JavaScript button event handler not working - javascript

I am learning javascipt and now i have a piece of code but i am unable to get this to work, javascript isn't executed. I have already searched the web but i can't find an answer. Maybe you guys can help me with this.
HTML
<html>
<head>
<title>Text Game</title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
<script type="text/javascript" src="javascript.js"></script>
</head>
<body>
<button><span id="click">0</span></button>
</body>
</html>
Javascript
// Variables
var waarde = {
amount:2
};
$(document).ready(function() {
updateValues();
});
function updateValues() {
document.getElementById("click").innerHTML = waarde.amount;
}
$('#click').click(function() {
waarde.amount = waarde.amount + 1;
updateValues();
});

You have a couple of issues here:
Issue #1:
The element does not exist in the DOM to bind to yet, so do any or all of the following:
Move your script tag to the footer, right before the closing </body> tag (generally best practice anyway).
Use event delegation to bind to events on future elements.
Put all the JavaScript in the ready handler.
Issue #2:
You should not bind a click event handler on an element inside a button, it will not work in specification compliant browsers as the button consumes the event, and it not propagated to children.
See the HTML5 spec for button for reference:
Content model:
Phrasing content, but there must be no interactive content descendant.
Instead, bind the click event handler to the button itself.
// Variables
var waarde = {
amount: 2
};
$(document).ready(function(){
updateValues();
});
function updateValues(){
document.getElementById("click").innerHTML = waarde.amount;
}
// Binding to the button element using event delegation.
$(document).on('#button').click(function(){
waarde.amount = waarde.amount + 1;
updateValues();
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button id="button"><span id="click">0</span></button>
Also, unless you need the span element for something else, you could get rid of it and just use:
document.getElementById("button").innerHTML = waarde.amount;

You should put this code:
$('#click').click(function(){
waarde.amount = waarde.amount + 1;
updateValues();
});
Inside of $(document).ready(function(){}) function. $('#click') isn't in the DOM yet..

You have to write "Click" event in document.ready
var waarde = {
amount: 2
};
$(document).ready(function () {
$('#click').click(function () {
waarde.amount = waarde.amount + 1;
updateValues();
});
updateValues();
});
function updateValues() {
document.getElementById("click").innerHTML = waarde.amount;
}

The problem with your code is you are not assigning an event handler when javascript loads the js file. It should be called in the ready function.
var waarde = {
amount:2
};
$(document).ready(function(){
$('#click').click(function(){
waarde.amount = waarde.amount + 1;
updateValues();
});
});
function updateValues(){
document.getElementById("click").innerHTML = waarde.amount;
}

You should wrap it inside the ready method!
// Variables
var waarde = {
amount:2
};
$(document).ready(function() {
$('#click').click(function() {
waarde.amount = waarde.amount + 1;
updateValues();
});
});
function updateValues() {
document.getElementById("click").innerHTML = waarde.amount;
}
Here's a codepen link http://codepen.io/anon/pen/vKXQza

Two points:
You should put your jQuery event listener inside the document.ready.
There is no guarantee to work click event on span.
// Variables
var waarde = {
amount:2
};
$(document).ready(function(){
updateValues();
$('#click2').click(function(){
waarde.amount++;
updateValues();
});
});
function updateValues(){
document.getElementById("click2").innerHTML = waarde.amount;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.3/jquery.min.js"></script>
<button id="click2">0</button>

You can see your problem solution is here
You are missing button click event in $(document).ready(function(){}(;

Related

Use off() inside event jquery

$(function(){
$("#selector").on("someevent", function(){
let variable = some_value;
$("#anotherselector").click(function(){
//code involving variable here
if(condition){
$(this).off(reference to click event here);
}
});
});
});
Is there any way to turn off an event from inside its handler? I'm trying to do something like the code above, and I need it to turn off ONLY that specific click event (each click event is different).
To reference the click event, you can simply pass it 'click' and the selector for which to disable the event:
$(function(){
$("#selector").on("someevent", function(){
$("#anotherselector").click(function(){
if(condition){
$('#anotherselector').off('click');
}
});
});
});
let numHandler = 0;
$('#register').click(function () {
let counter = 0;
let num = ++numHandler;
$('#clickme').click(function handler () {
counter++;
console.log(`Handler ${num} clicked!`);
if (counter == 3) $('#clickme').off('click', handler);
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button id="clickme">Click me!</button>
<button id="register">Register new handler</button>
You can read more about the off function in the jQuery documentation.

