For a JQuery Mobile site, I need an new image to load on page navigation. The image only displays on the homescreen.
So for example, you load m.smellyeggs.com which has image_A.png as the top banner. You select menu item 1, then press back and now image_B.jpg is showing as the top banner.
I was able to get it working using cookies. I get an array of potential images, then use cookies to traverse the array. This works on page reload, but any cache loading of a page (e.g. href="/" or using "Back" in mobile or the browser) would not call the javascript. Thus the image would not actually alternate.
var images = new Array();
<% banner_mobile_uris( controller.conference ).each do |url| %>
images.push( "<%= url %>" );
<% end %>
inc_banner_cookie();
load_banner();
To fix this, I use the following code, which deletes the image, forcing an image refresh whenever the homepage is loaded.
$( 'a' ).live( 'click', function( ev ){
var banner = $('#m_banner').load(htm_file);
banner.empty().remove();
});
This code removes the "Back" button from any subsequent page navigation that occurs.
Well that's unacceptable! Any advice on a better approach? I'd rather not implement my own "Back" button unless that is absolutely necessary.
Thanks for reading (and hopefully helping ).
The answer lies in using pageinit to detect successful JQuery Mobile page loads...
$(document).on('pageinit', function(){
inc_banner_cookie();
load_banner();
});
This will not disable the back button. And cause image reloads on any type of page navigation. Well almost any type...
As it turns out, this appraoch is fragile when AJAX redirects occur, and subsequent pageinits may not work. See my question concerning this issue.
Related
I'm developing jQuery Mobile (jQm) app.
I wanna utilize taphold event to some crucial elements, such as remove button, to assure, that this element is secured from unwanted trigger.
I created Remove button on jQm popup and aded some JS to it, but I cannot force default action to quit, not with event.preventDefault() and event.stopImmediatePropagation(), nor with return false.
I prepared jsFiddle as duplicate of my code. The popup there contains simple progress bar as indicator of holded tap. You can try it here: jsFiddle (note: HTML5 data tag taphold="true" is not jQm default)
As a workaround, I'm currently replacing <a href="#" data-role="button"...></a> with <div>styled like button. This works well, since it doesn't have any default action, but I'm curious why the "proper" solution doesn't work?
$("a:jqmData(taphold='true')").bind("vmousedown vmouseup", function(event) {
event.preventDefault();
event.stopImmediatePropagation();
The event.preventDefault(); and event.stopImmediatePropagation(); used in the above piece of code, refer to the vmousedown and vmouseup events and not to every event which is bound to the selected element(s).
This means that the default behaviour for the click event still exists. So when you click the remove button, the click event is triggered and that's why the pop up closes immediately.
I hope this helps.
I have the following problem: When I use either the jQuery Mobile back-button or the changePage function of jQuery Mobile to return to the previous page it doesn't show any data on the page. All javascript gets executed but page remains empty..
Any ideas?
This was a problem I faced when I was removing pages from the DOM via javascript to prevent the first page from sticking into the DOM. All it would show was a blank page when clicking the back button.
Are you removing previous pages from the DOM in your javascript?
And when you say the page "remains empty", is it just the data within the content tags, or is nothing appearing on the page at all (including jquery mobile enhancement markup)?
You should post your changePage function here so that I and others can help you out.
Context: asp.net MVC 3 app. Page1 is a mobile page using jquery mobile and it contains a link to Page2 which is a normal page which uses a specific stylesheet.
Issue: on my phone, when I click the link on Page1, it goes to Page2 (with a horizontal sliding effect) but the stylesheet is not loaded. If I force a reload of Page2 then the stylesheet is loaded. Also, on the iphone, if I press the link to show the "open in new window" button and click it, it loads well in the new window.
Debug: if I simulate this on a desktop computer (by forcing mobile views) the same happens. The back button does not even work well. When loading Page2, Firebug, in the Net tab, displays as if I was still loading Page1 (it displays Get Page1) even if this is the text of Page2 that appears (without the css), and it doesn't show a line saying that it tries to load the css.
Update: I was using 1.0. I just tried the latest 1.1 and this is even worse. When clicking on the link, the title for Page2 appears in my firefox tab, the address bar shows the new url but Page2 is not displayed (even if Firebug shows it loads something).
To turn off AJAX page transitions:
$(document).bind("mobileinit", function () {
$.mobile.addBackBtn = false;
$.mobile.ajaxEnabled = false;
$.mobile.ajaxLinksEnabled = false;
});
EDIT
To change single links to non-ajax or vice verca you can use this code:
jQuery:
$("a").attr("data-ajax", "false");
Or you can simply do <a href="somepage" data-ajax="false" >Link</a>
All of the JQuery Mobile documentation I can find about navigating backwards assumes I am going to do this using an anchor tag and suggest I add data-rel="back" to the tag.
