Develop Reference

Passing function as a parameter into another function error

I'm getting a 'navigateTo is not defined' error in my JS with the following. I'm pretty sure I have passed the function navigateTo as a parameter to the openCart() function so unsure where I'm going wrong?
$(function() {
var form = $('form#checkout-form'),
$sections = $('[data-step]');
function navigateTo(index) {
$sections.removeClass('is--active').eq(index).addClass('is--active');
}
});
$(document).on('click', 'nav.main a.cart', function(e) {
openCart();
});
function openCart(navigateTo) {
navigateTo(1);
disableScroll = false;
}

your function openCart should go to inside the dom ready function otherwise it doesn't call the function and another thing you need to pass the callback as parameter navigateTo into the opencart function like openCart(navigateTo);
$(function() {
var form = $('form#checkout-form'),
$sections = $('[data-step]');
function navigateTo(index) {
alert(2);
$sections.removeClass('is--active').eq(index).addClass('is--active');
}
$(document).on('click', 'div', function(e) {
openCart(navigateTo);
});
function openCart(navigateTo) {
navigateTo(1);
disableScroll = false;
}
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>hahah</div>

It's a scope issue. Wrap your whole script in a closure and you'll be fine;
(function($) {
// your script here
})(jQuery)
But get rid of the $(function() { } around the first block as well.

How do I execute a function once per page refreshing?

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.

Create Jquery Plugin

I creating jquery Plugin with simple alert option. I did this way see below is my code.But it doesn't work.
Below code is the seperate js file.
(function($) {
$.fn.gettingmessage = function() {
var element = this;
$(element).load(function() {
alertingcontent();
function preventnextpage() {
return false;
}
function alertingcontent() {
alert("nicely done");
});
};
})(jQuery);
I called this function as
this way
$(function(){
$("body").gettingmessage();
});
I am not sure how can i fix this any suggestion would be great.
JSFIDDLE
Thanks

First, you're missing a closing bracket.
Second, the load() function doesn't do what you're searching for, use ready() instead of.
Updated code :
(function($) {
$.fn.gettingmessage = function() {
var element = this;
$(element).ready(function() {
alertingcontent();
function preventnextpage() {
return false;
}
function alertingcontent() {
alert("nicely done");
}
});
};
})(jQuery);
$(function(){
$("body").gettingmessage();
});
Updated jsFiddle

Function becomes undefined after first trigger

I have a block of code like so:
function doSomething() {
someVar.on("event_name", function() {
$('#elementId').click(function(e) {
doSomething();
});
});
}
// and on document ready
$(function () {
$('#anotherElemId').click(function () {
doSomething();
});
});
The problem that I'm encountering is that when I call doSomething() from anotherElemId click event(that is binded on document ready) it works as expected, but calling it recursively from elementId click doesn't work.
Any ideas? Thinking is something trivial that I'm missing.

Is someVar an actual jQuery reference to a dom element? (e.g. $('#someitem'))
The second problem is you cant put a .click event inside a function that you would like to instantiate later on. If you are trying to only allow #elementId to have a click event AFTER some previous event, try testing if a tester variable is true:
var activated = false;
$(function () {
$('#anotherElemId').click(function () {
activated = true;
});
$('#secondElemId').on("event_name", function() {
if (activated) {
// code that happens only after #anotherElemId was clicked.
}
});
});

How to call a function within $(document).ready from outside it

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?