Develop Reference

Make browser's back button work when using hide and show (jquery)

I've seen the new website of megaupload (mega) and we've got this:
Ok, if I press on left-menu contacts, it only reloads the white part on the image, if I press messages, the same, it only reloads white part. But if I go from contacts to messages and I press browser's back button, it goes from messages to contact and only reloads white part as always.
In my website, I do the same using jquery hide and show, but obviously, if I press browser's back button it doesn't hide the div and shows the other one.
My web site is only one html file and there are 4 div that get shown or hidden depending on the button you press, this is an example:
$("#btn_contact").click(function () {
$("#content_contact").show();
$("#content_home").hide();
$("#content_products").hide();
$("#body_aux").hide() ;
$(this).addClass('visited');
$('#btn_products').removeClass('visited');
$('#btn_home').removeClass('visited');
});
Can anybody tell me how to find this with jquery or whatever I have to use.
I don't know if I've explained myself well, if not, ask me to do it better.
I would appreciate any help. Thanxs a lot.

Maybe it'd be easier for you and more appropiate to make "content_contact.html", "content_home.html", and so on and use .load() function as Ozan Deniz said. You wouldn't have to change margins, positions, etc. and back button would work withouth programming. I think is not appropiate to make the whole website using just one html file, showing and hiding div's, ofcourse you can do this but maybe is not the right way. I'm newbie at this, but that's what an expert told me beacuse I was doing something similar to that.
Hope to help you.

You can use jquery load function to load white part
For example;
$('#result').load('ajax/test.html');
And in back button event you can load the white part
jquery hide and show
window.onbeforeunload = function() { $('#result').hide(); }; or
window.onbeforeunload = function() { $('#result').show(); };
jquery load function
window.onbeforeunload = function() { $('#result').load('ajax/test.html'); };

Warning when clicking external links and how to add it to a link class

I'm not sure how to do a pop-up that warns when you are clicking on external links, using javascript.
I figured that it would be handy to put a class on my external links as well, but I'm not quite sure it's done correct as it is now either. This is the HTML I'm using at the moment:
<div id="commercial-container">
<img src="picture1.jpg" />
<img src="pciture2.jpg" />
<img src="picture3.jpg" />
<img src="picture4" />
</div>
I'm very new to javascript and very unsure on how to solve my problems. The pretty much only thing I figured out so far is that I will have to use window.onbeforeload but I have no clue on how to figure out how to write the function I need.
I want to keep my javascript in a separated .js document instead of in the HTML as well.

Call the confirm() function from the onClick attribute. This function returns true if the user clicks OK, which will open the link, otherwise it will return false.
<img src="picture1.jpg"/>
Hope this helps.

You can do it by adding a click event handler to each link. This saves having to use a classname.
window.onunload will run even if the user is just trying to close your site, which you may not want.
staying in site
going external
<script>
var a = document.getElementsByTagName('a');
var b = a.length;
while(b--){
a[b].onclick = function(){
if(this.href.indexOf('yourwebsitedomain.com')<0){
//They have clicked an external domain
alert('going external');
}
else{
alert('staying in your site');
}
};
}
</script>

Since you're new to Javascript I advice you to use a javascript framework to do all the "heavy work" for you.
For example with JQuery you can easily bind an onClick event to all external links by doing:
$(".external").click(function(event) {
var confirmation = confirmation("Are you sure you want to leave ?");
if (!confirmation) {
// prevents the default event for the click
// which means that in this case it won't follow the link
event.preventDefault();
}
});
This way every time a user clicks on a link with the external class, a popup message box asking for a confirmation to leave will be prompt to the user and it will only follow the link if the user says "yes".
In case you want only to notify without taking any actions you can replace the confirmation by a simple alert call:
$(".external").click(function(event) {
alert("You are leaving the site");
});

If the user click an image,div,.. you need to look for the parent node. !There could be several elements wrapped with a-tag.
document.addEventListener('click',function(event){
var eT=(event.target||event.srcElement);
if((eT.tagName.toLowerCase()==='a' && eT.href.indexOf('<mydomain>')<0)
|| (eT.parentNode!==null && eT.parentNode.tagName.toLowerCase()==='a'
&& eT.parentNode.href.indexOf('<mydomay>')<0))
{
//do someting
}
else if(eT...){
...
}
},false);
Two side notes:
If you want to keep track a user by cookie or something similar, it's good practice to check external links, set a timeout and make a synchronic get request to renew.
It's better to add the event to the document or a div containing all events and decide on target.

jQuery click not recognized

I have a test page here: http://www.problemio.com/test.php
and if you press "Click To Test Signup" you get a form. If on that form, you click "Log In" it recognizes that you clicked that, and opens the login form.
But the problem is that on the login form, if you press "create profile" it actually goes to the url of the href tag and not to the jQuery click event.
My quetion is what is the best practice of doing this? I hered of something called "prevent default behavior" but not sure how/when it should be used.
I am guessing that if the user has JS disabled, they should still be able to log in. How can I set it up so that users can log in and make accounts in the jQuery way first, and some default way if they have JS disabled?
Thanks!

