Executing an external script via Javascript rather than <script src="external.aspx"> - javascript

1) Here is what works just fine:
SearchTool.aspx (in the code snippet below) is a 3rd party product that will actually insert an iframe into the page at page load time with the search tool inside of it.
<html>
<head>....</head>
<body>
...
...
<h2>Search Tool</h2>
<script type='' src='http://foo.com/SearchTool.aspx</script>
...
</body>
</html>
2) Here is what I want to do:
I want my page to load quickly without the search tool being loaded at the same time. The user can read through my page and then, if they want, they can click on a button to load the search tool thereby delaying the tool load time to when they want it.
I want to be able to invoke the SearchTool.aspx from the click of a button as below, but I don't know what the code would look like in the showSearch() function below:
<h2>Search Tool</h2>
<script type='text/javascript'>
function showSearch(){
**** What would go here? *****
}
</script>
<input .....="" onclick="showSearch();"></input>
3) I have already explored creating the iframe manually:
In the code snippet #1 above that works just fine, if I do a view source and then create an iframe exactly like they do with all of the same properties, the Search Tool doesn't completely work properly. Weird I know, but true. So this is NOT an option.

Wrap your script tag in a div with the style display:none to hide it:
<h2>Search Tool</h2>
<div id="searchTool" style="display:none">
<script type='' src='http://foo.com/SearchTool.aspx</script>
</div>
...
Then, in your function, just show it :
function showSearch(){
document.getElementById("searchTool").style.display = 'block';
}

Related

HTML/javascript: prevent paint before code executes

I have a page with a javascript file at the end. the file is placed at the end so that I get access to all the dom elements.
let us say the markup looks like this
<html>
<head></head>
<body>
//lot of markup here
<script src="my-js.js"></script>
<body>
the sample markup is just to show the location of my js file.
the first like in the js file (my-js.js) is
document.body.style.visibility = 'hidden';
After the code runs I set the visibility back to hidden
From what I have understood(from a lot of articles related to this including in stackoverflow ones) is that the browser reaches the js, then executes it, and then continues with render and then paints.
If that was true, my code as described should work fine.
However, what is happening now is that, the page is shown (for less than 500ms) as it is before the code executed, then quickly hidden and then shown again after the code executed.
in short, what I want is:
page is hidden > code executes > page is shown
instead what I get is
page is shown > page is hidden > code executes > page is shown
My question is why is the page shown for that split second? what am I doing wrong here?
PS: Please note that I cannot change the location of the js nor add another. So, do not post any solution that suggest the same.
More importantly, I want to know why my code is wrong.
You might be interested in using the defer method.
defer means “wait for the parser to finish to execute this”. It’s roughly equivalent to binding your script to the DOMContentLoaded event, or using jQuery.ready. When the code does run, everything in the DOM will be available for you to use. Unlike async, defer’d code will run in the order it appears in the HTML of the page, it is just deferred until after the HTML is fully parsed.
For example:
<script src="my-js.js" defer></script>
See more here
Put the script tag right at the start of the body so it will be evaluated almost exactly as the body is rendered.
<html>
<head></head>
<body>
<script>
document.body.style.visibility = 'hidden';
</script>
<p>Sample text</p>
</body>
</html>
You can also add a style tag to set the body's visibility to hidden.
body{
visibility: hidden;
}
<html>
<head></head>
<body>
<p>Sample text</p>
</body>
</html>

Calling external javascript from HTML button

I'm trying to set up a page that calls an external Javascript function when the user presses a button in an html form. The function name is lock(), and my code for the button is as follows:
<form>
<button type="button" onclick="lock()">Pause/Play</button>
</form>
Trying to run the code gives the following error:
The value of the property 'lock' is null or undefined, not a Function object
I have confirmed that the function I'm trying to call is a global one in the scope of the .js file, and I know that the .js file is being loaded when the page starts because all of the functionality except for this button works. Am I missing any obvious steps and, if not, what do I need to verify? Thanks.
if you open up dev tools, such as f12 in chrome, and enter lock in console, does it return the function? or undefined?
its impossible ot tell whats going on without seeing your code.
a few things you can try:
1.Include the script tag right above the closing tag of the body, to ensure that the script is loaded after the button.
Attach the event handler to the button not inline, but in the domcontentloaded event.
to debug, try calling some other function from same button, to islotate the problem, and vice versa, try attaching the function to a different button, see if it works there.
Where did you have the javascript line in your html that calls the function from other source? If you had that plotted inside <head></head>, then try move the line way further to below in your html file like right before </body> like as for example:
<html>
<head>
<title>My HTML</title>
</head>
<body>
<blah></blah>
<script type="text/javascript" src="myexternal.js"></script>
</body>
</html>

