Load screen on page reload(); - javascript

I have a small Phonegap app and on a button click I have it refresh the page via:
window.location.reload();
It loads pretty fast. However, although fast, you can see a flash of some elements being loaded before others. I would like to do some sort of load screen during this time, which I think will be a nice touch.
What might be the best way for me to do this? It wouldn't be at application start, but somehow tied into the button that calls for the page to be refreshed.
BTW, I am not using Jquery Mobile or Zepto .
Thanks

I'm not too privy on phonegap but I believe it is just normal HTML, CSS and JS no? So then why not just have an AJAX request that grabs your data, so the page itself is not actually refreshed but the data within the container. Then just have a div prepended to the body on the refresh call that contains your loader information (spinning gif, loading, etc). Then disappears on the ajax callback.

Related

jQuery Mobile Load Content Via Ajax Before Page Shown

I am very experienced with jquery, but jquery mobile is very new to me. I am developing an app using cordova and jquery mobile.
So i have a multi page setup in the html, with navigation bars that switch the pages. All works great there, however, i need to load the page content via ajax when the page is changed.
I am managing to do this with a post request to an external web server that generates the content, then caches it inside a local database via the app. I am currently doing this with the "pagebeforeshow" event.
The problem is, when the user clicks the menu item, jquery mobile has already switched the page before the ajax call in "pagebeforeshow" is fired, which means we see a blank page delay while the content is requested.
So my question is: Is there a way to either prevent jquery mobile from switching the page automatically on menu click so that i can catch the event, grab the content and then manually display the page with changePage() or is there an event i can hook into that fires well before the transition takes place?
So the idea is they click the menu item, a full screen loader shows (which works) , load the content and then display the page, not display the page then load the content....
Make sense?
The way I'd go about it would be to not use pagebeforeshow and instead have the page initally covered by a splash screen.
Then when the splash screen is loaded and displayed (image onLoad or similar) start the AJAX call, which once finished, fades out the splash screen and shows the actual content.

Why is the Facebook button only appears after all the images are loaded?

This is not about loading Facebook asynchronously or any kind of optimization here but to load it as fast as possible rather than as slow as possible ;)
My website contains a LOT of images. And I need the Facebook Like button to show up as soon as possible. But it seems the button doesn't load: it waits for all the images to be loaded before loading itself. Since I have many images, of course the Like button shows up very late. If the connection is really slow, that might even take one minute. You can see the issue here: http://www.totorotimes.com.
Any idea how I could do this?
Thanks a lot!
Take all the javascript code that is for the social media buttons out of your body tags, put them in a file called: "social.js" and then insert that file right above all the js files in yourhead tag. This will make your buttons load before the actual web page loads.

Reloading Website without stopping JS code

I am trying to run a JS script on a website (not my own) and I want it to refresh the website, in order to check for updates. However, I have only found code online for reloading the entire page (location.reload(true), etc...), which clears any code that I have running through the console. I am new to JS so is there any way to refresh a page and keep the JS code running? Also might there be a way to only reload load a certain portion of the page?
Basically,
Reload website without stopping code
Using jQuery you can easily load any part of a page from a URL using AJAX. To fill the body element with the contents of a URL:
$('body').load('/page');
Your URL can respond with the segment of HTML you want to render, or you can request a full web page and grab just the segment you want buy adding a selector:
$('body').load('/page body');
The page isn't technically refreshed, just the HTML content inside the body (or whatever element you select) is replaced. Any previously loaded header content like JS remains and keeps running.
There is no way to actually refresh the entire page without stopping the execution of the JavaScript code.
For doing updates on the page there would be two possibilities:
Use of AJAX (Asynchronous JavaScript and XML) to check for new updates on the page. There are some very good tutorials out there on the internet – just google »AJAX JavaScript«.
Use of IFRAME. Make a page and stuck all the stuff in it and then put that page in an iframe and then reload the iframe instead of reloading the entire page.
Hope I could help you.

Window like facebook chat

The Facebook chat window remains open, unchanged, to refresh the page, or even when we change page. How to reproduce something similar? Tried with frameset, but it did not work.
How to keep a div open a window similar to the internal, even after refreshing the page or clocar on a website link?
Like them, you can try -
The data is shared between facebook pages. Probably HTML5 localStorage? Cookies? I'm not sure.
If you notice, they don't "refresh" the page, they ajax-refresh the content on the page for subsequent loads. (unless you manually navigate to the same page, of course.)
Finally, its all CSS mainly some z-index put to use.
I hope those 3 are enough to get you started.
I don't think the whole page of Facebook is loaded. Every link has it's own 'target'. Most of them fetch a page (I think with simply AJAX) to show, others to just change some partials of the screen. So let's say, you have two divs. One div is the chat-div. Positioning fixed and all, z-index on 100, it will always stay on top. The rest of the page is the other div. Within this div, you can load certain pages with AJAX, without the whole screen to refresh.
As with reloads of the screen: you can easily save (also with AJAX) whether the user closed the chat screen or has it opened. Just create a table in a database called 'chats' or something, then when a chatscreen is opened you put an entry in that table with 'person_1', 'person_2' 'lastmessage' and 'active'. When they close the chat, you can put the 'active'-field to false. Then, whenever someone loads the entire website, you check the table chats for active chats, and shows them when there are any.
I would look into qjuery-qjax: https://github.com/defunkt/jquery-pjax
From their docs:
pjax works by grabbing html from your server via ajax and replacing the content of a container on your page with the ajax'd html. It then updates the browser's current url using pushState without reloading your page's layout or any resources (js, css), giving the appearance of a fast, full page load. But really it's just ajax and pushState.

Navigation bar that doesn't reload

I have what is probably a very stupid question. I have been writing a Ruby On Rails app for the last few weeks, using the excellent Bootstrap/Twitter components to avoid me having to do anything artistic.
I noticed on that site, the navigation bar does not appear to ever reload.
http://twitter.github.com/bootstrap/javascript.html
Clicking on the links at the very top (Overview, Scaffolding, etc) causes the page to change, and the URL to change, but the topbar itself does not appear to reload.
I can't detect anything AJAX-y going on that would do this (using Chrome's dev toolbar etc). I can only imagine that it's:
An optical illusion, and it is reloading just it's so fast I can't see it. But then why does it not appear to reload at the same time as the content?
Some undetectable AJAX going on
Some sort of browser caching going on (can you do that for a rendered page element)
Something completely different
Any thoughts most welcome :)
The boostrap site's navbar does seem to be static during reloads but it isn't some clever js that is doing that. There is no hidden content that is being displayed.
What's happening here is a very fast page load. The guys at boostrap moved all their js links and scripts to the bottom of their html so their pages load faster, they even say that in their html. The pages load so much faster that certain elements like the navbar don't seem to change at all. I tried it on my on site and low and behold the static navbar illusion.
So maybe moving your js and scripts to the bottom of your html can help you achieve the same trick.
The entire page (each tab) is loaded, and hidden when the page loads.
The URL is changed using location.hash when the links are clicked (and JavaScript is blocking navigation).
When the hash is changed, the onhashchange event is ran, and the correct div is shown.
Here is an example: http://jsfiddle.net/uFgtS/ (Well, I guess you can't see the url change. Copy the HTML, CSS and JS into a file and run it.)

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