Binding click function to dynamic divs

There will be number of such div created with unique div id,
when i click on click me it should show an alert for that productid,
i am doing it like
<div id="xyz{productid}">
Click Me
</div>
.....
<script type="text/javascript">
var uuid="{productid}"
</script>
<script src="file1.js">
code from file1.js
$(function () {
var d = "#xyz" + uuid;
$(d).click(function () {
alert("Hello" + uuid);
return false;
});
alert(d);
});
So code is also ok,but the basic problem with it is,
since i m doing it on category page where we have number of products,this function is getting bound to last product tile only,
I want it to be bound to that specific div only where it is been called
..............................
got a solution
sorry for late reply,was on weekend holiday, but i solved it by class type of architecture, where we create an object with each tile on page,and at page loading time we initialize all its class vars,so you can get seperate div id and when bind a function to it, can still use the data from its class variables, i m posting my code here so if any one want can use it,
UniqeDiv= new function()
{
var _this = this;
var _divParams = null;
var _uuid=null;
//constructor
new function(){
//$(document).bind("ready", initialize);
//$(window).bind("unload", dispose);
_uuid=pUUID;
initialize();
$('#abcd_'+_uuid).bind("click",showRatingsMe)
dispose();
}
function initialize(){
}
function showRatingsMe(){
alert(_uuid);
}
function dispose(){
_this = _divParams = null
}
}
//In a target file, im including this js file as below
<script type="text/javascript">
var pUUID="${uuid}";
</script>
<script type="text/javascript" src="http://localhost:8080/..../abc.js"></script>
You can use attribute selector with starts with wild card with jQuery on() to bind the click event for dynamically added elements.
$(document).on("click", "[id^=xyz]", function(){
//your code here
alert("Hello"+this.id);
return false;
});
I would add a class to each of your dynamic divs so that they are easier to query. In the following example, I'm using the class dynamic to tag the div's that are added dynamically and should have this click listener applied.
To attach the event, you can use delegated events with jQuery's on() function. Delegated events will fire for current and future elements in the DOM:
$(function() {
var d="#xyz"+uuid;
$(document).on('click', 'div.dynamic', function() {
alert("Hello"+uuid);
return false;
});
});
You can read more about event delegation here.
You can use
$("[id*='divid_']").click(function(){
});
but for this you need to make sure that all div IDs start with "divid_".

Firing code on load of page not working

I have this code tied to a button that when clicked, executes code to hide a table row:
<script>
$(function hideinstr() {
$('tr.parent td').on("click", "input.instr", function () {
var idOfParent = $(this).parents('tr').attr('id');
$('tr.child-' + idOfParent).toggle('slow');
});
});
</script>
I would like this code to execute by default when the page loads, and let the user click the button if the want to reveal the table row. How can I do this when the 'click' is built right into this code?
Your solution never executes the function hideinstr(). Also, consider using $(document).ready if your code is executed in the <head>. Add extra parentheses to execute the function, or remove the surrounding function (function hideinstr).
<script>
$(document).ready(function hideinstr() {
$('tr.parent td').on("click", "input.instr", function () {
var idOfParent = $(this).parents('tr').attr('id');
$('tr.child-' + idOfParent).toggle('slow');
});
}());
</script>
or
<script>
$(document).ready(
$('tr.parent td').on("click", "input.instr", function () {
var idOfParent = $(this).parents('tr').attr('id');
$('tr.child-' + idOfParent).toggle('slow');
});
);
</script>
And to execute the event script directly, use $('tr.parent td').click();.

