Hello my questions is about how a webpage is loaded! Here is my code:
<!DOCTYPE html>
<html>
<head>
<title>JavaScript</title>
</head>
<body>
<h1>Waiting</h1>
<script type="text/javascript">
alert("Why?");
</script>
</body>
</html>
I cannot for the life of me figure out why the alert is running before the heading is displayed. It is my understanding that since the alert is right above the closing body tag it will be the last thing run. Why is the page waiting for me to close out the alert before displaying the heading?
Thanks for the help!
Edit: I ran this code in firefox rather than chrome and it worked how I wanted it to - the heading displayed first before the alert ran.
You need to execute your script after the page loads with
<body onload="script();">
An external script will execute before the page loads.
<body onload="script();">
<h1>Waiting</h1>
<script type="text/javascript">
function script() {alert("Why?");}
</script>
</body>
You can use setTimeout() to show the alert after a few seconds (when the page should have loaded).
<!DOCTYPE html>
<html>
<head>
<title>JavaScript</title>
</head>
<body>
<h1>Waiting</h1>
<script type="text/javascript">
setTimeout(function(){
alert("Why?");
}, 1000);//wait 1000 milliseconds
</script>
</body>
</html>
You can check if the header (the h1 tag) is there and only alert if it is there.
<!DOCTYPE html>
<html>
<head>
<title>JavaScript</title>
</head>
<body>
<h1 id="header">Waiting</h1>
<script type="text/javascript">
var x;
x = setInterval(function(){
if(document.getElementById("header")){
alert("Why?");
clearInterval(x);
}
}, 100);
</script>
</body>
</html>
The simplest workaround code without using JQuery I could write is this. Please check it.
<!DOCTYPE html>
<html>
<head>
<title>JavaScript</title>
</head>
<body>
<h1>Waiting</h1>
<script type="text/javascript">
window.onload = function(){
setTimeout(()=>{
alert("Why?");
},10)
}
</script>
</body>
</html>
The cleanest way to do this seems like it would be to put your javascript in a separate file, and load it with the defer attribute. This will cause it to fire after the DOM loads (technically, just before DOMContentLoaded, but it doesn't work consistently across browsers unless there is a src attribute, which is why you would need to move it to an external file.
<script src="myScript.js" defer></script>
Oddly, adding some CSS to your heading could also affect this since JS is supposed to execute in order after any pending CSS.
The timeout function or a $(document).ready() function will do what you need in theory, but a timeout could need to be adjusted based on the complexity of the page, and if you aren't already using jQuery, you probably won't want to add it just to use $(document).ready().
Related
My current code:
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body onbeforeunload="return close()">
<script>
function close() {
window.open("http://www.google.com");
}
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body onbeforeunload="return close()">
<script>
function close() {
window.open("http://www.google.com");
}
</script>
</body>
</html>
I am trying to create a new window when the website is closed, but it just closes by itself. I am new to web coding, so please do not judge my code
This was the best way to accomplish what you're trying to do, however if it's a modal you're looking for, unfortunately they don't exist yet, upon research this was the best solution I had, you could use another script that auto runs to close this page. However, as comments above describe this looks fishy to viewers, and also causes skepticism to google as to why you're doing this for your web page.
<!DOCTYPE html>
<html>
<body onBeforeUnload=" return myFunction()">
<p>Close this window, press F5 or click on the link below to invoke the onbeforeunload event.</p>
Click here to go to w3schools.com
<script>
function myFunction() {
window.open("new 2.html"); // or whatever link you'd like, must be .aspx, or .html page etc.
}
</script>
</body>
</html>
I apologize in advance if this has been asked before. So the circumstances I mentioned in the title is this:
I am writing html into a new window.document.open() object. The html I am writing also includes in the head.
This is the script I am not able to run,
<script type="text/javascript" src="https://code.jquery.com/jquery-2.2.3.min.js"></script>
<script>
$(document).ready(function(){
alert('This is working!');
});
</script>
The interesting thing is that every other jquery code works. For example in my html I have a button with id='but' and this script works
$('#but').click(function(){
alert('you clicked a button')'
});
so why is the $(document).ready() not working? Is this because window.document.open() doesn't count as document for jquery?
