I would like to pass a parameter (i.e. a string) to an Onclick function.
For the moment, I do this:
'<input type="button" onClick="gotoNode(' + result.name + ')" />'
with result.name for example equal to string "Add".
When I click on this button, I have an error that says that "Add is not defined". Since this function call works perfectly with a numeric parameter, I assume that it has something to do with the symbols "" in the string.
How can I fix this problem?
It looks like you're building DOM elements from strings. You just need to add some quotes around result.name:
'<input type="button" onClick="gotoNode(\'' + result.name + '\')" />'
You should really be doing this with proper DOM methods though.
var inputElement = document.createElement('input');
inputElement.type = "button"
inputElement.addEventListener('click', function(){
gotoNode(result.name);
});
document.body.appendChild(inputElement);
Just be aware that if this is a loop or something, result will change before the event fires and you'd need to create an additional scope bubble to shadow the changing variable.
A couple of concerns for me with respect to using string escape in onClick and as the number of arguments grow, it will become cumbersome to maintain.
The following approach will have a one hop - On click - take the control to a handler method and handler method, based on the event object, can deduct the click event and corresponding object.
It also provides a cleaner way to add more arguments and have more flexibility.
<button type="button"
className="btn btn-default"
onClick="invoke"
name='gotoNode'
data-arg1='1234'>GotoNode</button>
In the JavaScript layer:
invoke = (event) => {
let nameOfFunction = this[event.target.name];
let arg1 = event.target.getAttribute('data-arg1');
// We can add more arguments as needed...
window[nameOfFunction](arg1)
// Hope the function is in the window.
// Else the respective object need to be used
})
}
The advantage here is that we can have as many arguments (in above example, data-arg1, data-arg2, etc.) as needed.
I suggest not even using HTML onclick handlers, and use something more common such as document.getElementById.
HTML:
<input type="button" id="nodeGoto" />
JavaScript:
document.getElementById("nodeGoto").addEventListener("click", function() {
gotoNode(result.name);
}, false);
This is a nice and neat way to send a value or object.
<!DOCTYPE html>
<html>
<body>
<h1 onclick="test('wow',this)">Click on this text!</h1>
<script>
var test = function(value,object) {
object.innerHTML= value;
};
</script>
</body>
</html>
I am guessing, you are creating a button using JavaScript itself. So, the error in your code is that, it will render in this form
<input type="button" onClick="gotoNode(add)" />'
At this current state, add will be considered as an identifier like variables or function calls. You should escape the value like this
'<input type="button" onClick="gotoNode(\'' + result.name + '\')" />'
Try this...
HTML:
<button id="a1" type="button" onclick="return a1_onclick('a1')">a1</button>
JavaScript:
<script language="javascript" type="text/javascript">
function a1_onclick(id) {
document.getElementById(id).style.backgroundColor = "#F00";
}
</script>
Note: be sure of sending arguments between ' ' signs like ('a1') in HTML code
If your button is generated dynamically:
You can pass string parameters to JavaScript functions like the below code:
I passed three parameters where the third one is a string parameter.
var btn ="<input type='button' onclick='RoomIsReadyFunc("+ID+","+RefId+",\""+YourString+"\");' value='Room is Ready' />";
// Your JavaScript function
function RoomIsReadyFunc(ID, RefId, YourString)
{
alert(ID);
alert(RefId);
alert(YourString);
}
Also you can use the grave accent symbol ( ` ) in a string
Try:
`<input type="button" onClick="gotoNode('${result.name}')" />`
For more information, visit MDN and Stack Overflow.
By Chrome, Edge, Firefox (Gecko), Opera, Safari support, but it does not support Internet Explorer.
If the requirement is to reference the global object (JavaScript) in your HTML code, you can try this. [Don't use any quotes (' or ") around the variable]
Fiddle reference.
JavaScript:
var result = {name: 'hello'};
function gotoNode(name) {
alert(name);
}
HTML:
<input value="Hello" type="button" onClick="gotoNode(result.name)" />
Multiple parameters:
bounds.extend(marker.position);
bindInfoWindow(marker, map, infowindow,
'<b>' + response[i].driver_name + '</b><br>' +
'<b>' + moment(response[i].updated_at).fromNow() + '</b>
<button onclick="myFunction(\'' + response[i].id + '\',\'' + driversList + '\')">Click me</button>'
);
You can pass a reference or string value. Just put the function inside the double commas "" as per the below snapshot:
If to use for generation of a set of buttons with different parameters of handlers.
let some_button = document.createElement( "button" );
some_button.type = "button";
some_button.onclick = doWithParam( some_param );
function doWithParam( param ){
return function(){
alert( param ); // <-- Your code here
}
}
If we do:
some_button.onclick = foo( some_param );
function foo( param ){
alert( param );
}
then function foo starts after every updating page.
