Develop Reference

jquery mobile trigger 'create' not working except the first time

I am using jQuery Mobile to create a site, in the index page I placed here a form for a search. I hooked submit event for ajax post. When ajax success get the resource
(html,<ul>...</ul>), placed in the target container, then trigger the create event for enhance the view. This work fine in the first time. When I click back to index page and search again I got a raw listview without enhance, who can tell me why? ps: I have tried many methods but there is more and more problem, the official document was so poor.
$(document).bind('pageinit',function(){
$("#search").submit(function(){
var searchdata = $("#search").serialize();
$.ajax({
'type':"POST",
'url':"/server/jnulib.php?action=search",
'data':searchdata,
'success':function(data){
$("#searchresultfield > ul").remove();
$("#searchresultfield").html(data).find('ul').trigger('create');
try{
$("#searchresultfield > ul").listview('refresh');
}catch(e){
}
$.mobile.changePage("#searchresult");
//$("div[data-role='header'] > a").
}
});
return false;
});
});
EDIT： Test Url： http://ijnu.sinaapp.com
Another problem: the second ajax request failed and the browser navigate to the ajax target straightly.

You could try changing:
$("#searchresultfield").html(data).find('ul').trigger('create');
to:
$("#searchresultfield").html(data).find('ul').listview().listview('refresh');
Anytime you append or remove elements you need to refresh, and if you remove the whole list, you need to reinitialize it.
Also I have had issues with listview('refresh') rendering improperly if it was not visible.
$(document).on('pageshow','div',function(event, ui){
if($("#searchresultfield > ul").is(":visible")) $("#searchresultfield > ul").listview('refresh');
});

For me, .trigger('create'); always works if applied to the element with data-role="page"
For example
HTML Code
<div data-role="page" id="somePage">
...
</div>
Javascript Code
$('#somePage').trigger('create');
Hope it helps

Try:
$("#searchresultfield > ul").empty();
instead of
$("#searchresultfield > ul").remove();

I think the problem is that jquery mobile loads all pages despite all being from different files into one big page and navigation is based off going to different points in this page, so that when you go onto it the first time the page you access is considered created however when clicking the back button and navigating away from the page that page is still considered created so the event well not fire again,
What I used was:
$('#oppList').live('pageshow',function(event){
getList();
});
Where #opplist is the id of the data-role="page" for the page I just load, this does not matter whether this happens the first time the page is loaded or after because the event is fired whenever the page is displayed.
See Here foe jquery mobile events
Also see here for jquery mobile navigation
Hope this helps !

Maybe you should try to unhook the submit event once it's been handled. And initiate it again once you go back to the page where you were before. Adding eventhandlers multiple times can cause a lot of problems.

Detect first page load with jQuery?

I need to detect the first time a page loads in jQuery so that I can perform some actions only when the page loads the first time a user navigates to that page. Similar to server side code page.ispostbasck. I have tested $(document).ready and it fires every time the page loads so this will not provide what I need. I have also tried the jQuery Load function - it also fires every page load. So by page load an example is that I have an HTML input tag on the page of type button and it does not fire a postback (like an asp.net button) but it does reload the page and fires $(document).ready
Thanks

You will have to use cookie to store first load information:
if (! $.cookie("cookieName")){
// do your stuff
// set cookie now
$.cookie("cookieName", "firstSet", {"expires" : 7})
}
Note: Above example uses jQuery Cookie plugin.

An event doesn't exist that fires only when the page is loaded for the first time.
You should use jQuery's .ready() event, and then persist the fact that you've handled a first time page load using your method of choice (i.e. cookie, session variable, local storage, etc.).
Note: This method will never be fool proof unless you can store this information at the user level in a DB. Otherwise, as soon as the user clears their cookies, or whatever method you choose, the "first time loaded" code will fire again.