Calling javascript function

I have the problem, that my javascript function isnĀ“t when I press the button:
<script type="text/javascript" language="javascript">
(function ($) {
$.fn.addToList = function (opts) {
var input = $(this);
opts.button.click(function () {
opts.list.append("<li>" + input.val() + "</li>");
});
};
}(window.jQuery));
$("#zutat").addToList({
button: $("#btn"),
list: $("#list")
});
</script>
and
<input type="text" id="zutat" name="zutat"></input>
<input type="button" id="btn" value="Click">
<ul id="list"></ul>
How do I call this javascript function? What is my problem?
If your script tag is before the #zutat" stuff, then you are trying to manipulate on #zutat when the DOM elements are not ready yet. In this case, When the jQuery selector is being executed, it will not match the elements, since they are not available yet.
To fix it, you should wrap your codes by the $(document).ready function or put it at the bottom of body tag.
<script type="text/javascript" language="javascript">
(function($) {
$.fn.addToList = function(opts) {
var input = $(this);
opts.button.click(function() {
opts.list.append("<li>" + input.val() + "</li>");
});
};
$(document).ready(function() { // <<<<<<< execute after document ready.
$("#zutat").addToList({
button: $("#btn"),
list: $("#list")
});
});
})(window.jQuery);
</script>
I think you should move the parenthesis this way
})(window.jQuery);
In Firefox (I am using Firebug to test this) if you do this
function(){ alert("GONG"); }();
It gives you an error but if you wrap the function with parenthesis
(function(){ alert("GONG"); })();
The anonymous function will be executed.
You should also wrap the call to the dom elements in a $(document).ready(); call as showed in qiao's answer.
if you want to add <li>s to a <ul> when you click a button, you are going about it in a very round about way. you don't need to extend jquery or object prototype to do that.
try the following
$("#button").click(function() {
var val = $("zutat").val();
$("#list").append($("<li>" + val + "</li>"));
});
Normally the click event is handled like this
$('#btn').on("click",function(){
// code
});
I don't know what your code does exactly but not that what you want.

jQuery - Dynamically Create Button and Attach Event Handler

I would like to dynamically add a button control to a table using jQuery and attach a click event handler. I tried the following, without success:
$("#myButton").click(function () {
var test = $('<button>Test</button>').click(function () {
alert('hi');
});
$("#nodeAttributeHeader").attr('style', 'display: table-row;');
$("#addNodeTable tr:last").before('<tr><td>' + test.html() + '</td></tr>');
});
The above code successfully adds a new row, but it doesn't handle adding the button correctly. How would I accomplish this using jQuery?
Calling .html() serializes the element to a string, so all event handlers and other associated data is lost. Here's how I'd do it:
$("#myButton").click(function ()
{
var test = $('<button/>',
{
text: 'Test',
click: function () { alert('hi'); }
});
var parent = $('<tr><td></td></tr>').children().append(test).end();
$("#addNodeTable tr:last").before(parent);
});
Or,
$("#myButton").click(function ()
{
var test = $('<button/>',
{
text: 'Test',
click: function () { alert('hi'); }
}).wrap('<tr><td></td></tr>').closest('tr');
$("#addNodeTable tr:last").before(test);
});
If you don't like passing a map of properties to $(), you can instead use
$('<button/>')
.text('Test')
.click(function () { alert('hi'); });
// or
$('<button>Test</button>').click(function () { alert('hi'); });
Quick fix.
Create whole structure tr > td > button; then find button inside; attach event on it; end filtering of chain and at the and insert it into dom.
$("#myButton").click(function () {
var test = $('<tr><td><button>Test</button></td></tr>').find('button').click(function () {
alert('hi');
}).end();
$("#nodeAttributeHeader").attr('style', 'display: table-row;');
$("#addNodeTable tr:last").before(test);
});
Your problem is that you're converting the button into an HTML snippet when you add it to the table, but that snippet is not the same object as the one that has the click handler on it.
$("#myButton").click(function () {
var test = $('<button>Test</button>').click(function () {
alert('hi');
});
$("#nodeAttributeHeader").css('display', 'table-row'); // NB: changed
var tr = $('<tr>').insertBefore('#addNodeTable tr:last');
var td = $('<td>').append(test).appendTo(tr);
});
You can either use onclick inside the button to ensure the event is preserved, or else attach the button click handler by finding the button after it is inserted. The test.html() call will not serialize the event.
You were just adding the html string. Not the element you created with a click event listener.
Try This:
<html>
<head>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js"></script>
</head>
<body>
<table id="addNodeTable">
<tr>
<td>
Row 1
</td>
</tr>
<tr >
<td>
Row 2
</td>
</tr>
</table>
</body>
</html>
<script type="text/javascript">
$(document).ready(function() {
var test = $('<button>Test</button>').click(function () {
alert('hi');
});
$("#addNodeTable tr:last").append('<tr><td></td></tr>').find("td:last").append(test);
});
</script>

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