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.
Related
i have this function in jQuery:
$(document).ready(function(){ function MyFunction() {alert('Hello!');} });
(For example only)
but, i'm want call this function with regular Javscript this way:
if(x == y){MyFunction();}
(For example only)
and i'ts not work.
However, When i try it:
function MyFunction(){alert('Hello!');} if(x == y){MyFunction();}
(Without jQuery function)
it's work.
Why?
if you put the function outside of the .ready() and call it in the ready function it will work, if you put it in the ready() and call it outside of ready it will give you an error you may have a function declared outside of ready state using jQuery code and call it inside.
function MyFunction(){
alert("hello!!");
}
//on ready
$(document).ready(function(){
if(x==y)
MyFunction();
});
I understand your issue like this {but not really clear what you are looking for imho}
Define function:
function MyFunction(){alert('Hello!');}
Call it on document ready:
$(MyFunction);
Now whenever you want, you could use:
if(x == y){MyFunction();}
this line:
if(x == y){MyFunction();}
should also be in the document.ready statement.
if you call it outside it will run before the function was actually defined and thus it will fail.
Lesonchi has it right. The issue is 'scope'.
The $(document).ready(...) call takes a function which is it's own scope (Javascript only has function scoping). So, anything defined inside the function you are passing to that call is ONLY available inside that function.
Based on your question, I assume you wanted to be able to call that MyFunction method elsewhere in the code and not just in the $(document).ready() - so, defining it outside the that call would give it 'global' scope, and hence could be used elsewhere in your code:
function MyFunction(){ /* do something */ }
$(document).ready(function(){
MyFunction(); // call it in this scope
});
// call it in 'global' scope
if (x == y) {
MyFunction();
}
See Also: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions_and_function_scope
I am studying a JavaScript file and saw in it that some of the methods are wrapped inside a jQuery function. Can Anyone help me how to invoke the following method? And may I know what is the advantage or why the method is wrapped in a function? Below is my sample JavaScript code.
JQuery/JavaScript
$(document).ready(function () {
//How to invoke "testMethod" method?
$(function () {
function testMethod() {
alert("this is a test method");
}
});
});
As you've declared it, testMethod() is a local function and is only available inside the function scope in which it is declared. If you want it to be callable outside that scope, you will need to define it differently so that it is available at a broader scope.
One way of doing that is to make it a global function:
$(document).ready(function () {
//How to invoke "testMethod" method?
$(function () {
window.testMethod = function() {
alert("this is a test method");
}
});
});
testMethod(); // available globally now
It could also be attached to a global namespace or it could be defined at a higher scope where it would also solve your problem. Without specifics on your situation, we can't suggest which one would be best, but the main thing you need to do is to change how the function is declared so it is available in the scope in which you want to call it from.
P.S. Why do you have one document ready function nested inside another? That provides no extra functionality and adds unnecessary complexity. Also, there's really no reason to define testMethod() inside your document ready handlers if you want it available globally.
Before anything else:
$(document).ready(function(){...});
//is the same as
$(function(){...}}
As for your question, here's are potential ways to do it:
If that function is some utility function that everyone uses, then have it available to all in some namespace, like in this one called Utility:
//Utility module
(function(ns){
//declaring someFunction in the Utility namespace
//it's available outside the ready handler, but lives in a namespace
ns.someFunction = function(){...}
}(this.Utility = this.Utility || {}));
$(function(){
//here in the ready handler, we use it
Utility.someFunction();
});
If they all live in the ready handler, and want it to be used by all code in the handler, have it declared in the outermost in the handler so all nested scopes see it.
$(function(){
//declare it in the outermost in the ready handler
function someFunction(){...}
//so we can use it even in the deepest nesting
function nestedSomeFunction(){
someFunction();
}
someElement.on('click',function(){
$.get('example.com',function(){
someFunction();
});
});
nestedSomeFunction();
someFunction();
});
Your call needs to be within the $(function.
It's all about scope and you need to break the testMethod out of the $(function.
Can you perhaps further explain your requirement so that we can maybe help a little better?
Into ready event:
$(document).ready(function () {
//How to invoke "testMethod" method?
var testMethod = function () {
alert("this is a test method");
}
// V0.1
testMethod();
// V0.2
$('#some_id').click(testMethod);
});
In other part:
myObj = {testMethod: null};
$(document).ready(function () {
//How to invoke "testMethod" method?
myObj.testMethod = function () {
alert("this is a test method");
}
});
// Something else
if( myObj.testMethod ) myObj.testMethod();
I am using Phonegap and JQueryMobile to create a web application. I'm new to javascript and am having an issue.