Force browser to download multiple script tag with same src

I have a script tag like
<div id='CommentBox'></div>
<script src="http://www.mywebsite.com/widget.js" type="text/javascript" />
This javascript creates a comment box. (like facebook comment box)
But when users copy/paste same exact script tag more than once Chrome and IE9 does not request 2nd, 3rd file again, because it is cached. But actually people want to use comment box more than once in the same page. How can I break browser cache and force it to download as many as people pasted in their blog?
You're doing it wrong.
If you want two or more comment boxes just call the code twice. A script include is not like a function call.
Instead of Code that you write use this code:
Main HTML File:
<html>
<head>
<script src="http://www.mywebsite.com/widget.js" type="text/javascript" />
</head>
<body>
<div id="CommentBox"></div>
<script type="text/javascript">
Func1();
</script>
</body>
</html>
widget.js File:
function FUNC1(){
alert("Hello");
}

JavaScript Reload Page Script

<html>
<head>
<script type="text/javascript">
function show_confirm(){
var r=confirm("Hello or Goodbye?");
if (r==true){
alert("Hello");
window.location.replace("http://www.google.com/");
} else {
alert("Goodbye");
}
}
</script>
</head>
<body>
<input type="button" onclick="show_confirm()" value="Show a confirm box" />
</body>
</html>
I'm learning JavaScript, and I'm using W3School's Tryit Editor, and this code wasn't working like I hoped. I want it to redirect me to google after someone hits 'OK' twice, but it doesn't seem to work. Can someone help me out?
The problem is that the Try-It Editor is using an IFrame. When I try it in Chrome and open up my developer console, I get the following error:
Refused to display document because display forbidden by X-Frame-Options.
This is because what your code is trying to do is change the location of the current frame, not the entire page.
You can do one of three things:
Try your HTML outside of an IFrame and you should get it to work then.
Try using window.top.location.replace("http://www.google.com/"); instead of window.location
If you must change the location of an iframe with JavaScript, you'll have to either do so outside of the frame or make sure it stays within the same domain as the parent document. (You'll notice that window.location.replace("http://www.w3schools.com") works just fine.)

How do I display a jquery dialog box before the entire page is loaded?

On my site a number of operations can take a long time to complete.
When I know a page will take a while to load, I would like to display a progress indicator while the page is loading.
Ideally I would like to say something along the lines of:
$("#dialog").show("progress.php");
and have that overlay on top of the page that is being loaded (disappearing after the operation is completed).
Coding the progress bar and displaying progress is not an issue, the issue is getting a progress indicator to pop up WHILE the page is being loaded. I have been trying to use JQuery's dialogs for this but they only appear after the page is already loaded.
This has to be a common problem but I am not familiar enough with JavaScript to know the best way to do this.
Here's simple example to illustrate the problem. The code below fails to display the dialog box before the 20 second pause is up. I have tried in Chrome and Firefox.
In fact I don't even see the "Please Wait..." text.
Here's the code I am using:
<html>
<head>
<link type="text/css" href="http://jqueryui.com/latest/themes/base/ui.all.css" rel="stylesheet" />
<script type="text/javascript" src="http://jqueryui.com/latest/jquery-1.3.2.js"></script>
<script type="text/javascript" src="http://jqueryui.com/latest/ui/ui.core.js"></script>
<script type="text/javascript" src="http://jqueryui.com/latest/ui/ui.dialog.js"></script>
</head>
<body>
<div id="please-wait">My Dialog</div>
<script type="text/javascript">
$("#please-wait").dialog();
</script>
<?php
flush();
echo "Waiting...";
sleep(20);
?>
</body>
</html>
You'll need to run that piece of code immediately after your <body> tag, something like:
<html>
<head>
</head>
<body>
<div id="please-wait"></div>
<script type="text/javascript">
// Use your favourite dialog plugin here.
$("#please-wait").dialog();
</script>
....
</body>
</html>
Note I omitted the traditional $(function (){}) because you need this to be loaded as soon as the page is shown, not after the whole DOM is loaded.
I've done this before and works great, even if the page has not finished loading yet.
EDIT: you'll have to be certain the jQuery dialog plugin you're using is loading before your entire DOM loads. Usually this is not the case, you it won't work. In that case, you'll need to use a g'old plain JavaScript solution, such as Lightbox 1 or Lightbox 2.

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