In the past I have developed large extjs single page applications. Many users get frustrated for not being able to use the Back or Fwd buttons or reload the page.I would also like to warn the user if they navigate away from a page without completing a work flow, and enable users to directly access particular views.
For the next application, I am thinking of using the Codeigniter php MVC framework. It is possible to something similar to this example. I am stucked thinking about the navigation. If I load the ExtJs for each view, that is a significant slowdown.
How best to approach this?
Have a look at the Ext.History class (Ext.util.History on Ext4). With it you can register listeners for changes to the hash:
Ext.History.on('change', function( token ) {
console.log('token changed to: ', token);
});
The Ext.History singleton includes forward() and back() methods for triggering navigation from within the client-side code.
By having only the hash part of the URL change the browser stays on the same page, thus eliminating the need to reload the Ext library.
How this would integrate with your PHP framework I cannot say. I am not familiar with CodeIgniter and your example link goes to a dead page.
Also, do note a caveat with History in that under Ext3 at least it may give you issues with newer browsers. If this is the case an alternative is to code your own History-like solution using the 'hashchange' browser event as illustrated in this answer.
Related
I am coding a website for a client and they requested that because they have so many sidebar pages under one parent, that when the page link is clicked, it loads in the same area every time without the page reloading. They also requested that the URL changes on reload and that you can visit each page by going to that specific url. Unfortunately, I don't know how to do this. I have found a lot of tutorials and snippets that are half way there but they don't offer the exact functionality.
For example, if you go here: http://lookseewatch.com/independentinsurance/commercial-insurance/
You'll see a long sidebar of different types of commercial insurance they offer. When you click on "Automobile," or any link for that matter, the page should be loaded into the div area on the right of the sidebar. The url then should change to reflect this change to http://lookseewatch.com/independentinsurance/commercial-insurance/automobile/. All of these pages are separate and dynamic in Wordpress.
Can anyone offer me some assistance? This is currently how the sidebar is being generated:
wp_list_pages('title_li=&child_of='.$post->ID.'');
Let me know if you need any other code from me or have any questions about the functionality.
Thank you!
This is kinda complicated. There are a lot of ways of catching user events, stopping default behavior and running custom code over it. For exemple, you can listen to anchor clicks and return 0 to not load their links.
But if you change URL in browser address bar, as long as I know, a JS can't control it, because it's outside of a webpage domain, and controling browser components from an external webpage would open a lot of security flaws.
This looks like they wanna avoid banners loading to count less hits :P If performance is the issue, first of all you can use a cache plugin, that will store in HD all DB queries, and use those files in future pageloads instead of making new queries.
You can also build a full sidebar into a PHP variable, cache it in HD and read from there, instead of building the whole code everytime. It will be like adding static HTML snippet.
This can be done with a technique called pushstate combined with AJAX. There's a great jQuery plugin that's called PJAX that implements this. http://pjax.heroku.com/
I have just published a plugin called WP-PJAX that makes to whole wordpress site PJAX driven. I'm not sure if this solves your problem, but it might be something for you.
https://github.com/pelmered/wp-pjax
I inherited a site that's completely built using Ajax so I'm using this code to detect pageloads:
(the standard GA code)
var _gaq=[["_setAccount","UA-#######-#"],["_trackPageview"]];
(function(d,t){var g=d.createElement(t),s=d.getElementsByTagName(t)[0];g.async=1;
g.src=("https:"==location.protocol?"//ssl":"//www")+".google-analytics.com/ga.js";
s.parentNode.insertBefore(g,s)}(document,"script"));
and the gaq.push:
_gaq.push(['_trackPageview', '/#pagename']);
except this is a big site with over 30 pages and I dont want to have to write in every one. is there a script that can find the paths/pagenames and put it in there for me?
I don't know Ajax OR Javascript, so apologies if this is not worded correctly.
You can use the _push function however because an AJAX request can mean so many things (sometimes a page load, sometimes a postback of data, and sometimes just a ping to make sure the user is still alive) you wouldn't want to track every XMLHttp request.
Depending on what language your site is written in, I would strongly suggest making use of some form of partial page component (php include, ASP.NET MVC Partial, ServerSide Include) etc which would stop you re-writing the code a million times if you change it.
However you will still need to edit your 30'odd pages if they are hard-coded. Or one master page if its a sensible design.
Check out this link for a sample on how to track ajax requests using the push method.
Is there any way I can change the URL or add more history to the "back button" without having to refresh the entire page?
My application is AJAX based and I'd like to add some "undo" events to history so that the user can simply hit back and retain the old values.
What's possible today? I hear some of this may be in HTML5 but haven't checked whats supported in current browsers.
I think you can use window.location.hash to track the #part of the page, in your case, #state1, #state2 and so on.
window.location.hash = '#state' + (++ stateN) to set and
stateN = parseInt(window.location.hash.match(/\d+$/)[0])
See On - window.location.hash - Change? for more details about how to detect location hash changes.
You could use 301 redirection. Personally, I would use cookies on the client side, or sessions in your back end, to store the breadcrumbs. Storing state information in the URL is a bad idea for AJAX applications, because people might return to a url that the server side is not in the right state to respond to.
Another option would be to provide your own Back button that knows which page to go back to.
The answer for this question will be more or less the same as my answers for these questions:
How to show Ajax requests in URL?
