$.getJSON callback does work - javascript

I am experimenting with jQuery and I try to use the $.getJSON function
I red that "A reference to a function declaration could equally be provided as the callback". So instead of an anonymous function, I use a reference to a function declaration like this
$('#letter-b').click(function(e) {
e.preventDefault();
$.getJSON('b.js', outside(data));
});
function outside (data){alert(data);}
I get no alert. Instead I get Uncaught ReferenceError: data is not defined
What am I missing? Is it my syntax?
Thanks in advance

You must give the reference to your function. Like this :
$('#letter-b').click(function(e) {
e.preventDefault();
$.getJSON('b.js', outside);
});
If you write outside(data), you just execute your function.

Related

call jquery document.ready function inside another jquery or javascript function

I am facing one problem
I am trying to call document.ready() function inside another JavaScript function but when I am calling it, it says "function is not defined
Here is my code :
this is first function that is document.ready() function
$(document).ready(function ExpandMessageBox() {// this is my document.ready function. I have given the name of it as "ExpandMessageBox"}
this is another regular JavaScript function in which I am trying to call above function
function ShowMessageBox() {
ExpandMessageBox();}
But this is giving me an error as :
"Uncaught ReferenceError: ExpandMessageBox is not defined"
Where I am doing wrong...
Please Help
Tons of thanks in advance
You need to define ExpandMessageBox function in the common scope. Something like this:
function ExpandMessageBox() {
//your staff
}
function ShowMessageBox() {
ExpandMessageBox();
}
$(document).ready(ExpandMessageBox);

Overload a JS plugin function with a function from inside

I want to call a function which is in my plugin.
I overloaded a function but I want to call another function from it.
$("mySelector").Myplugin({
My_function : function (){
*do some stuf*
function_from_the_plugin();
}
});
An error appears that says "Unknown function". I think it do not search the function in the plugin but outside.
Do you know how I can do?
I already try with "this", a variable corresponding to my plugin object.
If you have an idea please share it with me.
Thank you for reading this post.
Add this.function_from_the_plugin(); in code where Myplugin() is initialized.

How to call javascript from Jquery function?

I want to call jquery function in side of java script. My code is:
<script type="text/javascript">
function calljs(){
getUserMail(usermMail);
}
$(function() {
function getUserMail(usermMail) {
***some code*****
}
});
</script>
I got error from browser console:
ReferenceError: getUserMail is not defined.
How to solve this problem?
As far as i understand, the method is not defined when the method is being called. So define it before it is getting called
<script type="text/javascript">
function getUserMail(usermMail) {
***some code*****
}
function calljs(){
getUserMail(usermMail);
}
$(function() {
//
});
</script>
hope it helps
If it is really compulsory to put the function with in the jquery's ready callback (which I don't think is compulsory) use the following way
<script type="text/javascript">
var getUserMail = null;
function calljs(){
if ( null !== getUserMail ) {
getUserMail(usermMail);
}
}
$(function() {
getUserMail = function (usermMail) {
***some code*****
}
});
</script>
You can simply do ,
$(document).ready(function(event) {
getUserMail(usermMail);
});
and define it like ,
function getUserMail(usermMail){
. . .
}
or using jquery ,
$(document).on('click', ".selector", function);
trigger a function on an event
getUserMail is not defined in a scope that is accessible to calljs. This is why you get the ReferenceError; in the context in which you tried to invoke getUserMail there was no function with that name available.
// At this point nothing is defined
function calljs(){
getUserMail(usermMail);
}
// now calljs is defined as a global and can be invoked from anywhere
$(function() { // this line is calling a function named $ (an alias for jQuery)
// and passing it an anonymous function as a parameter.
function getUserMail(usermMail) { // This function is being defined inside
// the scope of the anonymous function,
// it can be used anywhere inside the
// anonymous function but not outside it.
// ***some code*****
}
});
// we are now outside the scope of the anonymous function,
// getUserMail is no longer in our scope and can't be called from here.
The easiest and likely best solution for most situations would be to make sure that any functions that call each other are in the same scope.
From what I can tell you don't really need calljs, you were just trying to use it to poke a hole into the scope of the anonymous function where getUserMail is defined.
Instead you should probably get rid of calljs and move any code that is calling getUserMail inside the ready callback. If getUserMail needs to wait for the ready callback to be fired before you call it, any code that invokes it also should be inside the ready callback too. (Things like event handlers that call it should already be inside the ready callback anyway.)
If there is a reason that you can't move it into the ready callback, such as something in another .js file needs to be able to call it etc, your application might be too complicated to be realistically maintained as jQuery soup. It might be worth the effort to port it to a framework such as Ember or Angular.
Also so you know, there is no need to use the type attribute on your script tags. JavaScript is the only language that has wide support in the browser and all browsers default to using JavaScript for script tags.

Calling function and passing parameters to iframe from parent

I am trying to call a function and pass a parameter to a iframe javascript function from the parent.
I have
document.getElementById('iframeD').contentWindow.detect(name);
in my parent javascript
in my iframe..if I have
function detect(name){
console.log(name);
}
it will gives me
Uncaught SyntaxError: Unexpected token name
However, if I only call the function without parameter
document.getElementById('iframeD').contentWindow.detect();
and make my iframe function
function detect(){
console.log('I want to pass the pare');
}
it will works.
What can I do to solve this? Thanks for the help!!!
name is a reserved keyword in JS, so you can't use it for variables/arguments. Just use a different name both for your argument and when you call detect. Your code looks otherwise fine.

Passing argument to function. What's wrong?

In this jsFiddle
am I trying to pass an argument to a function, but it doesn't receive the argument or it isn't executed.
Details
JQuery
$(document).ready(function() {
function addRemove(u) {
alert(u);
}
});
Any ideas what's wrong and how to fix it?
Your function only exists within the scope of the ready event handler, you need to move function addRemove outside of the ready function.
http://jsfiddle.net/EcCTx/2/
Your code was wrapped in an onload event by jsfiddle (drop-down menu on the left). So if you add a function it won't be global, but your onclick event calls a global function by the name addRemove.
You need to define your function outside of the $(document).ready().
I haven't tested it, but my guess is this: things inside of a function can't be accessed from outside of a function. For example,
$(document).ready(function() {
function addRemove(u) {
alert(u);
}
});
console.log(addRemove); // reference error or something similar
You should define addRemove function outside of $(document).ready.
the addRemove function must be outside of $(document).ready(function(){...});
In case Davin doesn't come back, here's the answer: jsFiddle defaults to wrapping your JS in the 'onLoad' method - and we can't allow that.
http://jsfiddle.net/nqbWe/
You had no defined function called addRemove in the Fiddle!
I've added this, and removed the inline javascript calls.
See this for better way of doing it:
http://jsfiddle.net/EcCTx/6/
There is nothing specifically calling that function. In the document ready part you have the function set up, but the anchor will not call that function by itself. In this instance it will only be called when someone clicks on that link.
You could give the link a class and data attribute and use those with jQuery to have something happen on page load.

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