Render optionally needed content only when needed on dynamic JS page - javascript

I am building a web application which I intend it to work like a traditional 'software': as few page reload, and page redirect as possible.
My solution to page reload and redirect is to have them as 'tabs' within the app, so when you click on another tab, the div of your current content will shrink to 0 width.
My question is: how do I prevent the content (writtent in JS, w/ PHP backend) in a tab to load unless when it's clicked on?
(Assuming this is what I should do to reduce unnecessary load)

Just don't load it until the link/button/etc. to the tab is clicked.
See also the jQuery tab implementations.

If your back-end is in PHP, you should control what you send to the client from there.
By the time the js gets the code, it is too late to control what not to load. You can hide it, or remove it, but it has already been loaded.
So, to reduce unnecessary load, and as a good practice, you should only send to the client the active 'tab'. That has to be done in PHP in your case.

Related

How to properly implement loading bar for loading urls?

I think this question was asked in a similar form before but I didn't get a clear understanding how to implement it properly.
I have a site, which has different pages on their own urls, like '/contact', '/about', '/products'.
What's the technique to put a top bar on the top like this one http://nanobar.jacoborus.codes/?
Here is what I need:
User clicks a link on the page.
JavaScript handles the click, shows the progress bar, starts growing it then passes the event to browser.
Browser starts loading the page. At this moment, page clears and becomes white and blank.
As the progress bar was in some position that is not zero, say, 63%, and now there is no information on the new page about where it was.
So, I can technically run some function on every page, like showGrowingProgressBar(value), but since I don't know where it left, I cannot put it in the same progress state as where it left.
How do I make it look natural, like the user didn't leave the page, but more like an SPA experience?
I guess you want to build an one page web application where things load in the same page without refreshing.
You can use AJAX to do this. you can populate a particular div with the new html without refreshing.
It can be handled more easily using Angular JS. You can define routes for every page and can also have templates for different page, and can load that template when user clicks on the link. It will just replace the container div with new html codes and you can also handle the urls easily.
Turbolinks seems to be what you are looking for. It dynamically loads your pages and shows a loading indicator.
Turbolinks makes navigating your web application faster. Get the performance benefits of a single-page application without the added complexity of a client-side JavaScript framework. Use HTML to render your views on the server side and link to pages as usual. When you follow a link, Turbolinks automatically fetches the page, swaps in its , and merges its , all without incurring the cost of a full page load.
Your approach is:
User clicks a link on the page.
JavaScript handles the click, shows the progress bar, starts growing it then passes the event to browser.
Browser starts loading the page. At this moment, page clears and becomes white and blank.
As the progress bar was in some position that is not zero, say, 63%, and now there is no information on the new page about where it was
Your approach should be:
User clicks a link on the page.
JavaScript handles the click, browser starts loading the page. At this moment, page clears and becomes white and blank.
New page shows the progress bar, starts growing it then passes the event to browser. The growth can be picturized by the no. of API call completed divided by total no. of api calls, required for that page.

Tabbed Page layout lost state when when refreshed

We have designed the application with tabbed pages layout.
Tabbed Page Style
the tabs are page and are created on click of menu, these are and added in parent container as child DOM element,it is a new form which has input elements,we could have many tabbed pages at a time. my application is in Spring MVC ,PostgresSQL ,Jquery.
What happens when refreshed, lost all the added dynamic new tabs (tabs are pages and we lost the current state).
I could share the reference code if required.
Please suggest how could I manage the state of application.
Window reload/refresh is a pure browser event that ends the execution of the page, you can't really have script continuity after it.
One option is to attach an alert to window.onbeforeunload informing the user that the content will be lost if they reload - this will work with closing the window and refreshing it.
If, however, you need to be able to reload (eg, to load fresh data in the tabs) while preserving tabs, you can use window.onbeforeunload to prompt the user whether they want to save the data/layout before closing, and if so, execute an AJAX call to the server, where you save the tabs (associating it with the session). This would mean that on loading the page you need to first check if there is tab data associated with the session, and load from there.
Other option - and this would be my preference - is to use window.localStorage to save the data on user's disk, and on page load check if there is data in localStorage. It has pretty wide browser support at this point, and there are good libraries that make using it a breeze. I have used store.js and can vouch for its ease and reliability.