How does Gmail handle back/forward in rich JavaScript?
In summary, two projects that you'll probably want to look at which explain the whole hashchange process and using it with ajax are:
jQuery History (using hashes to manage your pages state and bind to changes to update your page).
jQuery Ajaxy (ajax extension for jQuery History, to allow for complete ajax websites while being completely unobtrusive and gracefully degradable).
It is possible to use ASP.NET's built in Script Manager to update the browser's history. A full how-to to do this is located here:
http://www.asp.net/aspnet-in-net-35-sp1/videos/introduction-to-aspnet-ajax-history
I thought I would ask here about how to develop a wiazrd like control
in ajax for MVC before I started it.
The control will have pages that have data entry controls and
on each page submission insert data into a database.
Any ideas how to go about this?
Malcolm
Are you using a JavaScript library? I know dojo has a wizard in dojox namespace, and I'm pretty sure there are wizards for jquery. If not, I'd do a wizard just like I would tabs, without the tab bar, and each view contains a form and next, previous, cancel and or restart buttons, all of which would handle the ajax calls/state management and change the view.
If it's a wizard you probably actually should use separate web pages rather than having a single page that's updated through ajax calls, that way the forward and back buttons can work as nature intended in the browser for moving forward and back through the wizard.
Of course you can use fragment tricks to get forward / back working in a single page but in my experience this is tricky.
I'm writing an AJAX app, but as the user moves through the app, I'd like the URL in the address bar to update despite the lack of page reloads. Basically, I'd like for them to be able to bookmark at any point and thereby return to the current state.
How are people handling maintaining RESTfulness in AJAX apps?
The way to do this is to manipulate location.hash when AJAX updates result in a state change that you'd like to have a discrete URL. For example, if your page's url is:
http://example.com/
If a client side function executed this code:
// AJAX code to display the "foo" state goes here.
location.hash = 'foo';
Then, the URL displayed in the browser would be updated to:
http://example.com/#foo
This allows users to bookmark the "foo" state of the page, and use the browser history to navigate between states.
With this mechanism in place, you'll then need to parse out the hash portion of the URL on the client side using JavaScript to create and display the appropriate initial state, as fragment identifiers (the part after the #) are not sent to the server.
Ben Alman's hashchange plugin makes the latter a breeze if you're using jQuery.
Look at sites like book.cakephp.org. This site changes the URL without using the hash and use AJAX. I'm not sure how it does it exactly but I've been trying to figure it out. If anyone knows, let me know.
Also github.com when looking at a navigating within a certain project.
It is unlikely the writer wants to reload or redirect his visitor when using Ajax.
But why not use HTML5's pushState/replaceState?
You'll be able to modify the addressbar as much as you like. Get natural looking urls, with AJAX.
Check out the code on my latest project:
http://iesus.se/
This is similar to what Kevin said. You can have your client state as some javascript object, and when you want to save the state, you serialize the object (using JSON and base64 encoding). You can then set the fragment of the href to this string.
var encodedState = base64(json(state));
var newLocation = oldLocationWithoutFragment + "#" + encodedState;
document.location = newLocation; // adds new entry in browser history
document.location.replace(newLocation); // replaces current entry in browser history
The first way will treat the new state as a new location (so the back button will take them to the previous location). The latter does not.
SWFAddress works in Flash & Javascript projects and lets you create bookmarkable URLs (using the hash method mentioned above) as well as giving you back-button support.
http://www.asual.com/swfaddress/
The window.location.hash method is the preferred way of doing things. For an explanation of how to do it,
Ajax Patterns - Unique URLs.
YUI has an implementation of this pattern as a module, which includes IE specific work arounds for getting the back button working along with re-writing the address using the hash. YUI Browser History Manager.
Other frameworks have similar implementations as well. The important point is if you want the history to work along with the re-writing the address, the different browsers need different ways of handling it. (This is detailed in the first link article.)
IE needs an iframe based hack, where Firefox will produce double history using the same method.
If OP or others are still looking for a way to do modify browser history to enable state, using pushState and replaceState, as suggested by IESUS, is the 'right' way to do it now. It's main advantage over location.hash seems to be that it creates actual URLs, not just hashes. If browser history using hashes is saved, and then revisited with JavaScript disabled, the app won't work, since the hashes aren't sent to the server. However, if pushState has been used, the entire route will be sent to the server, which you can then build to respond appropriately to the routes. I saw an example where the same mustache templates were used on both the server and the client side. If the client had JavaScript enabled, he would get snappy responses by avoiding the roundtrip to the server, but the app would work perfectly fine without the JavaScript. Thus, the app can gracefully degrade in the absence of JavaScript.
Also, I believe there is some framework out there, with a name like history.js. For browsers that support HTML5, it uses pushState, but if the browser doesn't support that, it automatically falls back to using hashes.
Check if user is 'in' the page, when you click on the URL bar, JavaScript says you are out of page.
If you change the URL bar and press 'ENTER' with the symbol '#' within it then you go into the page again, without click on the page manually with mouse cursor, then a keyboard event command (document.onkeypress) from JavaScript will be able to check if it's enter and active the JavaScript for redirection.
You can check if user is IN the page with window.onfocus and check if he's out with window.onblur.
Yeah, it's possible.
;)