I have the problem, that my javascript function isn´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.
Related
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(){}(;
I have a script that produces a number of buttons with a class and I want it to alert the data attribute on click but it's not working.
Here is the output of HTML
<button class="request box-button" data-value="18492500814">Request</button>
jQuery code
$(document).ready(function(){
$('.request').each(function () {
var photoID = $(this);
photoID.click(function () {
alert($(this).data('value'));
});
});
});
Since your elements don't exist when the page loads, the event won't be bound to them. Fix that by using event delegation:
$(document).ready(function(){
$(document).on('click','.request', function () {
alert($(this).data('value'));
});
});
JS Fiddle demo with dynamically generated elements
Note: Here, I used $(document).on() because I don't have your page's structure. But if you insert the buttons in a container that already exists in your HTML, use this instead: $('#myContainer').on(). It won't be noticeable, but it is best for performance.
Why not just have the listener on request, instead of inside of the loop. Also use the attr to get the data-value
$(document).ready(function(){
$('.request').click(function () {
alert($(this).attr('data-value'));
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"></script>
<button class="request box-button" data-value="18492500814">Request</button>
Try with attr method.
$(document).ready(function(){
$('.request').each(function () {
var photoID = $(this);
photoID.click(function () {
alert($(this).attr('data-value'));
});
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<button class="request box-button" data-value="18492500814">Request</button>
I'm attempting to use html onload event to trigger javascript, but is not working. The original code was:
html:
<div id='map' onload="generateMap.createMap();"></div>
JS:
var generateMap = function(){
return{
createMap: function(){
console.log(this.attr('id'));
element = this.attr('id');
navigator.geolocation.getCurrentPosition(initialize);
}
};
}
In an attempt to test, I changed the html to:
<div id='map' onload="alert('test');"></div>
Can anyone tell me why nothing is working?
First, the onload attribute is not valid for a div tag. You most likely intended to place the onload in the body tag.
Unfortunately, that's not the only problem.
In your onLoad you are referencing generateMap as if it is an object with method createMap. However, this is not the case. You have assigned generateMap to an anonymous function.
To get your code working, generateMap needs to be an object with method createMap.
You just need to set it as an object in the first place:
var generateMap = {
createMap: function(){
console.log(this.attr('id'));
element = this.attr('id');
navigator.geolocation.getCurrentPosition(initialize);
}
};
Or if you need to retain the anonymous function for whatever reason, you can use an immediately executing function:
var generateMap = (function(){
return {
createMap: function(){
console.log(this.attr('id'));
element = this.attr('id');
navigator.geolocation.getCurrentPosition(initialize);
}
})();
There is no onload event for a div. You can use the script tag just after the div tag to emulate onload behavior.
Use this
<head>
<meta charset="utf-8">
<script type="text/javascript">
var generateMap = {
createMap: function(element) {
navigator.geolocation.getCurrentPosition(initialize);
}
};
</script>
</head>
<body>
<div id='map'></div>
<script type="text/javascript">
generateMap.createMap('map');
</script>
</body>
Assuming Chrome.. div tags do not have an onload event. Check the following two jsfiddles:
Does not work:
http://jsfiddle.net/o81e4dkr/
Works:
http://jsfiddle.net/p3osqrdn/
I do not know of a way to have an event fired when a div is loaded, unless it is being loaded in via jQuery.load(), in which case you can use the callbacks.
If you're using jQuery then I like the following function which adds onload capability to all tags:
$(document).ready (function () {
jQuery.each ($("[onload]"), function (index, item) {
$(item).prop ("onload").call (item);
return false;
});
});
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();.
I have an <input> field in my web page, and I want to add a particular method on it, let say fooBar().
Here is what I do:
<input id="xxx" .../>
<script type="text/javascript">
$("xxx").fooBar = function() { ... };
</script>
This works well. However, for some reasons I will not detail here (in fact the HTML is generated by JSF components), the <script> will be declared before the <input> tag.
So in others words, I will have that in my HTML:
<script type="text/javascript">
$("xxx").fooBar = function() { ... };
</script>
<input id="xxx" .../>
So of course this code will not work correctly, as the script will try to get ($("xxx")) and modify an element that does not exist yet.
If I want to stick on the exact order of these two tags, what is the best way to accomplish what I want?
Edit
In my case, $ refers to prototype, but I am also using jQuery in my application. And I must be compatible with IE6 :o(
You need to run your script after the document is loaded. With jQuery you'd do that with:
$(document).ready(function () {
//do stuff here
});
I can't tell which library you're using here, but they all have an equivalent of jQuery's document ready.
Here's the prototype equivalent:
document.observe("dom:loaded", function() {
// do stuff
});
Try putting your code in load event:
$(window).load(function(){
$("#xxx").fooBar = function() { ... };
});
If the code has to be directly before the input, you can check if it has loaded after a certain period of time.
<script type="text/javascript">
//Sets up a function to execute once the input is loaded
f = function ()
{
//Checks if 'xxx' exists (may vary between frameworks)
if ($("xxx") !== undefined)
{
$("xxx").fooBar = function() { ... };
//Escapes the timer function, preventing it from running again
return true;
}
//If still not loaded check again in half a second (0.5s or 500ms)
setTimeout(f,500);
return false;
}
f();//Initialize the timer function
</script>
<input id="xxx" .../>
Instead of adding a method to the dom node, why not make it a separate function, so instead of
$("xxx").fooBar = function() {
doStuff(this);
};
you would have something like
function xxx_fooBar () {
var me = document.getElementById('xxx');
doStuff(me);
};
Another suggestion: If you can add attributes to the <input> element, you could do something like this...
<script>
function xxx_init (e) {
e.fooBar = function () {
doStuff(this);
};
}
</script>
<input onload="xxx_init(this)" id="xxx" .../>
Or you could do as others suggest and attach the scripts to the window.onload event.