);
this.target.addEventListener('change',this.changed.bind(this),false);
}
this.oldstate = "";
}
PasteMonitor.prototype = Object.create({},{
pasted:{ value: false, enumerable: true, configurable: true, writable: true },
changed:{ value: function(evt){
//elements content is changed
if(typeof this.onChange == "function")
{
this.onChange(evt);
}
if(this.pasted)
{
if(typeof this.afterPaste == "function")
{
this.afterPaste(evt);
this.pasted = false;
}
}
}, enumerable: true, configurable: true, writable: true },
inPaste:{ value: function(evt){
var cancelPaste = false;
if(typeof this.beforePaste == "function")
{
// process pasted data
cancelPaste = this.beforePaste(evt);
}
if(cancelPaste == true)
{
evt.preventDefault();
return false;
}
this.pasted = true;
setTimeout(function(){
var evt = document.createEvent("HTMLEvents");
evt.initEvent("change", false, true);
this.target.dispatchEvent(evt);
}.bind(this),0);
}, enumerable: true, configurable: true, writable: true }
})
PasteMonitor.prototype.constructor = PasteMonitor;
//PasteMonitor usage
//var element = document.getElementById('paste_area');
var msgArea = document.getElementById('message');
var myMonitor = new PasteMonitor("paste_area");
//or use and object as argument => var myMonitor = new PasteMonitor(element);
myMonitor.onChange = function(evt){
if(this.pasted)
{
//do something on paste change
msgArea.innerHTML = "onChange by paste";
this.oldstate = this.target.value;
}
//check to prevent processing change event when the element loses focus if the change is done by paste
else if(this.target.value != this.oldstate)
{
msgArea.innerHTML = "onChange by typing";
}
};
myMonitor.afterPaste = function(evt){
// do something after paste
msgArea.innerHTML = "afterPaste";
};
myMonitor.beforePaste = function(evt){
// do something before the actual paste
msgArea.innerHTML = "beforePaste";
//return true to prevent paste
return false;
};