My issue is with calling a function I have in a file named "testscript.js", the function is called testFunc. The testscript.js containts only this:
function testFunc() {
console.log("Yes I work");
}
Within my html page I have the following code:
<script>
$('#pageListener').live('pageinit', function(event)
{
testFunc();
});
</script>
The test function is found within my "testscript.js" which I am including with this line within the head tags:
<script src="testscript.js"></script>
The error I get is a "testFunc is not defined".
I am assuming its some type of scope issue as I'm able to call other jquery functions such as:
alert("I work");
and I am able to call my functions by sticking them within script tags in the html elsewhere.
I've tried all sorts of ways of calling my function with no success, any help is appreciated!
You must include the testscript.js before the other jquery code in your html. Like this:
<script src="testscript.js"></script>
<script>
$('#pageListener').live('pageinit', function(event)
{
testFunc();
});
</script>
As long as testscript.js has been loaded by the time PhoneGap fires the pageinit event, and provided the testFunc function is a global, there's no reason that shouldn't work.
You haven't shown us your testFunc, but my guess is that it's not a global, but rather you have it inside something like, for instance:
$('#pageListener').live('pageinit', function(event)
{
function testFunc()
{
// Do something here
}
});
or just a scoping function
(function()
{
function testFunc()
{
// Do something here
}
})();
Either way, since it's declared within another function, it's local to that function, not global. To call it from another script file, you'll need to be able to get at it from the global namespace (sadly). The best way to do that is not to make it a global, but to create just one global that you'll put all of your shared stuff on, like this:
(function()
{
if (!window.MyStuff)
{
window.MyStuff = {};
}
window.MyStuff.testFunc = testFunc;
function testFunc()
{
// Do something here
}
})();
...which you call like this:
$('#pageListener').live('pageinit', function(event)
{
MyStuff.testFunc(); // Or: window.MyStuff.testFunc();
});
*Is there a way to call a function defined inside another function in javaSCRIPT? For example:
window.onload() = function() {
function my_function(){
print("Blah");
};
};
function function_two(){
my_function();
};
Is there a way to do something like the above (calling my_function in function_two even though it's defined inside the window.onload() function)? In my actual code, which also uses the raphael.js library, I'm trying to write a button in HTML, which using the onClick function, calls a function(like function_two) that runs the function defined in window.onload() (like my_function). However the console says that the my_function is undefined.
The scope of the function is the core issue here, as Zeychin and Trevor have said. I thought I'd offer another way of handling it. Basically, you can set your function to a variable that's in a higher scope (that is, accessible to both the onload and function_two functions), while defining it inside the onload function as you originally have:
var myFunction; //This is the placeholder which sets the scope
window.onload() = function() {
myFunction = function() { //Assign the function to the myFunction variable
print('blah');
}
}
function function_two() {
myFunction();
}
This might be handy if you only know the information you need for myFunction once you're in the onload event.
You can not do what you are asking to do.
The function my_function()'s scope is only within the anonymous function, function(). It falls out of scope when the method is not executing, so this is not possible.
Trevor's answer is the way to do this.
window.onload = function() {
my_function()
};
function my_function(){
alert("Blah");
};
function function_two(){
my_function();
};
I am writing an AngularJS web app and have a function outside of any scope that needs to call a function inside of a scope. I call the function and follow the instructions given in this answer.
function returnDest(callback) {
$(document).ready(angular.element(document.getElementById('body')).scope().getTask(function() {
if(callback) {
callback(locationInfo);
}
}));
}
It works often, but sometimes the function does not successfully run. A debugger gives me:
Uncaught TypeError: Cannot read property 'getTask' of undefined
I do not know why the function is being called on undefined when $(document).ready should have the function fire only after the DOM has been loaded. The same error pops up if I use $(window).load(). What can I do to ensure this function runs successfully?
For reference, here is the line in the HTML file where the 'body' element is defined
<body style="background-color:#e6e8f3" ng-app="app" ng-controller="controller" id="body">
$(document).ready should be outside of your function:
$(document).ready(function returnDest(callback) {
angular.element(document.getElementById('body')).scope().getTask(function() {
if(callback) {
callback(locationInfo);
}
})});
You're using .ready incorrectly. The moment you call returnDest, which is happening before the DOM is ready, it tries to get an element with the ID of body. Since it's not loaded, body can't be accessed. Instead, omit the body ID and use it like this:
function returnDest(callback) {
$(document).ready(function() {
angular.element(document.body).scope().getTask(function() {
if (callback) {
callback(locationInfo); // Not sure where locationInfo is coming from
}
});
});
}
angular.element returns a jQuery object.
ready() expects the argument you pass it to be a function that it will call when the document is ready.
It sounds like you need to wrap everything you are trying to pass to ready in function () { ... }.