Recreate lifehacker ajax article page refresh, right menu is always visible, url & article changes

On lifehacker.com when a user clicks a article on the right menu sidebar, the article & the page url changes, but the #rightcontainer always stays visible and , you never see it blink on the change of the page url, and when the article is ajaxed in (this is easy),
How would you change the page URL with a DIV staying visible on the page the whole time.
How is this possible? Javascript of some sort? (I think its freezing the browser then doing something, getting the data ready? )
I always thought you couldn't change the page url with javascript because of security issues.
I think you are looking for State Handling :)
It used to be done by adding # at the end of the URL, but now HTML5's State Handling features allow us to change the URL completely (ofc, within our domain)
The answer you need is located here:
https://github.com/browserstate/History.js/
Each url can include the same source as right container it won't refresh/blink as in browser cache.
you couldn't change the page url with javascript because of security
issues
A link can be followed via JavaScript if you require, its not regarded as bad practice (afaik). But there is no need to use javascript it could just be normal anchor/href.

Preloading page between two asp.net pages

I posed a question that related where I could display "Page loading" in asp.net page using jQuery. But, I had no luck.
So, say I have page1 and it navigates to page2 and page2 doesn't some heavy data access. Is there any way I could show the "preloading" page while the page2 is finished.
I want to navigate from Page1 -> "Preload" -> Page2(once page2 is completed).
I want to know if this is possible using Javascript in the code behind.
Thanks.
The way you would typically do this is have a page that shows the message and uses AJAX, in my example using jQuery, to load the other page onto the current page.
<body>
<div id="content">
Page loading
</div>
<script type="text/javascript">
$(function() {
$('#content').load('/url/to/other/page');
});
</script>
</body>
I've omitted loading jQuery itself.
Note: you could do this on a single page by having it generate different content based on some query parameter. You don't need to actually have a separate "loading" page -- though you could probably make that work for several different pages as well.
If using JavaScript is OK, redirect the user to the Preload page, and then use JavaScript to take the user to Page2. This will make the Preload page stay visible while Page2 is loading.
(Also, "JavaScript in the codebehind"? Don't tell me you're using JScript.NET or something as your server side language)
No matter what you do, to begin loading Page2 you'll have to navigate away from Page1 (unless you get complicated and wrap your pages in another container on a single page and navigate within your container).
Otherwise the default content for Page2 should be a "Preloading" message that gets taken away once the document has finished loading its content.
Is a possible solution to have an almost empty page with a few placeholder divs in the right places containing a loading image. Then run web service calls to populate each placeholder in jquery/javascript?

How to determine what in my script is blocking my HTML rendering?

I have a web application that uses quite a bit of JavaScript.
When the page loads, it's very clear visually that something is blocking the rendering of a particular portion of the web site. This portion is generated by a Tabber Tabify JavaScript library.
How can I determine what's blocking the HTML rendering specifically so that I can modify my code to prevent this blocking?
Can I use Firebug, or some other tool, to walk through my HTML/JavaScript to determine where the HTML rendering is being blocked and if so, how?
UPDATE:
YSlow gives my web-application a score of "A" and Page Speed give a score of 94/100.
UPDATE 2:
The live site is linked below.
http://www.elite.com
What I'm specifically referring too is the actual Tabs themselves being rendering (and NOT the panel content inside the tab panes). It seems strange to me that the Tab headings themselves are taking so long to generate on the first (empty cache) page load.
A few possibilities:
Loading scripts in your page will block rendering (the only fix for this is to put them in the head (blocks initial rendering) or at the end just before the </body> or load them after the page is loaded (e.g. onload)
Whatever the Tabber/Tabify tool is, needs time to process content... see if there is a way to optimize it.
Either way, if you post some code we can likely be of more help
Update:
If I load the page with my cache cleared, I see content rendering on the screen, then hiding (as it becomes hidden tab content)
Changing the non-visible content to display:none; when loading, and then only setting it back to display:block; once the Tabify stuff is done might help (a) speed up the rendering and (b) remove any flash of content that later gets hidden.
The RadComboBox'es you have load inline (which means the scripts block rendering)... if you can delay this until the onload event fires it will speed up rendering.
I would move the Unica Page Tag (tracking) to the end of your page too.
You have 8 external script files - if there is any way you can combine them it would be good.
You don't have gzip turned on for most of those script files
All of your static content (images, css, scripts) don't have an expires header which means they won't get cached, which means pages won't load fast after the first page.

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