You can do this with pure jQuery with
$("#createprofilelink").click(function(event) {
event.preventDefault();
{create profile logic}
});
more details of this can be seen in the jQuery documentation http://api.jquery.com/event.preventDefault/
Edit: I removed this because of #maxedison comment that it stops the jQuery event from firing but I have just tested this and the jQuery event fires but the link does not go to the address.
<a id="thelink" href="http://www.google.com" onclick="return false;">the link</a>
<script>
$('#thelink').click(function(){alert('alert me');});
</script>
As for the JS being disabled part of the question the link really should point to to a real form to fill in, as Taryn East correctly says, so the user gets the same functionality even if the user experience is lower by not using JavaScript.
You could even go down the noscript route
<noscript>
<div>Your user experience would be far improved if you
enable JavaScript but if you insist,
Click Here to create your profile</div>
</noscript>

To fix you link-gazumping problem, indeed, as #kamui says, use return false;
But as to your JS-disabled question - point the href at a real URL -> preferably the same URL as your JS-enabled stuff - or the same form, but in a new window.

I could not follow the link due to firewall restrictions on my side but...
You'll want to use whats called unobtrusive javascript.
http://en.wikipedia.org/wiki/Unobtrusive_JavaScript
This means if JS is available it will use it, if not continue working as plain html.
using jQuery you would first attach the click event to your button in the $.Ready() method.
<a id='btnTest' href='login.html' />
$(document).ready(function () {
// Attach click event to btnTest
$("#btnTest").click(function (e) {
// do logic
return false; // Returning false here will stop the link from following login.html.
});
});
Hope this helps.

Javascript alert popup form

i have search this whole site and google but cannot find it so, here goes!
i would like a way to show a form when using alert.
for example, when user click post, a dialog pop with asking user a few question like a html form and allow user to click submit or reset or cancel, without loading a new page.
i have seen this done but cannot find the same site again.
i have tried putting htm to alert with little success of posting.
any Help is Highly Appreciated!

What you are looking for is a Prompt Box:
<script type="text/javascript">
function show_prompt() {
var name = prompt('Please enter your name','Poppy');
if (name != null && name != "") {
alert(name);
}
}
</script>
example taken from here: http://www.w3schools.com/js/js_popup.asp

you can do this with jQuery dialogs -- load the dialog on user click and have a form presented in the dialog. have a look at the demos here: http://jqueryui.com/demos/dialog/

To complete #Liv's answer you can use jQuery's UI
Reference: Modal Form
The example shows how to create a new user. It will pop up a dialog where you complete a form and you can submit it or you can cancel it.
Use a modal dialog to require that the user enter data during a multi-step process. Embed form markup in the content area, set the modal option to true, and specify primary and secondary user actions with the buttons option.
It pretty much what I understood you need.
Good luck!

HTML can't be placed in system dialogs generated by alert(), confirm() or prompt(). However, you can download jQuery UI and set it up on your Website. (Make sure you have the "dialog" component chosen on the download page.) Then in your JavaScript:
$("<div>Place your HTML here</div>").appendTo("body").dialog({
modal: true,
title: "Enter a title here"
});
Make sure you run this code after the page has loaded by using either window.onload or $(document).ready().
Ad#m

You will not be able to do this with alert, but you should take a look at how to create modal windows.

I recommend you to use a div popup. What you have to do is setting a background on top of all other elements except the div where your form is. The css property display will be set to 'none' until the form is then activated, by setting display = "block". That can be performed using javascript.

jQuery dialog call redirecting page

I'm using the jQuery dialog plugin.
The dialog div is set up (but not opened) on page load:
$(document).ready(function(){
$('#foo').dialog({autoOpen:false});
});
Then a hyperlink is supposed to open the dialog:
Show dialogue box
But this opens the dialog then a fraction later redirects to a page with the URL javascript:$('#foo').dialog('open');!
I have tried returning false:
Show dialogue box
But then the link doesn't respond at all when I click on it.
I know this must be to do with one of JavaScript's infamous subtleties but I can't work it out.
Can anyone help?

Then a hyperlink is supposed to open the dialog:
Show dialogue box
But this opens the dialog then a fraction later redirects to a page with the URL javascript:$('#foo').dialog('open');!
That shouldn't be happening. The pseudo-protocol javascript: doesn't involve a page load, and certainly not one via HTTP. I don't recommend it (I'd use jQuery's click handler instead), but it should work.
I have tried returning false:
...
But then the link doesn't respond at all when I click on it.
That also shouldn't be happening.
Your code as quoted is fine (works here, for instance: http://jsbin.com/inixa5), so the problem must lie in some other part of the page.
Update: Okay, that's weird, IE6 and IE7 didn't like that; I think it's because dialog returns a value. You can get around that either by wrapping up your call to open the dialog in a function and doesn't explicitly return anything:
Click Me
<script>
$("#foo").dialog({autoOpen: false});
function showDialog(selector) {
$(selector).dialog('open');
}
</script>
Or (and this is mega-hacky) by making sure the last expression in the javascript: block is undefined:
Click Me
<script>
$("#foo").dialog({autoOpen: false});
</script>
Or by using onclick:
Click Me
<script>
$("#foo").dialog({autoOpen: false});
</script>
But in any case, strongly recommend hooking things up with a DOM2 style event handler:
<a href="#" name='openSesame'>Click Me</a>
<script>
// This _can_ be immediately after the anchor, but I'd put it in
// a separate, since .js file for the page that you load just before
// the closing body tag.
$("#foo").dialog({autoOpen: false});
$("a[name=openSesame]").click(function() {
$("#foo").dialog('open');
return false;
});
</script>
Live example (Obviously, you can use any selector that makes sense, you don't have to give the anchor a name [or id].)
One of the nice things about this is that you can then have the anchor take the user somewhere meaningful and/or useful if JavaScript is disabled (something called progressive enhancement).

Change the link to:
<a href="javascript:void(0)" onclick="$('#foo').dialog('open')">
Show dialogue box
</a>
Best avoid putting javascript in the href.
Even better would be giving it a class and than adding a click event to it through jquery.