Thanks in advance.
edit: I think my question is unclear. I am terribly sorry about that. Here's the situation:
I have a javascript file that essentially has this:
var w=window.open();
var temp=`
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title> Template for converted files</title>
<script type="text/javascript" src="https://code.jquery.com/jquery-2.2.3.min.js"></script>
<script type="text/javascript" src="file.js"></script>
<script>
$(document).ready(function(){
alert('This is working!');
});
</script>
</head>
<body class="body">
<button id='but'>click me!</button>
</body>
</html?
`;
w.document.open();
w.document.write(temp);
the file file.js has the following:
$('#but').click(function(){
alert('you clicked a button')'
});
now when I run the first JS file, I am able to open a new window with the button. when clicked it says "you clicked a new button"
But the alert "This is working!", isn't working.
Hope this makes the situation clear. I am really sorry for not being clear from the start.
Because jQuery has no method open() in it's api.
open() is a window method only.
You can refer to the new window by passing it to a variable:
var win = window.open(url[,options])
the code is somewhat like
<body onload="testFunc();">
<div></div>
<script type="text/javascript" src="/js/test.js"></script>
</body>
and the testFunc is inside test.js
and sometimes its not getting called
The onload attribute fires when an object has been loaded.
onload is most often used within the element to execute a script once a web page has completely loaded all content (including images, script files, CSS files, etc.).
<!DOCTYPE html>
<html>
<head>
<script>
function myFunction() {
alert("body loaded");
}
</script>
</head>
<body onload="myFunction()">
<h1>body loaded!</h1>
</body>
</html>
I use CEF(chromium ebedded Framework) load a html page:
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<script src="phantom-limb.js" type="text/javascript"></script>
</body>
</html>
and it works ok. now, I modify the page as follow:
<!DOCTYPE html>
<html>
<head>
</head>
<body>
</body>
</html>
and after cef loaded it, I use cef's ExecuteJavaScript method to execute the same phantom-limb.js, but nothing appear.
how can I load the js file and execute, or, the js file has some limit?
thx:)
As you can see at the end of the source code of you JS file, the startOnLoad config parameter is set to true by default.
In this way a listener to the DOMContentLoaded is added, which is never called because your page is already loaded.
So, you just have to append the line start(); to your source code, then call your ExecuteJavaScript and it will work even after the page is loaded.
I'm trying to use an external JavaScript file in order to write "Hello World" into a HTML page.
However for some reason it does not work, I tried the same function and commands inline and it worked, but not when it's using an external JavaScript file. The part I commented out in the JS file was the previous method I was trying to use. Those lines of could worked when I ran the script from the header, and inline. Thanks
Html file:
<html>
<head>
</head>
<body>
<p id="external">
<script type="text/javascript" src="hello.js">
externalFunction();
</script>
</p>
<script type="txt/javascript" src="hello.js"></script>
</body>
</html>
JavaScript file
function externalFunction()
{
var t2 = document.getElementById("external");
t2.innerHTML = "Hello World!!!"
/*document.getElementById("external").innerHTML =
"Hello World!!!";*/
}
In general, you want to place your JavaScript at the bottom of the page because it will normally reduce the display time of your page. You can find libraries imported in the header sometimes, but either way you need to declare your functions before you use them.
http://www.w3schools.com/js/js_whereto.asp
index.html
<!DOCTYPE html>
<html>
<head>
<!-- You could put this here and it would still work -->
<!-- But it is good practice to put it at the bottom -->
<!--<script src="hello.js"></script>-->
</head>
<body>
<p id="external">Hi</p>
<!-- This first -->
<script src="hello.js"></script>
<!-- Then you can call it -->
<script type="text/javascript">
externalFunction();
</script>
</body>
</html>
hello.js
function externalFunction() {
document.getElementById("external").innerHTML = "Hello World!!!";
}
Plunker here.
Hope this helps.
Script tags with SRC values do not run the contents. Split it to two script tags. One for the include, one for the function call. And make sure the include is before the call.
use onload eventListener to make it simple
<script>
window.onload = function() {
externalFunction();
}
</script>
You're trying to call the function before it has been loaded.
Place the load script above the declaration:
<html>
<head>
<script type="txt/javascript" src="hello.js"></script>
</head>
<body>
<p id="external">
<script type="text/javascript">
externalFunction();
</script>
</p>
</body>
</html>
Also you have a typo:
<script type="txt/javascript" src="hello.js"></script>
Should be:
<script type="text/javascript" src="hello.js"></script>
The script type needs to be "text/javascript" not "txt/javascript".