I just ran into this problem and this is how I handled it. Keep track of the first time the page loads by using a variable initialLoad:
var initialLoad = true;
$(document).ready(function() {
...
...
...
initialLoad = false;
});
Then in other functions, you can do this:
if (initialLoad) {
//Do work that is done when the page was first refreshed/loaded.
} else {
//Do work when it's not the initial load.
}
This works well for me. If the user is already on the page and some jQuery functions run, I now know if that user just loaded the page or if they were already on the page.

The easy solution is to use jQuery ‘Once’ plugin
$(element).once('class-name', function() {
// your javascript code
});

jQuery Mobile showPageLoadingMsg()/hidePageLoadingMsg() methods not working on initial page loadn

I am writing a webapp using jQuery Mobile that calls a function to load records into localStorage and create a listview from a remote JSON file when the page is initially created (using the live.pagecreate() event for the page). At the beginning of this function is the jQuery Mobile method $.mobile.showPageLoadingMsg() and $.mobile.hidePageLoadingMsg() is at the end of the function.
On the initial pagecreate, the loading message does not appear (on iPhone 4 with iOS 4.3 Safari, Chrome 13 and Firefox 5). However, I also have a refresh button on the page; this button clears the associated records in localStorage then calls the same function used to initially populate the listview. However, when calling the same function from the refresh button the showPageLoadingMsg() and hidePageLoadingMsg() both work correctly and the Loading screen appears and disappears as it should. Am I missing something here?
ETA Here is the gist of the code (not in front of the actual code right now, if you need more I will put it in tonight). I also should mention that I've tried to put showPageLoadingMsg in (document).ready and have tried to bind it to mobileinit and neither have worked:
function loadListView(){
$.mobile.showPageLoadingMsg();
//ajax call to pull JSON
//$.each loop to load localStorage and listview
$.listview.refresh('list');
$.mobile.hidePageLoadingMsg();
}
$(#listpage).live('pagecreate', function(event){
loadListView(); // showPageLoadingMsg() and hidePageLoadingMsg do not work when the function is called here
});
function clearList(){
//for loop that clears each item in localStorage that matches the key prefix set in loadListView
}
//runs when refresh button is clicked
$('listrefresh').live('click',function(){
clearList();
loadListView(); //showPageLoadingMsg() and hidePageLoadingMsg() work when the function is called here
});

For these handlers to be invoked during the initial page
load, you must bind them before jQuery Mobile executes. This can be
done in the mobileinit handler, as described on the global config
page.
Docs:
http://jquerymobile.com/demos/1.0b2/#/demos/1.0b2/docs/api/events.html
Triggered on the page being initialized, after initialization occurs.
We recommend binding to this event instead of DOM ready() because this
will work regardless of whether the page is loaded directly or if the
content is pulled into another page as part of the Ajax navigation
system.
Example:
http://jsfiddle.net/phillpafford/mKn8Y/8/
In the example none of the live events fire on initial page load, you have to configure this type of action in the mobileinit:
http://jquerymobile.com/demos/1.0b2/#/demos/1.0b2/docs/api/globalconfig.html

Prevent an exception with jQuery UI Tabs

I am adding some custom tabs to a jquery ui tab control.
$("#tabs").tabs("add","#tabContent0","CLICK ME TO CHANGE PAGE",0);
$('a[href="#tabContent0"]').attr("href","javascript:window.location='http://www.google.co.uk';");
Yes this is a bit of a hack, but it is exactly what i need and provide a nice way to give links back to previous parent pages.
jquery throws the following exception: "jQuery UI Tabs: Mismatching fragment identifier."
This is thrown on the line which appears to attempt to make the tab container visible in jquery ui (exact line wont help as is minified and custom build from official site).
Obviously im just redirecting but jquery has additional code to select the tab (which doesnt exist). In internet explorer, if the user has script errors enabled they will see the exception be thrown just before the window location changes, which I just cant have happen.
I cant put try catch around this code because it is the code inside jquery ui that throws the exception.
Is there anyway I can prevent this exception being thrown or achive the same thing but a different way without having to modified jquery ui ?
Edit: I am now wondering if there is a way to override the on click event hook placed on the element by jquery .. its definitely doing something there i cant see.
Edit: I have to log off now but I have made some progress, if someone can just help me get the right URL, using this code it prevents the exception, but redirects me to "http://myurl/undefined"
$('#tabs').bind('tabsselect', function(event, ui) {
if(ui.index<2) //ignore this will change to get current tab count -1 (so the end tab is left as it is
{
window.location=$('#'+ui.tab).attr("href"); //attr href is undefined, how do i use ui.tab properly to get the right url
return false;
}
});