I'm not navigating from a tag, I'm mixing with PhoneGap which means I'm calling javascript functions like PhoneGap.something(goForwardOnSuccess,goBackwardsOnFailure);
where
function goFowardOnSuccess()
{
$.mobile.changePage('#next', { transition: 'pop' });
}
function goBackwardOnFailure()
{
$.mobile.changePage(/* I HAVE NO IDEA WHAT GOES HERE */);
}
One of the main things I'm using this sort of thing for is putting up a "Busy Doing Something In Native Code Don't Touch Me..." click shield screen with the "loading" stuff and then closing it in the completion functions.
However, I find when I try that from a button on a screen I "popped" into place, I find myself back at the home page (goes back two levels).
The documentation is maddeningly vague about how to navigate backwards from pure javascript. Any clues would be very nice.
Notice also that I tend to pop these busy screens from everywhere so explicitly coding a transition back to the screen I want isn't really an option.
It's definitely not clear in the documentation, but there are small allusions to it.
Try using:
$.mobile.back();
it makes sense to use data-rel="back" for something like that:
<a href="#" data-rel="back" ...
but it is better to use history.back(); inside javascript code blog i.e
.....
.....
var cId = $(this).val();
// do something with control ID then
.....
.....
goBackParent();
}
function goBackParent(){
history.back();
}
Why not just use data-rel="back" as an attribute to your back button, this will take the user back 1 page.
Also equivalent to history.back()
You are going back "two levels" because if you fire changePage programmatically via
$.mobile.changePage('#next', { transition: 'pop' });
and omit all the other options, you are triggering two functions:
changePage
hashChange
Normally on a regular transition, the hashChange is blocked, while on backwards transitions, the changePage should be blocked (not sure here...). So in your case you have your (wanted) hashChange and an unwanted (changePage) transition.
Check the JQM docs for the options you can pass along in your changePage call or look in the 1.0 source code #3140 for all available options. I would try also passing changeHash:false or fromHashChange:true along in your function call and see what happens.
If you want to dig deeper you will have to look for ignoreNextHashChange and how its value changes though JQM.
A call to history.back() will do that.
Add changeHash: true from where you are redirecting.
And then use 'history.back()' or 'history.go(-1)' from your current page. It will only take you 1 page back.
$.mobile.changePage("yourpage.html",{ transition: "flip", changeHash: true});
I use this in my Index.aspx:
<%= Html.StandardOverlayCreateButton() %>
<div class="apple_overlay" id="overlay">
<div class="contentWrap">
</div>
</div>
Which is translating into this:
<button type="button">Create</button>
<div class="apple_overlay" id="overlay">
<div class="contentWrap">
</div>
</div>
When you press the button the popup with the Create.aspx occurs. Look at this -> Loading external pages into overlay
For me it seems that the overlay performance is slow.
And there is some strange behaviour, because I can nearly everytime see the old values in the popup. If I click the edit button and then close the popup and click another edit button, I can see the old values for a short time.
Is there a better approach of doing a popup using ASP.NET MVC and jQuery?
Are there tutorials?
Everything is being done client-side so the performance is purely down to JavaScript and jQuery code and nothing to do with any server-side code such as ASP.NET MVC.
You're using quite a few sophisticated effects with that popup, I see <div /> resizing animations, transparency, drop-shadows, the works. JavaScript performance has come on leaps and bounds with recent browsers, but it's performance but still be slow for doing very extravagant visual effects. Have you tried tuning down the visual effects with whatever modal popup JavaScript library you're using.
"And there is some strange behaviour,
because I can nearly everytime see the
old values in the popup. If I click
the edit button and then close the
popup and click another edit button, I
can see the old values for a short
time."
I assume the pop-up is actually loading an iframe which points to the 'Employee/Create' page. My guess is that when the pop-up is closed and then re-opened again with a different page, the previous page will still be sitting in the pop-up's iframe, and the "load-new-page/url" event isn't fired until the pop-up re-appears, hence why you're seeing the old page very briefly.
I had a similar problem to this, you need to tune the modal pop-up behaviour slightly so that it first loads the new page then opens the pop-up, rather than the other way around which is what it's currently doing. My solution to this was a bit hacky in that the page inside the iframe has an $(document).ready({}); event that called some JavaScript function the the iframe's parent to load the pop-up. eg. put this in your page that sits inside the iframe:
<script type="text/javascript">
$(document).ready(function()
{
window.parent.openPopup();
});
</script>
Then you need to define the 'openPopup()' JavaScript method in the iframe's parent (ie. the main page the lists your records).
do you really need the animation?
maybe you don't need the effect: 'apple' attribute?
Effects are slow, especially on IE.
http://flowplayer.org/tools/overlay/index.html#api
Look here - different post but answer is related to your question about MVC & jQuery.