If we do:
for( let i = 0; i < 10; ++i ){
var inputElement = document.createElement('input');
inputElement.type = "button"
inputElement.addEventListener('click', function(){
gotoNode(result.name);
});
document.body.appendChild(inputElement);
}
then for all buttons created in the loop, the last value of the parameter is "result.name".
Here is a jQuery solution that I'm using.
$("#slideshow button").click(function(){
var val = $(this).val();
console.log(val);
});
<div id="slideshow">
<img src="image1.jpg">
<button class="left" value="back">❮</button>
<button class="right" value="next">❯</button>
</div>
If you need to pass a variable along with the 'this' keyword, the below code works:
var status = 'Active';
var anchorHTML = '<a href ="#" onClick = "DisplayActiveStatus(this,\'' + status + '\')">' + data+ '</a>';
<!---- script ---->
<script>
function myFunction(x) {
document.getElementById("demo").style.backgroundColor = x;
}
</script>
<!---- source ---->
<p id="demo" style="width:20px;height:20px;border:1px solid #ccc"></p>
<!---- buttons & function call ---->
<a onClick="myFunction('red')" />RED</a>
<a onClick="myFunction('blue')" />BLUE</a>
<a onClick="myFunction('black')" />BLACK</a>
This is work for me:
$(element).attr("onClick", 'functionName(' + "\"" + Object.attribute + "\"" + ')');
Just add \ slash in ()
※Multiple parameters example
"functionName(" + "'" + parameter1 + "','" + parameter2 + "','" + parameter3 + "','" + parameter4 + "','" + parameter5 + "','" + parameter6 + "')"
For passing multiple parameters you can cast the string by concatenating it with the ASCII value. Like, for single quotes we can use ':
var str = "'" + str + "'";
The same parameter you can pass to the onclick() event. In most of the cases it works with every browser.
<style type="text/css">
#userprofile{
display: inline-block;
padding: 15px 25px;
font-size: 24px;
cursor: pointer;
text-align: center;
text-decoration: none;
outline: none;
color: #FFF;
background-color: #4CAF50; // #C32836
border: none;
border-radius: 15px;
box-shadow: 0 9px #999;
width: 200px;
margin-bottom: 15px;
}
#userprofile:hover {
background-color: #3E8E41
}
#userprofile:active {
background-color: #3E8E41;
box-shadow: 0 5px #666;
transform: translateY(4px);
}
#array {
border-radius: 15px 50px;
background: #4A21AD;
padding: 20px;
width: 200px;
height: 900px;
overflow-y: auto;
}
</style>
if (data[i].socketid != "") {
$("#array").append("<button type='button' id='userprofile' class='green_button' name=" + data[i]._id + " onClick='chatopen(name)'>" + data[i].username + "</button></br>");
}
else {
console.log('null socketid >>', $("#userprofile").css('background-color'));
//$("#userprofile").css('background-color', '#C32836 ! important');
$("#array").append("<button type='button' id='userprofile' class='red_button' name=" + data[i]._id + " onClick='chatopen(name)'>" + data[i].username+"</button></br>");
$(".red_button").css('background-color','#C32836');
}
If you are using ASP.NET you can use JavaScript:
<input type='button' value='test' onclick='javascript: EditSelectedOptionName(x,y)' />"
function EditSelectedOptionName(id, name) {
console.log(id);
console.log(name);
}
If you are adding buttons or link dynamically and facing the issue then this may be help. I solved it by this way:
var link= $(contentData1[i]).find("td:first font b a").attr("href",'javascript:onClick=openWin(\'' + tdText + '\')');
I am new to HTML, jQuery and JavaScript. So maybe my code will not be optimized or syntax, but it was working for me.
In Razor, you can pass parameters dynamically:
<a href='javascript:void(0);' onclick='showtotextbox(@Model.UnitNameVMs[i].UnitNameID, "@Model.UnitNameVMs[i].FarName","@Model.UnitNameVMs[i].EngName","@Model.UnitNameVMs[i].Symbol" );'>@Model.UnitNameVMs[i].UnitNameID</a>
You can use this:
'<input id="test" type="button" value="' + result.name + '" />'
$(document).on('click', "#test", function () {
alert($(this).val());
});
It worked for me.
let task = {....}
<button onclick="myFunction('${task}')">Continue task</button></li>
<button style="background-color: gray;color:white;" onclick="displayAlert('the message')">alert</button>
<script>
function displayAlert(msg){
alert(msg);
}
</script>
You can use this code in your button onclick method:
<button class="btn btn-danger" onclick="cancelEmployee(\''+cancelButtonID+'\')" > Cancel </button>
The following works for me very well,
<html>
<head>
<title>HTML Form</title>
</head>
<body>
<form>
<input type="button" value="ON" onclick="msg('ON')">
<input type="button" value="OFF" onclick="msg('OFF')">
</form>
<script>
function msg(x){
alert(x);
}
</script>
</body>
</html>
