I have a code like this:
function myfunc () {
alert('executed');
}
$('.classname').on('click' function () {
myfunc();
});
I want to run myfunc once. I mean I don't want to execute it every time when user clicks on .classname element. I guess I need to warp function-calling into a condition. Something like this:
if ( /* that function never executed so far */ ) {
myfunc();
}
How can I do that?
The simplest way with jQuery is to use .one
function myfunc() {
alert('executed');
}
$('.classname').one('click', function() {
myfunc();
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button class="classname">click here!</button>
You should remove the event listener in the function you're calling:
function myfunc () {
alert('executed');
$('.classname').off('click', myfunc);
}
$('.classname').on('click', myfunc);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class='classname'>Click Me</div>
Don't set a global variable like the other posts describe - there's no need for that and then you're still doing an unnecessary function call. This ensures the function is never called again and the event isn't being listed for.
$( document ).ready(function() {
var hasBeenExecuted = false;
function myfunc () {
alert('executed');
hasBeenExecuted = true;
}
$('.classname').on('click' function () {
if(!hasBeenExecuted){
myfunc();
}
});
});
var functionWasRun = false;
function myfunc () {
functionWasRun = true;
alert('executed');
}
$(document).ready(function() {
$('.classname').on('click', function () {
if (!functionWasRun) {
myfunc();
}
});
});
I would suggest, as an alternative to a global variable, assigning a property to the function.
function myfunc () {
alert('executed');
myfunc.executed = true;
}
$('.classname').on('click', function () {
if(!myfunc.executed) {
myfunc();
}
});
This has the advantage of working the same way while not polluting the global scope unnecessarily. However, if skyline3000's answer works for you, you should use that instead as it's cleaner and more sensible overall.
Related
I have only ONE function inside script tag in my HTML and will be used for event click. Is it possible to make this function not in global scope?
<script type="text/javascript">
function myFunction(sender, args) {
}
</script>
You can use IIFE, and register event handlers in that only, something like this
(function () {
function myFunction(sender, args) {}
$(".your_button").on("click", function () {
myFunction();
});
})();
Similar to IIFE, as you've tagged this [jquery], you can wrap it all in doc.ready:
<script type="text/javascript">
$(function() {
function myFunction(sender, args) {
}
// example use:
$(".button").click(function() { myFunction(this); });
});
</script>
myFunction will only be available to code within the { } of the doc.ready.
Note: if you're using onclick= in your HTML, it won't be able to find functions that are not global.
Maybe if you use let as the type of class, combined with a lambda(arrow) expression?
let myFunction = (sender, args) => {
}
Check this out: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/let
I wand to call a jquery click function using JavaScript
<input type='button' class="button" value='+Add' id='addImage'>
when i click this button the following function will run
$("#addImage").click(function () {
//my code.....
}
but i need to call this function using another JavaScript function like fn_name()
You can use trigger and the name of the event, like so (the example below uses a self-executing function for simplicity):
$("#addImage").click(function() {
alert('Clicked')
});
(function(){
$("#addImage").trigger('click')
})();
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type='button' class="button" value='+Add' id='addImage'>
use trigger
$("#addImage").trigger("click")
you have this ugly way too, but not recommended:
https://jsfiddle.net/96oxhwsf/
function fn_name() {
$("#addImage").click(function() {
alert('test')
});
}
fn_name()
beatiful way:
function fn_name(elID) {
let btn = document.getElementById(elID);
btn.addEventListener('click', function() {
alert('Test');
}, false)
}
// still need call the function
fn_name('addImage');
even better:
var addImg = () => {
let btnAdd = document.getElementById('addImage')
btnAdd.addEventListener('click', () => {
alert('test')
}, false)
}
declare function
bind click event
call function
//declare
function test(){
//my code.....
}
function callTest(){
// call function
test();
}
function callAClick(){
//trigger
$("#addImage").trigger('click')
}
// bind click
$("#addImage").click(test);
$(function() {
function say() {
alert("hello");
}
});
Is there a way to call say() from the console ?
Well, it not make sense but...
$(function() {
function say() {
alert("hello");
}
window.say = say;
});
I want to call a function with a namespace based on its name.
Perhaps some background: What I want is, dynamically bind pages via $.mobile.loadPage(inStrUrl, { showLoadMsg: false }); and then, based on the current page, invoke a function within a loaded page. For example: each page has a showFilter function, the Event is attached to a main.html - page which should call the matching function in the current page.
I also tried some solutions, with jquery too, but nothing works for me.
This is my function code:
function namespace() { }
namespace.showFilter = function () {
alert("Test");
}
And want to "invoke" or "call" it via its name.
This is what i tried at least.
$(document).ready(function() {
var fn = window["namespace.showFilter"];
fn();
});
I get error TypeError: fn is not a function
Here is a fiddle http://jsfiddle.net/xBCes/1/
You can call it in the following way:
$(document).ready(function() {
window["namespace"]["showFilter"]();
});
or
$(document).ready(function() {
window["namespace"].showFilter();
});
or
$(document).ready(function() {
window.namespace.showFilter();
});
I found that I had to manually set it to window.
window.namespace = function() { }
window.namespace.showFilter = function () {
alert("Test");
};
$(document).ready(function() {
var fn = window["namespace"]["showFilter"];
fn();
});
http://jsfiddle.net/xBCes/4/
Like this:
$(function() {
window.namespace.showFilter();
});
P.S. I shortened the $(document).ready(...)
function namespace() {}
namespace.showFilter = function () {
alert("Test");
}
$(document).ready(function() {
var fn = namespace.showFilter();
fn();
});
http://jsfiddle.net/xBCes/3/
How do you call function lol() from outside the $(document).ready() for example:
$(document).ready(function(){
function lol(){
alert('lol');
}
});
Tried:
$(document).ready(function(){
lol();
});
And simply:
lol();
It must be called within an outside javascript like:
function dostuff(url){
lol(); // call the function lol() thats inside the $(document).ready()
}
Define the function on the window object to make it global from within another function scope:
$(document).ready(function(){
window.lol = function(){
alert('lol');
}
});
Outside of the block that function is defined in, it is out of scope and you won't be able to call it.
There is however no need to define the function there. Why not simply:
function lol() {
alert("lol");
}
$(function() {
lol(); //works
});
function dostuff(url) {
lol(); // also works
}
You could define the function globally like this:
$(function() {
lol = function() {
alert("lol");
};
});
$(function() {
lol();
});
That works but not recommended. If you're going to define something in the global namespace you should use the first method.
You don't need and of that - If a function is defined outside of Document.Ready - but you want to call in it Document.Ready - this is how you do it - these answer led me in the wrong direction, don't type function again, just the name of the function.
$(document).ready(function () {
fnGetContent();
});
Where fnGetContent is here:
function fnGetContent(keyword) {
var NewKeyword = keyword.tag;
var type = keyword.type;
$.ajax({ .......
Short version: you can't, it's out of scope. Define your method like this so it's available:
function lol(){
alert('lol');
}
$(function(){
lol();
});
What about the case where Prototype is installed with jQuery and we have noconflicts set for jQuery?
jQuery(document).ready(function($){
window.lol = function(){
$.('#funnyThat').html("LOL");
}
});
Now we can call lol from anywhere but did we introduce a conflict with Prototype?