I'm sorry if this question is too trivial. Since I'm a beginner, it is difficult for me to understand some explanation. What is the meaning of the following statement?
"To keep the browser from executing a script when the page loads, you can put your script into a function."
I think the author meant that if you do this:
<script>
alert('Hello');
</script>
The script will run when the page load. But you can wrap that in a function:
<script>
function hello() {
alert('Hello');
}
</script>
So instead of popping "Hello" the script will register the function that can be called later from another place/script to display "Hello" on the screen.
The script wont be executed until the function is called, otherwise the script will automatically execute when it the page loads. :)
Consider the following script
alert("hey");
Browser pauses html rendering and tries to download the javascript and execute it.
This code simply involves an alert message,there could be dom search ,so to avoid this you consider doing as follows
Greet();
function Greet(){
alert("hello");
}
In this, until you call greet method ,script wont execute .So html rendering does not stop.
Consider if your code has dom search, even adding functions would not help
Here, you should consider using window.onload or $(document).ready
window.onload=function(){
var div= document.getElementsByTagName('div');
div[0].innerHTML="Hello";
}
<div>
</div>
Related
is there a better way to replace this kind of js function by simply collapse/toggle a div and show/hide its content?
$(function() {
$('#destselect').change(function(){
$('.dest').hide();
$('#' + $(this).val()).show();
});
});
The reason this is happening is because your js file is called on the head of your page.
Because of this, when you document.getElementsByClassName('collapsible');, colls result in an empty array, as your elements in body are not yet created.
You could either create a separate js file and add it at the end of your body (in that way you make sure your colls are created when your javascript is executed), or just wrap your code on a DOMContentLoaded event listener that will trigger your code once the document has completely loaded.
My guess would be that you are loading your script before browser finishes loading dom conetent and so when it runs the elements it is trying to add event listeners to, don't yet exist.
Try wrapping all you javascript in that file in this:
document.addEventListener("DOMContentLoaded", function(event) {
// all your code goes here
});
The above makes sure that your script is run after loading all elements on the page.
You could add a script tag to the header of your HTML file, this will import the JS file into your current page as follows
<script src="File1.js" type="text/javascript"></script>
Then call the function either in onclick in a button or in another script (usually at the bottom) of your page. Something like this:
<body>
...
<script type="text/javascript">
functionFromFile1()
</script>
</body>
Seems like your script is not executing properly due to a missing variable.
In this script https://www.argentina-fly.com/js/scripts.js
Naves variable in function UpdateDetailsDestination() is not defined.
I think you should resolve this first and then check your further code is working on not.
Please take a look into Console when running page. You'll see all JavaScript related errors there.
In a website, there is a js file like:
<script src="/somescript.js"></script>
somescript.js includes:
<script>
function hi(){alert('Hi');}
function sup(){alert('Sup!');}
hi();
sup();
</script>
When I enter the index page, my browser automatically runs the function hi()
How can I prevent browser to run the function hi() or change it into something i want.
Website is not mine.
Thanks
This will call the functions, the need to be removed from the script if you don't want them run.
hi();
sup();
You can also specify functions as exports and import them as show in this answer.
I have a javascript function, "loadFramework()" that modifies an HTML document. Specifically, it repeatedly runs the jQuery command $("#element-id").load("document/name.html"), which injects the HTML in document/name.html directly into the element with #element-id.
Originally, I ran loadFramework() in a script in the document's header. However, since then I've realized that the function fails if the page has not loaded yet, since it relies on there being an element with #element-id.
I can't figure out how to get this function to run when it should. A simple solution seemed to be setting it to be the document.onload function:
document.onload = function() {
loadFramework();
}
But in this case it never seems to run at all.
How do I make sure a header function runs only after the document has loaded?
You should use window.onload if you are looking for a vanilla JS option
window.onload = function() {
loadFramework();
}
Jquery load takes additional argument "complete". You can run the javascript there. So the code would be:
$("#element-id").load("document/name.html", function(){
loadFramework();
});
You can also use $(document).ready(function{loadFramework()}) inside the html you are loading.
If you want to execute the loadFramework() method after "document/name.html" is loaded, I would suggest the following code.
$(function() {
$("#element-id").load("document/name.html", function(){
loadFramework();
});
});
I have a div which looks like
<div>
//Useful content
<script type="text/javascript">
function(){
//some useful code
}
</script>
</div>
Now am getting this div as a response of an Ajax call and appending that into body. Now when the gets appended to body, the function inside the script tag should get executed. But not.. what is the problem here?
You should be using document.createElement("script"); if you need to insert some script dynamically. This is recommended approach.
Anyway, following code is working just fine for me:
var str = "<script>alert('Hi!');</scr"+"ipt>";
$('#container').append($(str)[0]);
Make sure you escape you script properly.
Your function is not executing because it is not being called.
You should use a self-executing function that will just run as soon as it's loaded:
(function() {
alert('hello world!');
})();
here is the problem..
i have a javascript file which is named javascript.js like this
$(document).ready(function(){
function init()
{
//code goes here
}
}
now the index.html file has a command button which should call the init() function.
<html>
<head><script src=javascript.js ....></script>
<body><button type="button" onclick="init()">Call Init!</button></body>
</html>
But it doesn't call it. Nothing happens as expected. Please suggest a solution.
You should define your function outside $(document).ready() scope.
The onclick attribute will be executed in a global context. Your init function is scoped to the anonymous function which you pass to jQuery. Three solutions:
Move the init function outside of the ready function, into the global scope
export the init function by making it a property of the global object: window.init = function() {…};
as you use jQuery, you should not need to define any handlers in attributes. Instead use (inside the ready function): $("button").click(function init() {…}); Even better use an id to reference the button.
Try viewing the page in chrome. Hit F12 to view the console. You'll be able to quickly debug the issue. At first glance, however, I do see that your $(document).ready function is not closed properly. Add ');' at the end of the code you included. Also, add quotes around javascript.js in your script tag. See if that helps.
Why don't you use
function init()
{
$(document).ready(function() {
//code goes here
});
}
You can use flag too in order to keep track if the "//code goes here" proceeded or not. So in case of document not ready yet, you can use while loop with setTimeOut function for some pause interval "In order to not hang the client browser".