It works OK for me in Chrome and IE8.
I also tried this code and it worked:
$("#tabs").tabs("add","#tabContent0","CLICK ME TO CHANGE PAGE",0);
$('a[href="#tabContent0"]').click(function() {
document.location='http://www.google.co.uk/';
});
Instead of changing href attribute, I add a handler on the click event of the new tab. This will make the tab to be switched and then the location changed.

From the jQuery UI docs:
$('#example').tabs({
select: function(event, ui) {
var url = $.data(ui.tab, 'load.tabs');
if( url ) {
location.href = url;
return false;
}
return true;
}
});
Though, jQuery's tabs, uh, method, ought to support passing in a selector for the tabs and panels so you could just make things links, instead of having to kick against the pricks.

onHashChange running onLoad... awkward

So I'd like my page to load content if a window's hash has changed.
Using Mootools, this is pretty easy:
$extend(Element.NativeEvents, {
hashchange: 1
});
and then:
window.addEvent('hashchange', function() {});
However, the hashchange event is firing when the page is being loaded, even though the specification require it not to fire until the page load is complete!
Unless I am loading the page for the first time, with no hash, then all works as expected.
I think the problem here is the fact that the browser considers the page load "complete", and then runs the rest of the JavaScript, which includes hash detection to load the requisite page.
For example, if I typed in http://foo.bar/, all would work fine. However, http://foo.bar/#test would, ideally, load the initial page, detect the hash, and load the "test" content.
Unfortunately, the browser loads the initial page, considers it "domready", and THEN loads the "test" content, which would then fire onHashChange. Oops?
This causes an infinite loop, unless I specifically ask the browser NOT to update the hash if an onHashChange event is firing. That's easy:
var noHashChange;
noHashChange = true;
var hashes = window.location.hash.substr(1).split("/"); // Deciphers the hash, in this case, hashes[0] is "test"
selectContent(hashes[0]); // Here, selectContent would read noHashChange, and wouldn't update the hash
noHashChange = false;
So now, updating the hash AFTER the page has loaded will work properly. Except it still goes nuts on an initial page load and fetches the content about 3 or 4 times, because it keeps detecting the hash has changed. Messy.
I think it may have something to do with how I am setting the hash, but I can't think of a better way to do so except:
window.location.hash = foobar;
... inside of a function that is run whenever new content is selected.
Therein lies the problem, yes? The page is loaded, THEN the content is loaded (if there is content)...
I hope I've been coherent...

Perhaps you could check the hash first to eliminate the recursion:
if(window.location.hash != foobar){ window.location.hash = foobar;}
Why is the onHashChange handler changing the hash anyways? If there's some default that it's selecting first before loading the content, then perhaps that could go in a seperate function.
(I say this because it looks like you've some sort of directory structure-esque convention to your location.hash'es, perhaps you're selecting a specific leaf of a tree when the root is selected or something?)

you could implement an observer for the hash object that will trigger a function when the has object has changed.it does nothing to do with the actual loading of the page.
the best way to do this is via Object.prototype.watch
see other pages on same topic : On - window.location.hash - Change?

have a look at MooTools History it implements the onhashchange if the new html5 history api isn't available, no need to reinvent the wheel :)